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HomeMy WebLinkAboutSusitna-Watana Hydro Project Engin Feasibility Report Appendix B (B1-B3) Dec 2014SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. Report -14-21-REP v0.0 Susitna-Watana Hydroelectric Project Engineering Feasibility Report -Appendix B (B1-B3) AEA11-022 Prepared for:Prepared by: Alaska Energy Authority MWH Americas,Inc. 813 West Northern Lights Blvd.1835 South Bragaw St.,Suite 350 Anchorage,AK 99503 Anchorage,AK 99508 December 2014 Significant parts of this report are subject to FERC CEll regulations and should not be disclosed. a)=>ALASKA 13-1421-REP-073114 (ME ENERGY AUTHORITY SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. Susitna-Watana Hydroelectric Project Engineering Feasibility Report -Appendix B (B1-B3) December 2014 Significant parts of this report are subject to FERC CEIl regulations and should not be disclosed.MWHAmericas,Inc.14-21-REPv0.0 a ALASKA ENERGY AUTHORITY AEA11-022 SUSITNA-WATANA HYDRO ENGINEERING FEASIBILITY REPORT Clean,reliable energy for the next 100 years. Appendix B1 Geotechnical Data Report (Placeholder) Saved Februmuy 20/5 Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No.14241 December 2014 an ALASKA ENERGY AUTHORITY AEA11-022SUSITNA-WATANA HYDRO ENGINEERING FEASIBILITY REPORT Clean,reliable energy for the next 100 years. Appendix B2 Site Specific Seismic Hazard Analyses 12-02-TM_Seismic Hazard Characterization and Ground Motion Analyses Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No.14241 December 2014 --Z- SUSITNA-WATANA HYDROELECTRIC PROJECT NTP 6 Seismic Studies Technical Memorandum No.4 v0 Seismic Hazard Characterization and Ground Motion Analyses for the Susitna-Watana Dam Site Area AEA11-022 Sedaithaphes eo wayfi=,és a 7 a RNINGS..Roa.?40 wey:weil ae?'Weed iy Fi ere Lr deters : Prepared for:Prepared by: Alaska Energy Authority Fugro Consultants,Inc.for MWH 813 West Northern Lights Blvd.1777 Botelho Drive,Suite 262 Anchorage,AK 99503 Walnut Creek,CA 94596 February 24,2012 {=ALASKA TM-06-0004-120224 (GE ENERGY AUTHORITY The following individuals have been directly responsible for the preparation,review and approval of this Technical Memorandum. Fugro Consultants,Inc. Prepared by:Justin Pearce,Dean Ostenaa,Roland LaForge Seth Dee,Jason Altekruse QC Review by:Keith Kelson la)pr .weMe Md --Justin Pearce,'Project ManagerP.G/7752 (CA);C.E.G.2421 (CA)J Approved by: MWH: Technical Reviewers:Norman Abrahamson,Consultant;Peter Dickson and Michael Bruen,MWH;Rich Koehler,ADGGS Approved by:Uy.2 (Erte.Michael Bruen,Design Manager Approved by:Brian Sadden,Project Manager . Disclaimer This document was prepared for the exclusive use of AEA and MWH as part of the engineering studies for the Susitna-Watana Hydroelectric Project,FERC Project No.14241,and contains information from MWH which may be confidential or proprietary.Any unauthorized use of the information contained herein is strictly prohibited and MWH shall not be liable for any use outside the intended and approved purpose. THIS PAGE INTENTIONALLY LEFT BLANK -Z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Table of Contents 1.0 EXECUTIVE SUMMARY...........cccccccsssserenssssssececcssssssscccessessesseesaseseeeseeeesceeeecoesarens 1 2.0 INTRODUCTION ........ccscccssssssccsccssssscceccssseseeeecceaeeeecccesessesscoesseeessoceesaseessocecsensesees 5 2.1 STore)0[-0)i'h\(0)9,eee 5 2.2 Regulatory Guidance ..............cccccccccccssseecccccnecescececsaassecececueseeceseesaceeeeeeeaaessseseesa 6 2.3 Approach and Goals ............ccccceeecceccccseeececceneeeeeceesaaesseeceaauseeessensaueeeeeessaeeseeeena 7 2.4 PYLeVIOUS StUGIES 2.0...cecccceccceseeeecceeeeeseeeceesseseecceesaessceessseessceeeesaesaeeessseaanseees 7 2.4.1 Woodward-Clyde (1980,1982).........eeccceceeeseseeeeeeeeteeseeeeeeeeeneuaaseeeaananeaneees 8 3.0 GEOLOGIC AND SEISMOTECTONIC SETTING..........ccccccssssssssseessscessseeessceeees 12 3.1.Tectonics and Regional Stratigraphy ..................ccccceceeeceeeeeeeeeneseeeeeeeeeeeeeeeenenea 12 3.2.Significant Historical Earthquakes...........cc ecceeceeeeeeeeeeeeeeeeeeeteeeeneeeeneeenea 16 3.2.1 2002 Denali fault earthquake 2.00.0...ccccccccssseeseeeecceeeeeesseeeeesseeseeeaeeteneees 17 3.2.2 1964 Great Alaskan earthquake...cccccccscccccnsesecceeeeseuseeeceseesetsaeceeanees 17 3.2.3 1912 Delta River earthquake...ccccccecsccccssssssceesseeeeeesesseeeeseeeeeeneeeeseneea 18 3.3 Quaternary GeOlOGY.........ccceccsseseeeeseeeceeceeeeeeaaaeseeseeeeeeeeeeeeeeeaeeeaseeeaceeeenseeeess 18 3.3.1 PLeVIOUS WOFK........ccc ccccccccssssecccecnseseeeceeeaeeeeeceseaeseeessaeeeeeseesaaeesesessesaeneseeeeaa 19 3.3.2 Quaternary Geologic SettING 2.0.2...cceccececcceenceeeeeeaaaeeeeeeaaaaaeeseeeenaeeeseenegs 20 3.3.3 Quaternary geology in the Site VICINItY.........ee cccccceseeeececeeeeneeeeeeeeaeeeeeeeees 21 3.3.4 Relevance to seismic hazard evaluation ..............ccecccccccsseccccccecceeneeeeeeeaeeeeees 23 3.3.5 Surficial geology at the dam Site ALPOa ou...eee ec eeeeccccceceeeeeeeeeaeeesseeeseeeeeeees 23 3.4 Dam Site Area Geology ............ccccccccssseecccccnesseeceeeenseeseeeeeseeesseeeeessasaseeeeesnaaseees 24 3.5 Site Bedrock Velocity ........ce eeccccccssssescceeeeeeeeseceesseeessceesseaesseeeseesseeeeseenaaaeeess 25 4.0 SEISMIC SOURCE CHARACTERIZATION................:cccccececcescccccccssenneesnenseesenes 27 4.1 Subduction Related Sources...cceccccccccesssecceeeceeeececeeseeeseseesseeeeeseneaaa 27 4.1.1 Plate interface 20.0.0...cccccecccccssssecceceseeeeeeeeeesseseeeeseeaeeeeeeseseaeessseeessuaeeeseeeeea 27 4.1.2 IMtrASlAD 22.2.0...cece eeceeccceeeeeeeececaaseseccecsueessceeseesesseseeesaaedeeeeeeeeeueneeeeesaeaneeess 28 4.2 Quaternary Crustal Faults 0.0.0...ceccccccccceseecceceeeeseseeeeeeeeeeceeeseesseeseseeseaneeess 28 4.2.1 Demriall fault 2...cccccceseeseeeeeeeeeeseeeessssaaeesecsseeeeeseeeneneacaaaaaeaaeeeeeeseerees 31 4.2.2 Castle Mountain fault 20.00...cccccccessssesesseseseceeeeeeeeeeeeaeaaaaaaaaeneeneeeenes 33 4.2.3 Pass Creek -Dutch Creek fault ......i cccececccceseeeeeeeeenaeaeaaaeaeeneeseeeeeeeereeeea 34 4.2.4 East Boulder Creek fault 0.0.0.0.....ccccccccccccsssseeeesescseeeececeeeeeeneeaaaaasaseceeeeseeeeees 34 4.2.5 Matanuska Glacier fault ..............cccecccccccccessseecceceeeaeeeeeceeaaeeeecesseceaueeeeeeeesansees 35 Page i of x 2/24/12 -z- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 4.2.6 Sonona Creek fault .0......0 ccc cc cecccccecsececcessececscseececcucusaeaecsseateneausntateetaees 35 4.3.Zones of Distributed Deformation 2.0.0...eee ceceeccceceeceectcceceecnscseencceseeees 35 4.3.1 Northern foothills fold and thrust belt ZoNG 2.0...eee ceceeccereeenecencees 35 4.3.2 Southern Denali faults ..........cece eecacceccnceccececceaeccececucecaecuscececaeavenseeeess 36 4.4 Talkeetna Block Structures 000.0...cecceceececceececcsececcueeeseeevscuseuenevaseeneaeees 38 4.4.1 Talkeetna thrust fault /Talkeetna Suture .20.0...ee eeccescceececeeveceseneees 38 4.4.2 Susitna lineaMent......cee ec cececceececececenececcecsecersuenesaneessuscensaveateeecs 39 4.4.3 Shorter structures proximal to the dam Site@..........cc eeeeeeeseeeeeeeeeeeeeeeeeeaees 40 4.5 Crustal SeISMICIY ........eee eects eene eee eaaeaenaaeeeeeeereeeeeesesseauaaeteeeteeeeeeseneaaeaa At 4.5.1 Earthquake catalog .00....ec cccecceeeeereceeeeeesenceeseeereeeeeseeeeaseaaaeeteeeeeteeseetnenaaaa 41 4.5.2 Stress data o.oo...cccccecscccecscceccececcccaccuscavecsecseavcesenssauececuecesaueaeenssecesseseneess 42 4.5.3 Crustal SOUPCE ZONES ..........cccccccceccececceeccececcecaececuceucusseceecucusesscetaeeueaesaeasaeees 42 4.6 Earthquake Recurrence from SeisMiCity ............ccc scseeeeeeeeeeceeeeeeeeeeeeeeeeeeseeeeeees 43 5.0 PROBABILISTIC SEISMIC HAZARD ANALYSIS METHODS AND INPUTS...44 5.1 PSHA Code and Methodology .............ccceecssseesecceeeeeeereeeeeeaeeeceeceeeeseeeeeeseaeseeess 44 5.2 --_GM PPES eee cee ceccecccccucceccccccuccecnecceccenscsecececeeacscecceeceetecteetersecuseueceseeenususseseusees 44 5.3 Sensitivity Evaluations 200.0...cccccceecceceeeeeeeceeeeeeeeeeeeeaeeeeeeesaueaereeesausaeesesenanaa 45 5.3.1 Time dependencee .............ccceccececccneceeeeeeeeeeeeeeeaaeeeeeeeecaeaeeeeesaaaaeeeeessaaneeesenaes 46 5.3.2 Relative contributions of sources and distance ............cee eeeeeeceeceeeeeoeees 46 5.4 -PSHA Inputs 2000 cceeceeeneeeeeeceteeeeeeeteeeeeeeeeeeeeeeeeeeeaaaaaeseeereeseeterenaaaneea 47 5.4.1 Subduction related SOUCES ........0...cee ces eececesseseseucceceececescececcreusescesaeaeenecs 47 5.4.2 InterSlab SOULCES 220...cceccceccsccesseecscccvsceccucesacensuscuececececatcuceecusesestnsaveneness 48 5.4.3 Crustal faults .........ccc ccc ccccccccceccecceccceecceecuccecececuecuecusececusecersecseceecserseaneceecers 48 6.0 PSHA RESULTSW000.....ccccecccsecceccceccnscceucsesseccusccuscosncussaceecuuecaesucaeucecesceessescuecoreaes 54 6.1 Hazard Curve ..........ccccceccccecuscecusceccececvsvesecccsceseseeceseeceseuseessescecstaecuetesttanenens 54 B.2 HS ieee cece ccc cccccccccceccnccecceccecceccuscueccececuuecseeenseneseneececseedeeuueeusseecescersececeneraeeeces 54 6.3 -De aggregations...cccccccccccccecececeececeesnneeeeeeeeeeeeeeeeteeeeeeeeseceeceeseectteneaeeeeerees 54 7.0 CONDITIONAL MEAN SPECTRA...ccc ccccccscccesccecccscccucccecsecseeccessonescesscessees 57 7.1 Methodoloy ...........ccccccccececcceeeaaaeeeseeeeesesnccsgessseseeeeeeeeeeeeeeeeesseeseeaseesesesseeeeees 57 7.2 CMS ReSUIts .........cccccccccecceccesccecceccuscaccceecsecucecaaecuessesececauecesersetaseesesaucecseneees 61 8.0 DETERMINISTIC EVALUATIONSuuu...ccsceccsscceccsececccsceccsscessseccccserescancasss 62 8.1 Selection and Evaluation of Critical Sources.........cece eecceeceecceecececeeserees 62 8.2 Deterministic Ground Motion Estimates ........0..0....ccccceeeceecaecccececescescsceueesenecs 66 8.3.Comparison to Previous Studies...eee ccecceeceeeeeeeeeeeeceeeeeeeeesseeseesenees 67 9.0 INITIAL SURFACE FAULTING AND GEOHAZARD IDENTIFICATION ...........71 Page ii of x 2/24/12 -yZ SUSITNA-WATA NA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 9.1 Watana LINGCAMENL.............cccccccccecccccecceceececceceeececcuscesaueceseeeeaecsteueeeeeusensneeeneaes 71 9.2 Northwest-striking Structures in the Site Vicinity...eeeeee rere 72 9.3.The Talkeetna Thrust Fault /Talkeetna Suture Zone...eee ces eeeeeeees 72 9.4 Other Potential Seismic Hazards ...............cccececccsececcecceececeecscnceuseesaneesseeseeeaees 74 10.0 SUMMARY uuu...ccccscccescesceccesccecccecceccecsnuscucceuccuccensnneesusecarsuscerceecerscessuscvesseatease 76 11.0 REFERENCES (2...0....cccccccccsceccsccecceccecceccecsccascerseccensescuecuscessateccuccencuserscccessueceesanss 78 Page iii of x 2/24/12 -z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 List of Tables Table 1.Summary of Site Bedrock Seismic Velocity Data ...........cc eccccccccessesseesseeeneres 26 Table 2A.Fault Characterization ........0.....cccceceeeeceeceeeeeeeeeeneeeeeeeeeeeseeeeaasaaeeeueseseneetniaaaaes 30 Table 2B.Northern Foothills Fold and Thrust Belt (NFFTB)Fault Data..........0..0..0..31 Table 3.Ground Motion Prediction Equations Used in PSHA...............cccccccesseeseceeeeeeeee 45 Table 4.Site Region Faults Excluded from the PSHA Source Model .................cccccc0e 50 Table 5.Geometric Fault Parameters for Susitna Source Model,as Modeled for PSHA ;bee e cent ene eeeen EE e nee EAU EEE AAA EEE OUD E EEO E eee E ee nna Eee eta pecan Enea tee cane eee a eee e cae eeesaeeesaeeeeeaaeeeenaeeeegens 5 Table 6.Fault slip rate and magnitude parameters,as modeled for PSHA...................53 Table 7.Areal Zone Discrete Depth Distributions ............ce ecccesceeeeeeeceeesasaeeeseeseeeees 53 Table 8.Total Hazard,Mean Probabilistic Acceleration Amplitudes (g).................000008 55 Table 10.Megathrust -Deaggregation Results for BCH11T .............ceececceceeeseesseeeeeeeeeee 59 Table 11.Megathrust -Deaggregation Results for ZHOGT..............ccccecccccssesseseeeeeenseeess 59 Table 12.Intraslab-Deaggregation Results for ABOSID 0.0.0.0...ccceeeeeeseeseeeeeseeeeaaaees 60 Table 13.Intraslab -Deaggregation Results for BCH111 oo...eecceeeceecceeneeeeeees 60 Table 14.Intraslab -Deaggregation Results for ZHOG].............cc cccccecccsessseseeeeeeeeeeeeeeees 61 Table 15.Deterministic Hazard Input Parameters...................cecccccseeeeeceneeeeeeeeeeaeeeeeeenaes 64 Table 16.Crustal Seismicity (10,000 yr)Period-Dependent Deaggregation Results SUIMIMALY .......seeccceecccccccececceneeaeeneeeeeeeeeeeeeceeeeeaeaaeeneeeeeseeseceeeeeseeeeeeeaaassesceeeeeseeeeesunaeagaseeees 64 Table 17.Deaggregation Results,Crustal Seismicity (10,000 yr)«0.0.0...eecceceeeeee 65 Table 18.Crustal Seismicity (10,000 yr)Single-Earthquake Deterministic Parameters 65 Table 19.Deterministic Result Comparison between Woodward-Clyde (1982)and this StUGY...cccccccccccccceceecceeeeeeeeeeeeeeeeeeeeeeeeeeseedseeeeeeeeeeneeecsteeeaaueeeeeeeeeeeeeeeeeeeesseeeseesseeeseeeseeeeees 69 Page iv of x 2/24/12 zw _SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. List of Figures Major Physiographic Provinces Tectonic Overview of Central Interior Alaska Site Region Faults Tectonostratigraphic Terrane Map of the Talkeetna Block Rupture Areas for Historical Alaskan Subduction Zone Earthquakes Denali Fault Characterization Northern Foothills Fold and Thrust Belt Castle Mountain Fault Generalized Cross Section of Quaternary Deposits and Surfaces Figure 10.Site Vicinity Quaternary Geology Figure 11.Site Geology Figure 12.Watana Dam Site Top of Bedrock and Surficial Geologic Map Figure 13a.Site Region Geology Figure 13b.Site Region Geology Legend Figure 14.Map and Cross Section of Subduction-Zone Earthquakes Figure 15.Subduction Interface Model Figure 16.USGS Intraslab Model,31-50 Mi (50-80 Km) Figure 17.USGS Intraslab Model,50-75 Mi (80-120 Km) Figure 18.Denali Fault Slip Rates Figure 19.Sonona Creek Fault Trace Figure 20.Sonona Creek Fault Scarp Figure 21.Site Vicinity Tectonic Features Figure 22.Simplified Geologic Map and Cross Section Figure 23.Unfiltered Earthquake Catalog Figure 24.Declustered Earthquake Catalog Page v of x 2/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Figure 25.Stress Tensor Inversion Results from Crustal Earthquake Focal Mechanisms Figure 26.Stress Tensors Inversion Results for Individual Crustal Data Volumes in South Central Alaska Figure 27.Areal Zone Latitude Vs.Depth Earthquake Plots Figure 28.Areal Zone Seismicity Depth Histograms Figure 29.Final Recurrence Catalogs Figure 30.Magnitude Vs.Time Prior to 2011 Figure 31.Maximum Likelihood Recurrence Curves for SAB Areal Zones Figure 32.Maximum Likelihood Recurrence Curves for NFFTB Areal Zones Figure 33.Crustal Fault Model Figure 34.Hazard Curves for Peak Horizontal Acceleration Figure 35.Hazard Curves for 0.5-Second Spectral Acceleration Figure 36.Hazard Curves for 1.0-Second Spectral Acceleration Figure 37.Hazard Curves for 3.0-Second Spectral Acceleration Figure 38.Mean Uniform Hazard Spectra,Total Hazard Figure 39.Relative Contributions,Peak Horizontal Acceleration Figure 40.Relative Contributions,0.5-Second Spectral Acceleration Figure 41.Relative Contributions,1.0-Second Spectral Acceleration Figure 42.Relative Contributions,3.0-Second Spectral Acceleration Figure 43.Deaggregation for the Megathrust,Peak Horizontal Acceleration,2500-Year Return Period Figure 44.Deaggregation for the Megathrust,1.0-Second Spectral Acceleration, 10,000-Year Return Period Figure 45.Deaggregation for the Intraslab,0.5-Second Spectral Acceleration,2500- Year Return Period Figure 46.Deaggregation for the Intraslab,3.0-Second Spectral Acceleration,10,000- Year Return Period Figure 47.UHS and CMS,Megathrust,10,000-Year Return Period Page vi of x 2/24/12 Zw-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Figure 48.UHS and CMS,Intraslab,10,000-Year Return Period Figure 49.UHS and Extended CMS,Megathrust,10,000-Year Return Period, Alternative 1 Figure 50.UHS and Extended CMS,Megathrust,10,000-Year Return Period, Alternative 2 Figure 51.UHS and Extended CMS,Intraslab,10,000-Year Return Period,Alternative 1 Figure 52.UHS And Extended CMS,Intraslab,10,000-Year Return Period,Alternative 2 Figure 53.Intraslab Deterministic Hazard Compared to the Total Hazard UHS Figure 54.Megathrust Deterministic Hazard Compared to the Total Hazard UHS Figure 55.Denali Fault Deterministic Hazard Compared to the Total Hazard UHS Figure 56.Castle Mountain Fault Deterministic Hazard Compared to the Total Hazard UHS Figure 57.Fog Lake Graben Deterministic Hazard Compared to the Total Hazard UHS Figure 58.Southern Alaska Block Central Period-Dependent Deterministic Hazard Compared to the Total Hazard UHS Figure 59.Southern Alaska Block Central Single-Earthquake Deterministic Hazard Compared to the Total Hazard UHS Page vii of x 2/24/12 -zw-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 List of Appendices APPENDIX A.TIME-DEPENDENT CALCULATIONS APPENDIX B.DEAGGREGATION STACK PLOTS APPENDIX C.CONDITIONAL MEAN SPECTRA RESULTS APPENDIX D.MERCALLI EARTHQUAKE INTENSITY SCALE Page viii of x 2/24/12 -Z-SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 SAB Explanation of Abbreviations Alaska Energy Authority Alaska Earthquake Information Center Alaska subduction zone Brownian passage time Conditional mean spectra Copper River basin Fugro Consultants,Inc. Federal Energy Regulatory Commission gravitational acceleration Ground motion prediction equation Global positioning system Thousands of years ago (kiloannum) Earthquake magnitude,moment scale Maximum credible earthquake Earthquake magnitude,surface-wave scale MWH Americas,Inc. Northern foothills fold and thrust belt Next generation of attenuation equations Peak horizontal acceleration Probabilistic seismic hazard analysis Reservoir-triggered seismicity Spectral acceleration Southern Alaska block Page ix of x 2/24/12 ALASKA ENERGY AUTHORITYTESUSTTNAWATANAAEA11-022 TM-06-0004-120224 UHS Uniform hazard spectra USGS United States Geological Survey Vs30 Average shear wave velocity in the top 30 meters of ground surface wcc Woodward-Clyde Consultants Page x of x 2/24/12 -y.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 1.0 EXECUTIVE SUMMARY The proposed Susitna-Watana Dam is a hydroelectric power development project being planned by the Alaska Energy Authority (AEA).This site-specific seismic hazard update and probabilistic seismic hazard analysis (PSHA)is developed to support MWH Americas (MWH)analysis of conceptual dam design alternatives,selection of the preferred dam type,and preparation of the Pre-Application Document submittal to Federal Energy Regulatory Commission (FERC). This report reviews the previous studies,develops an updated site-specific seismic source model,and presents initial ground motion parameters (based on FERC guidelines).As part of the hazard update,a new seismic source characterization model of the dam region and site was constructed.Most recent ground motion prediction equations (GMPEs)including next generation attenuation (NGA)relationships for shallow crustal sources,and a recently developed GMPE for the Cascadia subduction zone,are used in the probabilistic and deterministic seismic hazard analysis for the Susitna-Watana Dam. Site specific seismic hazard studies for the dam site were undertaken previously by Woodward-Clyde Consultants (WCC,1980,1982).This technical memorandum is based on review of these previous studies,syntheses of existing geologic maps and reports,field geotechnical investigations,as well as new regional geologic and seismologic information including data developed from recent,large earthquakes that have occurred since the early 1980s. Since the previous seismic hazard study (WCC,1982),new geologic and seismic hazard information has been developed from field work and research,observations and investigations of large earthquake events,and development of new numerical relationships,most recently for subduction zone earthquakes.These include Quaternary geologic mapping (Williams and Galloway,1986),new stratigraphic models based on geologic map data (Carter et al.,1989);regional fault activity mapping by Plafker et al.(1994),the occurrence of the 2002 Denali earthquake,recent investigations by Alaska Geologic Survey (e.g.,Hauessler,2008),and the 2010 Chile and 2011 Japan subduction earthquakes.Some newly developing information,such as the new Alaska Quaternary fault and fold database (Koehler et al.,2011a),were not fully available at the time of this report. The regulatory process for seismic hazard evaluation defined by FERC specifies that both probabilistic and deterministic evaluations be conducted.In accordance with these Page 1 of 146 2/24/12 -2Z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 requirements,this seismic hazard assessment includes:an updated seismic source model (Section 4);updated probabilistic seismic hazard analysis (Sections 5 and 6); Conditional Mean Spectrum analysis (Section 7);deterministic seismic hazard analysis informed by PSHA (Section 8);and an initial assessment of potential surface fault rupture hazards and identification of other potential seismic hazards (Section 9). An updated seismicity catalog was developed from data available from the U.S. Geological Survey (USGS)and Alaska Earthquake Information Center (AEIC).These data include nearly three decades of additional seismicity,and following a declustering procedure,are the basis for the earthquake recurrence analysis. The updated seismic source model includes structural elements that are relatively consistent with previous studies,such as the Denali fault,Castle Mountain fault, subduction-related sources,and "background”sources.New data and observations from tectonic,geologic,paleoseismic,and seismologic studies,as well as data from recent large earthquakes,are incorporated into the new source model.Based on these data,the new seismic source model also considers the potential implications of newly recognized zones of distributed tectonic deformation within the region,potentially active structures within the Talkeetna block,time-dependent scenarios for the subduction interface to consider the effects of the Great Alaskan 1964 earthquake,and time- dependent scenarios for the Denali fault based on the 2002 earthquake. A probabilistic seismic hazard analysis (PSHA)was completed using an initial seismic source model that includes a limited number of weighted scenarios to capture uncertainty in the source characterization for elements such as slip rates,and time- dependent behavior for well-studied faults.Other elements of the source model,many of which have limited available data (such as the Fog Lake graben source),are included with preliminary source characterizations that may be conservative,as sensitivity tests to gauge impacts on the computed total hazard.Uncertainty in the selection of appropriate attenuation parameters is considered through use of multiple GMPE's for each class of seismic source in the PSHA model. The results of the PSHA are portrayed as hazard curves showing the total model results and contributions of each seismic source.Uniform hazard spectra (UHS)are computed for the 100,250,1,000,2,500,5,000,and 10,000 year return periods.Deaggregation of total UHS was performed for peak horizontal acceleration (PHA),0.5 second,1.0 second,and 3.0 second periods.The deaggregation results indicate that the primary seismic source contributors are the subduction-related plate interface source (megathrust),and the intraslab source down dip of the megathrust.These sources Page 2 of 146 2/24/12 2 SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 dominate the ground motions for the PHA and 0.5-,1.0-,and 3.0-second spectral accelerations (SA),with the subduction interface source becoming increasingly dominant at longer periods.Although assigned a conservative probability of activity of 1.0,the Fog Lake graben source does not contribute significantly in the PSHA,because of its relatively low slip rate. Conditional mean spectra (CMS)were developed from the UHS for the above mentioned spectral response periods,for return periods of 2,500,5,000,and 10,000 years.These were modified so that the envelope of the ensemble spectral response periods,for a given return period,matched the UHS. Deterministic ground motion estimates were developed for six critical seismic sources based on maximum magnitude estimates,site to source distances,and the weighted GMPE's used for each source in the PSHA analyses.The deterministic sources are the subduction interface,subduction intraslab,Denali fault,Castle Mountain fault,Fog Lake graben faults,and a 10,000-year return period earthquake for the background source derived from deaggregation of the PSHA results.The 84"percentile deterministic results are compared to total UHS,except for the Fog Lake graben source,in which the median values are compared following FERC guidance for low slip rate faults. The seismic source characterization and ground motion results from this study include most elements from the prior Woodward-Clyde (1980,1982)studies but are not directly comparable due to many changes in practice and methodologies.The major fault sources represented in the prior Woodward-Clyde studies are included with updated seismic source characterizations.The detection level earthquake (Woodward-Clyde, 1982)concept is superseded by the use of probabilistic analyses of the background seismicity in the site and region.In addition,this present study includes seismic sources (e.g.,subduction intraslab source)not characterized in the prior Woodward- Clyde studies.Notably,conventions for use of earthquake magnitude scales have changed,as have data and practice for use of ground motion predictive equations. There are general similarities between results of this study with the prior results,but also significant differences due to differing seismic source characterizations, methodologies,and ground motion attenuation parameters. Mean PHA from the deterministic fault sources included in this study are generally lower than values for the same deterministic fault sources as listed in Woodward-Clyde (1982).This difference is mostly a result of the different GMPE's used in the current study.However,the current study includes an additional deterministic source,the subduction intraslab source that was not included in Woodward-Clyde (1982),but Page 3 of 146 2/24/12 -zZ SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 results in the largest deterministic mean PHA among the present study deterministic sources,and is slightly larger than any deterministic values presented in the previous Woodward-Clyde reports. The probabilistic methodologies used in the previous Woodward-Clyde studies are not described in detail,so it is not possible to identify specific reasons for differences in the results.In general,in the present study,mean PHA for return periods less than 2500 years is slightly smaller than estimates from Woodward-Clyde.For a return period of 10,000 years,the mean PHA from the present study is significantly higher than the previous Woodward-Clyde estimates. A review of the previous surface fault rupture hazard assessments indicates lineaments that are very near to,or project beneath,the proposed dam facilities or toward the anticipated reservoir.Specifically,these include the Watana lineament,the northwest- striking shear zones near the Watana site area,i.e.,the "Fins”feature of earlier studies, and the Talkeetna thrust fault.The previous Woodward-Clyde studies concluded that these lineament features were either:(a)not a tectonic fault,or (b)not a "recently active”fault,but presented limited direct geologic evidence demonstrating fault inactivity. This scope of this seismic hazard characterization study excluded an evaluation of fault activity,assessment of the potential for generating seismically-induced seiche (a large wave)within the reservoir,nor an assessment of potential for reservoir-triggered seismicity.These potential seismic hazards are planned be analyzed as part of future studies. Page 4 of 146 2/24/12 -yw.SUSITNA-WATA NA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 2.0 INTRODUCTION The proposed Susitna-Watana Dam is a hydroelectric power development project planned to be constructed on the upper Susitna River under the auspices of the Alaska Energy Authority (AEA).The proposed dam would be constructed near about River Mile 184 on the Susitna River,north of the Talkeetna Mountains near the Fog Lake area (Figure 1).Current concepts envision a dam approximately 700 feet high,impounding a reservoir with a maximum water surface elevation at about 2000 feet.At this elevation, the dam would impound a reservoir of approximately 8,900 acre-feet.This configuration would allow for development of a powerhouse with installed hydroelectric capacity of about 600 MW. MWH Americas (MWAH)is the prime contractor providing engineering and geotechnical services to AEA for the project development and submittal of licensing documents to the Federal Energy Regulatory Commission (FERC). Under subcontract to MWH,Fugro Consultants,Inc.(FCL)prepared this seismic hazard characterization and ground motion analyses in support of MWH's development of conceptual dam design alternatives,selection of the preferred dam type,and preparation of the Pre-Application Document. 2.1 Scope of Work The scope of work for this investigation is defined under Task Order T1011562-96192- OM dated June 29,2011 (NTP-6),and amendments thereafter.In general,the scope of services under this task order is to complete an updated seismic hazard characterization and preliminary ground motion analysis for the proposed Susitna- Watana Dam.Specific technical activities within the scope of work include literature review and research,compilation of an updated seismicity catalog,identification and characterization of the seismic sources that may influence the project,initial evaluation of surface faulting and other geohazards,and estimation of the expected ground motions at the dam site based on probabilistic seismic hazard analysis (PSHA)and deterministic analyses.Other activities specified in the task order include coordination and documentation of the study results in this technical memorandum. At the time of this report,LIDAR-based topographic data were not available for the study area and,therefore,an update to the previous lineament analysis (WCC,1980;1982) was not included as part of this scope.By extension,detailed assessment of fault activity,including geologic mapping or trenching,was excluded from this current scope Page 5 of 146 2/24/12 2 SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 of work.Development of time histories for the critical seismic sources,analysis of potential reservoir-triggered seismicity,and assessment of potential seismically-induced seiche in the reservoir also were not included as part of this scope.Future studies are planned during licensing and design to address fault mapping and fault activity issues, as well as these other potential seismic hazards. 2.2 Regulatory Guidance The proposed project will be licensed by FERC and evaluated under the FERC Engineering Guidelines for the Evaluation of Hydropower Projects (FERC,2011). Guidance for the evaluation of seismic hazards is provided under a Draft version of Chapter 13,Evaluation of Earthquake Ground Motions (Idriss and Archuleta,2007). These guidelines were put forward for review and further development by FERC,but have been used for several years on an interim basis. The Chapter 13 draft guidelines are intended to provide FERC with a basis for evaluating the adequacy of the seismic hazard evaluation of the site,which is ultimately the basis for establishment of seismic design criteria for the project.The guidelines identify required geologic and seismologic studies including: e Identification of faults and seismic sources in the region that may be significant to the dam site.This includes characterization of the degree of activity,style of faulting,maximum magnitudes,and recurrence information for each seismic source. e Development of maps and tables that depict the spatial and geometric relations of the faults and seismic source zones to the site along with specific distance parameters needed to evaluate ground motions from each source. e Collection of historical and instrumental seismicity data for the region, including information on the maximum and minimum depth of events. The draft FERC guidelines describe requirements for both deterministic and probabilistic development of ground motions for rock conditions at the site.Under both approaches,use of the most recent and multiple attenuation or Ground Motion Prediction Equations (GMPEs)is recommended.Use of site-specific results are recommended for analyses and design;USGS website (http://earthquake.usgs.gov/hazmaps/)values are to be used only for comparison. Page 6 of 146 2/24/12 Zz SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 2.3 Approach and Goals The goal of the seismic hazard evaluation is to provide a technical basis for dam alternatives analysis by using recent historical and instrumental seismicity data to raise the level of understanding to the current state-of-the-practice by using new methods that result in a defensible,up-to-date seismic hazard characterization for the dam site. The overall approach was to update and re-evaluate the existing site seismic hazard and ground motion studies based on a new seismotectonic model that identifies and characterizes seismic sources of potential significance to the project.This model synthesizes new and available data for the Alaskan subduction zone,the Denali fault, the Castle Mountain fault,and other potential seismogenic sources in the site region. The seismic source characterization provides updated delineation of possible extent and locations for seismic sources,along with estimates of maximum earthquake magnitude,fault type,style of faulting,geometry and seismogenic depth,and recurrence.For this evaluation,the seismic source characterization will identify uncertainties and data gaps that may contribute to uncertainties or may require further evaluations for design. 2.4 Previous Studies This section identifies the relevant inventory of Susitna-specific seismic hazard investigations and regional tectonic studies known to this seismic hazard update and assessment.These existing data and reports are the basis for this office-based seismic hazard update.Previous seismic hazard studies used both deterministic and probabilistic approaches to estimate ground motion hazard (WCC,1980,1982).The site investigation prepared by WCC (1980,1982)included micro-seismicity network installation and monitoring,surficial geologic mapping,lineament analysis,and paleoseismic trenching to assess fault activity and potential surface fault rupture in the dam site vicinity.Review of the WCC ground motion analysis was completed by R&M Consultants (R&M,2009),which used U.S.Geological Survey (USGS)regional probabilistic seismic hazard maps to estimate peak horizontal ground motions near the dam site,and compare to the WCC results.To date,the WCC (1980,1982)reports are the most detailed investigation of seismic hazards for the site that included field geologic data collection,lineament analysis,Quaternary geologic mapping,and paleoseismic trenching. In addition to the WCC (1980,1982)analyses,two other previous studies provide relevant information to this project.First,the USGS regional hazard maps (Wesson et Page 7 of 146 2/24/12 -Z- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 al.,2007)prepared for Alaska show ground motion values (peak ground acceleration and spectral amplitude at periods of 0.2,0.3 and 1.0 seconds)at probabilities of exceedance of 2 percent and 10 percent in 50 years,and ground conditions of NEHRP B/C (Vs30 =2,493 ft/s [760 m/s]).Second,a probabilistic seismic hazard analysis for the Port of Anchorage was prepared by URS (2008)to estimate the levels of ground motions at the site in Anchorage (about 120 miles southwest of the dam site)at probabilities of exceedance of 50 percent,10 percent,and 2 percent in 50 years. Available geologic and seismologic data were used to evaluate and characterize potential seismic sources,the likelihood of earthquakes of various magnitudes occurring on those sources,and the likelihood of the earthquakes producing ground motions over a specified level.A deterministic analysis was also performed to compare with the PSHA results and to generate target spectra for development of time histories. 2.4.1 Woodward-Clyde (1980,1982) WCC (1980,1982)summarized a multi-year,multi-task study evaluating the seismic hazards and development of seismic design parameters for the Susitna Hydroelectric Project.The technical evaluation considered: e Evaluation of geologic framework and tectonic setting e Geologic evaluation of faults and lineaments,and recency of fault activity e Evaluation of historical seismicity e Detection level earthquake and estimating the maximum credible earthquake e Estimation of ground motion parameters e Assessment of potential for reservoir-triggered seismicity 2.4.1.1 Geologic evaluation of faults and lineaments,and recency of fault activity To assess the presence or absence of potentially significant faults,WCC (1980)defined a framework and approach to identify features of potential importance (e.g.,structural lineaments,topographic lineaments,alignment of geomorphic features)that may represent near-surface expression of faulting.The approach used office-based techniques to identify potential candidate features.Criteria based on length of feature Page 8 of 146 2/24/12 -yZ- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 and distance of feature from the site (>62 mi [100 km])were used to screen those candidate features.Thirteen significant features were identified by WCC (1980)for more detailed evaluation,including field geologic investigations. Subsequently,WCC (1982)completed additional investigations operating under the definition that faults with "recent displacement”would be considered capable of generating earthquakes that may cause ground motions of potential significance to the project.WCC (1980)defined faults with surface rupture in the past 100,000 years have "recent displacement”and should be considered in seismic design.Faults with no evidence of "recent displacement”were not considered further as seismic sources, although direct geologic evidence demonstrating inactivity was lacking. Based on those data and analysis,WCC (1980,1982),concluded there was no evidence of "recent”activity on these thirteen significant features.None of the thirteen features were considered as potential seismic sources,and none were considered capable of surface fault rupture.Separately,the "detection level earthquake”was considered as an independent seismic source of potential significance to the project. 2.4.1.2 Detection level earthquake and estimating the maximum credible earthquake A "detection level earthquake”was defined as the largest earthquake that might have occurred without leaving any detectable geologic evidence (e.g.surface geomorphic expression or a rupture scarp)(WCC,1982).This event was considered a separate potential seismic source;a crustal earthquake of unknown fault location,but in proximity to the dam site.The goal was to assess what lower-bound earthquake magnitude could occur that may not necessarily be detected by geologic investigations.Inclusion of the detection level earthquake accounted for potential faults along which no geologic evidence of surface rupture was observed by the investigation.This concept is not used explicitly in the current study.Unknown locations or sources of future earthquakes are accounted for in the present study through the characterization of background zones of crustal seismicity. The WCC (1982)evaluation included assessing the dimensions of surface faulting associated with worldwide earthquakes in similar tectonic environments,comparison to threshold of surface faulting for well-studied California earthquakes,and analyzing the potential degree of preservation of fault-related geomorphic features in the Talkeetna Terrane (generally corresponding to the Talkeetna block of this study,see Section 3.1). Based on this evaluation,the detection level earthquake,a crustal earthquake occurring Page 9 of 146 2/24/12 ze.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 within the Talkeetna Terrane was defined.WCC (1982)study provided estimates of the maximum credible earthquake (MCE)with ground motions for selected seismic sources, based on the attenuation relationships existing at that time.The potential seismic sources identified by WCC (1980)are:the Castle Mountain fault,the Denali fault, Benioff zone interplate (megathrust)region,Benioff zone intraplate region (slab),and the "detection level”source (within the Talkeetna Terrane). The MCE estimates for the two crustal faults were as follows:the Denali fault was estimated capable of a magnitude (Ms)8 at 44 mi (70 km)distance;and the Castle Mountain fault was estimated capable of a magnitude (Ms)7%at 65 mi (105 km) distance. For the two Benioff zone sources,the subduction interface (interplate)was estimated capable of magnitude (Ms)8%(Mw 9.2)at 40 mi (64 km)distance from the site and the intraplate zone was estimated capable of magnitude (Ms)77%at 31 mi (50 km)distance. The detection level earthquake (or,regional background crustal source)was estimated to be a magnitude (Ms)6 within 6 mi (10 km)from the site. 2.4.1.3 Estimation of ground motion parameters Based on the potential seismic sources identified,WCC (1982)estimated ground motion parameters for design using deterministic and probabilistic methods.WCC (1982)list seven of GMPEs that were considered in the selection of attenuation relationships.While it is stated that one group of relations was selected for crustal earthquakes and another for subduction zone earthquakes,it is not stated which were used for each,nor what weighting,if any,was applied.Some are published and readily available,while some are contained in conference proceedings and difficult to obtain. However,all are for peak horizontal acceleration (PHA)only,as WCC (1980)applied spectral shapes tied to the PHA value.The results of the WCC (1982)deterministic estimates of ground motions and parameters were: e Benioff zone (interplate)source produced 0.35 g acceleration for 45-second duration e Denali fault produced 0.2 g acceleration for 35-second duration e Detection level earthquake produced 0.5 g acceleration for 6-sec duration Page 10 of 146 2/24/12 -Z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 The detection level earthquake yields very high accelerations because of the close source-to-site distance (6 mi [10 km]). The results of the WCC (1982)probabilistic estimates of ground motions and parameters were: e The 50%probability of exceedance in 100 years yielded 0.28 g e 10%probability of exceedance in 100 years yielded 0.41 g e 1%probability of exceedance in 100 years yielded 0.64 g The Benioff zone interplate (megathrust)source dominated the probabilistic estimates. 2.4.1.4 Reservoir-triggered seismicity The proposed Susitna-Watana reservoir will be very large ( 8,900 acre-feet)and very deep ( 650 feet).WCC (1982)assessed the potential effects of the proposed reservoir with respect to potential for generating reservoir-triggered seismicity (RTS).The assessment was based on a comparison to similar reservoirs worldwide.The estimated RTS magnitude was assumed to be limited by "natural”events independent of RTS. The probability of RTS was estimated to be 0.46.However,the RTS was considered to be of limited impact due in large part to the concluded absence of faults with recent displacement within the hydrologic regime of the reservoir (WCC,1982). Page 11 of 146 2/24/12 ze.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 3.0 GEOLOGIC AND SEISMOTECTONIC SETTING South-central Alaska experiences rapid rates of tectonic deformation driven by the obliquely convergent northwestward motion of the Pacific Plate relative to the North American Plate.In southern and southeastern Alaska,the convergent and oblique relative plate motion is accommodated by subduction of the Pacific Plate at the Alaska- Aleutian megathrust and dextral (right-lateral)transform faulting along the Queen Charlotte and Fairweather fault zones.In the interior of south-central Alaska, transpressional deformation primarily is accommodated by dextral slip along the Denali and Castle Mountain faults,as well as by horizontal crustal shortening to the north of the Denali fault (Figure 2). 3.1 Tectonics and Regional Stratigraphy The Susitna-Watana Dam site is located within a distinct crustal and geologic domain referred to in this report as the Talkeetna block.The Talkeetna block is bounded by the Denali fault system to the north,the Castle Mountain fault to the south,the Wrangell Mountains to the east and the northern Aleutians and Tordrillo Mountains volcanic ranges to the west (Figure 1).The Talkeetna block encompasses the north-central portion of the Southern Alaska block (SAB)of Haeussler (2008)(Figure 2).Major strain release occurs on northern and southern block boundaries (i.e.,Denali and Castle Mountains bounding faults),but mechanisms of strain accommodation are less well defined to the east and west.There is a relative absence of large historical earthquakes within the Talkeetna block (Section 4.5),as well as a lack of mapped faults with documented Quaternary displacement within the Talkeetna block (Figure 3). The Talkeetna block is comprised of three principal physiographic provinces:the Susitna basin,Talkeetna Mountains,and the Copper River basin (Figure 1).The Susitna-Watana dam site is located within the Talkeetna Mountains province.The Copper River basin is an intermontane basin surrounded by the Alaska,Talkeetna, Chugach and Wrangell mountains.The basin is characterized by flat lying to hummocky topography and is overlain by extensive glacial,glacio-fluvial,and glacial- lacustrine deposits.The Susitna basin is a north south-trending basin and is the principal depocenter for alluvium transported by numerous major river systems which originate in the surrounding mountains.Talkeetna Mountains are an elevated block which lies between the Copper River and Susitna basins,with glaciated peaks between 6560 feet and 9840 feet (2000 and 3000 m)in elevation.The Susitna River heads in the ranges north of the Copper River basin and flows westward through the northern Copper River basin and through the Talkeetna Range following a deeply incised Page 12 of 146 2/24/12 ---yz.SUS ITNA-WATA NA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 canyon.Downstream,sediments from the river contribute to alluvial deposition in the Susitna basin. The Talkeetna Mountains consist of an assemblage of northeast trending tectnostratigraphic terranes including the North Talkeetna Flysch basin,the Wrangellia Terrane,and the Peninsular Terrane (Glen et al.,2007b).The Wrangellia and Peninsular Terranes are comprised of largely late-Paleozoic to early Mesozoic metavolcanic and metasedimentary rocks that originated well south of their current ( 30°latitude)position,and likely were sutured together in the Late Jurassic (Csejtey et al.,1982).The terranes were accreted onto North America in the mid-to late- Cretaceous and translated northward to approximately their current location via strike- slip faults on the continental margin (i.e.Fairweather fault)(Ridgeway et al.,2002).The North Talkeetna Flysch basin is part of the Kahiltna Assemblage,which consists of strata deposited in an oceanic basin between the Wrangellia Terrane and North America prior to and during the early stages of accretion.The North Talkeetna flysh basin consists of sediments shed to the northwest from the Wrangellia Terrane (Glen et al.,2007a).Following deposition,the basin sediments were obducted on to the continent during Wrangellia emplacement.The northeast striking Talkeetna thrust fault/ Talkeetna suture zone is the principal terrane-bounding structure in the region, separating the North Talkeetna flysch basin in the northwest from the Wrangellia Terrane in the southeast (Figure 3 and 4).In addition to the three principal tectonostratigraphic terranes,numerous narrow,fault-bounded terranes are tectonically intermixed within the Kahiltna Assemblage between the Denali fault and the Talkeetna suture zone (i.e.Chulitna Terrane)(Nokleberg et al.,1994).Late Cretaceous through Tertiary volcanic and hypabyssal intrusions are found throughout the Talkeetna Mountains,and often intrude or overlie the Cretaceous accretionary structures. Early tectonic studies of the Talkeetna Mountains described the Talkeetna thrust fault as a southeast-dipping thrust that accommodated the middle to late Cretaceous emplacement of the Wrangellia Terrane (Csejtey et al.,1982;Nokleberg et al.,1994). The thrust trace is recognized by the juxtaposition of the Triassic and Permian metavolcanic and metasedimentary Wrangellia Terrane rocks on the south and Late Jurassic through Cretaceous sedimentary rocks of the Kahiltna Assemblage on the north.The approximate fault trace follows a broad topographic lineament striking northeast across the Talkeetna Mountains (Figure 3).On older maps,the southwestern margin of the fault is mapped as overlain or terminated by Tertiary intrusive and volcanic rocks (Csejtey et al.,1978);to the northeast,the fault is interpreted to terminate or merge against the younger,north-dipping Broxson Gulch fault (Nokleberg et al.,1994). Page 13 of 146 2/24/12 -2Z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Mapping by O'Neill et al.(2003a)along the northeastern reaches of the Talkeetna fault found little evidence for penetrative deformation adjacent to the fault and stratigraphic relationships,which suggest limited displacement along the fault.Based on these observations,they concluded that major contractional displacement has not occurred along the Talkeetna thrust fault.O'Neill et al.(2003a)further propose that the principal suture zone is located to the northwest near Broad Pass where mini-terranes of uplifted Wrangellia Terrane basement rocks are exposed.They characterize the Talkeetna suture zone as a deep crustal structure bounding the northwestern edge of the Wrangellia Terrane,overlain by a wide zone (0.5-12 mi [1-20 km])of Tertiary or younger faults.Glen et al.(2007b)use tectonic analysis of gravity and magnetic data to propose replacement of the term Talkeetna thrust fault with the Talkeetna suture zone.Glen et al.(2007b)and O'Neill et al.(2003b)propose that the surface fault structures may have been reactivated in the late Tertiary as a broad dextral shear zone associated with movement along the Denali fault.Geologic constraints on the most recent movements within the Talkeetna suture zone are further discussed in Section 4 and Section 9. The Alaska-Aleutian subduction zone is one of the longest and most tectonically active plate boundaries in the world.It extends for nearly 2,485 mi (4,000 km)from south central Alaska to the Kamchatka peninsula,and has produced some of the world's largest earthquakes,such as the 1964 M 9.2 Good Friday (or,Great Alaskan) earthquake (Figure 5).The subduction zone has three tectonic regimes:continental subduction in the east,an island arc along the central Aleutian volcanic chain and oblique subduction and transform tectonics in the west (Nishenko and Jacob,1990). The eastern continental subduction zone,in the vicinity of Prince William Sound,is significant in the evaluation of the seismic hazards at the Watana dam site.In this region,the Pacific Plate is converging with North American Plate at a rate of 54 mm/yr (2.1 in/yr)at a slightly oblique angle (DeMets and Dixon,1999;Carver and Plafker, 2008).The subducting slab has a shallow,10°or less,dip (Carver and Plafker,2008) and a typical forearc basin.Transform motion along the eastern edge of the subducting slab is accommodated by the Queen Charlotte and Fairweather fault zones. The transition from subduction to transform tectonics is complicated by the allocthonous Yakutat microplate which is colliding with southern Alaska along the eastern edge of the subducting slab (Figure 2).The collision of the Yakutat microplate is considered to have substantial influence on the deformation and counterclockwise rotation in the interior of south-central Alaska (Haeussler,2008).GPS velocity measurements show that the microplate is moving northwest at 50 mm/yr (2.0 in/yr),a velocity that is similar in magnitude to the subducting Pacific Plate.The similarity in motion vectors suggests substantial coupling between the two plates (Elliott et al.,2010).Block modeling by Page 14 of 146 2/24/12 -yzw SUS ITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Elliott et al.(2010)indicates that Yakutat is converging with southern Alaska at a rate of 45 mm/yr (1.7 in/yr). Dextral crustal stress in the region primarily is accommodated by the Denali fault to the north and the Castle Mountain fault to the south.The Denali fault predominantly shows right-lateral,strike-slip fault motion,and in map view has an arcuate shape (Figure 6). Along its eastern extent,the fault strikes northwest.The fault trace turns increasingly to a westerly to southwesterly strike toward its western extent. The Denali fault defines the northern margin of the Southern Alaska block of Haeussler (2008)(Figure 2)and has been a major structural component of Alaska since it formed as a crustal suture during the Late Jurassic to early Cretaceous (Ridgeway et al.,2002). Offset of 56 Ma metamorphic and intrusive rocks suggests at least 249 mi (400 km)of total right lateral displacement along the fault (Nokleberg et al.,1985).Offset is further constrained in the Denali region where the 38 million year old Mt.Foraker pluton is displaced 24 mi (38 km)from the McGonagal Pluton (Reed and Lamphere,1974).In 2002,the Denali fault produced a M 7.9 earthquake,the largest strike-slip earthquake to occur in North America in almost 150 years (Eberhart-Phillips et al.,2003.Detailed studies of offset glacial features along the fault following the 2002 earthquake have demonstrated a clear westward decrease in the Quaternary slip rate along the fault (Matmon et al.,2006;Meriaux et al.,2009)(Figure 6). Along the north and south sides of the Denali fault are two zones of deformation.To the north of the fault is the Northern foothills fold and thrust belt (NFFTB),a zone of variably dipping,but generally north-vergent Quaternary thrust faults and folds that accommodates transpressional deformation along the north side of the Alaska Range (Figure 7).Surface structures likely sole with depth into a master detachment with a surface trace along the northern margin of the fold and thrust belt (Bemis et al.,in press).The westward reduction in Denali fault slip rate (Figure 6)is considered to be largely the result of strain partitioning onto the NFFTB (Haeussler,2008;Meriaux et al., 2009). South of the Denali fault are several south-vergent thrust faults that splay off from the central section of the Denali fault (Figure 6).Most of these faults are recognized as Tertiary terrane-bounding features where Mesozoic or Paleozoic rocks are thrust over Tertiary sediments and volcanics (Haeussler,2008).Rupture along the previously unmapped Susitna Glacier thrust fault during the 2002 Denali fault earthquake highlighted the potential for seismogenic activity in this area,in contrast to the relatively sparse mapping of Quaternary faults south of the Denali fault.This concept is well Page 15 of 146 2/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 expressed in the Neotectonic Map of Alaska fault explanatory note (Plafker et al.,1994; back panel): The map represents an analysis of data from published or publically available unpublished material,supplemented by reconnaissance field investigations of most of the younger onshore faults. Additional faults undoubtedly exist but have not yet been recognized because of the reconnaissance nature of much of the geologic mapping or because they are concealed beneath unconsolidated deposits or water.Future geologic and seismologic investigations will undoubtedly identify many more faults and will provide evidence,requiring changes...for faults shown on this map. The geometry of the NFFTB and the thrust faults south of the Denali fault form a positive flower structure within the Alaska Range (Haeussler,2008).Positive flower structures are common in transpressional orogens where strain is partitioned between a master strike slip faults and thrust faults that dip towards,and sole into the strike slip fault at depth (Sylvester,1988).Spatial distributions of aftershocks from the 2002 Denali fault earthquake are consistent with the flower structure hypothesis (Ratchkovski et al.,2004). The Castle Mountain fault is a dextral oblique strike-slip fault whose western segment is defined by a 39-mi (62-km)long Holocene fault scarp;the eastern section primarily is recognized only in bedrock (Figure 8).Paleoseismic studies of the western section demonstrate four earthquakes on the fault in the past 2800 years,with a recurrence interval of approximately 700 years (Haeussler et al.,2002). 3.2 Significant Historical Earthquakes The region within the 124-mi (200-km)radius of the Susitna-Watana dam site,is seismically active as indicated by the occurrence of earthquakes with a magnitude greater than or equal to M 5 (AEIC seismicity catalog).The greatest number of these are deep (>25-mi (40-km)depth)events with magnitudes up to M 7.1,that likely are associated with the subducting Pacific Plate,and a smaller number of events to the southeast that likely are associated with tectonic under-plating of the Yakutat block. The remaining events are crustal earthquakes occurring at depths of about 19 mi (30 km)or less.The largest of those crustal earthquakes is the 2002 M 7.9 Denali fault earthquake (initiated on the Susitna Glacier fault),with an epicenter approximately 59 mi (95 km)from the dam site.Several of the M 2 5 events are associated with the Page 16 of 146 2/24/12 -z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Denali fault including:the M 6.7 foreshock of the 2002 earthquake (Nenana Mountain earthquake),several 2002-2003 aftershocks up to M 5.8,and six additional events up to M 6.4. Events up to M 7.2 are located in the Northern foothills fold and thrust belt and the Minto Flats seismic zone.The Northern foothills fold and thrust belt includes the Kantishna seismic cluster,the Northern foothills thrust,and the Molybdenum Ridge fault (Figure 7). An M 5.7 event in 1984 is associated with the Castle Mountain fault (Lahr et al.,1986). Many events cannot be spatially correlated with a documented Quaternary fault, including an M 7.2 earthquake in 1912. Seven historical earthquakes are documented within 31 mile (50 kilometers)of the site (AEIC catalog).Four of these earthquakes have depths between 30 to 60 mi (49 to 97 km),which places them within the subducting slab.The largest slab event within 31 mi (50 km)of the site has a magnitude of M 5.4.Three earthquakes are located at upper crustal depths (13-22 mi [21-36 km]),the largest of which has a magnitude of M 6.2. These three earthquakes occurred between 1929 and 1933,and spatially are not associated with any known Quaternary fault,though they may be inaccurately located, or have poor depth control,due to the lack of regional seismograph stations at that time. 3.2.1 2002 Denali fault earthquake The M 7.9 2002 Denali fault earthquake is the largest onshore strike-slip earthquake in North America in the past 150 years (Eberhart-Phillips et al.,2003).The earthquake initiated on the previously unmapped Susitna Glacier thrust fault (Figure 6)with a 30-mi (48-km)surface rupture and up to 36 feet (11 m)of displacement (Crone et al.,2004). The earthquake then propagated eastward rupturing 140 mi (226 km)of the central Denali fault and 41 mi (66 km)of the Totschunda fault.Average slip along the Denali fault was approximately 16 feet (5 m),with a maximum slip of 29 feet (8.8 m)west of the junction with the Totschunda fault (Haeussler et al.,2004).The earthquake caused no fatalities and minimal damage to infrastructure,likely due to the sparse population density near the fault.The estimated intensity of the earthquake at the Watana Dam site was Modified Mercalli scale VI (USGS,2003). 3.2.2 1964 Great Alaskan earthquake The M 9.2,March 28,1964 Great Alaskan earthquake had an epicenter directly south of the 124-mile (200-km)radius site region;however,the subsurface rupture area extends nearly beneath the site region (Figure 5).The isoseismal map of the event shows the Page 17 of 146 2/24/12 yz SUS ITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Watana Dam site experienced ground shaking with Modified Mercaili scale Vil intensity (Stover and Coffman,1993).The earthquake is the second largest recorded in the world since instrumental recordings began in the late 1800s (the one larger event was the 1960 M9.5 Chilean earthquake). The 1964 earthquake ruptured approximately 500 mi (800 km)of the Aleutian megathrust with left-lateral reverse-slip motion,and produced approximately 66 feet (20 m)of maximum displacement (Christensen and Beck,1994).The earthquake was felt over 700,000 square miles in Alaska and Canada (Hake and Cloud,1966)with an intensity of MM VII estimated at the Watana Dam site (Stover and Coffman,1993). Coseismic vertical displacements affected an area of about 200,000 square miles. Prince William Sound experienced up to 38 feet (11.5 meters)of uplift,and 7.5 feet (2.3 meters)of inland subsidence (relative to sea level)occurred (Plafker,1969).Fifteen fatalities were attributed to the earthquake,and 113 fatalities from the ensuing tsunami. In Anchorage,the earthquake destroyed structures up to 6-stories high and triggered numerous destructive landslides. 3.2.3 1912 Delta River earthquake A widely felt 1912 earthquake,commonly referred to as the Delta River earthquake,was relocated by Doser (2004)to a location within 6 miles (10 km)of the Denali fault,though with 95%error bounds of about 62 mi (100 km)in the east-west direction and 44 mi (70 km)north to south.Carver et al.(2004)interpreted healed tree damage as having resulted from surface deformation during the 1912 event.However,paleoseismic studies at several sites along the Denali fault do not show any evidence for a surface rupturing 1912 event (Schwartz et al.,2003;Plafker et al.,2006;Koehler et al.,2011b). Therefore,the event is considered as being unassociated with a particular known crustal fault. 3.3 Quaternary Geology Quaternary geologic information is relevant to understanding the geomorphic processes,resultant surficial geologic deposits as well as relationships amongst deposits,both stratigraphically and chronologically.Quaternary stratigraphy and chronology are used to establish geologic datum for evaluating tectonic (fault)activity during and since the late Quaternary. For this office-based seismic hazard update,assessing late Quaternary fault activity via existing data and literature helps provide a basis for including (or not including) Page 18 of 146 2/24/12 -z- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 particular faults in the seismic source model,and helps screen for the potential of surface fault rupture hazard.Synthesis and evaluation of existing Quaternary geologic mapping and related scientific publications are therefore crucial data for this assessment. 3.3.1 Previous work Quaternary geologic mapping has been completed for some of the Talkeetna Mountains region,as well as locally near the proposed Watana Dam site area.There is substantial variability in the scale,completeness,coverage,and level of detail across the existing geologic maps.The following paragraphs present a very brief summary of the available previous Quaternary studies and data relevant to the seismic hazard update. In the 1970s the U.S.Geological Survey (USGS)developed a key geologic map of the Talkeetna Mountains (Csejtey et al.,1978).Among other features,this map depicts a trace of the Talkeetna fault,labeled and symbolized as a thrust fault,but lacks detailed mapping of Quaternary deposits.Several scales of maps and Quaternary geologic field investigations were completed near the dam site by consultants in the early 1980s (e.g., WCC,1980;Appendix A in WCC,1982,).Some detailed,but aerially limited,geologic mapping of surficial deposits (e.g.lacustrine clay)were preliminarily prepared for the proposed project (WCC,1980),but were not finalized.There is reference to detailed mapping of deposits and moraines in WCC (Appendix A in 1982)but final maps were apparently not produced for,or included in,the final report.Project consultants completed detailed geomorphic mapping of terrain units based on air photo interpretation (Acres,1980;Geotechnical Report,Volume 2;Appendix G-K).The terrain maps were not synthesized into a geologic framework as developed in the WCC report.Limited mapping of Quaternary deposits also was developed near the site by Acres (1981,1982)and Harza-Ebasco (1984)as part of detailed geotechnical investigations for the Susitna-Watana Dam site. Additional,detailed Quaternary geological mapping of surficial deposits directly east of the site in the mid-1980s (with radiocarbon age data)was published by the USGS (Williams and Galloway,1986).Several publications after Williams and Galloway (1986)offer regional geologic and geomorphic conceptual models for explaining the distributions and relationships between different surficial deposits,based on evidence of large late Pleistocene inland ice-dammed lakes in the Copper River basin. The following sections provide an overview of the regional Quaternary geologic setting, briefly summarizes and evaluates the Quaternary stratigraphy and chronology Page 19 of 146 2/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 presented in WCC (1982),for the general dam site vicinity,and the relevance of the existing Quaternary geologic studies to the seismic hazard update for the Susitna Dam site evaluation. 3.3.2 Quaternary geologic setting Glacial ice fields and ice lobes spread over much of south central Alaska during the late Cenozoic.The Alaskan glaciations waxed and waned during the Quaternary period, and the repeated ice advances sculpted and formed much of the existing surficial deposits and geomorphic landforms.The dynamic fluctuations of ice created several depositional environments as well as various landforms,such as:outwash plains, proglacial lakes,ice-dammed lakes,bogs,kame terraces,moraines,till,drift,eolian loess,and localized glaciofluvial channels and deltas (Hamilton,1994). 3.3.2.1.Glaciations Late Cenozoic glaciations in Alaska usually are recognized as chronologic events that have relatively diffuse time boundaries because of the time-transgressive nature,and the variability in ice extent and timings of ice movement from place to place.Four main glacial episodes are identified in the south central Alaska region in the Quaternary. From young to older,these Pleistocene events are:Late Wisconsin glaciation ( 24 ka' to 11 ka),Early Wisconsin glaciation ( 75 ka to 40 ka),Illinoisan glaciation (>125 ka), and pre-lllinoisan glaciation ( 300 ka)(Hamilton,1994).The main glacial episodes may be further subdivided into "phases”or "stades,”based on local geologic relationships correlated to relatively regional deposits.Individual ice lobe advances in specific regions may be identified based on detailed mapping and age-dating of surficial deposits (e.g.,Williams and Galloway,1986). Numerous ice fields and glacial lobes existed in the Talkeetna Mountains as well as the Chugach Mountains to the south (Williams and Ferrians,1961).Mid to Late Wisconsin glacial advances in the Talkeetna Mountains region directly east of the Susitna-Watana Dam site are well documented by Williams and Galloway (1986).These mountainous regions developed alpine glacial lobes that flowed down their respective valleys and extended onto the Copper River basin floor to various lengths.As glaciers filled the Copper River basin,they created an ice dam which formed at least two,and probably more,aerially extensive ice-dammed lakes (Nichols,in Carter et al.,eds.,1989). 'Ka abbreviates "kiloannum;”thousands of years ago.For example,24 ka is read as 24,000 years ago. Page 20 of 146 2/24/12 -we-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Glaciers emanating from the ice fields in the Chugach,Wrangell,and the Alaska Range flowed down their valleys and terminated in the lake.The lake (i.e.,Lake Ahtna)may have episodically drained at different elevations and times during the late Wisconsin (Williams and Galloway,1986;Williams,in Carter et al.,eds.,1989;Ferrians in Carter et al.,eds.1989;Wiedmer et al.,2010).At their greatest extents,these glaciers coalesced and extended across the Susitna-Watana Dam site area;as the glaciers receded,the dam site was inundated by glacial Lake Ahtna. 3.3.3 Quaternary geoloay in the site vicinity The most extensive investigations of the Quaternary geologic deposits and history were completed in the late 1970s and early 1980s for the proposed hydroelectric project. Many of these studies were instrumental in providing data which later lead to the full recognition of the extent of Quaternary glaciation and glacial lakes in the region,but at the time of these studies,that framework had not been fully integrated.For the seismic hazard evaluation of the proposed hydroelectric project,the primary source of Quaternary geologic data in the site vicinity was developed for WCC (1980,1982) (Section 2.4).From their studies and mapping,a site vicinity stratigraphic and chronologic framework was developed (WCC,1982).The following paragraphs briefly examine and evaluate this stratigraphic and chronologic framework. 3.3.3.1 Stratigraphy Based on the Quaternary geologic mapping (Figures 9 through 11)and field work,the principal Quaternary deposits near the site vicinity include:Glacial drift and differing-age tills,re-worked till,well-sorted and stratified coarse-grained deposits from glaciofluvial outwash,well-sorted sands with sedimentary structures indicative of fluvial deltaic origin,and fine-grained deposits with massive to laminated structures indicative of lacustrine deposition.These deposits were identified at field exposures in outcrop,as shown on a cross sectional diagram (WCC,1982)(Figure 9).The cross section illustrates variable stratigraphy both laterally and vertically,with thick sections of lacustrine deposits overlain by oxidized till or highly oxidized reddish glaciofluvial deposits.The cross section also illustrates the elevational positions of the deposits. Terraced sands are shown stranded on topographic high points,and deltaic sands are shown at lower elevations that laterally grade into lacustrine deposits.No attempt was made to conceptually link the deposits together into a site-specific geologic model.The proposed conceptual geologic model of WCC (1982)involved assuming a particular geomorphic relationship of deposits in which,presumably younger deposits,are at Page 21 of 146 2/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 lower elevations and nested within (or,"inset into”),elevationally higher,presumably older,deposits (Figure 10);and that each subsequent ice lobe advance phase was of diminished aerial and vertical extent relative to the previous phase.Neither assumption was rigorously tested. WCC (1982)identifies thick lacustrine beds as owing to the formation of lakes by glacial ice damming (p 3-18).However,the data (WCC,1980;1982)as well as subsequent geological research (Williams and Galloway,1986;Carter et al.,1989;Hamilton,1994; Weidmer et al.,2010)more favor the presence of two or more large ice-dammed paleolakes that existed in the Copper River basin sometime during the late Pleistocene and perhaps into the early Holocene (Lake Susitna,older;Lake Ahnta,younger).These ice-dammed paleolakes may have occupied several elevations through time identified by abandoned shorelines and potential geologic "spillways”near the dam site area (Williams and Galloway,1986).Based on radiocarbon dating,the younger lake,Lake Ahtna,may have drained by at least 9,4004300 ka.The large and potentially youthful paleolake and lake-draining deposits may have key linkages to the stratigraphy near the dam site vicinity. 3.3.3.2 Chronology The WCC (1982)cross section illustrates presumed estimated maximum ice elevations for different Late Wisconsin glacial phases (Figure 9),as a partial basis for correlating deposits and assigning chronology.The other bases were relative and absolute dating techniques.The relative dating technique largely was indiscriminant and unsuccessful. For absolute dating,WCC (1982)obtained eleven radiocarbon dates in the surficial geologic deposits near the dam site vicinity.Of these eleven,five exceeded the method limit (i.e.,minimum age);four were early Holocene (circa 9,500 ybp);two were early Holocene (circa 3,000 ybp).None of the samples dated presumed Late Wisconsin deposits ( 24 ka to 11 ka)-an important age window for evaluating fault activity for critical engineered structures. Moreover,the WCC (1982)geologic map indicates that a substantial amount of the surficial deposits are greater than 11,000 years old (Figure 10).This gap or disparity between presumed deposit age based on elevation (i.e.the geologic map)and the results of the eleven age-dates implies that an adequate site stratigraphic chronology that directly links the surficial and subsurface deposits to their correct age (as well as sequence and genesis)was not established. Page 22 of 146 2/24/12 -Z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 3.3.4 Relevance to seismic hazard evaluation Overall,the geologic and chrono-stratigraphic model of WCC (1982)largely is based on presumed maximum Late Wisconsin ice elevations,assumed inset geomorphic relations,and regional correlation of deposits based on these presumed elevations of ice and positional relationships of deposits (e.g.Figure 10).This conceptual framework largely is based on inference and tenuous correlation of deposits based on elevation. Further,the model does not account for geomorphic process,sequence stratigraphy, variability of stratigraphy,or site-specific event chronology.This implies that the chrono-stratigraphic framework of WCC (1982)is inappropriate for evaluating seismic hazard,because a consistent stratigraphic or geomorphic datum for evaluating late Pleistocene fault activity was not established. Importantly,WCC (1982)absolute age data are not available for the time interval appropriate for seismic hazard evaluation.While the ages,timings,and extents of the ice-dammed paleolakes have been broadly estimated (e.g,Williams and Galloway, 1986),they have not been defined clearly or conclusive regionally and at the site level. The age and timing of lacustrine and paleolake-related deposits is relevant to this seismic hazard analysis because,based on the date and research published after 1982, the surficial deposits near the site vicinity may,in places,be younger than implied by the geologic map of WCC (1982).This has direct bearing on the presumed datum for assessing "recency”of fault activity in terms of:(1)potential near-field seismogenic sources,and,(2)evaluating potential surface fault rupture hazard (Section 9.1). 3.3.5 Surficial geology at the dam site area The surficial deposits at the dam site were mapped and correlated based on drill samples of the thick overburden on the north abutment during the geotechnical studies for the dam and construction materials (USACE,1979;Acres 1981,1982;Harza- Ebasco,1984). The Acres studies'geologic mapping at the site is presented in Figure 11,and top of bedrock contour mapping is presented in Figure 12.These studies subdivided the deposits into three distinct zones:top of slope deposits from approximate elevation of 2200 ft to 1900 ft),slope deposits from 1900 ft down to the river channel,and riverbed deposits (Acres,1981 and 1982).The top of slope marks the topographic transition from the "V”shaped canyon below and the relatively flat upland plateau above.Surficial deposits in this zone consist of till,alluvium and talus and are generally 20 to 50 feet thick with isolated bedrock outcrops.The slope deposits occur where the valley profile Page 23 of 146 2/24/12 zw- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 changes from a "U”shape to a "V”shape and consist of up to 40 feet of dominantly talus and rock avalanche deposits with abundant bedrock outcrop in cliff faces (Acres, 1981 and 1982). Geophysical surveys and borings above the Susitna River channel by Harza-Ebasco (1983)found that the channel is underlain by alluvial deposits with relatively uniform thickness up to approximately 80 feet (Harza-Ebasco,1984).The deposits are comprised primarily of well-graded coarse-grained gravels,sandy gravels and gravelly sands with cobbles and boulders.The underlying bedrock channel is generally symmetrical and nearly flat-bottomed with the exception of two pronounced depressions upstream of the dam site that have alluvial overburden up to 140-feet-thick.The depressions are not on strike with the principal bedrock shear zones identified in previous studies (Acres,1981 and 1982),however,the features are presumed to be located in areas of weaker,erodible bedrock. Deposits on flat uplands reach up to 550-foot thickness on the north abutment area,and 350 feet thick on the south abutment.Additional field investigations to the north of the dam site for construction material sources identified a relict channel incised into the bedrock and obscured by flat lying surficial deposits (Acres,1981 and Harza-Ebasco, 1984).The relict channel is comprised of two bedrock thalwegs up to 500 feet deep, filled with fluvial,glacial and lacustrine deposits.The channel is interpreted to have been a paleo-channel of the Susitna River in pre-glacial times.The channel may follow less resistive rock to the north of the massive diorite pluton that underlies the dam site and continued into the current lower reaches of Tsusena Creek.Subsequent glacial advance from Tsusena Creek would have diverted the channel into approximately its current alignment (Acres,1981). 3.4 Dam Site Area Geology The dam site area was first mapped by Csejtey et al.(1978)whose mapping of the Talkeetna Mountains Quadrangle was later incorporated into regional mapping compilations by Wilson et al.(1998 and 2009)(Figure 13).The Wilson et al.(2009) compilation includes previously unpublished lineaments and bedrock faults near the dam site.Detailed bedrock mapping at or near the dam site was performed in conjunction with the previous Watana Dam site investigations in the late 1970s and early 1980s (USACE,1975,1979;WCC,1980,1982;Acres,1981,1982;Harza- Ebasco,1984). Page 24 of 146 2/24/12 yz.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 The oldest bedrock unit proximal to the dam site is a flysch sequence comprised of Cretaceous shales (regionally altered to argillite)and lithic greywacke sandstone of the Kahiltna assemblage (Csejtey et al.,1978).These sediments were shed from sources in the east and northeast into a basin between the Wrangalia Terrane and North America during the Cretaceous orogeny (Glen et al.,2007a).Small bodies of Paleocene granite units with interfingering migmatite and pelitic schists,and granodiorites with minor diorite (Csejtey et al.,1978),regionally intrude the Kahiltna assemblage.The intrusive rocks are part of a large suite of largely granitic and granodioritic rocks which intruded between 53.2 Ma to 64 Ma during the late stages of accretionary tectonics.Diorite and quartz diorite bedrock underlies much of the dam site and is likely part of this regional intrusive suite (Acres,1981).The youngest bedrock units in the site vicinity are Paleocene to Miocene subaerial volcanic rocks and related shallow intrusives that may be related to the Paleocene plutons (WCC,1980).At the dam site these young volcanic rocks include andesite porphyry and numerous felsic through mafic dikes (Acres,1981).Basalt flows outcropping in Deadman Creek,to the east of the dam site have an early-mid Eocene age (approximately 48 Ma,based on Argon isotope analyses)(Schmidt et al.,2002). 3.5 Site Bedrock Velocity P-wave seismic velocities from seismic refraction surveys were measured during the earlier geotechnical evaluation of the dam site area and presented in Acres (1981, 1982).The velocity measurements from those studies are presented in cross sections in the Acres reports.The reports also present interpreted velocity ranges used to classify the various bedrock materials in the subsurface.Table 1 summarizes the estimated bedrock seismic maximum and minimum velocity ranges.The P-wave velocities (feet per second)have been converted to S-wave velocities (meters per second)using the conversion calculation of Aki and Richards (1980).These conversions suggest that S-wave velocities at the site range from about 3,950 ft/s to 12,800 ft/s (1,200 m/s to 3,900 m/s),and are further categorized by degree of rock weathering and alteration (Table 7). S-wave velocity for the site is a key input for the ground motion prediction equations (GMPE)as discussed in Section 5.2.Ground motion estimates developed for this study are intended as inputs to base models,in which effects of soils and structures are separately computed.For these types of analyses,ground motion estimates are input at the rock foundation interface or deep in the modeled foundation.Although specific details of foundation excavations have not been developed for dam alternatives,and no Page 25 of 146 2/24/12 -Z-SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 site-specific shear wave velocity measurements have been obtained for the site,the existing data provides a preliminary indication of the potential foundation conditions. Based on available data,it appears that S-wave velocities at the site for unweathered to lightly weathered rock which may form the majority of the structure foundation may well exceed 7,875 ft/s (2,400 m/s)(Table 1). Table 1.Summary of Site Bedrock Seismic Velocity Data Watana Dam Site and Vicinity Seismic Velocity Correlations P wave (ft/sec)'S wave (m/sec) minimal fracturing Material ----Minimum Maximum Minimum |Maximum Highly sheared weathered or altered 7,000 10,600 1,232 1,865bedrock Sheared,fractured weathered or 40,600 13,500 1,865 2.376alteredbedrock Bedrock,surface weathering or stress relief jointing to moderate depths,13,500 16,200 2,376 2,851 generally very competent Bedrock,fresh,extremely competent,16,200 22,200 2,851 3,907 Notes:(1)Data from Acres (1982)report,Table 5.1.(2)P wave (ft/sec)to S wave (m/sec)conversion = (P wave x 0.3048)/1.732 after Aki and Richards (1980). Page 26 of 146 2/24/12 -yzZ SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 4.0 SEISMIC SOURCE CHARACTERIZATION 4.1 Subduction Related Sources The Alaska subduction zone (ASZ)is one of the world's most seismically active subduction zones.Relative plate motion between the Pacific and North American Plates increases from about 5.4 cm/yr (2 in/yr)at its eastern end near the Talkeetna Mountains to about 7.8 cm/yr (3 in/yr)at the west end of the Aleutian arc (Figure 5). The ASZ is also termed the Alaska-Aleutian Arc.East of longitude 170 degrees West, the Pacific Plate is subducting beneath continental crust,while to the west it subducts beneath oceanic crust that was trapped after initiation of the arc in the middle Eocene. This results in a more shallow-dipping plate interface to the east than to the west. Earthquakes associated with the ASZ are of two main types:large "megathrust”events due to accumulated frictional strain between the two plates (most notable being the 1964 M 9.2 earthquake,described in section 3.2.2),and those occurring within the down going Pacific Plate as it descends into the mantle.These "intraslab”earthquakes, considered capable of reaching magnitudes of M 7.5,are due to factors such as spreading ridge push,gravitational pull of the plate due to density contrasts between it and the mantle,and metamorphic reactions due to increasing temperature and pressure within the down going plate.In this study,we model these two types of subduction earthquakes from the ASZ,termed interface (or megathrust),and intraslab. The dam site area lies at the eastern end of the ASZ.At this location the plate interface has an extremely low dip,almost flat (Figure 14B).The northern boundary of the interface is at a depth of about 22 mi (35 km)and lies about 50 mi (80 km)southeast of the site.To the northwest of this line intraslab earthquakes are produced as the plate dips more steeply as it descends into the mantle.Beneath the site the top of the plate is at a depth of about 31 mi (50 km)(Figure 14). 4.1.1 Plate interface The interface between the North American and Pacific Plates is the source of the largest magnitude earthquakes in the source model.Due to studies of the 1964 M 9.2 earthquake,seismic refraction/reflection surveys (e.g.Brocher et al.,1994),and research results from a regional seismograph network operated by the Alaska Earthquake Information Center (AEIC)(Ratchkovski and Hansen,2002),the geometry of the down going plate within a few hundred km of the site is fairly well known. Page 27 of 146 2/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 In this region,Wesson et al.(2007)following cross sections of relocated seismicity shown in Ratchkovski and Hansen (2002),modeled the interface as shown in Figure 15. In this figure the up-dip 20 km (12 mi)contour is seen to the southeast.The contour representing the down-dip boundary of the plate interface is seen to the northwest.To the southwest its depth is 40 km (25 mi),reflecting the steeper interface dip to the west, and at longitude 151 degrees West,it begins to shoal from 40 km (25 mi)to 33 km (20 mi)to the end of the interface at the northeast end.This reflects the slightly tilted interface seen in Figure 14 (Figure 6b of Ratchkovski and Hansen,2002). 4.1.2 Intraslab Intraslab earthquakes occur within the down going Pacific plate,after it breaks contact with the North American Plate in the megathrust zone,and assumes a steeper dip as it descends into the upper mantle.Notable earthquakes of this type include the M 6.5 1965 and M 6.8 2001 Nisqually,Washington earthquakes associated with the Cascadia subduction zone.As seen in Figure 14,in the site region this zone consists of two parts:an intermediate zone dipping about 25 degrees between depths of 31 and 50 mi (50 and 80 km),and a deeper zone from 50 to 93 mi (80 to 150 km)that dips more steeply.The physical sources of these earthquakes include ridge push from oceanic spreading ridges,gravitational pull of the slab due to density contrasts between it and the surrounding mantle,and chemical reactions due to increasing pressure and temperature. 4.2 Quaternary Crustal Faults The following section discusses all faults within 125 mi (200 km)of the dam site with evidence of historical or Quaternary activity,as well as suspicious faults that may or may not be active structures (Figure 3,Table 2A).(The activity term "suspicious”is from Plafker et al.(1994)).Fault parameters obtained from peer-reviewed references are summarized in Tables 3A and 3B.The primary compilation of faults in Alaska,and the initial basis for the model included is the "Neotectonic Map of Alaska”by Plafker et al.(1994).Quaternary faults identified after the Plafker et al.(1994)map and presented in published literature have also been included in the model.A Quaternary fault and fold database of Alaska is currently being compiled by the Alaska Division of Geological &Geophysical Surveys (Koehler et al.,2011a),however,final publication of the database is not expected until 2012.Table 5 numerates the closest distance from the site area to the faults listed in Tables 2A and 2B.In Table 5,"JB distance”is the closest Page 28 of 146 2/24/12 -yz.SUS ITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 distance to the horizontal projection of the fault plane,and "Rupture Distance”is the closest distance to the fault plane. Page 29 of 146 2/24/12 -Z-.SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120217 Table 2A.Fault Characterization :Age from Plafker et Age from Other Sense of .Seismogenic PFaultNameSectional.(1994)Sources Slip Dip Depth (km)Slip Rate (mm/yr)Recurrence (years) Eastern Eastern Castle ar Sag Historic based on 1984 °;lateral:0.5 -0.6 (Fuchs,1980)Castle Mountain =Historic,seismicity RL -Reverse 76°N (Lahr et al.,1986);2 N/AMountain-Caribou =(Lahr et al.,1986)thrust:?Caribou fault Pleistocene ”80°-90°(Fuchs,1980)_ Castle Mountain fault 20 [based on lateral:2.8-3.6,[preferred rate of 3.0 -3.2] Western Holocene 70°-90°N 1984 EQ (Willis et al.,2007);2.9 mm/yr (Wesson et al. Castle Holocene RL -Reverse 2007);0.45-0.63 (Koehler and Reger,2011)700 (Haeussler et al.,2002) f .(Haeussler et al 2000)(Lahr et al.,Mountain (Haeussler et al.,2002;1986)]Willis et al.,2007)thrust:0.07-0.14 380 (mean ages from Plafker Holocene et al.,2006 and DFWG?2 ;Eastern Holocene (Matmon et al.,2006)RL .'8.4 +-2.2 mm/yr (Matmon et al.,2006)summarized in Koehler et al., 2011) 12 [from 14.4 +-2.5 mm/yr (Matmon et al.,2006), Denali fault Holocene/Historic -2002 M7.9 75°-90°2002 85 km W =13.0 +-2.9 mm/yr 400 (mean age from DFWG Central Suspicious (Eberhart-Phillips et al.,RL (Haeussler et al.,2004)aftershocks 255-283 km W =9.4 +-1.6 mm/yr summarized in Koehler et al.,P 2003).”.(Ratchkovski |323 km W =6.7 +-1.2 mm/yr (Meriaux et al.,2011) et al.,2003)}2009)(distance relative to Totschunda junction) Holocene/????Western suspicious N/A RL d f f q Pass Creek -Dutch .Holocene 5 5 1.72 mm/yr min slip rate based on scarp 1340 max (Willis and Bruhn, Creek fault N/A Late Pleistocene |(yaeussler et al.,2008)Normal height of Willis and Bruhn (2006)2006) Holocene (Williams and >2 2 DySononaCreekfaultN/A N/A Galloway,1986)f f 1 7 ? Holocene (Plafker et al,East Boe Creek N/A Late Pleistocene 1994)2 ???? ;Holocene (Haeussler and .2 2 >>Matanuska Glacier fault N/A N/A Anderson,1995)Right normal f d 7 7 Historic2002 M7.9 19-48 4000SusitnaGlacierfaultN/A N/A (Eberhart-Phillips et al.,Reverse (Crone et al.,2004 and ??(Crone et al.(2004)2003).Ratchovski et al.,2003); Cenozoic 5-40 ?2 2BroxsonGulchfaultN/A Neogene (Ridgeway et al.,2002)Reverse (Stout and Chase,1980)?f ? McCallum-Slate Creek .Early Pliocene (Weber 5 7 5 >fault N/A Late Pleistocene and Turner,1977)Reverse ?d d d ? Bull River fault N/A suspicious N/A Reverse ???? Foraker fault N/A ?N/A Reverse ???? Broad Pass fault N/A ?N/A Reverse ???? Notes:See Table 2B for Northern foothills fold and thrust belt faults Page 30 of 146 2/24/12 ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 -Z- SUSITNA-WATANA HYDROELECTRIC PROJECT Table 2B.Northern Foothills Fold and Thrust Belt (NFFTB)Fault Data Age from Plafker |Age from Bemis et .DipFaultNameetal.(1994)al.(in press)Sense of Slip |(direction) .ws LL -Reverse ?Billy Creek fault suspicious Holocene (NW up)>60 (7) .LL -Reverse >60CanteenfaultLatePleistoceneHolocene(NW up)_(direction?) Cathedral Rapids fault N/A Holocene Reverse (S up)15-60 (S) Ditch Creek fault N/A Quaternary Reverse (SW up)|>60?(SW?)Donnely Dome fault Late Pleistocene Holocene Reverse (S up)45-90 (S) Dot "T"Johnson fault N/A Holocene Reverse (S up)15-45 (S) East Fork fault Holocene Holocene Reverse (N up)>60 (S?)| >60EvaCreekfaultN/A Quaternary Reverse (N up)(direction?) Glacier Creek fault N/A Quaternary Reverse (S up)30-60 (S) Gold King fault -. Section A N/A Late Pleistocene Reverse (S up)15-30 (S) Gold King fault - Section B N/A Quaternary Reverse (S up)10-30 (N) Granite Mountain fault Late Pleistocene Holocene LL -Reverse (NE >60Aup)(direction?) prante Mountain fault ||ate Pleistocene Quaternary Reverse (Sup)|30-60 (SW) Healy Creek fault Late Pleistocene Late Pleistocene Reverse (N up)60-90 (N) Kansas Creek fault N/A Quaternary RL -Mo)(S >30 (S) Macomb Plateau fault N/A Quaternary Reverse (S up)15-60 (S) McGinnis Glacier fault Holocene Reverse (SW up)>45 (SW?) Molyodenum Ridge N/A Holocene Reverse (S up)15-45 (S) Mystic Mountain fault Neogene Late Pleistocene |RL-Mop)(S >30 (S) Nern Foothills thrust N/A Late Pleistocene Reverse (S up)15-45 (S) Panoramic fault N/A Late Pleistocene Reverse (NE up)>60 (?) Park Road fault N/A Late Pleistocene Reverse (N up)30-90 (N) Peters Dome Fault N/A Quaternary Reverse (S up)15-45 (S) Potts fault N/A Quaternary Reverse (NE up)>60?(?) Red Mountain fault N/A Late Pleistocene Reverse (S up)30-60 (?) Rex fault N/A Late Pleistocene Reverse (S up)>30 Stampede fault N/A Late Pleistocene Reverse (N up)15-30 (N) Trident fault N/A Late Pleistocene Reverse (SE up)>30 (SE) Trident Glacier fault N/A Quaternary Reverse (S up)30-60?(S) Notes:(1)Fault Data from the NFFTB summarized from Bemis et al.(in press).(2)LL =left lateral,RL = right lateral. 4.2.1 Denali fault The Denali fault is a right-lateral fault with an arcuate shape striking to the northwest in the east,and an increasingly westerly and southwesterly strike to the west (Figure 6).A Page 31 of 146 02/24/12 -ze- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 typical geometry evoked for the fault includes an eastern section located east of the junction with the Totschunda fault,a central section between the Totschunda junction and an asperity in the fault strike near Denali,and a western section west of Denali. The western termination of active faulting is considered in the source model to be at latitude 154.7°W based on Wesson et al.(2007),who propose that slip tapers to 0 mm/yr at this location.Western continuation of the fault beyond this point would not be expected to have significant impact on the site ground motions due to the large distance, 202 mi ( 324 km),to the western end of the Denali fault.The fault sections outlined above serve solely for geographic reference,as there is no evidence that the section boundaries would inhibit seismic rupture. The largest historical earthquake on the fault is the 2002 M7.9 Denali fault earthquake, which had 211 mi (340 km)of total surface rupture.The earthquake initiating in the west and ruptured a 30-mi (48-km)long section of the previously unrecognized Susitna Glacier thrust fault.Slip propagated primarily eastward rupturing 140 mi (226 km)of the Central Denali fault.At the eastward limit of slip on the Central Denali fault the rupture stepped southeastward rupturing 66 km of the Totschunda fault (Haeussler et al.,2004). Subsequent studies of Quaternary slip rates along the fault using cosmogenic exposure dating of offset moraines and other glacial features show a westward reduction in slip rate on the Denali fault (Figure 6).Slip rates are summarized in Figures 6 and 18. Matmon et al.(2006)calculate an 8.4 +2.2 mm/yr slip rate for the eastern Denali fault, and a 6.0 +1.2 mm/yr on the Totschunda fault.The slip rates of the Totschunda and Eastern Denali faults sum to 14.4 +2.5 mm/yr at the eastern part of the Central Denali fault section.The preferred slip rates on the central Denali fault west of the Totschunda fault junction are:85 km west of the site is 13.0 +2.9 mm/yr (Meriaux et al.,2009),255- 283 km west is 9.4 +1.6 mm/yr (Matmon et al.2006),323 km west is 6.7 +1.2 mm/yr (Meriaux et al.,2009),and 626 km west is 0 mm/yr (Wesson et al.,2007).The westward reduction in slip rate is widely considered to be the result of the partitioning of slip onto the Northern foothills fold and thrust belt (Figure 7)(Bemis et al.,in press; Haeussler,2008;Matmon et al.,2006;Meriaux et al.,2009).These slip rates are in line with measurements of strain accumulation via geodetics,6.5 to 9 mm/yr (Fletcher, 2002),and InSAR,10 mm/yr (Biggs et al.,2007).The westward reduction in slip rate is also consistent with the westward decrease in displacement during the 2002 earthquake (Haeussler et al.,2004). Paleoseismic studies performed by the Denali Fault Working Group after the 2002 earthquake found that the penultimate slip events were of similar magnitude to the 2002 event (Schwartz et al.,2003).Carver et al.(2004)used tree ring counts from damaged trees near the Delta River to propose that the penultimate event was a M7.2 earthquake Page 32 of 146 02/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 on July 6,1912.Results from test pits adjacent to the Delta River by Plafker et al. (2006)suggest two paleo-events at 310 to 460 years before present,and 650 to 780 years before present.Trenching by the Denali Fault Working Group produced the following Denali fault earthquake chronology: e The 2002 rupture trace had earthquakes between 350 and 600 years before present,and between 715 and 1,080 years before present; e West of the 2002 earthquake the fault ruptured between 110 and 380 years before present,and between 560 and 670 years before present; e East of the Totschunda -Denali fault junction the fault experienced three events between 110 and 356 years before present;2560 and 690 years before present;and $1,020 and 1,230 years before present (summarized in Koehler et al.,2011b). Koehler et al.(2011b)trenched a site along the 2002 rupture trace and found that the penultimate event at this location was after 560 to 670 years before present.None of the paleoseismic trenching studies found evidence for the 1912 Delta River earthquake discussed in Carver et al.(2004)and Doser (2004). 4.2.2 Castle Mountain fault The Castle Mountain fault is an active,oblique strike-slip fault with a western and eastern section (Figure 8).The eastern section is combined with the Caribou fault of Plafker et al.(1994)due to their parallel geometry and the designation by Plafker et al. (1994)that both sections have evidence for Quaternary displacement.The eastern section-Caribou fault is primarily recognized in bedrock,has no evidence for Holocene surface rupture,and has historic seismicity to Mb 5.7 (1984 EQ documented in Lahr et al.1986).The western section is defined by a 39-mi (62-km)Holocene fault scarp (north side up);and has no known historic seismicity greater than M5 (Flores and Doser,2005).The fault trace was mapped in detail by Detterman et al.(1974 and 1976),and also by Haeusler (1998).Detterman et al.(1974)document a near surface fault dip of 75 degrees northward and seismic reflection data shows the fault to be steeply dipping (70 to 90 degrees)at depth (Haeussler et al.,2000). Paleoseismic investigations of the Castle Mountain fault have yielded varying Quaternary slip rates and interpretations of deformational style.Detterman et al.(1974) proposed a maximum age for the most recent event of 1860 +250 years based on a radiocarbon ages of a displaced soil horizon exposed in a trench across a 2.1 m (6.9 ft) Page 33 of 146 02/24/12 ze.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 high scarp.Detterman et al.(1974)also document 7 meters (23 feet)of horizontal displacement of a linear sand ridge across the fault.Trenching by Haeussler et al. (2002)on the western section identified 4 earthquakes on the fault (including one event on an adjacent fault strand)in the past 2800 years with a recurrence interval of approximately 700 years.The most recent rupture occurred 730-610 years before present.Haeussler et al.(2002)determined a shortening rate of 0.07 to 0.14 mm/yr (< 0.01 in/yr)but no lateral offset was observed in the trenches.Willis et al.(2007)use an offset post-glacial outwash channel on the western section to constrain a lateral slip rate of 2.8 mm/yr to 3.6 mm/yr (0.11 in/yr to 0.14 in/yr),with a preferred rate of 3.0 mm/yr to 3.2 mm/yr (0.12 in/yr to 0.13 in/yr).Koehler and Reger (2011)propose that a lateral slip rate of 0.45 to 0.63 mm/yr (0.018 to 0.025 in/yr)may be more appropriate for the western section.Fuchs (1980)proposed a post-Eocene slip rate of 0.5 to 0.6 mm/yr (0.020 to 0.024 in/yr)for the eastern section. 4.2.3 Pass Creek -Dutch Creek fault The Pass Creek -Dutch Creek fault is a northeast-striking,south side down,normal fault bounding the northern edge of the Peters Hills Basin (Haeussler et al.,2008) (Figure 3).The Peters Hills basin is a small Neogene basin that may be a piggyback basin in the hanging wall of a "Broad Pass fault”(see discussion on the Southern Denali fault zone below)(Haeussler et al.,2008).The Pass Creek -Dutch Creek fault forms a 21-ft (6.5-m)tall scarp that displaces Holocene sediments,and creates a vegetation lineament on the north side of the Skwetna River.The last significant rupture on the fault had >6.5 ft (>2 m)of uplift and cut a moraine with a radiocarbon age of 1340 +60 years before present (Willis and Bruhn,2006). 4.2.4 East Boulder Creek fault The East Boulder Creek fault is 14 mi (22 km)long,northeast striking and located south of and parallel to the Caribou fault section of the Eastern Castle Mountain fault system. Detterman et al.(1976)first mapped the trace of the fault based on surface features including notches,benches,saddles,linear gullies and scarps,but make no estimation of the faults age.They document evidence for south side up relative displacement along the fault.Plafker et al.(1994)depict the fault as having Late Pleistocene activity. Because of the fault's proximity and parallel orientation to the Castle Mountain fault,it is considered a potentially active right-lateral fault. Page 34 of 146 02/24/12 -Z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 4.2.5 Matanuska Glacier fault The Matanuska Glacier fault is classified as having Holocene activity in Plafker et al. (1994),based on mapping by Burns et al.(1983)and oral communication with Gar Pessel (2011).Haeussler and Anderson (1995)write that the fault is a "4-km long east- west-striking fault [that]apparently offsets tundra 30 cm vertically with a right normal sense of offset." 4.2.6 Sonona Creek fault The Sonona Creek fault is located in the western Copper River basin (Figures 19 and 20).The structure is mapped by Williams and Galloway (1986)as a 4-mi (7-km)long, active,northeast-striking fault with north side down sense of displacement,offsetting Late Pleistocene glaciolacustrine sediments.No information is provided to indicate further the age,sense or amount of displacement on this fault.This mapped feature is evident in Google Earth images (Figure 20).Although resolution is low,topographic height of the scarp appears limited,suggesting that at least the vertical slip rate is relatively low.As a singular surface rupture along a potentially active fault,the length of the scarp is relatively short.The presently available images in Google Earth are permissive of extensions and certainly do not rule out extensions of this fault in either direction. 4.3.Zones of Distributed Deformation Zones of distributed deformation are regions with poorly characterized or suspected active faults;where the Quaternary geologic and fault mapping may be incomplete, and/or the slip-rate and recurrence of individual faults is poorly understood.The site region includes two areas classified as zones of distributed deformation:the Northern foothills fold and thrust belt,and the Southern Denali faults. 4.3.1 Northern foothills fold and thrust belt zone The Northern foothills fold and thrust belt (NFFTB)is a zone of Quaternary faults and folds along the north side of the Alaska Range (Bemis and Wallace,2007;Bemis et al., in press)(Figure 7,Table 2B).The zone is primarily comprised of variably dipping thrust faults with dominantly north vergent deformation.Bemis and Wallace (2007) propose that much of the NFFTB is underlain by a gently south-dipping basal detachment that may daylight at the Northern foothills thrust along the northern margin of the NFFTB in the vicinity of the Nenana River.The surface trace of the basal detachment is not identified in the western and eastern margins of the NFFTB.The Page 35 of 146 02/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 western margin of the NFFTB is marked by the termination of uplifted topography northwest of the Peters Dome fault and the Kantishna Hills anticline.The eastern margin is constrained by the paleoseismic investigation by Carver et al.(2010)which found no evidence for Quaternary deformation east of the Cathedral Rapids fault in the vicinity of Tok,Alaska.Quaternary deformation is presumed across the uplifted region within the NFFTB;however,rates of Quaternary deformation along individual faults are still poorly constrained (Bemis et al.,in press).Mapping of deformation in Pleistocene gravels by Bemis (2010)suggests that the region west of the Nenana River has a maximum shortening rate of 3 mm/yr.Bemis et al.(in press)used offset Nenana gravel along the Granite Mountain fault to suggest horizontal shortening 1-4 mm/yr (0.04-0.16 in/yr)of in the eastern NFFTB.Meriaux et al.(2009)proposes that the partitioning of slip from the Denali fault onto the NFFTB could produce convergence rates up to about 4 mm/yr (0.16 in/yr)in the eastern NFFTB end,and about 12 mm/yr (0.47 in/yr)to the west.Due to the apparent variability in slip rates longitudinally across the NFFTB the zone is divided into a western and eastern zone. 4.3.2 Southern Denali faults The southern Alaska Range is characterized by numerous northeast-and east-trending, generally south vergent,thrust and reverse faults that splay off from the southern side of the Denali fault (Figure 6).Most of these faults have evidence for Tertiary activity and several bound disparate tectonostratigraphic terranes (Haeussler,2008;Glen,2004). Glen (2004)proposed that these faults are linked to dextral transport along the arcuate Denali fault and may accommodate compressional deformation as crustal blocks migrate around the restraining fault geometry.The only fault in the area with clear evidence for Quaternary activity is the previously unrecognized Susitna Glacier fault, which ruptured in the 2002 M7.9 Denali fault earthquake.The similar orientation and tectonic setting of the Tertiary faults to the Susitna Glacier fault suggests that these structures have the potential for Quaternary activity.Furthermore,many of these faults are located in glaciated remote regions where evidence for Quaternary activity may have been obscured or gone unrecognized.It is also likely that the current inventory of thrust faults splaying off the south side of the Denali fault is incomplete.The Southern Denali fault zone is a zone of distributed deformation that extends 16 mi (25 km)south of the trace of the Central Denali fault and includes the following six structures. 4.3.2.1 Foraker thrust The Foraker thrust is mapped as a northeast-striking,northwest-dipping thrust fault running through predominantly glaciated terrain between Mt.Foraker and Mt.McKinley Page 36 of 146 02/24/12 -z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 (Wilson et al.,1998).It is considered one of the principal thrust faults responsible for uplift of the high terrain in the Denali region and likely is kinematically linked to the nearby restraining bend in the Denali fault (Haeussler et al.,2008;Haeussler,2005). Haeussler (2005)states that the Foraker thrust is "difficult to constrain,but is likely young and possibly active.” 4.3.2.2 Bull River fault The Bull River fault is mapped as a northeast-striking,southeast-dipping thrust fault located between the Denali and Broad Pass regions (Wilson et al.,1998).The fault juxtaposes Cretaceous Kahiltna flysch sequence rocks in the hanging wall against Tertiary Tyonek Formation sedimentary rocks and Eocene Granites and granodiorites in the footwall.Plafker et al.(1994)classify the fault as having Neogene activity. 4.3.2.3 Broad Pass fault The Broad Pass fault is a poorly understood structure defined by a northeast-striking topographic lineament,Mesozoic rocks topographically above Neogene rocks in the Susitna basin,and scattered shallow thrust earthquakes northwest of Broad Pass (Haeussler,2008).The thrust has been evoked by Haeussler et al.(2008)as a possible master thrust underlying the Peter Hills piggyback basin. 4.3.2.4 Susitna Glacier fault The Susitna Glacier thrust fault was unrecognized prior to the 2002 Denali fault earthquake when 30 mi (48 km)of the fault ruptured with 13 ft (4 m)of average displacement (Crone et al.,2004).The fault has a northeast strike and a northwest dip of approximately 19°near the ground surface.Focal mechanisms from the 2002 earthquake found that the fault ruptured on a 48°dipping plane at 2.6 mi (4.2 km)depth (Ratchovski et al.,2003),which suggests that the fault steepens at depth.Crone et al. (2004)identified a pre-2002 fault scarp exposing volcanic ash in the hanging wall, indicating a penultimate earthquake that post-dates deposition of the ash.The offset ash is considered to be either the Jarvis Creek ash (3.6 ka)or the Hayes Tephra (upper Holocene),suggesting at least one additional Holocene earthquake on the fault. Recent,uninterpreted trenching data from the fault presented by Personius et al.(2010) shows a single paleoevent that ruptures a peat layer with radiocarbon ages ranging from 660-4570 calendar years before present. Page 37 of 146 02/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 4.3.2.5 Broxson Gulch fault The Broxson Gulch fault is an east-and northeast-striking and north-dipping thrust fault located in the eastern Alaska Range,north of the Copper River basin.Plafker et al. (1994)classify the fault as having Neogene activity and Ridgeway et al.(2002)suggest the fault is late Cenozoic in age.The thrust separates Maclaren Terrane rocks on the north from Wrangalia rocks in the south,and is typically mapped as cutting the Talkeetna thrust fault to the southwest (Ridgeway et al.,2002;Wilson et al.1998) Stout and Chase (1980)found the fault to have a 5-40°dip along its eastern edge.Both Haeussler (2008)and Glen (2004)note the likely kinematic connection between the Broxson Gulch fault and the Denali fault. 4.3.2.6 McCallum-Slate Creek fault The McCallum-Slate Creek fault is a southeast-striking,north-dipping thrust fault that parallels the Denali fault immediately east of the Broxson Gulch fault.The fault does not splay off the Denali fault with a counterclockwise orientation like the other thrusts in the region,but its geometry suggests that they connect at depth (Haeussler,2008). Plafker et al.(1994)classify the fault as having late-Pleistocene activity.Weber and Turner (1977)document offset in a 5.25 Ma tephra layer along the fault suggesting early Pliocene activity. 4.4 Talkeetna Block Structures The region is characterized by bedrock faults and distributed deformation associated with Cretaceous accretion of the Wrangellia Terrane (Csejtey et al.,1978 and 1982; Ridgeway et al.,2002)and post-accretionary right-lateral bulk shear in the Tertiary (O'Neil et al.2005,Glen et al.2007b).To date,no direct geologic evidence to conclusively evaluate the late Quaternary fault activity in the Talkeetna Block exists. The proximity of the Talkeetna block structures to the Watana Dam site area requires a thorough discussion of the previously mapped faults with respect to the seismic hazard characterization. 44.1 Talkeetna thrust fault /Talkeetna suture A mapped through-going structure within the Talkeetna block is the Talkeetna thrust fault or Talkeetna suture.The Talkeetna thrust is mapped as a northeast-striking, southeast-dipping fault by Csejtey et al.(1978),WCC (1981),and Wilson et al.(1998) (Figure 13A and 21).The fault juxtaposes Triassic and Permian metavolcanic and metasedimentary Wrangellia terrane rocks on the south against late Jurassic through Page 38 of 146 02/24/12 -ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Cretaceous sedimentary rocks of the Kahiltna Assemblage on the north.The mapped trace of the fault terminates in the northeast against the younger Broxson Gulch thrust and is mapped as being obscured in the southwest by Tertiary igneous rocks (Figure 13A).The approximate fault trace follows a broad topographic lineament striking northeast across the Talkeetna Mountains;however,the precise location of the fault (expressed as a lineament)is obscured along much of its length by Tertiary igneous rocks and Quaternary sediments.Well-documented exposures of the fault are located at Talkeetna Hill in the southwest near the Talkeetna River,Butte Creek in the northeastern Talkeetna Mountains.(WCC,1981)(locations 1 and 4 respectively in Figure 21),and in the Clearwater Mountains (O'Neill et al.,2003a).The investigation by WCC (1982)found indeterminate geologic evidence for conclusively evaluating Quaternary activity along the fault. O'Neill et al.(2003a)mapped structural and stratigraphic relationships at Butte Creek (location 4 in Figure 21)and Pass Creek along the northeastern reaches of the fault. They found that the Kahiltna Assemblage sedimentary rocks in the footwall of the fault were derived from relatively proximal Wrangalia Terrane rocks.O'Neill et al.(2003a) also found no evidence for penetrative deformation associated with the fault.Based on these observations,O'Neill et al.(2003a)concluded that major contractional displacement has not occurred along the Talkeetna thrust.They conclude that the tens of kilometers of tectonic transport during emplacement of the Wrangellia Terrane are expected to be localized on structures to the northwest. Glen et al.(2007b)use tectonic analysis of gravity and magnetic data to propose replacement of the term Talkeetna thrust fault with the Talkeetna suture zone.They describe the Talkeetna suture zone as a deep crustal structure bounding the northwestern edge of the Wrangellia Terrane.Surface structures near and overlying the Talkeetna suture zone occupy a wide zone of complex faulting that includes the Susitna lineament and a range front fault along the south side of the Fog Lakes lowland (Figure 22). Modeling of geophysical anomalies across the suture zone by Glen et al.(2007a)show the suture zone as dipping steeply both to the northwest and to the southeast.They propose that this indicates either variations in dip along strike,or that the modeled anomalies are offset by individual segments within a fault zone with varying orientations. 4.4.2 Susitna lineament The Susitna lineament is a pronounced northeast-southwest trending lineament located near the dam site area (Figure 21).Gedney and Shapiro (1975)described the feature Page 39 of 146 02/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 as a fault based on differential K-Ar cooling data in the Talkeetna Mountains and seismicity.However,subsequent mapping by Csejtey et al.(1978)found no evidence for a major fault in the location of the Susitna lineament.The lineament is mapped near Butte Lake by Smith et al.(1988)and through the central Talkeetna Mountains near the dam site by Clautice (1990).Fault and lineament mapping by Wilson et al.(2009) shown no northeast trending faults in the vicinity of the Susitna lineament but do show several short lineament segments (5-7.5 mi [8-12 km])that are adjacent to,and parallel with,the previously mapped lineament trace (Figure 13).WCC (1982)found the Susitna lineament to be a bedrock feature not related to faulting,except for possible erosion along a minor shear zone parallel to the fault.This conclusion was based on bedrock and surficial mapping,a magnetometer survey,and paleoseismic trenching along the trace of the lineament. Glen et al.(2007b)describes the Susitna lineament as a series of 6-12 mi (10-20 km) long en echelon segments stepping eastward along strike to the north.They report east side down motion on the lineament which exposes Eocene volcanic rocks and Miocene and Oligocene sedimentary rocks in the Fog Lakes and Watana basins.O'Neill et al. (2003b and 2005)suggest that the en echelon pattern of the lineament may be the result dextral motion during post-accretion right-lateral bulk shear. 44.3 Shorter structures proximal to the dam site In addition to the Talkeetna suture and the Susitna lineament,there are numerous northeast-and northwest-striking bedrock faults and lineaments in the Talkeetna block. Several of these structures,proximal to the Watana Dam site area (i.e.the northwest- striking shear zones ("Fins”feature and the Watana lineament)),were studied in detail by WCC (1982)and are discussed further in Section 9.Additional faults and lineaments are shown in mapping by Wilson et al.(2009)(Figure 13). The northeast-southwest structures likely originated during Cretaceous accretionary deformation (Csejtey et al.,1978 and 1982;Ridgeway et al.,2002).Post-accretionary deformation driven by Tertiary right lateral bulk shear in the Talkeetna block has been proposed by several studies (O'Neil et al.2005,Glen et al.,2007a and 2007b).These studies suggest that Tertiary transtensional deformation reactivated northeast- southwest oriented structures and produced several prominent grabens and_half grabens including the Watana Creek lowland,and Fog Lakes lowland.Glen et al. (2007a)propose that the Fog Lakes lowland is bounded on the west by the Susitna lineament,and to the east by a series of range front normal faults (e.g.Talkeetna fault) defining a Fog Lakes graben (Figure 21 and 22). Page 40 of 146 02/24/12 -Zz-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 4.5 Crustal Seismicity 4.5.1 Earthquake catalog 4.5.1.1 Earthquake data source and magnitudes A catalog of earthquakes for the study area was compiled starting with the Alaska Earthquake Information Center (AEIC)earthquake catalog.The catalog contains earthquakes of magnitude 3.0 and above,down to a depth of 62 miles (100 km),and from 1899 through December 31,2010.The base AEIC catalog was supplemented with the undeclustered (includes aftershock earthquakes)USGS catalog from the 2007 Alaska hazard maps (Wesson et al.,2007).In addition,the earthquake locations, depths,and/or magnitudes were updated using the results of relocation studies by Doser (2004),Doser and Brown (2002),Doser et al.(2002),Doser et al.(1999),and Ratchkovski et al.(2003).The AE!IC catalog mb,ML,and MS magnitudes were converted to moment magnitude (Mw)following the relations of Ruppert and Hansen (2010),which apply to earthquakes from 1971 to the present.Earthquakes prior to 1971 were assigned Mw magnitudes according to:(1)the relocation studies noted above,(2)the 2007 USGS Alaska catalog,or (3)following the relation which agrees with the magnitudes used by the USGS.The updated catalog (Figure 23)was declustered (remove aftershocks)using the Gardner-Knopoff algorithm (Gardner and Knopoff,1974).An aftershock exclusion zone was used to identify likely aftershocks of the 2002 Denali earthquake (Figure 24).Earthquakes within the exclusion zone,post- dating the 2002 event were removed from the catalog.The 2002 Denali earthquake itself is also removed from the catalog as it is directly associated with the Denali fault, and,therefore,is inappropriate to remain in the catalog database used to derive aerial source zone earthquake recurrence.This event is accounted for in hazard calculations through the characterization of the Denali fault discussed later in the report in Sections 5.3.1 and 5.4.3. 4.5.1.2 Earthquake magnitude completeness In order to analyze catalog completeness as a function of magnitude,a "Stepp”plot was constructed which shows the event rate per year as a function of time since the present. This is shown in Figure 30 using 5-year bins,and indicates completeness for M 3 since 1970,M 4 and 5 since 1965,and M 6 since 1930.M 7 events are few,thus, completeness for these should rely on population density and reporting.Wesson et al. (2007)estimated completeness for M 4.5 since 1964,M 6 since 1932,and M 6.9 since Page 41 of 146 02/24/12 -z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 1898 for their Alaska catalog.Because the results shown in Figure 30 are consistent with Wesson et al.(2007)completeness estimates,the Wesson et al.(2007) completeness estimates are adopted for this study.The M 3 completeness since 1970 is consistent with seismic network information in Ruppert and Hansen (2010). 4.5.2 Stress data The evaluation of crustal stresses can aid in the understanding of faulting styles in areas of limited fault data.Ruppert (2008)generated Alaskan stress maps and stress tensor inversions derived from earthquake focal mechanisms (Figures 25 and 26).The crustal stress data in the site region,south of the Denali fault and north of the Castle Mountain fault,is heterogeneous but largely consistent with a transpressional tectonic setting and dominantly reverse and strike-slip faulting.The best fitting maximum stress for the crustal data surrounding the dam site is near horizontal and oriented west- northwest,and the minimum and intermediate stresses are steeply plunging (Figure 26). This stress orientation is consistent with right-lateral oblique faulting on northeast- oriented structures such as the faults bounding the Fog Lakes graben. 4.5.3 Crustal source zones Crustal thickness in the southern Alaska block (SAB)source zones is estimated to be 16 mi (25 km)in the West and Central zones,and 31 mi (50 km)in the East zone. However,the West and Central zones experience earthquakes associated with the subducting slab below 14 mi (23 km)depth (see Figure 27).The maximum depth for earthquakes in the recurrence catalog in the West and Central zones is reduced to 14 mi (23 km)to exclude these apparent slab events,but the source model for these zones allows earthquakes down to 16 mi (25 km),reflecting the uncertainty in crustal thickness.In comparison,WCC (1982)apparently used a seismogenic crustal thickness in their Talkeetna terrane of 12 mi (20 km).The Eastern zone is located off the northwest edge of the subducting slab so events as deep as 31 mi (50 km)are included in the recurrence catalog,and the source model allows for earthquakes down to 31 mi (50 km)as well. The majority of seismicity in NFFTB zones is located above 12-mi (20-km)depth,and most events below 12 mi (20 km)have high vertical location errors (>3 mi [5 km])(see Figure 28),thus seismicity in the recurrence calculations is constrained to a maximum depth of 12 mi (20 km). Page 42 of 146 02/24/12 Zz.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 4.6 Earthquake Recurrence from Seismicity Earthquake catalogs used for SAB and NFFTB areal source zone recurrence calculations are shown in Figure 29.Fewer earthquakes are shown in Figure 29 than in Figure 24 because of removal of some events after filtering for the completeness periods discussed in Section 4.5.1.The location of the 1912 Denali earthquake,as relocated by Doser (2004),is directly north of the Denali fault.Considering the large location error,the 1912 event conservatively is included in the SAB Central zone recurrence catalog instead of the NFFTB West zone.Figures 31 and 32 present the maximum likelihood recurrence curves for the SAB and NFFTB areal zones, respectively. Page 43 of 146 02/24/12 ze.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 5.0 PROBABILISTIC SEISMIC HAZARD ANALYSIS METHODS AND INPUTS 5.1 PSHA Code and Methodology The basic PSHA methodology employed here follows the precepts of Cornell (1968). The programs used were Fugro Consultants,Inc.codes fau/tsource_31 version 3.1.228 for fault sources,mrs5.2 version 5.2.228 for areal sources,and agrid1.1 version 1.1.228 for gridded seismicity sources.Earlier versions of these codes were vetted under the PEER PSHA Code Verification Workshop (Wong et al.,2004). 5.2 GMPEs Ground motion prediction equations (GMPEs)transform magnitude,distance,and other ground motion-related parameters into ground motion amplitude distributions for a wide range of vibrational frequencies.Such equations are continually being developed and refined as more strong motion accelerograms become available.For this project,three types of GMPEs were drawn upon:those for crustal sources,those for plate interface sources,and those for intraslab sources.The GMPEs and their weights for the three source categories were selected and are shown in Table 3. For the megathrust and intraslab GMPEs BCH11 is preferred model because it is based on a much larger data set that includes all of the data used by Zhao et al.(2006),and uses the Atkinson and Macias (2009)simulation result to constrain the break in the magnitude scaling at high magnitudes.The Atkinson and Boore (2003)relation uses the "global”version,as opposed to the Cascadia version.The crustal source GMPEs consist of four NGA GMPEs,each weighted equally. All of the GMPEs in Table 3 employ Vs30 (average shear-wave velocity in the top 30 meters)as a site condition parameter for linear and non-linear site response,either explicitly or as a site category indicator.Based on the initial data review,the hazard is computed using a reference Vs30 of 2,625 ft/s (800 m/s),as this is the range that is constrained by the empirical data,and adjustments to the site rock conditions value may be made after site characterization is complete.The 2,625 ft/s (800 m/s)is less than the estimates derived from measured P-wave velocities presented in the Acres (1982) report and summarized in Section 3.5.The P-wave derived velocity data from these reports are not included for the Vs30 parameter in the GMPE's due to the significant ambiguity in interpreting the velocity data from cross sections,and the potential error resulting from converting P-wave to S-wave velocity.The adopted value of 2,625 ft/s Page 44 of 146 02/24/12 Zz SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 (800 m/s)is considered a somewhat conservative velocity value that may be refined at a future date based on site-specific shear-wave data. Table 3.Ground Motion Prediction Equations Used in PSHA Sources GMPE Abbreviation Weight BC Hydro,2011'BCH11 0.50 Megathrust Zhao et al.,2006 ZHO06 0.25 Atkinson and Macias,2009 AMO9 0.25 BC Hydro,2011'BCH11 0.50 Intraslab Zhao et al.,2006 ZHO06 0.25 Atkinson and Boore,2003 ABO3 0.25 Abrahamson and Silva (2008)AS08 0.25 Crustal Chiou and Youngs (2008)CY08 0.25 Campbell and Bozorgnia (2008)CBO8 0.25 Boore and Atkinson (2008)BA08 0.25 Note:(1)as provided by N.Abrahamson,August 2011. 5.3 Sensitivity Evaluations Initial development of the source model and discussions with the project reviewers identified several topics for sensitivity analyses or additional consideration at the early phase of the ground motion analysis in order to assess their implementation in the PSHA.The objective of these evaluations was to focus resources and efforts on issues that have the most direct implications for the site hazard evaluations.Topics identified were: e Time dependent models for Alaska (Prince William Sound)megathrust Mw 9.2 and the 2002 Denali Mw 7.9 events e Relative importance of crustal areal and fault zones vs.megathrust,(as shown by hazard curves for PHA and 1.0 sec) o Relative contributions of distant crustal sources o Implications of additional seismic sources within the Southern Alaska block and Talkeetna Terrane e Sensitivity to depth in NGA GMPEs,implications Page 45 of 146 02/24/12 -yzZ.SUSITNA-WATA NA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 e Deterministic megathrust response spectra 5.3.1 Time dependence Models compared for the time-dependent vs.time-independent sensitivity include: Poissonian (time independent model -needs only return period,rate always the same); Lognormal distribution of inter-event times (time-dependent)model -needs median and standard deviation values;Brownian passage time (BPT)(time-dependent)-model needs median and aperiodicity parameter,similar to lognormal standard deviation. These are described more in Appendix A. The results of the time-dependent vs.time-independent calculations show that the probability of occurrence of a repeat of the 1964 M 9.2 event in the 150 year time window is less than 0.05 for the time-dependent models,while for the Poissonian rate it is 0.24.Similarly,for a repeat of the 2002 Denali fault rupture,time-dependent probabilities of occurrence are less than 0.06,while the Poissonian probability is 0.31. Conversely,the western Denali fault that did not rupture in 2002 has a time-dependent probability of occurrence in 150 years of 0.5 to 0.6,while under the time-independent assumption the probability would be 0.33.The time-dependent models are assigned a weight of 0.67,and the non-time-dependent model 0.33. 5.3.2 Relative contributions of sources and distance Initial evaluations,completed as part of this study,confirmed by the PSHA results (Section 6.1),indicate that the dominant seismic sources for the Susitna-Watana Dam site area are the two subduction related sources:subduction interface,and intraslab. Crustal sources are less significant.These initial evaluations also indicate that,given the relatively high slip rates and magnitudes associated with the Denali and Castle Mountain fault sources,crustal fault sources at greater distances with similar or smaller magnitudes would not provide significant contributions to the hazard for the site.Thus, fault sources more distant than the Denali and Castle Mountain faults were not considered further for the PSHA calculations. Although initial evaluation suggested that dominant hazard contributions would be from the subduction related sources,the potential impacts of crustal fault sources in the Talkeetna Terrain region near the site were considered as well.The potential impacts of additional crustal sources in this region can be evaluated through comparisons of the contributions of fault sources in this region such as the Sonona Creek fault and Fog Lakes graben faults to background crustal seismicity and the subduction-related Page 46 of 146 02/24/12 -zZ- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 sources.These crustal sources were included in the PSHA to illustrate this sensitivity as discussed in Section 5.4 below. 5.4 PSHA Inputs 5.4.1 Subduction related sources For the purposes of this study,the megathrust,or plate interface,geometry is modeled as a single plane (seen as the rectangle in Figure 15)dipping 2.6 degrees to the northwest with upper (southeast)and lower (northwest)depth bounds of 12 and 22 mi (20 and 35 km).This geometry also roughly corresponds to the estimated rupture extent of the 1964 event (Figure 5).The geometric parameters of this plane,including distances to the site,are listed in Table 5. Following Wesson et al.(2007),the largest megathrust event is modeled as a repeat of the M 9.2 1964 event.A time-independent (Poissonian)annual rate of 1/560 is assigned,based on paleoseismic investigations (Carver and Plafker,2008).The final rate of this magnitude event has been ultimately decreased due to inclusion of time- dependent models,described in Appendix A. Also following Wesson et al.(2007),the M 7-8 interface earthquakes are modeled as being exponentially distributed according to rates calculated from the Wesson et al. (2007)earthquake catalog.This catalog resulted from a hierarchical compilation of several catalogs,resolution of magnitudes to the Mw scale,and declustering to remove dependent events.The a and b Gutenberg-Richter recurrence values for this source were taken from Wesson et al.(2007).Earthquakes in this magnitude range were modeled as occurring on the fault plane shown in Figure 15.The interface earthquakes in the M 5-7 range are modeled as "gridded,smoothed seismicity.”As described in Wesson et al.(2007),this model is created by sorting this seismicity into 0.1 degree bins,and performing Gaussian smoothing with a correlation distance (Frankel et al., 1995)of 46 mi (75 km)(Figures 16 and 17).The grid sources were placed at a depth of 3 mi (5 km),as in Wesson et al.(2007).Although this depth is not realistic,given that the megathrust lies 12 to 19 miles (20 to 30 km)beneath the site,this depth was retained to maintain consistency with the Wesson et al.(2007)model.The geometry is modeled as a single plane (seen as the rectangle in Figure 15)dipping 2.6 degrees to the northwest with upper (southeast)and lower (northwest)depth bounds of 12 and 22 mi (20 and 35 km).This geometry also roughly corresponds to the estimated rupture extent of the 1964 event (Figure 5).The geometric parameters of this plane,including Page 47 of 146 02/24/12 2 SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 distances to the site,are listed in Table 5.Time-dependent models and their usage for this source are described in Appendix A. 5.4.2 Interslab sources For the intraslab source we have used the Wesson et al.(2007)model,which consists of gridded seismicity for two depth levels,31 to 50 mi (50-80 km),and 50 to 75 mi (80- 120 km),and a magnitude range of M 5 to M 7.5.Following Wesson et al.(2007),the depth for the 31 to 50 mi (50-80 km)sources was set to 37 mi (60 km),and 56 mi (90 km)for the 50 to 75 mi (80-120 km)points. 5.4.3 Crustal faults Five crustal faults are included in the PSHA with the source characterization parameters contained in Table 6.Two of these faults,the Denali and Castle Mountain,have been included in the previous USGS source model (Wesson et al.,2007).Based on data discussed in Section 4.2,the source characterizations for these faults have been updated,and include time-dependent alternatives for the Denali fault,as well.The Pass Creek-Dutch Creek fault was not included in the USGS source model,but previously was identified as a Quaternary fault in Plafker et al.(1994).A conservative slip rate distribution is included for this fault based on the data discussed in Section 4.2.3.The Sonona Creek and Fog Lakes graben are potential sources within the Southern Alaska block newly considered in this evaluation because of their potential proximity to the Susitna-Watana Dam site.Evidence to support full seismic source characterization for both sources is incomplete.There are no published estimates for Quaternary displacement on either of these faults.However,the structures are included in this evaluation with a full probability of activity,to test the sensitivity of their inclusion to the hazard estimates for the site.Thus,slip rate distributions for these sources span about 2 orders of magnitude,and range from 0.01 to 0.3 mm/yr to test a range of values that would reflect relative inactivity to an activity rate which is similar to the lower range of slip rates on the Castle Mountain fault. The Sonona Creek fault was identified based on mapping by Williams and Galloway (1986),and a simplified source trace extended from that mapping based on limited evaluation of Google Earth imagery (Figure 20).The source characterization assumes a relatively low slip rate based on the limited extent and apparently small height of the scarp shown on the Williams and Galloway (1986)map.Fault length was extended to provide sufficient length for fault rupture consistent with the M 7 assumed for the initial maximum event. Page 48 of 146 02/24/12 Zz SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 The Fog Lake graben structures also are included as a sensitivity test to the potential reactivation of existing structures within the vicinity of the Talkeetna thrust/Susitna lineament region near the site.An M 7 is assumed as a maximum event for this test, and fault-element length was chosen to accommodate rupture for this size event.The fault-element locations are based on the geomorphic expression along the ranges bounding the Fog Lakes graben,as generally outlined by Glen et al.(2007a).Slip rates are considered low,with the assumption that rates in excess of about 0.5 -1 mm/yr would produce readily identifiable geomorphic evidence of faulting. Several additional sources discussed in Section 4,including faults at distances greater than about 56 mi (90 km)from the site,were not included as seismic elements in the source model (Table 4).These crustal faults were not included based on initial evaluations (Section 5.3.2)that indicated that inclusion into the seismic source model and PSHA would have negligible impact on the computed hazard at the site.Existing data suggests all of the excluded faults would have contributions that were no greater than those of the Castle Mountain fault,because maximum magnitudes and slip rates are generally lower,and closest distances to the site are greater.The Castle Mountain fault does not appear on Figures 39 42 because its contribution is less than 5 percent, even with inclusion of potentially conservative slip-rate scenarios as discussed in Section 5.4.3.2.Thus,other faults in the region,including subsidiary faults to the Denali fault similar to the Susitna Glacier fault,would not be expected to have significant contributions to the ground motions at the Susitna-Watana site area unless slip rates on these faults were comparable or higher than those used in the present model for the Castle Mountain fault. Fault sources are modeled as one or more planar segments.The faults as modeled for the PSHA are shown in map view on Figure 33. Page 49 of 146 02/24/12 -Z SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 Table 4.Site Region Faults Excluded from the PSHA Source Model Fault Name Distance from Site (km)Distance from Site (miles) Faults in the Southern Alaska Block -South of Denali fault Broad Pass fault 63.8 39.6 Broxson Gulch fault 62.6 38.9 Bull River fault 78.2 48.6 Cathedral Rapids fault 244.1 151.7 East Boulder Creek fault 101.6 63.1 Foraker fault 135.5 84.2 Matanuska Glacier fault 136.4 84.8 McCallum-Slate Creek fault 153.9 95.6 McGinnis Glacier fault 147.0 91.3 Susitna Glacier fault 77.8 44.1 Faults in the Northern fold and thrust belt -North of Denali fault Billy Creek fault >70 >45 Canteen fault >70 >45 Ditch Creek fault >70 >45 Donnely Dome fault >70 >45 Dot "T"Johnson fault >70 >45 East Fork fault >70 >45 Eva Creek fault >70 >45 Glacier Creek fault >70 >45 Gold King fault -Section A >70 >45 Gold King fault -Section B >70 >45 Granite Mountain fault A >70 >45 Granite Mountain fault B >70 >45 Healy Creek fault >70 >45 Kansas Creek fault >70 >45 Macomb Plateau fault >70 >45 Molybdenum Ridge fault >70 >45 Mystic Mountain fault >70 >45 Northern Foothills thrust >70 >45 Panoramic fault >70 >45 Park Road fault >70 >45 Peters Dome fault >70 >45 Potts fault >70 >45 Red Mountain fault >70 >45 Rex fault >70 >45 Stampede fault >70 >45 Trident fault >70 >45 Trident Glacier fault >70 >45 Page 50 of 146 02/24/12 -yz SUS ITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 5.4.3.1 Denali fault The occurrence of an M 7.9 earthquake on the Denali fault in 2002 (Section 3.2.1)led to a number of scientific investigations that greatly improved the characterization of this fault for seismic hazard studies. As shown in Figure 33,two geometric models are considered for this study:one in which a repeat of the 2002 rupture occurs and the segment to the west ruptures independently;and another model in which the entire fault length ruptures.Each of these scenarios has a maximum magnitude of 7.9,and a maximum moment model is used for each (Table 6).The two scenarios are weighted equally. Following Wesson et al.(2007),the modeled slip on the Denali fault decreases monotonically from 14.4 mm/yr at the east end to zero at the west end.The estimated slip rate as a function of distance along the fault is shown in Figure 18.This was accounted for in the PSHA as follows:In modeling ruptures on a fault,a rupture that has less area than the fault itself is assumed to occur at any location with equal probability. Such ruptures are modeled by placing them sequentially along strike and up and down dip with some spacing interval (0.6 mi [1 km]in this study).A rupture will consequently correspond to a portion of the fault along the x-axis in Figure 18.The slip rate assigned to that rupture will,therefore,be the average slip rate along that portion of the fault. Alternative models of the Denali fault in which the fault extends farther west are not considered,because these models would primarily extend the fault beyond 200 mi (320 km)from the site and the initial sensitivity evaluations (Section 4.3.2)indicate no significant change in the ground motion results from this type of change to the source model. Time-dependent occurrence rate models also were employed for the Denali fault.The rationale is that since the 2002 rupture occurred so recently,another such event should be less likely than the average rate in the near future.By similar reasoning,an earthquake on the segment west of the 2002 rupture,which hasn't occurred for about 600 years,is more likely to occur in the near future than the average.Details and results of the time-dependent analysis are contained in Appendix A. 5.4.3.2 Castle Mountain fault The Castle Mountain fault,described in Section 4.2.2,is modeled as two scenarios:a segmented model where the east and west segments rupture independently,and an unsegmented model!where the entire fault length ruptures in one earthquake.The fault geometry and location are shown in Figure 33.These scenarios are weighted equally. Page 51 of 146 02/24/12 -zZ SUS ITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 To account for the uncertainty of the western segment slip rate (ie.Haeussler et al., 2002;Koehler and Reger,2011;Willis et al.,2007)two slip-rate scenarios are used (Table 6),also equally weighted.The higher slip-rate scenario reflects the rates used in prior USGS hazard models (Wesson et al.,2007),while the lower slip-rate scenario reflects more recent investigations (e.g.,Koehler and Reger,2011). 5.4.3.3 Pass Creek-Dutch Creek fault,Sonona fault,and Fog Lake Graben faults The Pass Creek-Dutch Creek,Sonona,and Fog Lake graben faults are described in Sections 4.2.3,4.2.6,and 4.4.3,respectively,and shown in map view in Figure 33. Their geometric properties are listed in Table 5,and maximum magnitudes and slip-rate distributions in Table 6.No alternative models were employed for these sources. Table 5.Geometric Fault Parameters for Susitna Source Model, as Modeled for PSHA 1 Depth Rupture JB Farthest Fault Mee)cm)Range Dip |Distance?|Distance®|Distance (km)(km)(km)(km) ASZ -megathrust |3199 |102,500 |20.0t035.0|2.6 78.4 70.2 529.4interfacemodel Denall-2002 |307.5 |4612 |0.0to15.0 |90.0]86.0 86.0 312.3rupture Denali -West 386.4 |5795 |0.0t0150 |900]71.2 71.2 324.0segment Denali -entire fault |726.0 10,889 0.0to15.0 |90.0 71.2 71.2 356.5 Castle Minfautt |1896 |3856 |0.0to200 |800|998 97.8 186.1 Castle Min West {|614 |1253 |0.0to20.0 |80.0 |136.9 135.4 186.1faulthigh Castle Min West |61.4 |1253 |0.0t020.0 |800]136.9 135.4 186.1faultlow CastleMin East |428.2 |2602 |0.0t020.0 |800}998 97.8 138.0 Pass Creek-Dutch |¢56 |1552 |0.0to020.0 |60.0]106.8 104.9 170.4Creekfault Sonona fault 36.9 749 |0.0t020.0 |800 |71.5 69.2 91.6 Fog Lake graben 60.9 1230 |0.0to20.0 |80.0 6.9 3.5 49.4 Fog rake graben 47.7 969 |0.0to20.0 |80.0 9.5 6.1 34.3 Notes:(1)Magnitude-area formula for strike-slip faults from UCERF2 (Field et al.,2009),all others from Wells &Coppersmith (1994).(2)Rupture distance is the closest distance to the fault plane.(3)Joyner- Boore distance is the closest horizontal distance to surface projection of the fault plane. Page 52 of 146 02/24/12 -Z-.SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 Table 6.Fault Slip Rate and Magnitude Parameters,as Modeled for PSHA .Slip Rate . Fault 'rom |rmiyy |Oistbution |annum Denali System Unsegmented 0.0-14.4 N/A tapered”7.9 West of 2002 rupture segment 9.8-0.0 N/A tapered*7.9 2002 rupture segment'14.4-9.8 N/A tapered*7.9 Eastern segment Not modeled separately due to distance from site Southern Alaska Crustal faults Sonona Creek 0.1-0.5 0.3 triangle,sym 7.0 Pass Creek -Dutch Creek 0.5-1.5 1.0 triangle,sym 7.0 Fog Lake graben north 0.01 -0.3 (0.1)°0.14 triangle,asym*7.0 Fog Lake graben south 0.01 -0.3 (0.1)°0.14 triangle,asym*7.0 Castle Mountain fault scenarios Seqmented Model (weight 0.5) Castle Mtn east 0.5 0.5 none 7.2 Castle Mtn west (weight 0.5)0.4-0.6 0.5 uniform 7.2 Castle Mtn west (weight 0.5)2.1-3.6 2.9 uniform 7.2 Unsegmented Model (weight 0.5) Castle Mtn combined 0.4--0.6 0.5 triangle,sym 7.6 Notes:(1)2002 rupture segment includes the 72 km of the Totschunda fault ruptured in 2002.(2)See Figure 18.(3) Apex value for asymmetric triangular distribution in parentheses. Table 7.Areal Zone Discrete Depth Distributions Southern Areal Background Northern Foorhiis Fold and Thrust"len West Central East West East (n =72)(n =81)(n =18)(n =233)(n =18) Count |Weight |Count |Weight |Count |Weight |Count |Weight |Count {|Weight 2.5 22 0.31 17 0.21 1 0.06 13 0.06 8 0.44 7.5 22 0.31 19 0.23 3 0.16'64 0.27 6 0.33 12.5 18 0.25 25 0.31 2 0.10"109 0.47 3 0.17 17.5 9 0.12 15 0.19 9 0.50 47 0.20 1 0.06 22.5 1 0.01 5 0.06 1 0.06 ---- 27.5 ----1 0.06 ---- 32.5 ---------- 37.5 ---------- 42.5 ---------- 47.5 ----1 0.06 ---- Note:(1)weight reduced by 0.01 to account for rounding so the full weight =1.0. Page 53 of 146 02/24/12 2 SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 6.0 PSHA RESULTS 6.1 Hazard Curves A hazard curve consists of a ground motion level (in g)on the x-axis,and the mean annual frequency of exceeding that ground motion on the y-axis.Mean hazard curves were developed for four spectral response periods,peak horizontal acceleration (PHA), and 0.5,1.0,and 3.0 seconds acceleration response at 5%damping.These are shown in Figures 34 through 37.The major sources have been grouped together for purposes of presentation.For example,the interface curve contains the sum of the hazard from the three magnitude ranges described in Section 5.3.1,and the hazard from the M 9.2 scenario.Similarly,the combined hazard is shown for the Denali and Castle Mountain fault scenarios,the two Fog Lake graben fault elements,and the five areal sources. 6.2 UHS A uniform hazard spectrum (UHS)is developed from the suite of total hazard curves, each of which is calculated for a specific spectral period (or its inverse,spectral frequency)at the specified damping level.The spectrum is keyed to a return period, which is the inverse of annual frequency of exceedance.For example,to construct a 10,000-year uniform hazard spectrum,the ground motion level for PHA (0.00 or 0.01 spectral period)at the 0.0001 (1/10,000)y-axis level of that hazard curve is tabulated. The same is done for the hazard for the other spectral periods.The spectral period is then plotted on the x-axis,and the tabulated ground motion level on the y-axis.These spectra,therefore,indicate the ground motion amplitudes across the entire range of periods for a common hazard level. Mean uniform hazard spectra for the total hazard were developed for return periods of 100,250,1000,2,500,5,000,and 10,000 years.These results are shown in Figure 38, values are provided in Table 8,and also in Appendix C. 6.3 Deaggregations A deaggregation of the ground motion hazard was performed,based on the principles outlined in McGuire (1995)and Bazzurro and Cornell (1999).Bazzurro and Cornell (1999)provide a comparative review of different techniques and their implications. They point out that there is a tradeoff between matching the target spectrum precisely, and identifying the most likely event to produce the target motions.McGuire's (1995) method of collecting contributions that equa/the target motion for each GMPE was Page 54 of 146 02/24/12 ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 -Z-.SUSITNA-WATANA HYDROELECTRIC PROJECT applied here,and the deaggregation therefore is focused on matching the target spectrum. Source deaggregation plots are shown in Figures 39 through 42,one for each of the four spectral response periods (PHA,0.5 sec,1.0 sec,3.0 sec).Only sources contributing 5%or more at any ground motion level are plotted,so the minor sources are not shown.In Figures 39 through 42,the 100-and 10,000-year ground motion levels are shown,and in some cases,intermediate return periods.These values can be found in the appropriate cell in Table 8. Table 8.Total Hazard,Mean Probabilistic Acceleration Amplitudes (g) 'eee)100yrs_|250yrs |1,000yrs |2,500yrs |5,000 yrs |10,000 yrs 0.01 0.1270 0.1991 0.3671 0.5222 0.6641 0.8271 0.02 0.1397 0.2184 0.3997 0.5662 0.7179 0.8918 0.03 0.1578 0.2467 0.4506 0.6370 0.8064 1.0004 0.05 0.1855 0.2898 0.5275 0.7437 0.9394 1.1631 0.075 0.2417 0.3784 0.6914 0.9807 1.2461 1.5527 0.10 0.2895 0.4545 0.8344 1.1897 1.5184 1.9008 0.15 0.3007 0.4732 0.8782 1.2609 1.6152 2.0264 0.20 0.2780 0.4383 0.8181 1.1764 1.5067 1.8874 0.25 0.2430 0.3837 0.7175 1.0325 1.3231 1.6586 0.30 0.2140 0.3391 0.6373 0.9200 1.1816 1.4844 0.40 0.1717 0.2746 0.5204 0.7540 0.9703 1.2201 0.50 0.1387 0.2233 0.4255 0.6179 0.7969 1.0038 0.75 0.0938 0.1532 0.2963 0.4351 0.5661 0.7209 1.0 0.0713 0.1179 0.2304 0.3421 0.4496 0.5791 1.5 0.0466 0.0774 0.1529 0.2305 0.3085 0.4054 2.0 0.0345 0.0569 0.1125 0.1709 0.2313 0.308 3.0 0.0221 0.0364 0.0713 0.1093 0.1490 0.1995 The PHA hazard is dominated by the Alaska subduction zone intraslab at all return periods (Figure 39).This reflects the high rate of M 5 -7.5 events produced by this source.The results are mixed for the 0.5 spectral acceleration (SA),with intraslab seismicity dominating at return periods less than 2,500 years,and megathrust seismicity dominating at longer periods (Figure 40).A similar result occurs for the 1.0 second SA, but with megathrust activity dominating for the 1,000-year return period and longer (Figure 41).For 3.0-second response SA,the Alaska subduction zone sources,Denali fault,and areal sources contribute equally for the 100 year return period,but the Alaska subduction zone megathrust dominates at all longer return periods (Figure 42). Page 55 of 146 02/24/12 -z- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Plots showing magnitude,distance,and epsilon contributions to the total hazard were produced for the two major sources (the Alaska subduction zone interface and intraslab),for three return periods (2,500,5,000,and 10,000 years).Epsilon is the number of standard deviations above or below the median,from which a ground motion amplitude (for a given magnitude and distance)is contributing.Three GMPEs for each source,combined with four spectral response periods,results in 24 total hazard plots. While all are contained in Appendix C,four plots are discussed in this report body for characterization purposes.The four plots are described below. Figure 43 shows megathrust results for PHA,2,500-year return period,and the BC Hydro 2011 GMPE.The plot shows the dominant contribution from the M 9.2 earthquake,with minor contributions from M 7 events.Figure 44 shows the same results,but for 1.0-second response and a return period of 10,000 years.For these results,the distance to the megathrust is evident,48 mi (78 km)or greater.Figure 45 shows contributions to the total hazard from the intraslab source,for 0.5-second response,2,500-year return period,and the Zhao et al.(2006)GMPE.Since the dam site lies above this source,an exponential-appearing decrease with distance is evident. An exponential-appearing decrease also is seen with magnitude,because the magnitudes have an exponential rate distribution.Figure 46 shows the same source and GMPE,but for 3.0-second response and a 10,000-year return period.This plot shows that the intraslab contributions are coming only from higher magnitude events near the site,at the extreme tails of the ground motion distributions. Page 56 of 146 02/24/12 -yzZ.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 7.0 CONDITIONAL MEAN SPECTRA Conditional mean spectra (CMS)were generated for 3 return periods and 4 acceleration response spectral periods (5%damping).As described in the PSHA results (Section 6.3 Deaggregation),the two dominant sources for all spectral response periods and return periods of 2,500 years and greater are the megathrust and intraslab sources of the Alaska subduction zone.CMS were developed for those sources. The following sections consist of a description of the methodology used to develop the CMS,and the results.The UHS and CMS data are shown on figures in Appendix C. 7.1.Methodology The methodology of Baker (2011)was used to develop the CMS.CMS are generated from deterministic spectra based on the PSHA deaggregation results,which for each reference spectral period (T*)and return period,consist of a magnitude,distance,and epsilon.Epsilon is the number of standard deviations from the median ground motion from the ground motion prediction equation (GMPE)required to match the target UHS value. This combination of parameters should match the UHS target motion at T*.In actual practice,however,the match is never exact,due to the fact that the deaggregation procedure requires establishment of bins that account for a range of parameter values, rather than exact ones.The deaggregation values are the modal bin averages (Bazzurro and Cornell,1999).In addition,a seismic source often consists of a group of sources,and the deaggregation values represent the composite result of those sources. Therefore the epsilon for the CMS T*must be adjusted so that the amplitude at T* equals the UHS at T*.This new epsilon is termed e€(T*)in Baker (2011).CMS are computed for each GMPE,and weighted in the same manner as for the UHS. The deterministic spectrum is then modified by first multiplying the period and T* dependent correlation coefficients by ¢(T*): »=P(l.,T*)e(T*;Heazyecrs =PLT))(Equation 4,Baker (2011)) This is called the "conditional mean epsilon.”This,multiplied by the period-dependent sigma,is then added to the log of the median deterministic ground motion: Min sac,yinsaT*)-Hinsa (M,R,T,)+pW,T*)e(T*)o,.5,(G}) Page 57 of 146 02/24/12 -qZ SUS ITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 It should be noted that the correlation coefficient formulation of Baker and Jayaram (2008),which was developed for the Next Generation Attenuation (NGA)GMPEs and based on the intra-event residuals,was used here.This assumes that the correlation coefficients for the total residuals for the GMPEs used for this study will be similar.Al Atik (2011)showed that the correlations developed by Baker and Jayaram (2008)are similar to the correlation coefficients for the intra-event residuals for the BC Hydro subduction model GMPE.Al Atik (2011)showed that the correlations of the intra-event residuals are reasonable approximations for the correlations of the total residuals. The magnitude,distance,and epsilon values for the T*values (0,0.5,1.0 and 3.0 seconds)and the three return periods (2500,5000,and 10,000 years)are shown in deaggregation Tables 9 through 11 for interface fault source,and Tables 12 through 14 for the intraslab source.There is one table for each of the GMPE used in this study. See Section 5.2 and Table 3 for discussion of the GMPE's and acronyms.The magnitude-distance-epsilon values used are the modal bin values in the "Mod_MDE” column,as recommended by Bazzurro and Cornell (1999).CMS results from the GMPEs were interpolated to a common period set,and weighted as in Table 8. As recommended in the FERC guidance (Idriss and Archuleta,2007),the CMS were "extended”so that the envelope of the CMS for a given return period equaled the UHS. This is to assure that there are no gaps in CMS replication of the UHS. Because two of the critical response periods,PHA (T =0.0 or 0.01)and 3.0 seconds,lie at the ends of the UHS range,the manner in which the CMS are "extended”to fill in the UHS is ambiguous.For example,the period range from 0 to 0.5 seconds can be accounted for by raising either the 0.0-or 0.5-second period CMS to the UHS level.On the long period end of the spectrum,the 1.0-to 3.0-second range can be "filled in”by either the 1.0-or 3.0-second CMS.Therefore,CMS were computed for both alternatives. Table 9.Megathrust -Deaggregation Results for AM09 GMPE |Period |RP |Mbar |Dbar |Epsbar |Mod_MD Mod_MDE am09 |0 2.5k |9.2 78.4 |1.81 9.25-77.5 |9.25-77.5-1.90 am09 |0 5k 9.2 78.4 |2.25 9.25 -77.5 |9.25 -77.5 -2.30 amog |0 10k |9.2 78.4 |2.65 9.25-77.5 |9.25-77.5-2.70 amog ;0.5 2.5k |9.16 |78.8 |1.12 9.25-77.5 |9.25-77.5-1.10 am0g |0.5 5k 9.19 |78.4 |1.5 9.25-77.5 |9.25-77.5-1.50 am09 |0.5 10k |9.2 78.4 |1.86 9.25-77.5 |9.25-77.5-1.90 am0g |1 2.5k |9.06 |81 0.67 9.25-77.5 |9.25-77.5 -0.50 Page 58 of 146 02/24/12 ze.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM -06-0004-120224 GMPE |Period |RP |Mbar |Dbar |Epsbar |Mod_MD Mod_MDE amog |1 5k 9.14 |79.1 |0.99 9.25-77.5 |9.25 -77.5-0.90 am09 |1 10k |9.18 |78.5 |1.33 9.25-77.5 |9.25 -77.5 -1.30 am09g |3 2.5k |8.79 |85.2 |-0.5 9.25-77.5 }9.25 -77.5 --1.10 amog |3 5k 9.01 |80.8 |-0.23 9.25-77.5 |9.25 -77.5 --0.50 amo0g |3 10k |9.12 |79.1 |0.16 9.25-77.5 |9.25 -77.5 -0.10 Table 10.Megathrust -Deaggregation Results for BCH11T GMPE Period |RP |Mbar |Dbar |Epsbar |Mod_MD Mod_MDE bch11T 0 2.5k |9.16 |79.2 1.03 |9.25-77.5 |9.25-77.5 -0.90 bch11T 0 5k |9.18 |78.7 1.32 |9.25-77.5 |9.25 -77.5 -1.30 bch11T 0 10k |9.19 |78.5 1.6 9.25-77.5 |9.25 -77.5 -1.50 beh11T 0.5 2.5k |9.15 |79.3 0.88 |9.25-77.5 |9.25 -77.5 -0.90 bch11T 0.5 5k |9.17 |78.7 1.19 |9.25-77.5 |9.25-77.5-1.10 bch11T 0.5 10k |9.19 |78.5 1.48 |9.25-77.5 |9.25 -77.5 -1.50 bch11T 2.5k |9.15 |79.3 0.8 9.25-77.5 |9.25 -77.5 -0.70 bch11T 5k |9.18 |78.7 1.13 |9.25-77.5 |9.25-77.5-1.10 bcht1T 10k |9.19 |78.5 1.45 |9.25-77.5 |9.25 -77.5 -1.50 bch11T 5k |9.19 |78.4 1.33 |9.25-77.5 |9.25 -77.5 -1.30 bch11T 10k |9.2 |78.4 1.7 9.25-77.5 |9.25 -77.5 -1.70 1 1 1 beh11T 3 2.5k |9.18 |78.7 0.94 |9.25-77.5 |9.25-77.5 -0.90 3 3 Table 11.Megathrust -Deaggregation Results for ZHO6T GMPE |Period |RP |Mbar |Dbar |Epsbar |Mod MD Mod_MDE zhO6T 0 2.5k |9.19 |78.5 0.63 9.25 -9.25 -77.5 -0.70 zhO6T 0 5k 9.2 78.4 0.97 9.25 -9.25 -77.5 -0.90 zhoO6T 0 10k 9.2 78.4 1.29 9.25 -9.25 -77.5 -1.30 zho6T 0.5 2.5k |9.18 |78.8 0.54 9.25 -9.25 -77.5 -0.50 zhO6T 0.5 5k 9.19 |78.5 0.88 9.25 -9.25 -77.5 -0.90 zhO6T 0.5 10k 9.2 78.4 1.2 9.25 -9.25-77.5-1.10 zhO6T 1 2.5k |9.17 79 0.29 9.25 -9.25 -77.5 -0.30 zh06T 1 5k |9.19 |78.6 0.63 9.25 -9.25 -77.5 -0.70 zhO6T 1 10k 9.2 78.4 0.96 9.25 -9.25 -77.5 -0.90 zhO6T 3 2.5k |9.18 |78.8 0.12 9.25 -9.25 -77.5 -0.10 zhO6T 3 5k 9.19 |78.5 0.51 9.25 -9.25 -77.5 -0.50 zho06T 3 10k 9.2 78.4 0.9 9.25 -9.25 -77.5 -0.90 Page 59 of 146 02/24/12 ze.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Table 12.Intraslab-Deaggregation Results for ABO3Ib GMPE Period RP Mbar |Dbar |Epsbar Mod_MD Mod_MDE ab03lb 0 2.5k 7.33 |84.9 1.8 7.55 -62.5 7.55 -62.5 -1.10 ab03lb 0 5k 7.36 |84.2 2 7.55 -62.5 7.55 -62.5 -1.50 ab03lb 0 10k 7.38 |83.7 2.18 7.55 -62.5 7.55 -62.5 -1.70 ab03lb 0.5 2.5k 7.36 72 1.89 7.55 -62.5 7.55 -62.5 -1.10 ab03Ib 0.5 5k 7.39 70 2.1 7.55 -62.5 7.55 -62.5 -1.50 ab03!b 0.5 10k 7.41 |68.1 2.3 7.55 -62.5 7.55 -62.5 -1.90 ab03lb 2.5k 7.37 |73.6 1.77 7.55 -62.5 7.55 -62.5 -0.90 ab03lb 5k 7.39 |71.6 1.97 7.55 -62.5 7.55 -62.5 -1.30 ab03lb 10k 7.41 |69.6 2.18 7.55 -62.5 7.55 -62.5 -1.50 ab03lb 2.5k 7.41 |84.1 1.72 7.55 -62.5 7.55 -62.5 -0.70 ab03Ib 10k 745 |78.1 2.21 7.55 -62.5 7.55 -62.5 -1.70 ab03lb 2.5k 7.33 |84.9 1.8 7.55 -62.5 7.55 -62.5 -1.10 1 1 1 3 ab03Ib 3 5k 7.43 {|81.1 1.98 7.55 -62.5 7.55 -62.5 -1.30 3 0 Table 13.Intraslab -Deaggregation Results for BCH11I GMPE |Period|RP |Mbar |Dbar |Epsbar|Mod MD Mod_MDE bch111 0 2.5k 7.2 |832 |1.71 |7.55-625 7.55 -62.5 -0.50 bch111 0 5k 7.24 |81.1 |186 |7.55-62.5 7.45 -62.5 -0.90 bch111 0 10k 7.27 |79.1 |199 |7.55-62.5 7.55 -62.5 -1.10 bch111 0.5 25k |7.25 |83.7 |1.79 |755-625 7.55 -62.5 -0.70 bch111 0.5 5k 7.29 |81.4 |1.95 |7.55-62.5 7.55 -62.5 -1.10 bch111 0.5 10k 7.33 |79.2 |2.1 7.55 -62.5 7.55 -62.5 -1.30 beh111 1 25k |7.32 |83.3 |1.95 |7.55-62.5 7.55 -62.5 -1.10 beh111 1 5k 7.35 |80.8 |212 |7.55-62.5 7.55 -62.5 -1.30 bch111 1 10k 7.38 |78 |2.29 |7.55-62.5 7.55 -62.5 -1.70 bch111 3 25k |7.39 |814 |2.15 |7.55-625 7.55 -62.5 -1.50 bch111 3 5k 742 |77 |2.36 |7.55-62.5 7.55 -62.5 -1.90 bch111 3 10k 745 |726 |2.54 |7.55-62.5 7.55 -62.5 -2.30 Page 60 of 146 02/24/12 -qJ.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Table 14.Intraslab -Deaggregation Results for ZHO6I GMPE |Period |RP |Mbar |Dbar |Epsbar Mod_MD Mod_MDE zho6l 0 2.5k |7.25 76 1.74 7.55 -62.5 7.55 -62.5 -0.70 zhoél 0 5k 7.3 74.2 1.91 7.55 -62.5 7.55 -62.5 -0.90 zho6l 0 10k |7.33 |72.5 2.06 7.55 -62.5 7.55 -62.5 -1.30 zh0oé6l 0.5 2.5k |7.3 76.4 1.78 7.55 -62.5 7.55 -62.5 -0.70 zhoé6l 0.5 5k 7.33 |74.2 1.96 7.55 -62.5 7.55 -62.5 -1.10 zhodé6l 0.5 10k |7.36 |72.2 2.12 7.55 -62.5 7.55 -62.5 -1.50 zhoé6l 1 2.5k |7.33 77 1.86 7.55 -62.5 7.55 -62.5 -0.90 zhoé6l 1 5k 7.36 |74.6 2.04 7.55 -62.5 7.55 -62.5 -1.30 zhoe6l 1 10k |7.39 72 2.22 7.55 -62.5 7.55 -62.5 -1.50 zho6l 3 2.5k |7.4 76.3 2.14 7.55 -62.5 7.55 -67.5 -1.50 zhdé6l 3 5k 7.43 |72.2 2.36 7.55 -62.5 7.55 -62.5 -1.90 zho6l 3 10k |7.46 |68.2 2.55 7.55 -62.5 7.55 -62.5 -2.30 7.2 CMS Results Figures 47 and 48 show UHS and CMS results for the interface (megathrust)and intraslab,respectively,at a return period of 10,000 years.Figures 49 and 50 show interface UHS,the extended CMS,and the envelope of the extended CMS for the interface,for the two envelope procedures described above.In Figure 49,Alternative 1 shows the case where the period range 0.0 to 0.5 second is filled in by the 0.0 second CMS,and the 3.0-second CMS in unaltered.In Figure 50,for Alternative 2 the 0.0 second CMS in unaltered,the 0.0-to 0.5-second range is filled in by the 0.5 second CMS,and the 3.0 second CMS fills in the 1.0-to 3.0-second range. Figures 51 and 52 show similar figures for the intraslab source.Which alternative extension procedure is selected should depend on the engineering application of the CMS.For all cases,the envelope of the extended CMS is seen to be equivalent to the UHS,which is the intended result of the extension procedure. The UHS,CMS,and extended CMS data are shown on figures for all return periods contained in Appendix C. Page 61 of 146 02/24/12 -z- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 8.0 DETERMINISTIC EVALUATIONS The regulatory process for seismic hazard evaluation defined by FERC (Section 1.2) specifies that both probabilistic and deterministic evaluations be conducted.Draft guidance for the deterministic evaluation outlined in Section 5.1 of Idriss and Archuleta (2007)provides the general framework followed here. 8.1 Selection and Evaluation of Critical Sources The seismic source characterization (Section 4)and the PSHA results (Section 6) provide a basis for selecting critical seismic sources for the deterministic evaluation. These critical sources are selected primarily based on consideration of magnitude, distance,and their relative contributions of each source in the PSHA analyses.Other seismic sources in the region may have smaller magnitudes at similar or comparable distances to this group of sources,and are therefore not included in the deterministic evaluation. Four critical fault sources are identified:(1)subduction interface,(2)intraslab,(3)Denali fault,and,(4)Fog Lake graben (Table 15).For these fault sources,the same maximum magnitudes used in the both the probabilistic (Table 6)and deterministic evaluations (Table 15).Distances are measured from the site to the closest approach of the fault source as modeled in the PSHA model,except for the intraslab source.The intraslab source distance is estimated from cross sections which show seismicity associated with the down-going slab beneath southern Alaska and the site (Figure 14).Recurrence estimates associated with the largest events on the fault sources likely vary by more than an order of magnitude.Recurrence for the deterministic magnitudes on the Denali fault,subduction interface and intraslab sources are most likely less than 1000 years. Slip rates on these sources are high (greater than 0.1 mm/yr).Recurrence for an M 7 on the Fog Lake graben source is unknown,but potentially greater than 10,000 years. Slip rates on this source are also unknown (Section 4.4),but are included in the seismic source model as a range from 0.01 to 0.5 mm/yr.As a conservative approach and sensitivity test in the PSHA,a probability of activity of 1.0 is used for this source,but lack of data and evaluation of the Fog Lake graben source indicate that the present probability of activity should be considerably less than 1.0. Diffuse seismicity occurring throughout the region is not associated with specific faults, but modeled in the PSHA as background source zones with a maximum magnitude of M 7.3.The site area location is near the center of the Southern Alaskan block (SAB) central zone and a deterministic evaluation for this seismic source zone is derived from the 10,000-yr return period deaggregation results from the PSHA (Section 6.1, Page 62 of 146 02/24/12 -Z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Appendix B,pages B73-B88),and Table 16.These results indicate that different magnitude and distance pairs result for each spectral period.Thus,a separate deterministic magnitude -distance pair could be selected for each of the four spectral periods of interest. For consistency with the other deterministic evaluations,a single magnitude,distance, and epsilon were derived for this source.This was done by taking the average modal magnitude,distance,and epsilon for each GMPE over the four periods as shown in Table 17,and weighting those results equally.Table 18 gives the resulting parameters. In Table 18,the distance measure for BAO8 is Rjb (closest distance to horizontal projection of the fault plane),and Rrup (closest distance to fault plane)for the other three.In the PSHA,point sources are modeled for the areal zone.For simplicity,this study assumes depth to top of rupture to be a single value,10.8 km (6.7 mi),which is the mean of the distribution shown in Figure 28 (lower middle figure).In the averaging procedure,this depth was used to obtain Rrup for BAO8,and Rjb for the other relations. All other parameters required,such as Vs30,are those used in the PSHA.For ASO8, the depth to bottom of rupture is assumed to be the zone maximum,25 km (12 mi). Page 63 of 146 02/24/12 -ze- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Table 15.Deterministic Hazard Input Parameters Rupture JB Depth Ground Motion Distance |Distance |Epsilon (km)'Prediction Equations (km)(km)[weight] ZHO6 [0.25] Megathrust 9.2 78 n/a n/a 35 AMO9 [0.25] BCH11 [0.50] BAO8 [0.25] CY08 [0.25] CBO08 [0.25] AS08 [0.25] ZHO6 [0.25] Intraslab 7.5 50 n/a n/a 45 ABO3 [0.25] BCH11 [0.50] BAO8 [0.25] Fog Lake CY08 [0.25] graben 7.0 7.0 3.5 n/a 0-20 CB08 [0.25] AS08 [0.25] BAO8 [0.25] Castle Mtn.CY08 [0.25] fault 7.6 100 98 n/a 0-20 CB08 [0.25] AS08 [0.25] BAO8 [0.25]Crustalseismicity”6.48 16.9 13.0 0.59 |108°Coos O28(10,000 yr)ASO8 [0.25] MagnitudeSource(Mw) Denali fault 7.9 71 71 n/a 0-15 Notes:(1)Depth range indicates top and bottom of faults,individual depths indicate the rupture depth.(2) Based on weighted magnitude-distance-epsilon deaggregation for SAB Central source and 10,000-yr return period (Table 18).(3)Depth is the weighted average of the SAB Central depth distribution (see Table 7). Table 16.Crustal Seismicity (10,000 yr)Period-Dependent Deaggregation Results Summary Period =|Return |wpar Dbar_|Epsbar |Mod_MD Mod_MDE(sec)Period 0.0 10k |6.14 17.00 1.20 |5.38-10.0 |563-12.5-1.20 0.5 10k |6.44 21.70 1.23 |625-113 |650-188-0.90 4.0 10k |6.61 23.98 1.29 |648-113 |665-17.5-0.90 3.0 10k |6.84 24.10 1.48 |695-113 |7.13-188-0.90 Note:These inputs are the average of Next Generation ground motion prediction equations Abrahamson and Silva (2008),Boore and Atkinson (2008),Campbell and Borzorgnia (2008),and Chiou and Youngs (2008). Page 64 of 146 02/24/12 -Z-.SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 Table 17.Deaggregation Results,Crustal Seismicity (10,000 yr) GMPE Period |RP |Mbar |Dbar |Epsbar |Mod_MD |Mod_MDE BAOQ8 0.0 10k |6.29 12.8 1.20 5§.55-2.5 |6.65-12.5 -1.10 BAO8 0.5 10k |6.52 18.0 1.19 6.55-7.5 |6.75 -22.5 -1.30 BAO8 1.0 10k |6.60 22.2 1.21 6.55-7.5 |6.85-17.5 -0.90 BAQ8 3.0 10k |6.77 26.8 1.28 6.65-7.5 |7.15-22.5 -0.90 CY08 0.0 10k |6.06 18.1 1.02 5.35-12.5 |5.25-12.5-1.10 CY08 0.5 10k |6.33 19.4 1.20 5.95 -12.5 |5.95 -12.5 -0.90 CY08 1.0 10k |6.52 22.1 1.18 6.25-12.5 |6.25-12.5 -0.70 CY08 3.0 10k |6.75 23.1 1.39 6.75-12.5 |6.85 -12.5 -0.50 CB08 0.0 10k |6.17 15.0 1.58 5.55 -12.5 |5.55 -12.5 -1.50 CBO08 0.5 10k |6.47 18.7 1.50 6.55 -12.5 |6.55 -12.5 -0.70 CBO08 1.0 10k |6.65 20.1 1.61 6.55-12.5 |6.45-12.5 -1.30 CBO08 3.0 10k |6.90 20.7 1.70 7.25 -12.5 |7.25 -12.5 -0.90 ASO08 0.0 10k |6.05 22.1 0.99 5.05-12.5 |5.05-12.5-1.10 ASO08 0.5 10k |6.42 30.7 1.01 5.95 -12.5 |6.75 -27.5 -0.70 AS08 1.0 10k |6.68 31.5 1.14 6.55 -12.5 |7.05 -27.5 -0.70 ASO08 3.0 10k |6.92 25.8 1.54 7.15-12.5 |7.25 -27.5 -1.30 Table 18.Crustal Seismicity (10,000 yr)Single-Earthquake Deterministic Parameters Magnitude haat alae JB Distance (km)Depth (km)Epsilon m 6.48 16.9 13.0 10.8 0.59 Note:These inputs are the average of Next Generation ground motion prediction equations Abrahamson and Silva (2008),Boore and Atkinson (2008),Campbell and Borzorgnia (2008),and Chiou and Youngs (2008)over all periods. Page 65 of 146 02/24/12 -z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 8.2 Deterministic Ground Motion Estimates Deterministic ground motion estimates were developed for six critical seismic sources based on maximum magnitude estimates,site to source distances,and the weighted GMPE's used for each source in the PSHA analyses.The deterministic sources are the subduction interface,subduction intraslab,Denali fault,Castle Mountain fault,Fog Lake graben faults,and a 10,000-year return period earthquake for the background source derived from deaggregation of the PSHA results. The deterministic ground motion evaluation uses multiple GMPEs appropriate for each type of seismic source with weights shown in Table 15.The same weighting of GMPE's is used in the deterministic evaluation as was used in the PSHA (Section 5.2). The FERC guidelines (FERC,2011;Idriss and Archuleta,2007)recommend comparison of the deterministic results to the total UHS from the probabilistic evaluation.The weighted deterministic results,both median and 84th percentile,are shown as individually for each critical source in comparison to the total UHS from the probabilistic evaluation (Figures 53 -58).The guidelines recommend use of 84th percentile values for the highly active sources,but use of median values for sources with low average slip rates (Section 5.1 in Idriss and Archuleta,2007),such as the Fog Lake graben source. The deterministic evaluation indicates that the largest values of ground motions at the site are associated with the subduction interface and intraslab sources due to their large magnitude,relatively short distance,and GMPE's used for these sources.For the intraslab source,the deterministic results are generally similar to the 10,000-yr UHS, except at periods greater than 0.5 sec (Figure 53).At periods of about 3 sec,the intraslab source contribution corresponds to the 2500-yr UHS.In contrast,for the subduction interface source,the deterministic results are near the 2500-yr UHS for periods less than 0.2 sec,but are near the 10,000-yr UHS for periods greater than 2 sec (Figure 54). The median and 84"percentile results for the crustal sources indicate that these sources are relatively less significant compared to the subduction zone sources.The Denali fault source 84th percentile results correspond to the 100-yr UHS for periods up to about 0.2 sec and are below 1000-yr UHS at periods up to 3 sec (Figure 55).The Castle Mountain fault 84"percentile results are lower than the Denali fault,and are below the 100-yr UHS for periods up to about 1 sec and below 250-yr UHS for periods up to 3 seconds (Figure 56). Page 66 of 146 02/24/12 -z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Based on the low slip rate and a likely probability-of-activity that is less than 1,median motions are recommended for comparing the Fog Lake graben source to the UHS.For most periods,these motions fall between the 250-yr and 1000-yr UHS (Figure 57). Deterministic contributions from the seismicity in the SAB central source zone,including 84th percentile estimates,also plot between the 250-yr and 1000-yr UHS hazard (Figures 58 and 59). For the areal zone representing background crustal seismicity (SAB Central zone),two deterministic results were produced.The first derives period-dependent magnitude- distance-epsilon values from the four GMPEs shown in Table 15.These results,shown in Tables 16 and 17,indicate that high frequencies (PHA)are dominated by smaller magnitudes,while longer periods are dominated by larger magnitudes.This would have considerable impact if time histories were to be derived to account for the deterministic results.Figure 57 shows the results for the four considered periods,along with the UHS.The median results are consistent with the 250-year UHS at most spectral periods,and the 84"fractiles are at the 1000-year UHS level or less. The second areal zone deterministic analysis reduces the deaggregation information to a single magnitude and epsilon,and the two relevant distance measures.Figure 58 shows a similar result;the median deterministic values are roughly consistent with the 250 year UHS,and the 84"fractile with the 1000-year UHS. If a single deterministic earthquake for the areal Zone source is desired,the results in Table 18 and Figure 59 are recommended.If period-dependent earthquake scenarios are desired,the results in Table 16 and Figure 58 are recommended.Given the similarity of these results with those for the Fog Lake graben faults,the areal zone results should probably be classified as a "low average slip-rate”source under the FERC terminology. 8.3.Comparison to Previous Studies This section compares and contrasts the results of this study to the previous WCC results,for deterministic and probabilistic approaches.The seismic source characterization and ground motion results from this study include most elements from the prior Woodward-Clyde (1980,1982)studies,but are not directly comparable due to many changes in practice and methodologies.The major fault sources represented in the prior Woodward-Clyde studies are included with updated seismic source characterizations.The detection level earthquake (Woodward-Clyde,1982)concept is superseded by the use of probabilistic analyses of the background seismicity in the site and region.In addition,this present study includes seismic sources (e.g.,subduction Page 67 of 146 02/24/12 -z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 intraslab source)not characterized in the prior Woodward-Clyde studies.There are general similarities between results of this study with the prior results,but also significant differences due to differing seismic source characterizations,methodologies, and ground motion attenuation parameters. Table 19 compares deterministic results presented by WCC (1982)to those computed in this study.Mean PGAs for the megathrust seismic source are practically identical: 0.35 g compared to 0.33 g.The WCC (1982)characterization is a smaller magnitude event but closer distance than in this study,so it is difficult to assess which set of GMPEs is more conservative.WCC (1982)did not present a PGA for the intraslab, because they assumed that a smaller magnitude at a greater distance would produce ground motions lower than the megathrust source.However,the ground motions for this source presented here show that these motions are actually higher,by a substantial amount. However,the discrepancy between the Denali fault PGA in the WCC (1982)study (0.20 g)and the PGA in this study (0.09 g;Table 19),for the same magnitude and distance, indicates that the earlier GMPEs produced higher ground motions than those used herein.The GMPEs available in 1982 were derived from a limited set of ground motion recordings,in both number,quality,and sampling of tectonic environments,compared to what is available present-day. Seven GMPEs were considered by WCC (1982)in the selection of attenuation relationships.While it is stated that one group of relations was selected for crustal earthquakes and another for subduction zone earthquakes,it is not stated which were used for each,nor what weighting,if any,was applied.Some are published and readily available,while some are contained in conference proceedings and difficult to obtain. However,all are for peak horizontal acceleration (PHA)only,as WCC (1980)applied spectral shapes tied to the PHA value,as was common practice at the time of the WCC study. Page 68 of 146 02/24/12 -Z-.SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-06-0004-120224 Table 19.Deterministic Result Comparison between Woodward-Clyde (1982) and This Study Woodward-Clyde (1982)FCL (this study) Source MCE |Distance|Mean |mce |Rupture |JB |MeanDistance|Distance |PGAMs)"km)**|PGA(g)°*|(Mw Megathrust (interplate)8.5 64 0.35 9.2 78 70 0.33 intraslab (intraplate)7.5 50 Unavailable 7.5 50 0 0.53 Denali fault-entire |3 4 70 0.20 7.9 71 71 0.09fault Denali fault -2002 Not considered 7.9 86 86 . rupture Denali fault -west Not considered 7.9 71 71 - segment Castle Mtn fault -75 105 |Unavailable|7.6 100 98 - entire fault Castle Mtn West Not considered 7.2 137 135 - fault high Castle Min West Not considered 7.2 137 135 - fault low Castle Mtn East fault Not considered 7.2 100 98 - Pass Creek-Dutch Not considered 7.0 107 105 . Creek fault Sonona fault Not considered 7.0 72 69 - Fog Lake graben north Not considered 7.0 7 3.5 0.34 Fog Lake graben Not considered 7.0 10 6 - south Detection level 6.0 <10 0.50 niaearthquake Crustal seismicity nla 66 15.1 99 0.278(10,000 yr)::,: Notes:(1)From Table 8.1 in Woodward-Clyde (1982).(2)From Table 8.2 in Woodward-Clyde (1982).(3)From Section 8.3.2,p.8-8 in Woodward-Clyde (1982).(4)Distance assumed to be Rupture distance.(5)Mean PGA ground motions are the weighted sum of GMPE's listed in Table 15.(6)Magnitudes and distances for crustal seismicity are from Table 18. Table 20 compares the probabilistic results presented by WCC (1982)to those derived by this study.The probabilistic approach used by WCC was not described in great detail,and as with the deterministic comparisons discussed above,the details of GMPE's used in the WCC evaluations are unclear.However,it appears that for return periods up to about 2500 years,the WCC (1982)estimates are somewhat higher than Page 69 of 146 02/24/12 -zw-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 the mean PGA values resulting from this current study.However,for a 10,000-year return period,the current study results are significantly higher (0.64 g compared to 0.83 g).For both deterministic and probabilistic evaluations,the significant differences in input data,methodologies,and practice between the WCC studies and the current study make direct comparisons tenuous,at best. Table 20.Comparison of WCC (1982)and FCL (this study)hazard results WCC (1982)FCL (this study) Frobability of neguvaent d Mean PGA (g)Return Period |Mean PGA |Mean 1 sec in 100 years (years)(years)(g)SA (3) 100 0.13 0.07 0.50 144 0.28 250 0.20 0.12 0.30 280 0.32 0.10 949 0.41 1,000 0.37 0.23 0.05 1,950 0.48 2,500 0.52 0.34 5,000 0.66 0.45 0.01 9,950 0.64 10,000 0.83 0.58 Page 70 of 146 02/24/12 -z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 9.0 INITIAL SURFACE FAULTING AND GEOHAZARD IDENTIFICATION This section reviews the potential for surface fault rupture hazard at the site as characterized in the WCC (1982)study,based on desktop evaluations using updated literature evaluations and seismic source characterizations.WCC (1982)concluded that topographic lineaments near the dam site are either not tectonic faults,or are not "recently active”structures (within the past 100,000 years).However,recent earthquakes in the region have demonstrated the potential for fault rupture on poorly or un-characterized faults strands.Active or potentially active faults,or lineaments that underlie the proposed dam footprint or the upstream extent of the proposed reservoir must be evaluated for surface rupture hazard.Active faults have some potential for surface rupture during a seismic event,depending on strength of the earthquake and other factors.Suspected or known fault structures that underlie the facility footprint and have a poorly understood surface rupture history are considered potentially active. Faults classified as inactive have no potential for co-seismic surface fault rupture. This preliminary surface fault rupture hazard assessment is based upon features identified and evaluated during previous work for the Susitna-Watana dam site (WCC, 1980;1982;Harza-Ebasco,1984),recent relevant geologic publications (e.g.,O'Neill et al.,2005;Glen et al.,2007a),and preliminary office-based interpretation using new landscape assessment tools (Google Earth).This surface fault rupture hazard assessment is preliminary and intended as a review of the current state of understanding regarding these structures.Further investigation of the activity,and therefore,rupture hazard of each or some individual features,may be needed in the future to either confirm or update the WCC conclusions. Three structural features that underlie the dam site area or proposed reservoir were identified during the WCC studies (WCC,1980 and 1982)including:the Talkeetna thrust fault,the Watana lineament,and northwest-striking structures (Figure 21).The trace of the Susitna lineament as presented by WCC (1982)is located proximal to the dam site area,but does not appear to underlie the anticipated dam foundations or reservoir.Therefore,the Susitna lineament is not considered in this surface rupture hazard assessment.The Talkeetna thrust discussion below incorporates the recent reassessment of the structure by O'Neill et al.(2005)and Glen et al.(2007 a). 9.1 Watana Lineament The Watana lineament is an east-west trending lineament that passes through the dam site and approximately follows an east-west linear section of the Susitna River.The Page 71 of 146 02/24/12 -yzO SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 lineament was first identified by Gedney and Shapiro (1975).WCC (1982)performed bedrock mapping,evaluated angle boring logs and interpreted aerial photos along the lineament and concluded that it is comprised of a series of disconnected,short lineaments that are unrelated to Quaternary faulting.No further paleoseismic evaluation has been performed on the lineament.The conclusion of short, discontinuous lineaments (WCC,1982)does not necessarily demonstrate,nor preclude, fault inactivity,and no potential for surface fault rupture. 9.2 Northwest-striking Structures in the Site Vicinity Early site investigations identified is a zone of fractured and highly disturbed rock,with a prominent exposure in the cliffs along the north side of the Susitna River adjacent to the dam site (Acres,1981).The structure,termed the "Fins”feature in most early reports, strikes northwest-southeast between the Susitna River and Tsusena Creek and dips 70 to 75 degrees.The feature as mapped by WCC (1982)follows a morphological depression in the surficial units between the Susitna River and Tsusena creek,which is roughly coincident with a buried paleochannel.Along their southeastern edge,adjacent to the dam site,it is expressed morphologically as a series of northwest-striking gullies and ridges.The feature was judged to be a short (2-mile long)fault without "recent” displacement by WCC (1982).A subsequent geotechnical evaluation of the feature by Harza-Ebasco (1984)included detailed geologic mapping and geotechnical borings. This study concluded that the northwest-striking feature is not a "through-going structure,”but rather a zone of closely spaced fractures,some with slickensides and clay infilling suggestive of "minor shearing,”but with no evidence of "major faulting.” Borrow area and geotechnical evaluations in the Harza-Ebasco studies depict a sequence of Quaternary glacial deposits which would overlie the extensions of the northwest-striking feature and which appear to be unfaulted (also see Section 3.3).The northwest-trending topographic lineament identified by WCC (1982)is apparent in Google Earth.The topographic depression could be explained by differential erosion in a region of sheared bedrock.However,further field evaluation of the structure would be necessary to verify the conclusions of WCC (1982)and Harza-Ebasco (1984). 9.3.The Talkeetna Thrust Fault /Talkeetna Suture Zone The Talkeetna thrust fault /Talkeetna suture Zone is a major terrane-bounding structure associated with continental accretion in the late Cretaceous and early Tertiary.The traditional view of the Talkeetna thrust fault (i.e.,Csejtey,et al.1982;Nokleberg et al., 1994)has been questioned by Glen et al.(2007a;2007b),who propose that the Page 72 of 146 02/24/12 -z-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 structure is a deep crustal suture that branches upward into a wide (12-mi [20-km]) zone of Tertiary or younger faults. WCC (1982)evaluated the paleoseismology and recency of activity of the Talkeetna thrust fault,based on the assumption that the fault is a discreet upper crustal structure. The WCC (1982)study considered the likely fault trace to be concealed by young Cenozoic deposits along much of its length,with the exception of Talkeetna Hill to the southwest near the Talkeetna River (Location 1 in Figure 21).WCC (1982)constrained the concealed sections of the fault to a 3-mile-wide band along much of its length,and a 1-mile-wide band at the Susitna River.The WCC (1982)study concluded the Talkeetna thrust fault showed no evidence of "recent”displacement,based on the following observations and judgment (see Figure 21 for study locations): e Undeformed Tertiary volcanic rocks (50 Ma potassium-argon age)overlie the fault at location 1 (Figure 21). e Paleoseismic trenching at location 1 (Figure 21)revealed the fault trace in bedrock,but did not have age-appropriate deposits overlying the bedrock to positively evaluate fault activity. e Trenching of a geomorphic lineament near the Fog Lakes (location 2,Figure 21)revealed no evidence of faulting in units exposed with an approximate age of 15,000 to 25,000 years old.The lineament was judged to be of glacial origin. e Fold axis in Oligocene strata near Watana Creek (location 3,Figure 21)are oriented northwest-southeast,which is inconsistent with compressional stresses capable of reactivating the Talkeetna thrust. e Offset of the Talkeetna thrust by a younger unnamed fault near the Talkeetna River. e The assessment that the Talkeetna thrust fault is a late Cretaceous through early Tertiary accretionary structure.The active continental accretion is currently located over 340 mi (550 km)to the south-southeast. The recent geologic model of Glen et al.(2007a and 2007b)recasts the Talkeetna thrust fault /Talkeetna suture based on field mapping and assessment of gravity and magnetic data and suggests that the previous WCC (1982)be reconsidered in light of this new framework.In this new model,the dam site is located within the Fog Lakes Page 73 of 146 02/24/12 SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 graben,which overlies the deep crustal Talkeetna suture.The Fog Lakes graben is a rhombohedral zone bounded on the northwest by faults associated with the Susitna lineament,to the southeast by a series of unnamed range-front normal faults (Figure 21 and 22).The graben is interpreted to have formed as a basin in a broad zone of dextral transtensional shear,with probable development in the Eocene,Oligocene and Miocene.The spatial overlap of the Fog Lakes graben and the Talkeetna suture zone suggests that the two structures may be associated as reactivation structures along crustal weakness at the suture zone.An additional component of the Glen et al.(2007a and 2007b)model is that previously mapped surface traces of the Talkeetna thrust are reinterpreted as individual upper crustal faults that are components of a wide zone of deformation associated with the Talkeetna suture (i.e.Butte Creek fault and Watana Creek fault).The WCC (1982)evaluations were more focused on a concept of a single fault trace,and a tectonic model mostly associated with the older deformational elements in the Glen et al.(2007a,b)model.Undeformed Tertiary rocks identified by WCC (1982)at location 1 (Figure 21)would lie beyond the extent of the Fog Lakes graben of Glen et al.(2007a,b). The reassessment of the Talkeetna thrust by Glen et al.(2007a and 2007b)as a southeastern graben-bounding fault is a new model for a poorly documented structure. Glen et al.(2007a and 2007b)do not present a map trace for this structure,but describe it as a range-front fault along the southern edge of the Fog Lakes lowland,and depict the faults on an interpretive cross section offsetting Tertiary rocks at shallow crustal depths (Figure 22).The southwestern Fog Lakes graben fault shown in Figure 21 is interpreted based on the description of the fault as a range front structure.This interpreted fault trace strikes northeast and projects toward the upstream extent of the reservoir.Preliminary assessment in Google Earth confirms several tonal and topographic lineaments in the vicinity of,and parallel to the interpreted fault trace,which are distinct from those evaluated by WCC (1982).These lineaments may be the result of several possible geologic processes.Analysis of additional,more-detailed data (e.g. LiDAR)with respect to further evaluation of the Fog Lakes graben fault would help clarify the surface rupture hazard of the structure. 9.4 Other Potential Seismic Hazards This section identifies potential seismically-induced geologic hazards (e.g.landslides, seiche)that may be significant to the project facilities.The scope of work for this current study did not include a comprehensive evaluation of all potential geologic or seismic hazards.Geologic and seismic hazards specifically not addressed in this initial phase of work include confirmation or verification of fault activity judgments in WCC (1982),evaluation of potential reservoir-triggered seismicity (RTS)and the potential for Page 74 of 146 02/24/12 ys SUS ITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 seismically-induced seiche within the proposed reservoir.Additional studies will be needed to address significant seismic or geologic hazard issues,and future studies are planned during licensing and design to address these potential seismic hazards. Additional potential geologic hazards,e.g.,potential co-seismic liquefaction,also may be identified during future phases of Project work. Page 75 of 146 02/24/12 ze SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 10.0 SUMMARY The developed seismic source model considers several seismogenic and potentially seismogenic structures.These are:subduction-related sources (plate interface [megathrust],and plate intraslab),the Denali fault,Castle Mountain fault,Pass Creek- Dutch Creek fault,Sonona Creek fault,zones of distributed deformation north and south of the Denali fault,and Talkeetna block structures (Fog Lake graben). Mean hazard curves were developed for four spectral response periods,peak horizontal acceleration (PHA),and 0.5,1.0,and 3.0 seconds acceleration response at 5% damping.Mean uniform hazard spectra (UHS)were developed for return periods of 100,250,1000,2,500,5,000,and 10,000 years. Source deaggregation plots are developed,one for each of the four spectral response periods (PHA,0.5 sec,1.0 sec,3.0 sec).Only sources contributing 5%or more at any ground motion level are plotted on the de-aggregations.The PHA hazard is dominated by the Alaskan source zone intraslab at all return periods.This reflects the high rate of M 5 to M 7.5 events generated by this source. The draft FERC guidelines (FERC,2011;Idriss and Archuleta,2007)recommend comparison of the deterministic results to the UHS from the probabilistic evaluation. The seismic source characterization (Section 4)and the PSHA results (Section 6) provide a basis for selecting critical seismic sources for the deterministic evaluation. Four critical fault sources are identified:(1)Subduction interface,(2)Intraslab,(3) Denali fault,and,(4)Fog Lake graben.A deterministic evaluation for the southern Alaskan block (SAB)central zone seismic source zone is derived from the 10,000-yr return period deaggregation results from the PSHA.Deterministic evaluation of the Castle Mountain fault shows that it is less significant than the four critical fault sources or the SAB seismic source zone.The deterministic evaluation indicates that the largest values of ground motions at the site are associated with the subduction interface and intraslab sources,because of their large magnitude,relatively short distance,and GMPE's used for these sources.The deterministic results for the crustal sources (e.g. Denali fault,Fog Lakes graben,Castle Mountain fault,and 10,000-year crustal seismicity)indicate that these sources are relatively less significant,as compared to subduction megathrust and intraslab seismic sources. Comparisons between the ground motion results of the present study to the results from the WCC (1982)study are complicated by the differences in approach,state of practice, analyses tools,and input parameters.For the deterministic results (Table 19),a major difference arises because WCC (1982)chose to not consider the intraslab component Page 76 of 146 02/24/12 Ze.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 of the Alaska Subduction Zone as a separate seismic source with different GMPE, consistent with practice of the time.In the current study,the deterministic evaluation finds that the intraslab source produces the largest PGA at the site.For the probabilistic evaluation (Table 20),the present study results are slightly lower than those from WCC (1982)for return periods less than 2,500 years,but are higher than those from WCC (1982)for return periods of 10,000 years.It is difficult to examine the differences in the results due to the vast differences in input data and methodologies between the two studies. 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Woodward-Clyde Consultants (WCC),1980,Interim Report on Seismic Studies for Susitna Hydroelectric Project. Woodward-Clyde Consultants (WCC),1982,Final Report on Seismic Studies for Susitna Hydroelectric Project. Zhao J.X.,Zhang,J.,Asano,A.,Ohno,Y.,Oouchi,T.,Takahashi,T.,Ogawa,H., Irikura,K.,Thio,H.,Somerville,P.,Fukushima,Y.,and Fukushima,Y.,2006, Attenuation relations of strong ground motion in Japan using site classification based on predominant period”Bulletin of the Seismological Society of America, v.96,p.898-913. Page 86 of 146 02/24/12 62°0'0"Nwee152°0'0"W 148°0'0"W 144°0'0"W To:T ran alia a eal a ee ate a wea ee-"TALKEETNA'.-*..COPPER RIVERae"MINS,3 BASIN 'nilTOE"/WRANGELL (/-Ue MINS.©{”SUSITNA\BASIN a 4 = /xaw,ws ORDRILLOrTake STATE OF ALASKA ALASKA ENERGY AUTHORITY JENAMSTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MAJOR PHYSIOGRAPHICusesPROVINCES 02/02/12 FIGURE 1 Page 87 of 146 Ff ey FO Ne a Ee eed one oepfBrooksROEITEy YFB Oran-og : Kobuk fault ie 66°N L - 64°N i wee puosite c.4?+ye,SOUTHERN;ey tea ALASKA.fslcseOF BLOCK P£62°NF " 60°N L!of s é . -e,PACIFIC PLATE TAF 0 300 k Black lines are Neogene and active faults,dashed lines are anticlines.Triangles show active volcanoes.Crustal blocks are outlined in gray and are dashed where boundaries are uncertain.Faults:WDF,western Denali fault;CDF,central Denali fault;EDF,eastern Denali fault;NFB,northern foothills fold-and-thrust belt;NS, Nenana structure;TF,Totschunda fault;DRF,Duke River fault;LCF,Lake Clark fault;CMF,Castle Mountain fault;BBF,Bruin Bay fault;CSF,Chugach-St.Elias thrust fault;KIZ,Kayak Island fault zone;RMF,Ragged Mountain fault;AMT, Aleutian megathrust;TRF,Transition fault.Major roads are shown with thin black lines.AH,Alaska highway;PH,Parks highway;DH,Denali highway;RH,Richard- son highway;DH,Denali highway;TCH,Tok cutoff highway.Abbreviated river names mentioned in text:NR,Nenana River,Delta River (both rivers flow north); BR,Big River;WF,Windy Fork;KR,Kuskokwim River;SR,Skwentna River. Glaciers:SG,Straightaway Glacier;FG,Foraker Glacier;PG,Peters Glacier;MG, Muldow Glacier.Sedimentary basins:cm,Cook Inlet basin;SB,Susitna basin; CRB,Copper River basin;NB,Nenana basin;TB,Tanana basin;YFB,Yukon Flats basin.From Haeussler (2008). STATE OF ALASKA ALASKA ENERGY AUTHORITY (EADS! SUSITNA-WATANA HYDROELECTRIC PROJECT TECTONIC OVERVIEW OF CENTRAL INTERIOR ALASKA 02/02/12 FIGURE 2 Page 88 of 146 91jo6gebeg150°0'0"W 145°0'0"W "oy .7 0 °-50 mi L 't t J ao ,ae ee7050km NorthernFoothills Fold andThrust Belt-Ne xAF ge tud,fad ke72Denaitfault_- 7 :Sr7,A347 Matanisks per"farWe:2S,jy Glacier fault ” vr Segretn -J Explanation Fault Activity =-Historic ---Quaternary wee Unknown -=-Other IN..0,0.¢9Mecallum”=«ij4"State Creek fault Fault data from Cjestey (1978),Plafker et al.(1994), and Williams and Galloway (1986). GROoeeeeae|== me.ot awia4esa N.0,0.29STATE OF ALASKA ALASKA ENERGY AUTHORITY /=E>ENEAGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT SITE REGION FAULTS 02/02/12 FIGURE 3 Se tien tial ie i Ot elie.ifferentiated Peninsular Map based on the geophysical character of the terranes (Glen et al.,2007b). STATE OF ALASKA ALASKA ENERGY AUTHORITY tl «a_ BP ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT TECTONOSTRATIGRAPHIC TERRANE MAP OF THE TALKEETNA BLOCK 02/02/12 FIGURE 4 Page 90 of 146 160°E 170°E 180°W 170°Ww 160°W 150°W 140°W L ioonBSymbolKey :oon 4939)Earthquake 1938 -M 8.3 ma]"rupture area 1946 -M 7.9 -Bering block 1957 -M 8.6 GPS motion 1964 -M9.2 56°N-_-.Pacific plate 1965 -M 8.7 54 min/yq 56°Nmotion(NUVEL-1)1986 -M 8.0wy 57 mmiyr 78 mmilye SN DS 195 \Pacific Plate [*7™ 7 mmvy\75 mmiy\__72mmiyr 160°E 170°€180°W 170°Ww 160°W 150°W 140°W Motion of the Pacific Plate relative to North America is indicated by black arrows.Red arrows show motion of the Bering Block relative to North America. From Carver and Plafker (2008) ALASKA ENERGY AUTHORITY={=_>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT RUPTURE AREAS FOR HISTORICAL ALASKAN SUBDUCTION ZONE EARTHQUAKES 02/02/12 FIGURE 5 Page 91 of 146 OFJO26Bed-_a a 152°0'0"W 148°0'0"W 144°0'0"W d "T SO Oe oP Plas ney hada rss;ST aa de eee ry-Néithiem,RoothillsFold fee,la v/18fy.rand ThespBelty.cid es oe eee bSgtaePe7CEA51BFfwhehwofF.ee ©ae ee,LN,Sail ide rn#-G4+1 Cammy SIS we SEA RAL:vo bey vA *ay mr fe . "ow?Mae,--a :'¥*Yo Lew,a - ;eee an aé fo}oe z 7 Explanation Symbols Faults Abbreviations ®Earthquake epicenter Denali fault BR -Bull River fault . BP -Broad Pass fault CO Slip rate (sources 2002 Denali fault rupture,BG -Broxson Gulch fault SRTSTA ST discussed in text)Haeussler (2008)FF -Foraker fault ALASKA ENERGY AUTHORITY Southern Denali faults MSC -McCallum-Slate Creek fault {=SG -Susitna Glacier fault or ENERGY ASTHORITY --_Other fault SUSITNA-WATANA HYDROELECTRIC PROJECT DENALI FAULT CHARACTERIZATION mL "02/02/12 O-6 9plJo6abe150°0'0"W 145°0'0"W ee °1 n Foothillset Gold King fault g 3 3S z NE ot*McGinnis vA apes oe Dot -;] 3 o eC,">bake ¢7-4TiSfu<*WV fault ee fault'...we a25Denal Plateau faut*y,"4p = Se ET I eG eteveg,eae Cathedralharaetee,”Rapids fault Y*aby oy o w 3S 3 *z Key to Abbreviations BGF -Broxson Gulch fault CF -Canteen fault DC -Ditch Creek fault DD -Donnelly Dome fault GC -Glacier Creek fauit GM -Granite Mountain fault HF -Healy Creek fauit KC -Kansas Creek fault MM -Mystic Mountain fault MR -Molybdenum Ridge fault NFT -Northern Foothills Thrust PF -Panoramic fault {=PsF -Potts fault we EN onRM_Red Mountain fault SUSITNA-WATANA HYDROELECTRIC PROJECT SGF -Susitna Glacier fault STATE OF ALASKA ALASKA ENERGY AUTHORITY F NORTHERN FOOTHILLSUF-Unnamed fault FOLD AND THRUST BELT r UGRO ne 02/02/12 FIGURE 7 a 9PbJOv6abe151°0'0"W 147°O'0"W L? 150°0'0"W 149°0'0"W 148°0'0"W ieee WceePc raewrekets Explanation ©Earthquake epicenter Faults Paleoseismic Investigations C1 Hausler et al.,2002 Castle Mtn.fault,eastern segment Hi Willis et al.,2007 and Caribou fault --Other fault Note:Site is 100 km to the north Castle Mtn.fault,western segment T -N,.0,0029N..0.St0b9nm _ ° wo 0 2 2 ca io] Zz STATE OF ALASKA ALASKA ENERGY AUTHORITY a/@BE->ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT CASTLE MOUNTAIN FAULT O 02/02/12 O-8 IA A'B ' fe)te)#H- Ni5°E f- N90°E b-->N45°E b- N42°W_| 4400- 42004 ee4000-4eels Maximum elevation of Early Wisconsin Ice $40034sdo0a7| wl adlevionea Maximum elevation of Late Wisconsin Ice °1 32004Maximumelevationof/J .last stade of Late \i T Dead b Tributary Wisconsin Ice |3000+ "|::susena eadman elusion to wee Susitna River Creek Creek Creek Watana Creek Lacustrine deposits \// ye.B Exposures 8 50 Ta2N RSE saree ee y 78009Nyyore”B .ete a4 see 20 &30, ,saerzo0 ee KE)/a\ON ma)T32N,RSE,eievation of Tast stade Of bate Wiscon,.ts /2600+ >--"Ss es Osi G -x \a A "7 A \\;\Exposures a =/2400+ \Se A fi Not RSS re a ae SW%NE%sec 22 =fuss si 7 = '\ay iy asa tae ee hS alee SAAN 132N,R6E . _QD = Alt TA»i SSRI -mp ae GANALND axrwt IW &2200- la aximum ef vation of fy PT 3 fast 5 l@ of = LEGEND ?Late Wisconsin Ice i A 7 A iw 2000- Pre Late Wisconsin . >lacial deposits -Till TAUTESAY 1800-4 -Glaciofluviat Deposits 1600- -Lacustrine Deposits Thickness Thickness Thickness Thick Thick ick.P (fe)tm) ; tf)im)C tty im)D (ty tm)E tt)tedF Mid telG -Deltaic Deposits wae O70 Wiz Deltaic,tan Oy Of-=F Lacustrine,07 Ors 070 O7 Once 07 O-14004 oe 4 sand,terraced >tan,random.]"*,4 |ess q Deltaic,med- '_. .ona +Po:les up to 1 jee -q L lary?L . ne Ice Contact Deposits "aia e 1 ft dismeter q -,.*furan Yi:;1 jAesclium grained -Weathered Bedrock P10)4 piQ}ae common T'o/-rio yy Deltaic,silt to Trig sezZjsand 1 [+«I Til,gray 1 |*A.°]Ti,grav "|Tilt,gray ]1 ny comed end” - :;+a +|..gray,.-L .an Undifferentiated Bedrock a 50,slumping 50}||Gtaciottuvial,Soy I:«|Bross bedded,Lacustrine, L201 "{common L>oxidized +201-ripples common thinly lamin- i i ignati we 1 ['.*a°)Till,oxidized 1 ¢ ated fine sand $34 Field Location Designation 4 =Gieciofiuvial,1 |.°.*aland mottled T 'and silt 4 ray 4 :a = ..cee :.+«1 Glaciofluviat-x,Unconformity,queried laciofluvial,1004 Re 'é 100430)27"2|Lecustrine,tan 499430 Lacustrine,silt ”where inferred :peanhh idi 4 ,readin.Mably hd oF 27]to gray,silt with 00 --|Lacustrine,ten,-|and clay,varves Glaciofluvial,consolidated 7 -|moderately to j fine sand beds,=jrandom ice common slightly ox- -1 . e :Measured section $14 +]varves common -irafted cobbles idized sand -Contact,queried dantmee|Anguiar blocks of _[highly y °.. .13334 .NE%SW%sec 7,-Jand grave!Lf where inferred weathered bedrock,'|consolidated : A River tevel \Sample $34-1 dated T32N,R7E Tilt,gray :, >27,000 y.b.p.1504 160 ' I Section location and Measured section $234 4 Glaclofiuviol, designation NE%SE%sec 29,4 .|oxidized ; T3IN,R4E Lacustrine,:1753 ,4 ove aay.oe River ievet 4 silt and clay,4 14552 lBedrock Measured section S16 NOTE:2004 Sampie $29-1 199 bed 24 pirat ection $15 SW%SE%sec 15, J dated >37,000 y.b.p.River fevel 733N,RaW T33N,RIW 1.Section location is shown on Figure 3-2.q Swanweaes S44 ' 230++70}sec y,dogs eeasT32N,RIE 70 ne Lr,gray ..é 245) Vertical Exaggeration 26x e Measured section $48 NW%NW%sec 9, SCALE Measured section $29 T32N,R7E 0 5 10 Mites SW NW see 28.GENERALIZED CROSS SECTION OF --!----!: ]T32N,RAE QUATERNARY DEPOSITS AND SURFACES it)5 10 Kilometers From WCC (1982) a SCALE WARNING 0 %+Project 02.jo2N2 |cro ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIG PROJECT FIGURE Date vereYt---,oosoued 8 =_GENERALIZED CROSS SECTION Rorwesunee [oe KG =ALASKA OF QUATERNARY DEPOSITS FIGURE 9 REV DESCRIPTION ay |pare NOTTOSCALE-Prosaven a @@->ENERGY AUTHORITY AND SURFACES Late Wisconsin surfaces 11,000 to 9,000 y.b.p. LEGEND Tj Late Wisconsin surfaces 25,000 to11,000 y.b.p. Early Wisconsin surfaces 75,000 to 40,000 y.b.p. Pre-Wisconsin surfaces >100,000 y.b.p. s4-1@ Radiocarbon sample locality and number a Glacial Age Boundary Fig.3-5A Detailed study areas are shown in Figures 3-5 and 3-6. B' Generalized projected cross section is shown in Figure 3-3. A wl Watana Site DI Devil Canyon Site 1.Figure A-?shows the location of the Quaternary Study Region. SE INL,EIA,=eg ENE ES SAS.Bes NOTESNYie3-684 -".Ch:Es foe LANG ¢ 2.Areas with no color are bedrock and/or surfaces of undifferentiated glacial age.* 3.y.b.p.is the abbreviation for years before present 4,Glacial age boundaries are interpreted from morpho- stratigraphic relationships and age dates. -N- QUATERNARY GEOLOGY MAP 5 0 10 20 Miles t =e --)Ni E I I J .0 10 20 Kilometers 14 From WCC (1982) SCALE ;WARNING Pre ve,ona |ALAS Kae oFAAS ORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE IF THIS BAR DOES =Designed =<ALASKA SITE VICINITY FIGURE 10NOTMEASURE1"Drawn =QUATERNARY GEOLOGY REV DESCRIPTION BY |DATE NOT TO SCALE ed i a @@-ENERGY AUTHORITY 62°52'0"N62°50'0"N62°48'0"N62°46'0"N148°35'0"W148°40'0"W 148°30'0"W 148°25'0"W 148°20'0"W 148°15'0"W ”T 1 a t T l LJ |\¢Qid Qid Qu Qid tr .Qo a GA:eo i Ql |os a -)\al c = -Gf Qlea)Pe Ex.Pa SC .SWS py fb eS ee=See SSS: .2S :ate ,a *Qa root yo ae i x a E i FE 1 Geology from Acres (1982)QUATERNARYTERTIARYMESOZOICJUUOUUUUeeleeeExplanation Contact --4-4&Thrust fault Shear Alluvium,alluvial terraces and fans Ice disintegration deposits Till Outwash Surficial deposits,undifferentiated, generally thin Conglomerate,sandstone and claystone Volcaniclastic sandstone, siltstone and shale Andesite porphyry,minor basalt Diorite to quartz diorite, minor granodioite Biotite granodiorite CRETACEOUS -Argillite and graywacke TRIASSIC -Basaltic metavolcanic rocks, metabasalt and slate PALEOZOIC -Basaltic to andesitic metavolcanic rocks SCALE WARNING Project No.STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE o %1 Jo.02/02/12 Gro ALASKA ENERGY AUTHORITYTresampoes[oes zn <-FIGURE11KarieerenespoeseresRef=ALASKA SITE GEOLOGY REV DESCRIPTION BY |DATE TNOLTOSCALE @=-ENERGY AUTHORITY 43,221,000 1H S270 12009 MOS 2 eS ee REFERENCE: Locogiant TILL AND QUTWASH The BASE MAP FROM COE,1978-I"*200°'WATANA TOPOGRAPHY,SHEETS 8 ANO IS OF 26COORDINATESINFEET,ALASKA STATE PLANE (ZONE 4) LEGEND ul THOLOGY: OVERBUROEN:AREAS OF YALUS,OUTWASH,TILLANOALLUVIUM,AS SHOWN OIORITE TO QUARTZ DIORITE.INCLUDES MINORGRANODIORITE Ls 2. 4 ume vane ee 1980 wee yauys-..AUSa WATANA DAMSITE TOP OF BEDROCK ;7)AND SURFICIAL GEOLOGIC MAP OORITE PORPHYRY CONTACTS: CONTOUR LINES: -----TOP OF BEDROCK,CONTOUR INTERVAL 20 FEET OTHER: NOTES _--+AT 20°INTERVALS 2a ANGESITE ¥,INCLUDES MINOR DACITE ANO LATITE +--SURFICIAL DEPOSITS >+MEOROCK /SURFICIAL DEPOSITS>BEOROCK -TOP OF BEOROCK CONTOUR INTERVAL 100 FEET,30°CONTOURS DASHED TOPOGRAPHY,CONTOUR INTERVAL SO FEET 9 SPRINGS OTES SURFICIAL DEPOSITS MODIFIED FAOM COE,1976. TOP OF BEOROCK CONTOURS ARE INFERRED BASED ON GEOLOGIC MAPPING ANO SUBSURFACE EXPLORATIONS,ANO ARE SUBJECT TC VERIFICATION THROUGH FUTURE DETAILED INVESTIGATIONS, -_"7_-=CONTOURS BELOW Et 1400 7GNRIVERAREA)ARE SHCA an)2000 400 FEET ae FIGURE 5.1 ACS From Acres (1981) REV DESCRIPTION BY DATE SCALE WARNING.Project No. 0%1 Fite 02/02/12_|-aliFTHISBARDOES [Designed NOT MEASURE 1* THEN DRAWING IS NOT TO SCALE Drawn STATE OF ALASKA ALASKA ENERGY AUTHORITY =>ALASKA@@--ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT WATANA DAM SITE TOP OF BEDROCK AND SURFICIAL GEOLOGIC MAP FIGURE FIGURE 12 149°30'0"W 149°0'0"W 148°30'0"W 148°0'0"W 147°30'0"W 63°0'0"NOQS,Wilson et al.,1998 Cwilgon et.al.,2009 .Qs t,-6 eeyy&:Rees 9-oe ge ">" OFANa "Pom La o>aio .en _fe =eetaL”ar: sie ns ae."sie TW 62°30'0"Nvs -on a ;a2 Geology from Wilson et al.,1998 (USGS Open-File Report 98-133) and Wilson et al.,2009 (USGS Open-file Report 2009-1108)See Figure 13B for map legend SCALE WARNING Project No.STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 0 %1 Tou,02/02/12 ,GRO ALASKA ENERGY AUTHORITY IF THIS BAR DOES =Designed_____BW oe -a =<ALASKA SITE REGION GEOLOGY FIGURE 13A NOT MEASURE 1”mS a =THEN DRAWING Is J>' |---_____|@=_ENERGY AUTHORITYDESCRIPTIONBY|DATE NOT TO SCALE 1 a "g-:Ice fields or glaciers QUATERNARY DESPOSITS Surfical deposits,undifferentiated TERTIARY ROCKS Sedimentary Rocks Sedimentary rocks,unidivided Tn ;Nenana Gravel Tcb |Coal-bearing rocks Fluviatile sedimentary rocks and subordinate volcanic rocks Igneous Rocks Volcanic and Hypabyssal Rocks Tvu Tertiary volcanic rocks,undivided hf}Hypabyssal felsic and intermediate intrusions Hypabyssal mafic intrusions Intrusive Rocks CThf] Chol Granite and volcanic rocks,undivided EOCENE "Tegr|Granite and granodiorite PALEOCENE ..Tg j Granitic rocks TERTIARY AND/OR CRETACEOUS Igneous Rocks Intrusive Rocks [TKg]Granitic rocks Granodiorite,tonalite and monzonite dikes,and stocks Metamorphic Rocks TKgg Gneissose granitic rocks UNDIVIDED MESOZOIC ROCKS METAMORPHIC ROCKS iMzsa Schist and amphibolite Mzpcal Phyllite,pelitic schist,calc-schist,andamphiboliteoftheMcClarenmetamorphic belt Geology from Wilson et al.,1998 (USGS Open-file Report 98-133) and Wilson et al.,2009 (USGS Open-file Report 2009-1108) CRETACEOUS Melange Kmar|Melanges of the Alaska Range Limestone blocks Igneous Rocks Volcanic and hypabyssal rocks iKsva|Andesite subvolcanic rocks Intrusive Rocks [Kgu}Granitic rocks Granitic rocks younger than 85 Ma Ultramafic rocks CRETACEOUS AND/OR JURASSIC Sedimentary Rocks rkJs}Argillite,chert,sandstone,and limestone |KJf |Kahiltna flysch sequence cg;Conglomerate,sandstone,siltstone,shale, and volcanic rocks JURASSIC Igneous Rocks Mafic and ultramafic rocks Dad ]Alaska-Aleutian Range and Chitina Valley batholiths,undifferentiated Metamorphic Rocks JPaug Uranatina metaplutonic complex Sedimentary Rocks irri Limestone and marble [Jtk |Talkeetna Formation TRIASSIC Sedimentary Rocks ,Ircs |Calcareous sedimentary rocks Trk |Kamishak limestone Plutonic Rocks Gabbro,diabase,and metagabbro Volcanic Rocks Metamorphic Rocks Trn Metavolcanics and associated metasedimentary rocks Ci]Nikolai Greenstone and related similar rocks Crrnm] MESOZOIC AND PALEOZOIC Assemblages and Sequences 'JTrsu]Red and brown sedimentary rocks and basalt Utrct]Crystal tuff,argillite,chert,graywacke, and limestone Red beds 'TrDv|Volcanic and sedimentary rocks Serpentinite,basalt,chert and gabbro PALEOZOIC Assemblages and Sequences (Skolai Group) Eagle Creek Formation Station Creek and Slana Spur Fm., and equivalent rocks Teteina Volcanics Jpmu/Jpam P :PPast Streina metamorphic complex JPzmb,Marble Stratigraphic contact Shoreline or riverbank Ice contact (glacier limit) ---Lineament -_--Fault -Certain --Fault -Approximate ----Fault -Inferred easssanee Fault -Concealed --.Thrust fault -Certain -4- Thrust fault -Approximate ---4-Thrust fault -Inferred --4.-.4 Thrust fault -Concealed REV DESCRIPTION BY DATE SCALE WARNING Project No, 0%1 Voate 02/02/12 IF THIS BARDOES =gOesignedNOTMEASURE1”THEN DRAWING Ig J9rwn NOT TO SCALE ALASKA ENERGY AUTHORITY =ALASKA @@--ENERGY AUTHORITY/ STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT SITE REGION GEOLOGY LEGEND FIGURE FIGURE 13B A)Depth(km)60°N Bse'N 444°W ®150-200 km 50-=OoOo!150 200-McKinley block [ a -50 0 50 ss --- 100 TT ST IESEen 250 300 (A)Map of earthquakes showing location of cross section (dashed rectangle labeled C5)shown in (B),modified from Figure 5 of Ratchkovski and Hansen (2002).(B)Cross section (C5)of earthquakes,modified from Figure 6 of Ratchkovski and Hansen (2002).Triangle indicates approximate site location. STATE OF ALASKA ALASKA ENERGY AUTHORITY =ALASKAarENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MAP AND CROSS SECTION OF SUBDUCTION-ZONE EARTHQUAKES 02/02/12 FIGURE 14 Page 101 of 146 140°0'0"W150°0'0"W155°0'O"W160°0'0"145°0'0"W a wovv" WwW»O036g 5 ed ee fe ip& 2 N..0,00€9 N..0,0.09 N..0.002S 25=sEG)ETe I wT T s2 erik ZueoSAte} awtCEEe og <i < - g sulle5 a] Q < fe} 2™E 2D 4 Sc zZQ QaoS goO i oc 20 a> A tS aN Ww Ci 5228 : aS=5 oo a oO SofGofond = CcGySoESmoo 28538agWw geSENSS .mma aw,at xy ” WARAN : Ne ON hehae ON L. "ay € YA aS = -_ er tea) Jyyn ; £ rf oo o_ cos : oO- .gc.QoLS - a ee . . \. y :12 oto a Ce ee > = ; wy <6 Page 102 of 146 160°0'0"W 155°0'0"W 150°0'0"W 145°0'0"W 140°0'0"W T T Explanation M>6 per 100km?per 100 years x 10-4 []0-0.001 60°0'0"N63°0'0"Nz :{_]0.001000001 -0.01 © [7]0.010000001 -0.03 S [_]0.03-0.1 L__]0.100000001 -0.3 []03-1 [_]1.000000001 -3 -4 [__.]3.000000001 -10 \1 i From Wesson et al.(2007) ALASKA ENERGY AUTHORITYJ=ALASKAEEENEAGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT USGS INTRASLAB MODEL, 31-50 MI (50-80 KM) 02/02/12 FIGURE 16 Page 103 of 146 160°0'0"W 155°0'0"W 150°0'O"-W 145°0'0"W 140°0'0"W T 7 63°0'0"N60°0'0"NExplanation M>6 per 100km?per 100 years x 10-4 [__]0-0.001 [__]0.001000001 -0.01 [_]0.010000001 -0.03 4 [7]0.03-0.1 [__]0.100000001 -0.3 [|]0.3-1 [_]1.000000001 -3 (--]3.000000001 -10 E=3 10.00000001 -45 57°0'0"N!it From Wesson et al.(2007) STATE OF ALASKA ALASKA ENERGY AUTHORITY ==>ALASKAaENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT USGS INTRASLAB MODEL, 50-75 Ml (80-120 KM) 02/02/12 FIGURE 17 Page 104 of 146 c = E £ 2 3) a 2 ip) 18 16 14 Combined East DenaliA 13 and-Totschunda-]va slip rates 10 y 1 | 04 0 So 2002 RUPTURE EXTENT WA || -700 -600 -500 -400 -300 -200 -100 0 100 200 Distance from Denali Fault and Totschunda Fault Junction (km) Explanation -#-Central and western Denali fault slip rate --#-Eastern Denali fault slip rate -s8-Totschunda fault slip rate I Error bar STATE OF ALASKA ALASKA ENERGY AUTHORITY =>ALASKA/a ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT DENALI FAULT SLIP RATES 02/02/12 FIGURE 18 Page 105 of 146 hh Active (?)fault,lower Sonona Creek,offsetting U unconsolidated deposits. As shown above,Sonona Creek fault is 4.5 km long,and the site is 70 km to the west-northwest. From Williams and Galloway (1986). 02/02/12 STATE OF ALASKA ALASKA ENERGY AUTHORITY tm)[=a>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT SONONACREEKFAULTTRACE FIGURE19 Page 106 of 146 SUSITNA: oOlad - ftaO3 79) eettis 5 AsaBew! ype ajBoog wos4 psz5 = pO ft "he ol) pr rt] Easau:Oo7™E aZzOZzOip) FIGURE 2002/02/12 Page 107 of 146 9PL30gole6ed0 149°0'0"W 148°0'0"W ws Pay ina /|Za N >2it : y Explanation 4 @ "4WCC (1982)study location ay Butte Lake,p S --™Req.WCC (1982)tectonic feature G"EARWATERrdMOUNTAINS4we™™Fog Lakes graben fault Oem ee - }7 (interpreted from Glen,2007b) y b N..0.0.€9N..0,0€.29STATE OF ALASKA ALASKA ENERGY AUTHORITY /EALASKAHEENERGYAU SUSITNA-WATANA HYDROELECTRIC PROJECT SITE VICINITY TECTONIC FEATURES 02/02/12 FIGURE 21 yy,dy <'ame .-a ny @ : 63°- Legend (_]water [RB tr [=]Qu EB od {_]Ts Gl hd Cj El ion (T'gr El trwb El Tgn Brn EatKss (_]trPss WK EQ)TrMus ms 14MTstation0 **gravity station 0 '--By -1999-20026230725km+eo.a:a gravity stationes,pre-1999 ---*..= 149°148° Gravity =squares (1999-2000)and triangles;MT stations and potential field profiles =black lines A-A',B-B',and C-C';Qu =Quaternary sediments,undifferentiated;Ts =Tertiary nonmarine clastic sedimentary rocks;Tv =Tertiary volcanic rocks;Tgr =Tertiary granitoid intrusive rocks;Tgn =Tertiary gneiss and granitoid intrusive rocks,undifferentiated;TKss =Tertiary or Cretaceous sandstone;KJf = Jurassic to Cretaceous flysch,shale,sandstone,and conglomerate;Ja =Jurassic(?)argillite;Jtr = Jurassic trondjhemite;Jgd =Jurassic granodiorite;Jnd =Jurassic hornblende diorite;Jgn =Jurassic gneiss;Trwb =Triassic basalts of Whale Ridge;TrN =Triassic Nikolai Greenstone and gabbros;TrPss =Permian(?)to Triassic quartzosesedimentary rocks;TrMus =Mississippian to early Triassic siliceous and calcareous sedimentary rocks.Geology modified from Wilson et al.,1998,and unpublished U.S. Geological Survey mapping. Fog Lakes Graben Tgn neeesameounerenSusitna Lineament Range Front F.Grizzly F. D,U Ti rMu Transitional Crust [Resistive magnetic SY14Lt4hin Oceanic Crust Dense,magnetic NW A' 10 20 Distance (km) Simplified geologic map and cross section A'-A"along a transect through the northern Talkeetna Mountains, Modified from Figures 3 and 7 in Glen et al.(2007) 30 SE A' STATE OF ALASKA ALASKA ENERGY AUTHORITY = a_ BE ENEAGY AUTHORITYREEamerenarengEaPraep=etripreeSUSITNA-WATANA HYDROELECTRIC PROJECT SIMPLIFIED GEOLOGIC MAP AND CROSS SECTION 02/02/12 FIGURE 22 Page 109 of 146 OrtJOOL)ebed150°0'0"W 145°0'0"W paleant antintneet Explanation Fault Seismicity (Mw) 3 «3.0-3.9 ©40-49 73 @ 50-59 od:Outs Pr POONER 0h PS a ©60-69 ve :'.'J Ags O 70-79 iMod O 80-39 OL Be oe <*5 "Te >="rc ie 7 a O 90-92=4 aig z "«ty 7 ”;ge ].«(fp tfeer es:"5%,° itt tof oe !)4 &Note:Merged AEIC and USGS oe j catalogs,with earthquake relocations,as noted in text. Earthquake depths range from 0 to 126 km.N..0.0079o--O°44xa *si el eesNon=Seek ¢DEL E ia ; STATE OF ALASKA ALASKA ENERGY AUTHORITY =l=E>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT UNFILTERED UGRO EARTHQUAKE CATALOG 02/02/12 FIGURE 23 OvJOLLLe6eqa 150°0'0"W 145°0'0"W -reer 2 ted ecm i iy SicES enie a aeeetiIOtyanPeIAALloFeETN ExplanationaAtLrd:.laa -he me on nd Cp "ils ase.i ry.xtenLonseismicitys heed Say Ri ds MARGE cal a Sealesie Laiee a Fault ”4 "7 =e em roe -_---- sd=a Sonn pip tel,are SN sytedtuy .48%8 gM Tete aS e eten AE weyMID RS OE Md areAS2,Denali fault aftershock e a eo”.ZT 85°oe Xero nt ae th be VE tpl ser fomy::o . .%e os <9?* a Be OE GL NET he i g exclusion zone »4%«*n eo 9 ¢- *A?4 me gare 44 ft 2 oy Fee are NS +PA See Ee _A oo oe ALG a aor 3 Seismicity (Mw)-¢?=3 ok La Te °a o,f : ®VY ES Laer e ,4 4ASWgesnscaeesLes »30-39 oy e *e.- oo,*os ee oe *40-49 Give oe e 50-59 2 ie ta WE Leg ie ee4'Rory 4 ;ee Tt @ 60-69 e a spe . ;"@ "soeeteNeSSAB,Cental a aaa ys O 70-79 te Le.;i.og 6py,4e7 ex eten x)nye Oo 80-89 O 90-92 Note:Aftershocks of the 2002 Denali earthquake removed (aftershock exclusion zone),as noted in text. Earthquake depths range from 0 to 126 km.N..0.0.09NsuFSieiuteegsoToOREA |, os.ong ' a ye ar bdsm yo te 2MPOLSah?"iil STATE OF ALASKA ALASKA ENERGY AUTHORITY ta] =_ @aE_>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT DECLUSTERED EARTHQUAKE CATALOG 02/02/12 FIGURE 24 SHmax ____Strike-slip ____reverse reverse to strike-slip ___normal ____normal to strike-slip ____unknown SHmin ____Strike-slip ___reverse ___reverse to strike-slip ___normal ___.normal to strike-slip ___unknown Notes:1.Different faulting regimes are indicated by different colors. 2.BR -Brooks Range Cl -Cook Inlet DF -Denali fault DRF -Duke River fault KF -Kaltag fault TIF -Tintina fault ToF -Totschunda fault YB -Yakutat block 3.Open circles are locations of earthquakes used in the inversion. (a)Maximum horizontal stress SHmax (b)Minimum horizontal stress SHmin From Rupert (2008) STATE OF ALASKA ALASKA ENERGY AUTHORITY JE ALASKAaENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT STRESS TENSOR INVERSION RESULTS FROM CRUSTAL EARTHQUAKE FOCAL MECHANISMS 02/02/12 FIGURE 25 Page 112 of 146 Trend Plunge o1 95°10° o2 359°33° o3 200°55° South of cH we ]Denali Fault Eastern Castle Mnt.Fault Larger symbols (square,triangle,and circle)show locations of the best-fitting maximum,intermediate,and least stress axis,respectively.Black,maximum stress s1;red,intermediate stress s2;blue,least stress s3.Yellow circles shown on map are locations of crustal earthquakes. From Rupert (2008) STATE OF ALASKA ALASKA ENERGY AUTHORITY ==ALASKA/aE ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT STRESS TENSORS INVERSION RESULTS FOR INDIVIDUAL CRUSTAL DATA VOLUMES IN SOUTH CENTRAL ALASKA 02/02/12 FIGURE 26 Page 113 of 146 Northern Foothills Fold and Thrust Belt Areal Zones 63 0 63.2 63.4 63.6 63.8 64.0 64.2 0 °7...4 °rrr 7 .e aie &e 4 aaa « . a a .°ae a .7°* v _-¢.e Py - se. coe ?®ve *F ".'. h oa . . 18%.ot :»*"Rl.*°.-=en gg gg oe oe Me oe ee nn=10 °i 4 "2.oe oo ce.:x ¢@ a * £-_"Me "ae te?ive . .e=ee j Bgerg!3.'hed a6 *. s T *eo ee Ff ryaeeCadoGe....e .Pa °'"mee ah " .'4. e |bd a 'a 20 °20-km depth cutoff @ NFFTB West °4 (East and West) @ NFFTB East a e OVer”5km .a e ° A Ver >5 km a ae rv a 30 NFFTB areal zones,showing the 20-km depth cutoff used for both the East and West zone recurrence catalogs Southern Areal Background Zones 61.4 61.6 61.8 63.0 62.2 62.4 62.6 62.¢,Site 63.0 63.2 63.40©+A .°ee 'os e 'e a *-*4 °4,°''.ee "aa an 4 °bd e a"ry fe .eo.atJ22pary£.. |ary .e Py ry .oe?bd ..*oe °.°\ %°of Lebd...a ..i ° 10 =-+i *a= e oe °8 ° 2 *a&"e °e °ee?e .. = L °e .ene ee . |.ry e g ra . :e °°°°Pd °*e .e ”20 te,ar at tees .. "||@ SAB West Generali ''@ SAB Central _wStealzedsiab fs +|ws ee pone eee ee eneOeeo fd@SABEast'fos Ln SE a ee ee ; .23-km depth cutoff i .oe nn Fe a (Central and West only)©Var”5 km a |.|.e .e y.|4A Vor >5 km .|..°,°oe It NS -{j 30 T T T T t T a SAB areal zones,showing a schematic slab and the 23-km depth cutoff used for the Central and West zone recurrence catalogs. STATE OF ALASKA ALASKA ENERGY AUTHORITY JE NAIASUSITNA-WATANA HYDROELECTRIC PROJECT AREAL ZONE LATITUDE VS. DEPTH EARTHQUAKE PLOTS 02/02/12 FIGURE 27 Page 114 of 146 Depth(km)NFFTB West Depth Histogram NFFTB East Depth Histogram Count Count of 20.40 60 80 '100 0 0 20.40 60 80 190 13 [0.06]8 [0.44] 5 -5 - 64 [0.27]6 [0.33] 10 10+- 109 [0.47]3 [0.17] 15 154 = 47 [0.20]1 [0.06] -204 -=204 = E E == =254 -g 254 - a a o oO 9 304 HF =304 - 35-4 -35-4 - 40-4 -40-. 4544 -45+5 n =233 n=18 50 T T T I 50 T T T T T SAB West Depth Histogram SAB Central Depth Histogram SAB East Depth Histogram Count Count Count of 20.40 60 80 190 of 20.40 60 80 100 of 20 40 =60 80100 22 [0.31]17 [0.21]1 [0.06] 5 -5 -54 + 22 [0.31]19 (0.23]3 [0.16] 10 +10 -104 5 18 [0.25]25 [0.31]2 [0.10] 15 -15 -15++ 9 [0.12]15 [0.19]9 [0.50] 20-+Om 2044 +=204 - 1 [0.01]g 5 [0.06]E [1 (0.06) 25+Fg 254 FH =254 - o Fy 1 [0.06] 30-FH 68 304 +OF 30++ 35+-354 -854 - 40--40+-40+- 45+}-45-4 +H 454 5 n=72 n=81 1 [0.06]n=18 50 T T T T T 50 T T T T T 50 ee ee ee Depth histograms of events in each areal zone that have vertical errors <=5 km.These discrete distributions are used to model areal zone seismicity. STATE OF ALASKA ALASKA ENERGY AUTHORITY SKAxz[=ae ENFAGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT AREAL ZONE SEISMICITY DEPTH HISTOGRAMS 02/02/12 FIGURE 28 Page 115 of 146 971JOOL)ebed150°0'0"W 145°0'0'W oy aie Cs er teed noteMp mat Are,fed BF file ..vat a a A ee ale eer arkHe rots fi wl ae ph or Explanation a -ae tet :of dame S,a "4 menteyg 7 j ooo af pet ears sn tyes oisree A!ged Fault ee ON Nat UPS of aay a”os "13adte ae%ae SSa we oA AFC Seismicity (Mw)ted gh fed pean 4 ®at Se,OG et "Tre gow |at oe ih .wipe suger V4 Mp fo]e 30-39 " :ae :Wiz TL yey Ye ;=lis -a te ew!rd,|{@ 40-49eeeFas:sf =f a,1 =£.A .: > :43 Fa Ce 7 -at d iA re;,°5.0 -5.9 :hae ee a 2weeaf,a.a .oe,de "7 -ie eek a:Ba se sla Bs ee fo ftces MA.©60-69 wt v8:aeeekisPatt lng eu!fas 'at -,2 ©70-7.9 !irsoad on 'v=4%ml yy ,apptee Meagan aA a.aad ES :w e rm ry :vt 2 "teSamoAtcentralParfidesTOhphreea|eeaetgiv',ot aed Beaarrs Bs °ay SF at hl Ve Note:The 1912 event (yeltow circlea:a lies 8 a NSF ha ae,2 1 +..Pity bees!Pa if?.LEDBee \NE of site)is located in the 'de aay ai Lh,hf,¢eee Ding hang:of 'NFFTBWestzonebutis&ei ee oe IAG t - , .;..Bg ras ReSe)GE:'aoKeio di seer . YCite *%AA p,hay!\conservatively included in the'YS PD ad re ee=\4 love.oy a y *.:'Youle \SAB Central zone for theoir:om alTy,'hey TS esses)j recurrence calculation,as a ned ay ;"Wy 'i..Sasha ...Ke ae hy <ae SAB West BK as,aa discussed in text.Maximum pices Yn i)het Oe earthquake depths in each zoneynn/n oe!.Mg OY,P,<r ,r pe wae.sees Pay ap are discussed in text.N.0.0.2960 mi ; 60 km STATE OF ALASKA ALASKA ENERGY AUTHORITY = x a ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FINAL RECURRENCE CATALOGS 02/02/12 FIGURE 29 a ee NumberofEvents/Year=SoLs]T|TyPTriiiyTOTTinyTTPTT:f 7 Ms 1970 |t 10'S M4 1965 10° 10°S =M6 107 TT T T I I Time Prior to 2011 (years) STATE OF ALASKA ALASKA ENERGY AUTHORITY /EAASKAat_>ENF AGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MAGNITUDEVS.TIMEPRIORTO2011 02/02/12 FIGURE30 Page 117 of 146 IncrementalNumberofEventsperYearIncrementalNumberofEventsperYearincrementalNumberofEventsperYearSAB West Observation Maximum tikelihood fit 95%data bounds 95%model bounds DANRS REOEE ROBE OBO O EOE ee eee ee 3 1tonal1pinuulLpul1culaiuul35 4 45 5 55 6 65 7 75 8 Magnitude SAB Central Observation Maximum likelihood fit +95%data bounds '. ----95%model bounds + 35 4 45 5 55 6 65 7 75 8 Magnitude SAB East TTTTTMyTrrr=<Maximum likelihood fit +95%data bounds sy ----95%model bounds a Observation /a|ll45 5 Magnitude §5 6 65 7 ™Nonfor)3.5 4 02/02/12 STATE OF ALASKA ALASKA ENERGY AUTHORITY ==>ALASKA/E>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MAXIMUM LIKELIHOOD RECURRENCE CURVES FOR SAB AREAL ZONES FIGURE 31 Page 118 of 146 S 10!are rr errs er rr re rr iNFFTB Westa0210 Cc o >we 4071 rs) 8 + E 1072 =QO Observation AL240°3 -<Maximum likelihood fit ®+95%data bounds 5 ---95%model bounds 2 104 Prrrryprrrryprrrryrrerrprrrryprrrryprrrryprrrryprrerprerey 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 Magnitude -perelrrrirtipiertirszyzrtrrsrtliprrtlipprtipgerrtirertiienS101NFFTBEastoO [or2)10°c ® Go510 5 + He}E 10-2 =QO Observation .£.3]|Maximum likelihoodfit sAL@10+95%data bounds AL&----95%model bounds *s 2 1074 Prrrryprrrryprrrerprrrryrrrryprrrryrrrrprrreperreryperrey 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 Magnitude STATE OF ALASKA ALASKA ENERGY AUTHORITY (EAsAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MAXIMUM LIKELIHOOD RECURRENCE CURVES FOR NFFTB AREAL ZONES 02/02/12 FIGURE 32 Page 119 of 146 971JOOZLabegCRUSTAL FAULT MODEL pusra a a 02/02/12 FIGURE 33 a ee 152°0'0"W 148°0'O"W 144°0'0"W 4LAKES-GRABEN -"*Lee SOUTHHn pees Creek faultnents |neaeLy0Castleef:Bultae i: Explanation __Other crustal fault source (red =surface trace; yellow =down-dip projection) Denali Fault Crustal Sources 2002 rupture West of 2002 rupture @ummep Entire modeled Denali fault N..0,0.€9N..0,0.29STATE OF ALASKA ALASKA ENERGY AUTHORITY fe AREAENERGYAUT! SUSITNA-WATANA HYDROELECTRIC PROJECT AnnualProbabilityofExceedance|osoeOepiriiil1111ciiiilpoiiiilExplanation ----_Interface total stress Intraslab total -----Fog Lake graben faults -----Denali scenarios *--:-Castle Mtn.scenarios -Pass Creek-Dutch Creek fault vetreee Sonona fault ---Areal sources --Total 10 prrrrtTTTTTTFT}Peak Horizontal Acceleration (g)ReturnPeriod(years)STATE OF ALASKA /=AAaENERGYAUT ALASKA ENERGY AUTHORITY SKA MORITY SUSITNA-WATANA HYDROELECTRIC PROJECT HAZARD CURVES FOR PEAKAeeHORIZONTALACCELERATION a 02/02/12 FIGURE 34 Page 121 of 146 AnnualProbabilityofExceedancepiiiiilExplanation --Interface total - sorters Intraslab total ---Fog Lake graben faults ----Denali scenarios *--'-Castle Mtn.scenarios -Pass Creek-Dutch Creek fault verte Sonona fault 10 ----Areal sources --Total -prerrer'ySReturnPeriod(years)prrrrry=10° F 10° 0 0.5 1 1.5 0.50 Sec Spectral Acceleration (g) SUSITNA-WATANA HYDROELECTRIC PROJECT HAZARD CURVES GRo FOR 0.5 SECOND SPECTRALfesesACCELERATION $n 02/02/12 FIGURE 35 Page 122 of 146 AnnualProbabilityofExceedanceJrugruil|eeoeaExplanation Interface total Intraslab total Fog Lake graben faults Denali scenarios Castle Mtn.scenarios Pass Creek-Dutch Creek fault Sonona fault Areal sources Total TTTTTtTTTrTTTTTI|TTTTTTTTITrTTTT0.5 1.0 Sec Spectral Acceleration (g) 10 ReturnPeriod(years)-io)10 STATE OF ALASKA ALASKA ENERGY AUTHORITY =f=ENERGY KA AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT HAZARD CURVES Gra FOR 1.0-SECOND SPECTRALusesACCELERATION aS 02/02/12 FIGURE 36 Page 123 of 146 AnnualProbabilityofExceedance10 Explanation Interface total Intraslab total Fog Lake graben faults Denali scenarios Castle Mtn.scenarios Pass Creek-Dutch Creek fault - Sonona fault Areal sources Total 3,ReturnPeriod(years)-_,OoiN0.1 0.2 3.00 Sec Spectral Acceleration (g) 0.3 0.4 0.5 STATE OF ALASKA ALASKA ENERGY AUTHORITY (EAAAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT HAZARD CURVES FOR 3.0-SECOND SPECTRAL ACCELERATION 02/02/12 FIGURE 37 Page 124 of 146 > 2 bnm.a|ees.AccelerationResponse(g)2.5 1.5 0.5 ripziil 1 wm perptyppauyptaupitbaaimeer .mee mwoo-- a -"-"-- Explanation ----10000 yr --+-=5000 yr ce eeee 1000 yr ----250 yr ----100 yr veeto teetmtee Period (sec) STATE OF ALASKA ALASKA ENERGY AUTHORITY ALASKA=f=E>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MEAN UNIFORM HAZARD SPECTRA, TOTAL HAZARD 02/02/12 FIGURE 38 Page 125 of 146 RelativeContribution(%)100 foriiticsitiviitiveitirsitirirtrssitarsstiriitiiiad 90 |ne 80 7 -Fog Lake graben faults E70q-ere a ren scenarios Ea3 90 4 100 yrs 10,000yrs_-E 40 4 _ 30 4 E 20 =E 103 - ;0 a aaa LS 0 0.102 03 04 05 0607 08 09 1 Peak Horizontal Acceleration (g) STATE OF ALASKA ALASKA ENERGY AUTHORITY te)I=i ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT RELATIVE CONTRIBUTIONS, PEAK HORIZONTAL ACCELERATION 02/02/12 FIGURE 39 Page 126 of 146 RelativeContribution(%)portlettirirlipiscorobirrebarrsdeertacit-_Sofo]<=o”NoOOooO<=.7)=2oOoSoO<=”PIUTPErrryperrryrreeryverryrrerryrreryprreeprreryeere100 1 L L L |i n 1 L |n Explanation --Interface total uueeee Intraslab total ----Fog Lake graben faults ---Denali scenarios -----Areal sources 0.50 Sec Spectral Acceleration (g) STATE OF ALASKA ALASKA ENERGY AUTHORITY JE RASATHORITY SUSITNA-WATANA HYOROELECTRIC PROJECT RELATIVE CONTRIBUTIONS, 0.5-SECOND SPECTRAL ACCELERATION 02/02/12 FIGURE 40 Page 127 of 146 RelativeContribution(%)_©mMowotbaan®©©ooogo00000000-_hrope tyr re taorr rt trap r Pepa i tori i ti i EWERHEEFREESSERGECRETERRCCURREROGHEOROREOGREEExplanation Interface total Intraslab total Fog Lake graben faults Denali scenarios Areal sources .100 yrs 1000 yrs /_¥-77 Wt a -. 10,000 yrs TPUTUVPUITPVTeryrrreperrryyrerprrryyerrryryi<.<TT0 01 O02 0.3 0.4 0.5 mrrryprerrryprrrryprrrryprrr rp rer yp rr rs 0.6 1.0 Sec Spectral Acceleration (g) STATE OF ALASKA ALASKA ENERGY AUTHORITY ==>ALASKAaEENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT RELATIVE CONTRIBUTIONS, 1.0-SECOND SPECTRAL ACCELERATION 02/02/12 FIGURE 41 Page 128 of 146 RelativeContribution(%)1 00 L l l 1 |L 1 I l | ;Explanation F904-Interface total E 80 i ea Intraslab total P_ :-----Fog Lake graben faults E =----Denali scenarios 770J--Areal sources F 60 4 ; 50 4 100 yrs 10,000 yrs F 404 \=7 \304 \o..77art1acreC204ZR33.No 7 4 / "eke ee =10 :pe fen ssttirr it Sc ae FO.-y T T T EE 0 0.1 0.2 3.00 Sec Spectral Acceleration (g) STATE OF ALASKA ALASKA ENERGY AUTHORITY JE AaAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT RELATIVE CONTRIBUTIONS, 3.0-SECOND SPECTRAL ACCELERATION 02/02/12 FIGURE 42 Page 129 of 146 Zz9 § SS aN 28#2 SO z $_ nr 2D # reebsrcgk © eorpOkee s : Se ° = EOE KEOr an} law} = 92 aeo) «i535 mtOo 3 a>ReoOUF oo Ew 50 sWodh o 8n_§€ wiMiE SSE bm eas éG Eouse e boas SWE StS Meo 5°-8 2™ oeo> tO Lege 20052 72 S353 3 tlS a Eg_ hares 3 ee Ss SNBS EO 5<4 OSSS Ene N wo eat. ® , oa ° V9e.. pgOsaeBeHUE 0: SR@reas < CZSReEO4A & Zo N 5:03| ervr$$2 ys) rrrrrrre2 xOOtO6O8OLO09OFOFOFOFOF*UONNGINUOD % (Wed 2011 Oct 07 16:26:0 Page 130 of 146 1.000 sec.:10,000 year return period Target Amplitude:0.5791 g GMPE:BC Hydro,2011 Data file:gmt_dea Seismic Hazard Deaggregation Megathrust Watana Dam,AK gg.interface.1.000.bch11T.10k.txt 27:30 UONNGQHUOD % (Vad 2011 Oct0716IGM)| staot _ ZOwW 8KF Or& 3io) uw2D rer or320EO2OFkzLLse) Sagkezie z ao SOuD ER GOOF searens cluorgeekeHZOLal Hud 2k sik Ctcazc g g¢tirevu2E WE E> 20% O¢ 2© aseOS§Nfo) [ ]wge|& Page 131 of 146 0.500 sec.:2,500 year return period Seismic Hazard Deaggregation Intraslab Watana Dam,AK a' ig28 # }. rZ< Lu : oy igiS208:© o Ones Oiseau 295 isa5Moy ia aresugeyt Shi NON 'Wi S2o2c See LN)b 26eCeG Bde ()()9 2090 O*% a8! TOD i ges Ay OeNY, na§ Ba NOONONIN * 39 |(We 2011 Oct 07 15:00:33 g -+1 to +2 +0 to +1 -1 to +0 ]+2 to +3 06 52 02 Gl OlGF UONNGUIUOD % Page 132 of 146 3.000 sec.:10,000 year return period Target Amplitude:0.1995 g GMPE:Zhao et al.,2006 _deagg.intraslab.3.000.zh06I.10ktxtDatafile:gmt_dea; Seismic Hazard Deaggregation Intraslab Watana Dam,AK f f f La O€ GSE OF Gk Of UOUNGUUUOD % FIGURE 46 ALASKA ENERGY AUTHORITYJEALASKAE>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT DEAGGREGATION FOR THE INTRASLAB, 3.0-SECOND SPECTRAL ACCELERATION, 10,000-YEAR RETURN PERIOD 02/01/12 Page 133 of 146 J ;+1 to +2 +0 to +1 |-1 to +0 9 +2 to+3 Uipd 2011 Oct 07 15:02:22 AccelerationResponse(g)ritiil al. Explanation Period (sec) STATE OF ALASKA ALASKA ENERGY AUTHORITY = ex E>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT UHS AND CMS,MEGATHRUST, 10,000-YEAR RETURN PERIOD 02/02/12 FIGURE 47 Page 134 of 146 4aneff|AccelerationResponse(g)J L |oe Ga ||Ll i Lt L se ||1 | 274 Explanation = ]UHS r 4 PHA 5 5 ----0.5 sec r 1.57 .---1.0sec - 1-7 L 054 L 0 T TT fF |F J T T Tred |T 0.01 0.1 1 Period (sec) STATE OF ALASKA ALASKA ENERGY AUTHORITY =/BE ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT UHS AND CMS,INTRASLAB, 10,000-YEAR RETURN PERIOD 02/02/12 FIGURE 48 Page 135 of 146 - i -am mY "a me .a &..a a AccelerationResponse(g)=oO!ayil|jtfExplanation UHS e e@ @e CMSenvelope L PHA - ----05sec - ----1.0 sec TTTT]TTPeriod (sec) STATE OF ALASKA ALASKA ENERGY AUTHORITY JE ALASKAaEENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT UHS AND EXTENDED CMS, MEGATHRUST, 10,000-YEAR RETURN PERIOD, ALTERNATIVE 1 02/02/12 FIGURE 49 Page 136 of 146 =orye)-_|eeOeAccelerationResponse(g)2oL L roa aiiriil 1 i poitiil 1 Explanation UHS CMS envelope OOPeriod (sec) STATE OF ALASKA ALASKA ENERGY AUTHORITY JE ALASKAaENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT UHS AND EXTENDED CMS, MEGATHRUST, 10,000-YEAR RETURN PERIOD, ALTERNATIVE 2 02/02/12 FIGURE 50 Page 137 of 146 AccelerationResponse(g)1 i i |oe Ge |i iI 1 i ji}il L Explanation UHS 5 @ @ @ CMS envelope F- PHA r ---05sec ----1.0 sec Period (sec) STATE OF ALASKA ALASKA ENERGY AUTHORITY SE AAATHORHTY SUSITNA-WATANA HYDROELECTRIC PROJECT UHS AND EXTENDED CMS, INTRASLAB, 10,000-YEAR RETURN PERIOD, ALTERNATIVE 1 02/02/12 FIGURE 51 Page 138 of 146 AccelerationResponse(g)risiil 4 1 rari l 1 2on!1|a|Explanation UHS @ @ e CMS envelope PHA ----05sec ----1.0 sec TYYTfTTTTTT|T0.01 Period (sec) STATE OF ALASKA ALASKA ENERGY AUTHORITY ==>ALASKAaENEAGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT UHS AND EXTENDED CMS, INTRASLAB, 10,000-YEAR RETURN PERIOD, ALTERNATIVE 2 02/02/12 FIGURE 52 Page 139 of 146 AccelerationResponse(g)2.5 1.5 0.5 oe oe oe ||i Explanation 84th% Median 10,000 yr §000 yr 2500 yr 1000 yr 250 yr 100 yr riot 1 Lt ritetuppptippyLinusrrrryTrepprrrperryee om Period (sec) Red curves are intraslab deterministic hazard (M 7.5,50 km). Black curves are total hazard UHS. STATE OF ALASKA ALASKA ENERGY AUTHORITY ==>ALASKAaEENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT INTRASLAB DETERMINISTIC HAZARD COMPARED TO THE TOTAL HAZARD UHS FIGURE 5302/02/12 Page 140 of 146 AccelerationResponse(g)Na1.5 0.5 oO1 riiiil 1 wom __-=---__ ee)- Le ee ue resptianrrttirrrrterirttiiinnExplanation 84th% Median 10,000 yr 5000 yr 2500 yr 1000 yr 250 yr 100 yr rrerryporrreprerrryprrrrprrr.we ee Period (sec) Red curves are megathrust deterministic hazard (M9.2,78 km). Black curves are total hazard UHS. STATE OF ALASKA ALASKA ENERGY AUTHORITY ==>ALASKA ar ENFAGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MEGATHRUST DETERMINISTIC HAZARD COMPARED TO THE TOTAL HAZARD UHS 02/02/12 FIGURE 54 Page 141 of 146 AccelerationResponse(g)2.5 1.5 0.5 1 1 i puoi l 1 L ro er |l Explanation ---84th% --Median ocr ON ----10,000 yr /\-=--=5000 yr /.\-2500 yr/poe .,\\veeeees 1000 yr /7 "ON ----250yr .'100 yr TrTTTteyFrirft|1meee -_ -poodoraptaepataPa7rrryprerreryprerrtoo Period (sec) Red curves are Denali fault deterministic hazard (M7.9,72 km). Black curves are total hazard UHS. STATE OF ALASKA ALASKA ENERGY AUTHORITY JE ALASKA>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT DENALI FAULT DETERMINISTIC HAZARD COMPARED TO THE TOTAL HAZARD UHS 02/02/12 FIGURE 55 Page 142 of 146 AccelerationResponse(g)2.5 1.5 0.5 1 root 1 worereretypitpttapitbiait \7-o -”wee wre--”-__a ad -La ea ee - Explanation --84th% --Median ----10,000 yr --2500 yr oe 5000 yr -1000 yr 250 yr -100 yr rreryprrrryprrrryprrrryprrrPeriod (sec) Red curves are Castle Mountain fault deterministic hazard (M7.6,98 km). Black curves are total hazard UHS. 'STATE OF ALASKA ALASKA ENERGY AUTHORITY JENATHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT CASTLE MOUNTAIN FAULT DETERMINISTIC HAZARD COMPARED TO THE TOTAL HAZARD UHS 02/02/12 FIGURE 56 Page 143 of 146 GRO eis elBre3 mae 4|peer!AccelerationResponse(g)Nna1.5 0.5 oO1 1 terri l it tuiiriil L FoeeeGOGOaExplanation 84th% Median 10,000 yr 5000 yr 2500 yr 1000 yr 250 yr 100 yr rrryrrrprrrryprrrrpryPeriod (sec) Red curves are Fog Lake graben deterministic hazard (M7.0,7 km). Black curves are total hazard UHS. STATE OF ALASKA ALASKA ENERGY AUTHORITY ==>ALASKAaENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FOG LAKE GRABEN DETERMINISTIC HAZARD COMPARED TO THE TOTAL HAZARD UHS 02/02/12 FIGURE 57 Page 144 of 146 AccelerationResponse(g)riiricl 1Na a"2 woo /N /\ /. \ /"ON,\1.5 /NOON /74 . /, fs a 1 oT ae"- comer 0.5 weet'wm mee WwielopiabaPatt-"ae me-:---_oO --__--_-o "- A \X 84th% *K Explanation ----10,000 yr 5000 yr -2500 yr 1000yr ----250yr ----100yr Target % Median torfT|TOYfFFT|TTFTlTorTF|TTTt e,mee Period (sec) Red symbols are Southern Alaska Block Central areal source deterministic hazard (see Table 16 for magnitudes,distances,and epsilon values).Black lines are total hazard UHS. STATE OF ALASKA ALASKA ENERGY AUTHORITY = =”) EE FNERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT SOUTHERN ALASKA BLOCK CENTRAL PERIOD- DEPENDENT DETERMINISTIC HAZARD COMPARED TO THE TOTAL HAZARD UHS 02/02/12 FIGURE 58 Page 145 of 146 AccelerationResponse(g)Na1.5 0.5 ruil it ome FeOO'NExplanation 84th% Median ---10,000 yr 5000 yr 2500 yr 1000 yr ---250 yr 100 yr Period (sec) Red lines are Southern Alaska Block Central single-earthquake deterministic hazard (M6.6,Rrup =15 km,Rjb =10 km).Black lines are total hazard UHS. STATE OF ALASKA ALASKA ENERGY AUTHORITY =[=aE ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT SOUTHERN ALASKA BLOCK CENTRAL SINGLE EARTHQUAKE DETERMINISTIC HAZARD COMPARED TO THE TOTAL HAZARD UHS 02/02/12 FIGURE 59 Page 146 of 146 -z-..SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-01-0004-120224 Appendix A -TIME-DEPENDANT CALCULATIONS Cover Page -Zz-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120217 Appendix A -TIME-DEPENDENT CALCULATIONS 1.0 TIME-DEPENDENT CALCULATIONS A time-dependent occurrence rate for a seismic source supports the concept that if the last earthquake occurred recently,the longer it will be until the next one,and vice versa.These rates thus should be lower and higher,respectively,than the average (Poissonian)rate.For this study we have employed time-dependent rates for three sources:the megathrust,source of the 1964 M 9.2 earthquake,and two sections of the Denali fault.The eastern part of the Denali ruptured in 2002,but the western part,from paleoseismic evidence,has not ruptured for about 600 years.The Poissonian rate is simply the reciprocal of the average interevent time,and is constant from year to year. Two time-dependent models are utilized here,the lognormal model,and the Brownian Passage Time (BPT)model (Matthews et al.,2002).The lognormal model assumes that interevent times are lognormally distributed about a mean value,with a standard deviation. The BPT model is more complex,and claims to be more realistic in modeling interevent times. Each requires a parameter quantifying the uncertainty in interevent times.For the lognormal it is sigma (c),the standard deviation,and for the BPT it is alpha,the "aperiodicity parameter'. In California (Cramer et al.,2000)and Cascadia (Petersen et al.,2002)co was found to be about 0.5.The BPT alpha parameter is more difficult to quantify,but here we also use 0.5,as suggested in Petersen et al.(2002).The other two parameters both models require are the exposure period,in this case the life of the structure,and the number of years since the last earthquake exposure to the hazard begins. Results from the two time-dependent calculations were weighted equally.The time-dependent and Poissonian rates were weighted 0.67 to 0.33.In other words,it was felt that the time- dependent scenarios were twice as likely as the non-time-dependent scenarios. Table A-1 shows the input parameters and calculation results for the three sources.An exposure period of 150 years was assumed as the life of the structure,and a time-to-construct of 10 years from 2011. Figure TD1 shows probability of occurrence in the 150-year window on the y-axis,and probability of occurrence during that window as a function of fractional time into the average repeat time on the x-axis,for the megathrust source.The assumed "start date”,i.e.,initiation of dam operation,is shown as the red triangle.The 150-year occurrence probabilities from the start date are the intersections of the vertical projection of the start date with the three model results.It can be seen that since we are only 10%into the cycle,the probability of occurrence Page A1 of A6 02/17/12 -Ze-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120217 is very low.Those values are shown in Table A-1 rows 6 and 11..The Poissonian rate for a 150-year window is shown in row 5.The annual rates for the two time-dependent models are shown in rows 7 and 10.The ratios of the time-dependent rates to the Poissonian rate are in rows 8 and 11.These ratios are quite low.Row 12 contains the final weighted annual rate for the source,and row 13 contains the ratio of the final rate to the Poissonian rate.For the megathrust source the final rate is 63%of the Poissonian rate,or an effective return period of 886 years (row 14). Similar figures for the Denali-2002 Rupture and Denali-West of 2002 Segment are shown in TD2 and TD3.TD2 appears similar to TD1,but the long elapsed time since last rupture on the Denali-West of 2002 segment is evident in TD3.Table A-1 indicates an effective annual rate of 1/866 for the megathrust event,1/633 for the Denali-2002 segment,and 1/253 for the Denali- West of 2002 segment. Table A-1.Time-Dependent and non-Time Dependent (Poissonian)Rates Megathrust |°Rupture._|2002 Rupture1|Maximum magnitude 9.2 7.9 7.9 2 |Return period for maximum magnitude (years)560 398 380 3 |Years since most recent event 27 9 625 4 |Poissonian annual frequency 1.79e-3 2.51e-3 2.63e-3 5 |150-yr P(occurrence),Poissonian 0.235 0.314 0.326 6 |150-yr P(occurrence),lognormal 0.024 0.044 0.518 7 |Annual rate,lognormal 1.60¢e-4 2.93e-4 3.45e-3 8 |Ratio,lognormal to Poissonian 0.090 0.117 1.31 9 |150-yr P(occurrence),BPT 0.030 0.059 0.590 10 |Annual rate,BPT 2.00e-4 3.93e-4 3.93e-3 11 |Ratio,BPT to Poissonian 0.031 0.156 1.49 12 |Weighted annual rate'1.13e-3 1.61e-3 2.69e-3 13 i iPoissonian (non time dependent)annual rate 0.632 0.600 1.50 14 |Final effective return period (years)886 633 253 Note:(1)Lognormal and BPT weighted equally,time-dependent vs.Poissonian weighted 0.67 -0.33. 2.0 REFERENCES Cramer,C.H.,M.D.Petersen,T.Cao,T.R.Toppozada,and M.S.Reichle,2000.A time- dependent probabilistic seismic-hazard model for California.Bulletin of the Seismological Society of America 90,1-21. Page A2 of A6 02/17/12 -z..SUSITN A-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120217 Matthews,M.V.,W.L.Ellsworth,and P.A.Reasenberg,2002,A Brownian Model for Recurrent Earthquakes:Bull.Seismol.Soc.Am.,92,2233-2250. Petersen,M.D.,C.H.Cramer,and A.D.Frankel,2002.Simulations of seismic hazard for the Pacific Northwest of the United States from earthquakes associated with the Cascadia subduction zone.Pure and Applied Geophysics 159,2,147-2,168. Page A3 of A6 02/17/12 -Z-SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-00-0000-000000 M 9.2 0.6 1 1 i 1 1 J 1 1 1 0.5 5 L o ne )Lee ©eo 3 0.4 -cee r O -of ©7 4Fat 0.3 5 / i gs / <4 / a.7. ®0.27 foe r _/: rs foo 0.14 ye F y Poissonian oe Lognormal,sigma =0.5/Start Date ---BPT,alpha =0.5 0 --T T T T T T T T T 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Start Time -Fraction of 560 yr Return Period Figure A1.150-year probability of occurrence of M 9.2 megathrust. Page A4 of A6 10/14/11 -Z- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-00-0000-000000 Denali -2002 Rupture 0.7 i 1 !1 1 1 1 1 1 Poissonian ore nes Lognormal,sigma =0.5 0.64|---BPT,alpha=0.5 L ®Der TT -2 - ®0.5-y ee,L 5 a 8 /O 5 0.44 yo F 2 so '9 /.Ss 7 7°0.3 7 /a if 7 . L / o 0.27 /.br re)a a a0.17 ye L fe 0 ¥Start Date T T T T T T T T 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Fraction of 398 yr Return Period Figure A2.150-year probability of occurrence of M 7.9 Denali-2002 rupture. Page A5 of A6 10/14/11 -Z-SUSITNA-WATANA HYDROELECTRIC PROJECT ALASKA ENERGY AUTHORITY AEA11-022 TM-00-0000-000000 Denali -West of 2002 Rupture 0.7 1 1 1 1 i J i if 1 Poissonian me Lognormal,sigma =0.5 0.64/---BPT,alpha=05 2 |0 Le F o "7 2 Fee,®0.57 yo F 5 7 8 / O 7 6 0.47 /F 2 / =/ 8 7 o 0.3 7 / L oO / 3 /2oS0.24 F re)/ y- O14 7.b a . Start D 0 T T T T T T T Ww a ate 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Fraction of 380 yr Return Period Figure A3.150-year probability of occurrence of M 7.9 Denali-west of 2002 rupture. Page A6 of A6 10/14/11 -Z--.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Appendix B -DEAGGREGATION STACK PLOTS Cover Page 10/14/11 Watana Dam,AK Seismic Hazard Deaggregation SAB Central Areal Zone PHA:10,000 year return period Target Amplitude:0.3177 g GMPE:Atkinson and Boore,2008 Data file:gmt_deagg.centralzone.0.000.nga_ab08.10k.txt UOHNGHUOT) % LEWD]2011 Oct 11 09:21:32 | Page 1 of B88 Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK PHA:10,000 year return period Target Amplitude:0.3177 g GMPE:Abrahamson and Silva,2008 Data file:gmt_deagg.centralzone.0.000.nga_as08.10k.txt g9+@850UOUNGUIUOT % LeWp]2011 Oct 11 09:21:40 | B88Pa GMPE:Campbell and Bozorgnia,2008 Data file:gmt_deagg.centralzone.0.000.nga_cb08.10k.txt PHA:10,000 year return period Target Amplitude:0.3177 g Seismic Hazard Deagegregation SAB Central Areal Zone Watana Dam,AK 894UONNGINUOD % Wp]2011 Oct 11 09:21:48 | Page 3 of B88 Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK PHA:10,000 year return period Target Amplitude:0.3177 g GMPE:Chiou and Youngs,2008 Data file:gmt_deagg.centralzone.0.000.nga_cy08.10k.txt f 7 7 7 7 7 7 7 7 KA UOMNGIMUOT % LEWpy 2011 Oct 11 09:21:56 | 388Pag Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK 0.500 sec.:10,000 year return period Target Amplitude:0.3969 grr rr rya ny Es} GMPE:Atkinson and Boore,2008 Data file:gmt_deagg.centralzone.0.500.nga_ab08.10k.txt UOHNGQUHUOT) % 2011 Oct 11 09:22:04 | Page 5 of B88 0.500 sec.:10,000 year return period Data file:gmt_deagg.centralzone.0.500.nga_as08.10k.txt Seismic Hazard Deaggregation SAB Central Areal Zone Target Amplitude:0.3969 g GMPE:Abrahamson and Silva,2008 Watana Dam,AK UOWNGHUOT) % 2011 Oct 11 09:22:12 388Pag Data file:gmt_deagg.centralzone.0.500.nga_cb08.10k.txt 0.500 sec.:10,000 year return period GMPE:Campbell and Bozorgnia,2008 Seismic Hazard Deaggregation Target Amplitude:0.3969 g SAB Central Areal Zone Watana Dam,AK 89PYOHNYHUOTD) % 2011 Oct 11 09:22:19 Page 7 of B88 0.500 sec.:10,000 year return period Data file:gmt_deagg.centralzone.0.500.nga_cy08.10k.txt Target Amplitude:0.3969 g GMPE:Chiou and Youngs,2008 Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK GP jGg=FUONNGYHUOD % 2011 Oct 11 09:22:27 388Pag Watana Dam,AK Seismic Hazard Deaggregation SAB Central Areal Zone 1.000 sec.:10,000 year return period Target Amplitude:0.1973 g GMPE:Atkinson and Boore,2008 Data file:gmt_deagg.centralzone.1.000.nga_ab08.10k.txtne fYONNYHUOTD) % Cea]2011 Oct11 09:22:35 Page 9 of B88 1.000 sec.:10,000 year return period Data file:gmt_deagg.centralzone.1.000.nga_as08.10k.txt Seismic Hazard Deaggregation SAB Central Areal Zone Target Amplitude:0.1973 g GMPE:Abrahamson and Silva,2008 Watana Dam,AK rr a ee Es UONNGQUBUOD % +2 to +3 +1 to +2 +0 to +1 -1 to +0 Epsilon (€,) LEWD]2011 Oct11 09:22:41 B88Pag: Data file:gmt_deagg.centralzone.1.000.nga_cb08.10k.txt 1.000 sec.:10,000 year return period GMPE:Campbell and Bozorgnia,2008 SAB Central Areal Zone Target Amplitude:0.1973 g Seismic Hazard Deaggregation Watana Dam,AK a a a s eeesee,easS YOHNYHUOTD % 2011 Oct 11 09:22:48 Page 11 of B88 1.000 sec.:10,000 year return period Data file:gmt_deagg.centralzone.1.000.nga_cy08.10k.txt Target Amplitude:0.1973 g GMPE:Chiou and Youngs,2008 Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK 894UONGUUOD % LEW]2011 Oct 11 09:22:56| B88Pag: Watana Dam,AK Seismic Hazard Deaggregation SAB Central Areal Zone 3.000 sec.:10,000 year return period Target Amplitude:0.0560 g GMPE:Atkinson and Boore,2008 Data file:gmt_deagg.centralzone.3.000.nga_ab08.10k.txta i a asay iN YONNGYBUOTD % eWay 2011 Oct 11 09:23:04 | Page 13 of B88 Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK 3.000 sec.:10,000 year return period Target Amplitude:0.0560 g GMPE:Abrahamson and Silva,2008 Data file:gmt_deagg.centralzone.3.000.nga_as08.10k.txt g9tZSy9UONNGUHUOT) % 2011 Oct11 09:23:12 B88Page Data file:gmt_deagg.centralzone.3.000.nga_cb08.10k.txt 3.000 sec.:10,000 year return period GMPE:Campbell and Bozorgnia,2008 Target Amplitude:0.0560 g Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK en a rs en,waa UOUNGUYLOD % eWay}2011 Oct 11 09:23:16 | Page 15 of B88 3.000 sec.:10,000 year return period Data file:gmt_deagg.centralzone.3.000.nga_cy08.10k.txt Target Amplitude:0.0560 g GMPE:Chiou and Youngs,2008 Seismic Hazard Deaggregation SAB Central Areal Zone Watana Dam,AK rr rsa a a UONNGYHUOD % 2011 Oct 11 09:23:21 B88Pag GMPE:Atkinson and Martens,2009 Data file:gmt_deagg.interface.0.000.am09.10k.txt Sex PHA:10,000 year return period Target Amplitude:0.8271 g Seismic Hazard Deaggregation Megathrust Watana Dam,AK rs a rsrersreiiseyee|UOUNGQUULIOD % +2 to +3 [:]-2 to -1 LEW]2011 Oct 07 16:25:39 Page 17 of B88 PHA:2,500 year return period Target Amplitude:0.5222 g GMPE:Atkinson and Martens,2009 Data file:gmt_deagg.interface.0.000.am09.2_5k.txt SQ Seismic Hazard Deaggregation Megathrust Watana Dam,AK rraa aya i ryieiers| UOHNGYHUOD % -1 to +0 |-2 to -1 LEW]2011 Oct 07 16:25:45 B88Pag: -83 UN, ESBobs (/NO45, ee BOOS qeeseit POISON S2Os PSs . IOSAUNOMIGUSINIININIIND(XOIINIOINIYOS UINIINININY | OOIINOINT C LININGTNOSIN ONINUNININONINININOSY.8 XONINOINIIMINONOYOXINONONIN,"6OXY(ONOi]s§"6,ONY ")OXYYEOINWEOYY eerigy rs a,iaeeyeTa!ie|UOYNGUUOTD % 2011 Oct 07 16:25:51 Page 19 of B88 PHA:10,000 year return period Target Amplitude:0.8271 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.0.000.bch11T.10k.txt Soy fo7ai77i77 ral fi OOL06O8OZ090GOFOFO72OL "0 UONNQINUOTD % B88Pag -2 to -1 2011 Oct 07 16:25:57 PHA:2,500 year return period Target Amplitude:0.5222 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.0.000.bch11T.2_5k.txt Sty fF fiEfLfiaiés7OOL0608OL09OGOFOFO02OL "0 UONNGUILIOTD % Page 21 of B88 tf -2 to -1 2011 Oct 07 16:26:03 § (/)Nal Bde (ISOS 5fg! LIXINOSoe se ONINLONONNINONINYONIN(XIINININ)(SINIIONINON)LNIONNON NINN)DOUGUXININONININISONYYNUN NOOSINUNDY"g OXONINOONQM, fDONG(/OM,YTo§"y4 UONINONOYWEY ettres Oy E95925 OOL0608OL0909OFOF02OL "0 UOUNQUUILIOTD % 2011 Oct 07 16:26:09 f B88Pag PHA:10,000 year return period Target Amplitude:0.8271 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Megathrust Watana Dam,AK ryryeyrsrsryeyayaerae|UOLNGQYYUOTD) % Data file:gmt_deagg.interface.0.000.zhO6T.1 0k.txt SSE -]-1 to +0 "4 -2to-1 eM)2011 Oct 07 16:26:13 | Page 23 of B88 PHA:2,500 year return period Target Amplitude:0.5222 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Megathrust Watana Dam,AK rrrsaaaa iyeyae / LOBNPHUOTD eo Data file:gmt_deagg.interface.0.000.zh06T.2_5k.txt Sey |-2 to -1 KEWpy 2011 Oct 07 16:26:17 B88Pag PHA:5,000 year return period Target Amplitude:0.6641 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Megathrust Watana Dam,AK OOLOGOFOZO09OGOFOFO€Ol "0 UONNGBUOD % Data file:gmt_deagg.interface.0.000.zh06T.5k.txt SS Soy SS +0 to +1 -1 to +0 CEQ]2011 Oct 07 16:26:23 Page 25 of B88 Seismic Hazard Deaggregation Megathrust Watana Dam,AK nson and Martens,2009 agg.interface.0.500.am09.10k.txtomOD 0.500 sec.:10,000 year return period Target Amplitude:1.0038 g GMPE:Atk Data file:gmt_d ti)OOL0608OL0906OF0602OL%yUOWNQUUILIOTD % =SS85 +2 to +3 |+1 to +2 +0 to +1 1 to +0 2 to -1 Leb]2011 Oct 07 16:26:29 B88Page 0.500 sec.:2,500 year return period GMPE:Atkinson and Martens,2009 Target Amplitude:0.6179 g Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.0.500.am09.2_5k.txt Sty rrrsrsrraa i ieie ef UOUNGQUIIUOD % +2 to +3 ]-2 to -1 CWa}2011 Oct 07 16:26:35 | Page 27 of B88 0.500 sec.:5,000 year return period Target Amplitude:0.7969 g Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.0.500.am09.5k.txt Sex, GMPE:Atkinson and Martens,2009rrrraaaai ieieTe| UONNGLYUOD % B88Page +2 to +3 -2 to -1 LW]2011 Oct 07 16:26:41 | 0.500 sec.:10,000 year return period Target Amplitude:1.0038 g GMPE:BC Hydro,2011 Data file:gmt_deagg.interface.0.500.bch1 1T.10k.txt Soy SS Seismic Hazard Deaggregation Megathrust Watana Dam,AK rrrra,aaa aei eyre| UOUNGQUYLOD % 1-2 to -1 2011 Oct 07 16:26:46 Page 29 of B88 0.500 sec.:2,500 year return period Target Amplitude:0.6179 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.0.500.bch11T.2_5k.txt Sey rr rsesa ss esesaeTT| UONNGQUUOTD % B88Page +1 to +2 +0 to +1 -1 to +0 -2 to -1 +2 10 +3 2011 Oct 07 16:26:50 Epsilon (€,) 0.500 sec.:5,000 year return period Target Amplitude:0.7969 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.0.500.bch1]1T.5k.txt Sey aa sy aeeyee| YOHNGINUOTD % Page 31 of B88 1421043 KeWWp]2011 Oct 07 16:26:55 0.500 sec.:10,000 year return period Target Amplitude:1.0038 g Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.0.500.zh06T.10k.txt Sey GMPE:Zhao et al.,2006rrrya aa aeae ef is i UOMNGQUILIOTD % B88Pag -1 to +0 -2 to -1 Keuyay 2011 Oct 07 16:26:59 0.500 sec.:2,500 year return period Seismic Hazard Deaggregation Megathrust Watana Dam,AK xisabe\OOooOONoOSRssSNg iy 5 % ZaveER [) eas RY(} ES2! . aNé& y(} ee NY opa - landae /} EOS /} a aiaa aeisey|e| UOLNGQHUOT) % Page 33 of B88 +0 to +1 -1 to +0 "4 -2 to -1 KEW]2011 Oct 07 16:27:04 | 0.500 sec.:5,000 year return period Target Amplitude:0.7969 g GMPE:Zhao et al.,2006 Data file:gmt_deagg.interface.0.500.zhO6T.5k.txt Seismic Hazard Deaggregation Megathrust Watana Dam,AK OOLO06O8OL09OFOFOFOFOF " GONNGQHUOT) % +2 to +3 +0 to +1 -1 to +0 4-2 to -1 LEW]2011 Oct 07 16:27:09 B88Page nson and Martens,2009 agg.interface.1.000.am09.10k.txt "- © 1.000 sec.:10,000 year return period Target Amplitude:0.5791 g GMPE:Atk Data file:gmt_d Seismic Hazard Deagegregation Megathrust Watana Dam,AK +2 to +3 [+1 to+2 +0 to +1 1 to +0 2 to -1 2011 Oct 07 16:27:15 rrrr ys aeayae ef UONNGQIMUOTD % Page 35 of B88 5:2 ,()Oe) EBEo| (/)NO5% 3E92: ININUND 482B RNININONES eebedet of ANUNOINIININN SBerEL FMI)HOONOI ORNIINYUMEMiOIGONINTsODDOODIODONIININ)USOIINNIOSYNUNN NSONYY °s OSININONIND Dy¢'t ODY)NY)Pes*si)()ON)QCOROY eitiesr NA 55992 rrrseeeeeersaaeaaYVOHNGHUOD % LEW]2011 Oct 07 16:27:21 | B88Pag: 228 Ose ani Ln ee UXININO SS eeBST HNININO We gx88 PANINI)HNUNNINIINYUXOOMNININININT(NIINIONIININY(NOU MNININNNYUNININININININDNOXDNININONINONDUNOINIININDYDONONIONUNYOUI!SOONONOMINONOYNNONINIONINON,"4 UNOUINON"g OMNIMONOYNOY ae?2'er ONY eae Ss rya ne|| UOHNGHUOD % 2011 Oct 07 16:27:26 Page 37 of B88 1.000 sec.:10,000 year return period Target Amplitude:0.5791 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.1.000.bch11T.10k.txt Sox fT7f77FO FOP FBREQOL0608OL090GOFOF02OLaUOLNMYMUOD % B88Page +2 to +3 +1 to +2 -2 to -1 Kea]2011 Oct 07 16:27:30 1.000 sec.:2,500 year return period Target Amplitude:0.3421 g GMPE:BC Hydro,2011 Seismic Hazard Deagegregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.1.000.bch11T.2_5k.txt Soe rrrr sey5 ul YOHNYHUOTD % Page 39 of B88 +2 to +3 -1 to +0 4]-2to-1 KEW]2011 Oct 07 16:27:35 | 1.000 sec.:5,000 year return period Target Amplitude:0.4496 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.1.000.bch11T.5k.txt Soy, fwT tTvv7Fo Ff FfUR>7OOL0608OL090GOFOFOFOL "¢ UOMNGQUUOTDD % 'B88Pag +1 to +2 +0 to +1 -1 to +0 -2 to -1 |+2 to +3 2011 Oct 07 16:27:39 Epsilon (€,) 1.000 sec.:10,000 year return period Target Amplitude:0.5791 ¢ Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.1.000.zhO6T.10k.txt Sey GMPE:Zhao et al.,2006rraaaiia eyiTae| UONNGQUILUOT % Page 41 of B88 |-1 to +0 2011 Oct 07 16:27:43 1.000 sec.:2,500 year return period Target Amplitude:0.3421 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.1.000.zhO6T.2_5k.txt Lr TT 7FO FfOOLOGOfOL09OFOFOFOFOFUONNGQHUOT) % +2 to +3 'B88Pag +0 to +1 1-2 to -1 Epsilon (€,) ;+1 to +2 |-1 to +0 2011 Oct 07 16:27:49 1.000 sec.:5,000 year return period Target Amplitude:0.4496 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.1.000.zh06T.5k.txt Soy OOL0608OZ0905OFOFO02OL "0 UONNGIUUOTD % Page 43 of B88 +2 10 +3 {+1 to +2 +0 to +1 |-1 to +0 "|-2 to -1 2011 Oct 07 16:27:53 Epsilon (€,) fAp '. J§AUXXOXxO»1)41:yr|AXNNNWONXNiNfrJrr4;Ly4slL,ay tg'iyéO0L0608OLGyogavWY2§_ MD}20 14 Oa 07 16 27 57 | U0,WIN?QUILIO,D % B88Page 3.000 sec.:2,500 year return period Target Amplitude:0.1093 g Seismic Hazard Deaggregation Megathrust Watana Dam,AK GMPE:Atkinson and Martens,2009 Data file:gmt_deagg.interface.3.000.am09.2_5k.txt Sy, rsryaaa iyeyeTeTre|UONNGQHUOT) % +2 to +3 Page 45 of B88 +0 to +1 Epsilon (€,) |+1 to +2 |-1 to +0 f -2to-1 Leb]2011 Oct 07 16:28:02 | 3.000 sec.:5,000 year return period Seismic Hazard Deaggregation Megathrust Watana Dam,AK D_oOxSeNm2aeSSa - 7 8 \ Sat 10 ae355 /) =.e8 >() <<5 $(} gHe ,/}() apes &ses a)i) BeUOA vCNC)\Nd rsa rsa rereaea iea| ULONNGQHUOTDD % B88Pag +0 to +1 -1 to +0 -2 to -1 2011 Oct 07 16:28:07 3.000 sec.:10,000 year return period Target Amplitude:0.1995 g GMPE:BC Hydro,2011 Data file:gmt_deagg.interface.3.000.bch11T.10k.txt Soy Seismic Hazard Deaggregation Megathrust Watana Dam,AK 00L0608OL0909OF0E08OL%yUOUNGQUILIOTD) % Epsilon (€,) +2 to +3 +1 to +2 +0 to +1 -1 to +0 2011 Oct 07 16:28:13 Page 47 of B88 3.000 sec.:2,500 year return period Target Amplitude:0.1093 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.3.000.bch11T.2_Sk.txt Sey ryryrsaa a esaeie| UOMNGQLLULUOD % B88Pag -2 to -1 eWpb]2011 Oct 07 16:28:18| 3.000 sec.:5,000 year return period Target Amplitude:0.1490 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.3.000.bch11T.5k.txtrra rsa isi isryae UYOHNYHUOD % +2 to +3 +1 to +2 +0 to +1 Page 49 of B88 -1 to +0 Epsilon (€,) 2011 Oct 07 16:28:20 3.000 sec.:10,000 year return period Target Amplitude:0.1995 g Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.3.000.zh06T.10k.txt Sey GMPE:Zhao et al.,2006rrrsaaii iyieiere| UONNGYHMUOT) % 'B88Pag -1 to +0 4 -2to-1 KEW]2011 Oct 07 16:28:24 +0 to +1 3.000 sec.:2,500 year return period Target Amplitude:0.1093 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Megathrust Watana Dam,AK fééiaaééifi if OOLO06O8OL0908OFO€OZOL "0 UOUNGUILIOT % Data file:gmt_deagg.interface.3.000.zhO6T.2_5k.txt Soy SEES 2011 Oct 07 16:28:28 Page 51 of B88 3.000 sec.:5,000 year return period Target Amplitude:0.1490 g Seismic Hazard Deaggregation Megathrust Watana Dam,AK Data file:gmt_deagg.interface.3.000.zh06T.Sk.txt Sex, GMPE:Zhao et al.,2006fe7iiiZéf7ara7OOL0608OL09OGOFOFOFOL "o UOMNGLIUOT % f B88Pac +2 to +3 +1 to +2 +0 to +1 }-1to +0 -2 to -1 LEW]2011 Oct 07 16:28:33 Epsilon (€,) Seismic Hazard Deaggregation Intraslab Watana Dam,AK PHA:10,000 year return period Target Amplitude:0.8271 gOf GE OF GL OfG GMPE:Atkinson and Boore,2003 Data file:gmt_deagg.intraslab.0.000.ab031b.1 0k.txt UOUNGUIUOT % LEW]2011 Oct 07 14:58:55 Page 53 of B88 Data file:gmt_deagg.intraslab.0.000.ab03Ib.2_Sk.txt PHA:2,500 year return period Target Amplitude:0.5222 g GMPE:Atkinson and Boore,2003 Seismic Hazard Deaggregation Intraslab Watana Dam,AK HOON +1 to +2 +0 to +1 -1 to +0 Of GE OF Gk OL UONNGIUILOD % Leb]2011 Oct 07 14:59:00 | PHA:5,000 year return period Target Amplitude:0.6641 g Seismic Hazard Deaggregation Intraslab Watana Dam,AK Data file:gmt_deagg.intraslab.0.000.ab031b.5k.txt GMPE:Atkinson and Boore,2003Of G2 02GLOLGgUOUNOINUOD % gS KeQYp]2011 Oct 07 14:59:07 | Page 55 of B88 Watana Dam,AK Seismic Hazard Deaggregation Intraslab PHA:10,000 year return period Target Amplitude:0.8271 g GMPE:BC Hydro,2011 Data file:gmt_deagg.intraslab.0.000.bch1 11.10k.txt 06 G2 Of Gt OL UOUNGLUUOT % KEW]2011 Oct 07 14:59:14 | Watana Dam,AK Seismic Hazard Deaggregation Intraslab PHA:2,500 year return period Target Amplitude:0.5222 g GMPE:BC Hydro,2011 Data file:gmt_deagg.intraslab.0.000.bch111.2_5k.txt f i Z i 7 06 GF 02 Gt OL UOUNGQMUOT) % {+2 to +3 }+1 to +2 +0 to +1 -1 to +0 Epsilon (€,) LeWUp]2011 Oct 07 14:59:20 Page 57 of B88 PHA:5,000 year return period Target Amplitude:0.6641 g Data file:gmt_deagg.intraslab.0.000.bch]I1.5k.txt Seismic Hazard Deaggregation Intraslab .S<=5 > = a0O . a) ea) g oe) x) ®) S a, Q gS =Oo OSOMSONN) e ISO \ | : s ) §Beeeseres oeoeaoe B UOUNGQUULIOTD % B88Pag: PHA:10,000 year return period Target Amplitude:0.8271 g GMPE:Zhao et al.,2006 Data file:gmt_deagg.intraslab.0.000.zh06I.10k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK '\\ is +1 to +2 +0 to +1 1 to +0 Of GF Of Gl OL Fg UONNGQMUOTD % Page 59 of B88 KEW]2011 Oct 07 14:59:36 Seismic Hazard Deaggregation Intraslab PHA:2,500 year return period Target Amplitude:0.5222 g GMPE:Zhao et al.,2006 Data file:gmt_deagg.intraslab.0.000.zh06I.2_5k.txt Watana Dam,AK -1 to +0 f Uj Li LU f Of GE OF Gk Ob UOUNGQUUOTD % eV]2011 Oct 07 14:59:43| B88Pag: PHA:5,000 year return period Target Amplitude:0.6641 g GMPE:Zhao et al.,2006 Data file:gmt_deagg.intraslab.0.000.zh06I.5k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK y\\ -1 to +0 OF GE Of Gl OL¢ UONNGQIUUOTD % Page 61 of B88 2011 Oct 07 14:59:50 | Seismic Hazard Deaggregation 0.500 sec.:10,000 year return period Target Amplitude:1.0038 g Intraslab Watana Dam,AK Data file:gmt_deagg.intraslab.0.500.ab03Ib.10k.txt GMPE:Atkinson and Boore,2003 / i Li wa a OF GE OF Gh OF UONNGHUOTD % G KW]2011 Oct 07 14:59:55 B88Pag Seismic Hazard Deaggregation Intraslab Watana Dam,AK 0.500 sec.:2,500 year return period Target Amplitude:0.6179 gf / Ld ae y i Of GE OF GL OLG GMPE:Atkinson and Boore,2003 Data file:gmt_deagg.intraslab.0.500.ab03Ib.2_5k.txt UVOHNYUHUOD % 2011 Oct 07 15:00:01 Page 63 of B88 0.500 sec.:5,000 year return period Data file:gmt_deagg.intraslab.0.500.ab03[b.5k.txt Target Amplitude:0.7969 g GMPE:Atkinson and Boore,2003 Seismic Hazard Deaggregation Intraslab Watana Dam,AK f f ra Ll ra Of GF OF Gk ObG UOMNGQHUOTDD % Leb]2011 Oct 07 15:00:07 | B88Page 0.500 sec.:10,000 year return period Target Amplitude:1.0038 g GMPE:BC Hydro,2011 Data file:gmt_deagg.intraslab.0.500.bch111.10k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK Of SF OF Gk OF UONNGQIUOT % Le]2011 Oct 07 15:00:12| Page 65 of B88 0.500 sec.:2,500 year return period Data file:gmt_deagg.intraslab.0.500.bch111.2_5k.txt Target Amplitude:0.6179 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Intraslab Watana Dam,AK O€& GF OF Gk Ot UOMNGLUIUOT % LeWp]2011 Oct 07 15:00:20 | B88Page 0.500 sec.:5,000 year return period Target Amplitude:0.7969 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Intraslab Watana Dam,AK Data file:gmt_deagg.intraslab.0.500.bch111.5k.txt fo i LA YU? Of GZ O02 Gl OL FG UOMNGQMUOTD % Page 67 of B88 KEW]2011 Oct 07 15:00:27 Seismic Hazard Deaggregation Intraslab Watana Dam,AK 0.500 sec.:10,000 year return period Target Amplitude:1.0038 g Data file:gmt_deagg.intraslab.0.500.zh06I.10k.txt GMPE:Zhao et al.,2006Of GZ 02 Gl OL Gg UOUNGQUULIOT % KEWpI 2011 Oct 07 15:00:34 0.500 sec.:2,500 year return period Target Amplitude:0.6179 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Intraslab Watana Dam,AK Data file:gmt_deagg.intraslab.0.500.zh061.2_5k.txt f 7 7 i i v . 06 G@ O€ Gl OL Fg UONNGQUIUOTD % Q 2011 Oct 07 15:00:39 | Page 69 of B88 0.500 sec.:5,000 year return period Target Amplitude:0.7969 g GMPE:Zhao et al.,2006 Data file:gmt_deagg.intraslab.0.500.zh06I.5k.txt Intraslab Seismic Hazard Deaggregation Watana Dam,AK Of GZ Of Gl OLF UOMNGQIMUOTD % KEWpb]2011 Oct 07 15:00:45| B88Pag Watana Dam,AK 1.000 sec.:10,000 year return period Target Amplitude:0.5791 g Data file:gmt_deagg.intraslab.1.000.ab03Ib.10k.txt GMPE:Atkinson and Boore,2003 Seismic Hazard Deaggregation Intraslab O€ GZ Of Gl OL¢ UOUNGQIUOTD % Page 71 of B88 LeWbd 2011 Oct 07 15:00:51 | 1.000 sec.:2,500 year return period Data file:gmt_deagg.intraslab.1.000.ab03Ib.2_5k.txt Target Amplitude:0.3421 g GMPE:Atkinson and Boore,2003 Seismic Hazard Deaggregation Intraslab Watana Dam,AK 06 GE Of GL OL UOMNGQLIUOTD % 2011 Oct 07 15:00:56 B88Pag 1.000 sec.:5,000 year return period Data file:gmt_deagg.intraslab.1.000.ab03Ib.5k.txt Target Amplitude:0.4496 g GMPE:Atkinson and Boore,2003 Seismic Hazard Deaggregation Intraslab Watana Dam,AK Of G2 Of Gl OL¢ UOYNGQIUUOT % LEW]2011 Oct 07 15:01:02 | Page 73 of B88 1.000 sec.:10,000 year return period Target Amplitude:0.5791 g GMPE:BC Hydro,2011 Data file:gmt_deagg.intraslab.1.000.bch]11.10k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK KEW]2011 Oct 07 15:01:09| Of GZ Of Gl OL Fg UONNGIUOT % B88Page 1.000 sec.:2,500 year return period Data file:gmt_deagg.intraslab.1.000.bch111.2_5k.txt Target Amplitude:0.3421 g GMPE:BC Hydro,2011 Seismic Hazard Deaggregation Intraslab Watana Dam,AK 06 GZ Of GL OL Gg UOUNGIUOT) % ep]2011 Oct 07 15:01:16 | Page 75 of B88 1.000 sec.:5,000 year return period Target Amplitude:0.4496 g GMPE:BC Hydro,2011 Data file:gmt_deagg.intraslab.1.000.bch1 11.5k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK Of GF OF Gh OL UONNGHUOT) % 2011 Oct 07 15:01:23| B88Pag: 1.000 sec.:10,000 year return period Target Amplitude:0.5791 g GMPE:Zhao et al.,2006 Data file:gmt_deagg.intraslab.1.000.zhO6I.10k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK Of GF OF Gt Ob UOMNGHUOT % Wy 2011 Oct 07 15:01:29 Page 77 of B88 1.000 sec.:2,500 year return period Data file:gmt_deagg.intraslab.1.000.zh061.2_5k.txt Target Amplitude:0.3421 g GMPE:Zhao et al.,2006 Seismic Hazard Deaggregation Intraslab Watana Dam,AK O€& GF OF Gk OfG UONNGHNUOT) % revpy 2011 Oct 07 15:01:36 'B88Pag 1.000 sec.:5,000 year return period Target Amplitude:0.4496 g GMPE:Zhao et al.,2006 Data file:gmt_deagg.intraslab.1.000.zh061.5k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK / Li Li - 7 i ' Of GE OF Gk Ob GS UOYNNGQHUOTDD % Keb}2011 Oct 07 15:01:43 | Page 79 of B88 3.000 sec.:10,000 year return period Target Amplitude:0.1995 g Data file:gmt_deagg.intraslab.3.000.ab03Ib.1 0k.txt GMPE:Atkinson and Boore,2003 Seismic Hazard Deaggregation Intraslab Watana Dam,AK Of GZ Of Gl OL UOMNGLIUOD % 2011 Oct 07 15:01:49 | B88Page 3.000 sec.:2,500 year return period Target Amplitude:0.1093 g Seismic Hazard Deaggregation Intraslab Watana Dam,AK Data file:gmt_deagg.intraslab.3.000.ab03Ib.2_5k.txt GMPE:Atkinson and Boore,2003fv i if ra é OG GZ Of Gt OL UOUNGIUOD % KEW]2011 Oct 07 15:01:55| Page 81 of B88 3.000 sec.:5,000 year return period Seismic Hazard Deaggregation Target Amplitude:0.1490 g Intraslab Watana Dam,AK Data file:gmt_deagg.intraslab.3.000.ab03[b.5k.txt GMPE:Atkinson and Boore,2003OG G@ Of GL OL UONNQUILUOTD % LeWa]2011 Oct 07 15:01:59 | f B88Pac 3.000 sec.:10,000 year return period Target Amplitude:0.1995 g GMPE:BC Hydro,2011 Data file:gmt_deagg.intraslab.3.000.bch111.10k.txt Seismic Hazard Deaggregation Intraslab Watana Dam,AK Of GF OF Gl OL UONNGQIUUOT % LeWp]2011 Oct 07 15:02:05 | Page 83 of B88 3.000 sec.:2,500 year return period Data file:gmt_deagg.intraslab.3.000.bch111.2_5k.txt Target Amplitude:0.1093 g Seismic Hazard Deaggregation GMPE:BC Hydro,2011 Intraslab Watana Dam,AK Of GE OF Gk Ofg UONNGHUOTDD % 2011 Oct 07 15:02:12 | Watana Dam,AK Seismic Hazard Deaggregation Intraslab 3.000 sec.:5,000 year return period Target Amplitude:0.1490 g GMPE:BC Hydro,2011 Data file:gmt_deagg.intraslab.3.000.bch111.5k.txt Of GF OF Gl Ob UOUNGQUUODD % eXpy 2011 Oct 07 15:02:18 | Page 85 of B88 Watana Dam,AK Seismic Hazard Deaggregation Intraslab 3.000 sec.:10,000 year return period Target Amplitude:0.1995 g Data file:gmt_deagg.intraslab.3.000.zh06I.10k.txt GMPE:Zhao et al.,2006fo 7 i i aa Of GZ 0€ Gl OL UOMNGQIIUOT % G LEW]2011 Oct 07 15:02:22| "B88Pag 3.000 sec.:2,500 year return period Target Amplitude:0.1093 g Seismic Hazard Deaggregation Intraslab Watana Dam,AK Data file:gmt_deagg.intraslab.3.000.zhO06I.2_5k.txt GMPE:Zhao et al.,2006OF SE O¢ GI OL UOUNQUIUOD % LEW]2011 Oct 07 15:02:26| Page 87 of B88 Watana Dam,AK Seismic Hazard Deaggregation 3.000 sec.:5,000 year return period Target Amplitude:0.1490 g Data file:gmt_deagg.intraslab.3.000.zh061.5k.txt GMPE:Zhao et al.,2006 Intraslab Lj f oF ll SF OF Gk OL UOUNGQUUILIOD % 2011 Oct 07 15:02:31 | B88Page -ze-.SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-04-0000-120224 Appendix C -CONDITIONAL MEAN SPECTRA RESULTS Cover Page 02/24/12 C1 of 19 Interface,2500 yrs 1 1 i I |e oe a l 5 it 1 1 |ae Ge Ge I L --UHS BD i ea,Cs iris 0.01_sec a -J ----- 0.5_sec - ®1-"---=1.0_sec a ry Je ee Ce Pt 3.0_secoO4 L [oktop)4 . @o am 7 L neVY05frre ais -a .®Tee@QDITee L O O 4 LL <J L O T 1 LJ t TE d |Lj F T q TT POt?i |qT Period (sec) C2 of 19 Interface,2500 yrs L L iT L LL il L 7 L Lt Ll 1 -UHS )rr a,Cs Scere CMS_Envelope [ -J -----0.0_sec - ®1 |-_---0.5_sec 5 toe 1.0_sec Q.3.0_sec Tp)4 ®oc 4 S 5 er are =0.5-=0 -ip 2 eeeOo2 oO ©"a <A O T UJ T T |e one a |v UJ v v Torre l T 0.01 0.1 1 Period (sec) C3 of 19 Interface,2500 yrs rT iT L L Lj |L 1 L L Loi i i |lL -- UHS -,=Mm Fo fh NP ttt CMS_Envelope 4 -----_0.0_sec - D |_-_--0.5_sec Cc ee 1.0_sec Q 7 3.0_sec - "”)4 . ®'am -4 s a :60577-7777i40] -4 5 rn rrroOdeen i oOoO 7 . <,L O qT u i”ToT Tt |UJ u Lu T ToUnre |T 0.01 0.1 1 Period (sec) C4 of 19 AccelerationResponse(g)Interface,5000 yrs -onl-_-- -_---=--s-UHS a et eeees 0.0t_sec = ae 0.5_sec ---1.0_sec o---3.0_sec Period (sec) C5 of 19 AccelerationResponse(g)Interface,5000 yrs -ol!itwe time, UHS CMS_Enveiope 0.0_sec 0.5_sec 1.0_sec 3.0_sec 0 ahhh ee 0.01 0.1 Period (sec) C6 of 19 Interface,5000 yrs L 1 |as en ee ee l i L rT ji id |1 4 --UHS - S 5 se A CMS_Envelope [L 4 ----- 0.0_sec 5 2 4 4 men +coe 0.5 sec 5 Cc J tore 1.0_sec _ Le)a.4 3.0_sec i @ 17 T oc -Ss c 4 L. S jeccit---- - =Tete I©wo 0.5 -a (ad)reerer - ©5oO1i<=Sy LJ LJ qT ToT tig |T U U re ee ee |Uy 0.01 0.1 1 Period (sec) C7 of 19 AccelerationResponse(g)-o1Ne)1LliiI|iTiLlL|LliTi11ianhInterface,10000 yrs a UHS 0.01_sec 0.5_sec 1.0_sec 3.0_sec soto TTTFTTtTTFTTTTTTTTYTfTTqPeriod (sec) C8 of 19 AccelerationResponse(g)Interface,10000 yrs NOi-O1©oO-- UHS ----- 0.0_sec ----0.5 sec toe 1.0_sec -_3.0_sec penne CMS_Envelope oct -sjit||oeGeenee||Leilaoeee|TTTYTfTIToTTFi|LjqTqTqT©Period (sec) C9 of 19 AccelerationResponse(g)Interface,10000 yrs 1 2 4 --UHS - a Cs PCC CMS_Envelope -- 7 -----0.0_sec - 7 ---05.sec rT 1 5 _I 'Soe 1.0_sec = ' 4 -3.0_sec 5 4 - re "NER .- 4 S.5SSf"Sal 0 T qT 1 TT Pry |t LJ Tv v Le a |Lj 0.01 0.1 Period (sec) C10 of 19 Intraslab,10000 yrs - UHS2_i -r,s Se CMS_Envetope [-- -4 ---0.0_sec i 2 -_--0.5_sec r £15-eee 5Q.4 .O_!5 a 4 5a)4 5oO|5 c 17 L [S)mon : =d 5 oO joni:aoDJ5 o 05-7 5 ®]- oO 4 - zt 4 Sa OT 4 i O q qT rorererry 1 qT rorerrrry T 0.01 0.1 1 Period (sec) C11 of 19 AccelerationResponse(g)Intraslab,10000 yrs -Ol|uk©onlLitrT1|L1ii|l11LlToTYT|TTTTTTTTTITTTTTT7)rerereryry qT qT qT 0.1 Period (sec) C12 of 19 Intraslab,5000 yrs 1O15 D A Ww + c J ve)Q.+ g 1- oc 4 =A 2 7 -_-_©@ 0.5 -3B A Oo 4 Oo 7< oom UHS CMS_Envelope 0.0_sec 0.5_sec 1.0_sec 3.0_sec T T Lj 0.1 Period (sec) C13 of 19 rrerery T T T AccelerationResponse(g)Intraslab,5000 yrs _-ol!ot tet -UHS r teens CMS_Envelope -----0.0_sec 5 -oo 0.5_sec 5 Pee Cn [nn -1.0_sec 3.0_sec rerererry T LJ rorerrryry T 0.1 1 Period (sec) C14 of 19 Intraslab,5000 yrs UHS r wen eeee 0.01_sec _ ---£0.5_sec L -_--1.0_sec ome 3.0_sec Oo 1.5 D J Y = Cc 4 Oo a +ob)1-'agi = 7 J Ao)7 S sao0.5-oO 4 (®)4 O <| 0 reeerrry T T rerererrry T 0.1 1 Period (sec) C15 of 19 Intraslab,2500 yrs 1 1 rt |esEeas ee l iT 1 L |ee Gee Gn |il 1 _UHS S ss ie CMS_Envelope [ 4 ----- 0.0_sec D |_+---0.5_sec Cc ome 1.0_sec Oo 4Q.3.0_sec Vv)4 ® 'am c 4 =0.5-is =4 ® @o a oOOo = <"SeAA O LJ T t qT ae a |T qT qT 7 TT fT rT T 0.01 0.1 1 Period (sec) C16 of 19 Intraslab,2500 yrs 1 lL L i Ltt l rt 1 rT i |ae os a E l L - UHSSBaeCMS_Envelope [--J ----£0.0_sec - D 1 =tm 0.5_sec Cc te 1.0_sec o 7 3.0_sec nO 4 . @ 'am 4 bas 5 4 . =0.5 -i _-5 & ®7 a oO O 7 . <|=.a O T u Lj v es ee a ||T T UJ qT TUrye |LJ 0.01 0.1 1 Period (sec) C17 of 19 AccelerationResponse(g)Intraslab,2500 yrs UHS see neee 0.01_sec ----- 0.5_sec _-1.0_sec toe 3.0_sec TT Terry T Ly ' 0.1 Period (sec) C18 of 19 Intraslab,10000 yrs UHS seneeee CMS_Envelope ---0.0_secN ---0.5_sec eo 1.0_sec -_olaoe|Ieeeee||aoeoelLed|i_3.0_sec _,aomee AccelerationResponse(g)(o>)onTvqTT|qTvv'|qTTTT|TTLjLf}O q i forerrryry]T LJ rorerrrry T 0.01 0.1 1 Period (sec) C19 of 19 -zw- SUSITNA-WATANA ALASKA ENERGY AUTHORITY HYDROELECTRIC PROJECT AEA11-022 TM-06-0004-120224 Appendix D -MERCALLI EARTHQUAKE INTENSITY SCALE Cover Page 02/17/12 Mercalli Earthquake Intensity Scale' Value Description of shaking severity |Not felt I Felt by people sitting or on upper floors of buildings. tI Felt by almost all indoors.Hanging objects swing.Vibration like passing of light trucks.May not be recognized as an earthquake. IV Vibration felt like passing of heavy trucks.Stopped cars rock.Hanging objects swing.Windows,dishes,doors rattle.Glasses clink.In the upper range of IV,wooden walls and frames creak. V Felt outdoors.Sleepers wakened.Liquids disturbed,some spilled.Small unstable objects displaced or upset.Doors swing.Pictures move.Pendulum clocks stop. Vi Felt by all.People walk unsteadily.Many frightened.Windows crack.Dishes, glassware,knickknacks,and books fall off shelves.Pictures off walls.Furniture moved or overturned.Weak plaster,adobe buildings,and some poorly built masonry buildings cracked.Trees and bushes shake visibly. Vil Difficult to stand or walk.Noticed by drivers of cars.Furniture broken.Damage to poorly built masonry buildings.Weak chimneys broken at roof line.Fall of plaster,loose bricks,stones,tiles,cornices,unbraced parapets and porches.Some cracks in better masonry buildings.Waves on ponds. Vill Steering of cars affected.Extensive damage to unreinforced masonry buildings, including partial collapse.Fall of some masonry walls.Twisting,falling of chimneys and monuments.Wood-frame houses moved on foundations if not bolted;loose partition walls thrown out.Tree branches broken. 1 Descriptions are shortened from:Richter,C.F.,1958.Elementary Seismology.W.H.Freeman and Company,San Francisco,pp.135-149;650-653._http://quake.abag.ca.gov/shaking/mmi/ Page D1 of D2 IX General panic.Damage to masonry buildings ranges from collapse to serious damage unless modern design.Wood-frame structures rack,and,if not bolted,shifted off foundations.Underground pipes broken. Xx Poorly built structures destroyed with their foundations.Even some well-built wooden structures and bridges heavily damaged and needing replacement.Water thrown on banks of canals,rivers,lakes,etc. Xl Rails bent greatly.Underground pipelines completely out of service. Xll Damage nearly total.Large rock masses displaced.Lines of sight and level distorted.Objects thrown into the air. Page D2 of D2 an ALASKA ENERGY AUTHORITY AEA11-022SUSITNA-WATANA HYDRO ENGINEERING FEASIBILITY REPORT Clean,reliable energy for the next 100 years. Appendix B3 Interim Crustal Seismic Source Evaluation 14-01-TM_Interim Crustal Seismic Source Evaluation Susitna-Watana Hydroelectric Project Alaska Energy Authority FERC Project No.14241 December 2014 -sN- . SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. Technical Memorandum 14-01-TM v0.0 Susitna-Watana Hydroelectric Project Interim Crustal Seismic Source Evaluation AEA11-022 .Fag -.eee Sean zx wets fvrede eye,Ob wh:8aieateWf.de'ahi dls ricepHEDRee1,oes Se or Prepared for:Prepared by: Alaska Energy Authority Fugro Consultants,Inc.for MWH 813 West Northern Lights Blvd.1777 Botelho Drive,Suite 262 Anchorage,AK 99503 Walnut Creek,CA 94596 January 20,2014 )f=ALASKA 16-1401-TM-012014 @@mi_)ENERGY AUTHORITY THIS PAGE INTENTIONALLY LEFT BLANK The following individuals have been directly responsible for the preparation,review and approval of this Report. Prepared by:Justin Pearce,Cooper Brossy,Mark Zellman,Dean Ostenaa Reviewed by:Mike Bruen,Carolyn Randolph Loar,Jeff Bachhuber Approved by:GWU Af.CL Michael Bruen,Geology,Geotechnical,Seismic Lead FELhl,Brian Sadden,Project Manager Approved by: Disclaimer This document was prepared for the exclusive use ofAEA and MWH as part of the engineering studies for the Susitna-Watana Hydroelectric Project,FERC Project No.14241,and contains information from MWH which may be confidential or proprietary.Any unauthorized use of the information contained herein is strictly prohibited and MWH shall not be liable for any use outside the intended and approved purpose. THIS PAGE INTENTIONALLY LEFT BLANK --zw ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. TABLE OF CONTENTS EXECUTIVE SUMMARY ........ccccccssssseecerenecenccccseceeeneeceensensnsssseseseceeecocaoageassnseeeeceesonsanssseesessneeeees 1 1.INTRODUCTION ...........cccsecceceessseeesseceseccecseenesceeenesseneasseceenneeseeeesaeassesssasouseseneausasenssonsness 1 1.1 Background 00...cccceescssseececcsssessessceeesessesscssscssscssconecesecsaseaesssseseseeesaseseeesesseeeseseresensaeeenees 1 1.2 -Scope Of Work...eee ecceesssessceeecseceesseeseesssesenssseeesssecnsssesesasessceeesesesenseeseeaseseneseeneeuaea 2 2.APPROACH......cccccscsccccccceccessenseersescccccccsccccessneseesscasocusccceseeeensecsccascsseeseesetesecosocecsssseueetes 4 2.1 Geospatial Data oo...eee cececeeeereceeeesscneessecseesseerseeseasseseeesneusesnesssessseseesseusesseeeaesseseeseseeeaees 5 2.2 Desktop Approach for Lineament Evaluation...ses sesecseessesesessensesseseeeessseseeseeeeeeenses 6 2.2.1 Criteria for Selection of Lineaments Requiring Further Analysis .............ee:eeeee 6 2.2.2 Criteria for Evaluation of Lineaments,Summer 2013 Field Investigation............9 3.FIELD DATA EVALUATION FRAMEWORK ..........::::secseeeeseeeeeeeecneneeeeenenenseessensenecseeuens 12 3.1 Post-Field Data Evaluation of DEM Data...eee ceccessecsecseceeseeesseeseeseeneesnseesaseeseseeenes 12 3.2.Role of Geomorphic Processes for Creating Apparent Lineaments......0.eee eeeeeeeeeeees 13 3.2.1 Subglacial Channels and Basal Erosional Processes..........scesesscesessceeseeseeseteneees 14 3.2.2 SOlAUCTION 0.eee eeeeeseesseeeeneceeeesseceseecenersseesscceseeesseeesesseatsseeeseeseaersaneeseesnseesaes 15 3.2.3 Other Processes and Landforms ...........eeceecccsseeescecencesneeeneeseneesaeeeseesseeseaseesesenaees 15 3.3 Age Datums and Detectability Limits 00...eceseesceceeseseeeseesesesseeeseesssesesscessoseeseees 16 3.3.1 Quaternary Geology Model...eeeeeesseceseeeeeseceseceessnecenaeeesaeeceseeeecseesecaeteeaes 16 4.OBSERVATIONS AND INTERPRETATIONS OF LINEAMENT GROUP6G...................19 4.1 Discussion of the Talkeetna Fault Trench Locations of WCC (1982)...eeeeeeeeceeseeeee 61 5.SUMMARY OF FINDINGS..........cccccsscscssssccssesssescnesenssnesenscecsssnssssveeusnenenececssssseserseseeoone 63 5.1 Unresolved Lineaments and Areas .........ceeeesceeeesecesseeeeseeeesneessscecsesaececesecseesersaeserseeersaes 65 6.REFERENCE G........ccccsccssssssssscsscesssessencaseuseensseesssccuccccesesesteeeseesecanscscceseeensessseasassocsaeass 78 INTERIM DRAFT Page i 01/20/14 SUSITNA-WATANA HYDRO -yz ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014Clean,reliable energy for the next 100 years. List of Tables Table 2-1.Principal Data Sets Utilized During the Lineament Mapping ...........c:cccccscesessssseeessesseseessesees 6 Table 2-2.Criteria for Delineating Lineament Groups .............:ececesseceseeeeseeeseacecceseeeeseesessesesscsueateneseeasees 7 Table 2-3.Desktop Evaluation Exclusion Criteria.........cccccsscsscssesccesscesesssesssesesessecessecsscsecseessscsscsasceusens 8 Table 2-4.Criteria for Desktop Geologic Evaluation of Lineament Group..............:cccseessreseseessseseeveeseees 9 Table 2-5.Field Team Geologic Data Collection Guidance .........ccccceccsssssscessessecsasessececescseessscssseseseness 10 Table 2-6.Criteria for Evaluation of Field Data .0.....ce ccccsscssccstecsscesseeessesssceesseeeseecseeseesssevssesesssseesens 11 Table 5-1.Summary of Lineament Groups and Areas...........ccccsessssssessessscessessscsssescesseesscesseressrasssceasenaees 64 Table 5-2.Lineament Data Summarized from Section 4.0.........cccccccssscsssccssseeeescssseceseesssccsccsssscssscsneeses 67 List of Figures Figure 1-1 Location Map Figure 1-2A Site Region Geology from TM-8 Figure 1-2B Site Region Geology Legend Figure 1-3 Land Ownership and Lineament Groups Figure 2-1 2013 GPS Tracks Figure 2-2 Example of Lineament Group Map Data Figure 2-3 Example of Lineament Group Photographs Figure 2-4 Example of Strip Maps Explanation Figure 2-5 Extent of Geospatial Data Figure 3-1 Sub-ice Channels Cut Through Interfluves,Scotland,and Example Sub-ice Channel Morphology Figure 3-2 Example Sub-ice Channels,Greenland Figure 3-3 Sub-ice Channels,Finger Lakes,New York Figure 3-4 Late Wisconsin Glacier Limits and Age Control Figure 4-1 WCC Trench T-1 Location Map Figure 4-2 Photographs of WCC Trench T-1 Site Figure 4-3 Maps and Photograph of WCC Trench T-2 Area INTERIM DRAFT Page ii 01/20/14 za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. APPENDICES Appendix A:Strip Maps and Photographic Documentation of Lineament Data Presented in FCL (2013) Appendix B:Strip Maps and Photographic Documentation of Lineament Data for Lineaments Mapped by Reger et al.(1990) INTERIM DRAFT Page iii 01/20/14 -za-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Explanation of Abbreviations AEA AEIC DEM FCL FERC GIS GPS INSAR Alaska Energy Authority Alaska Earthquake Information Center Digital elevation model Fugro Consultants,Inc. Federal Energy Regulatory Commission Geographic information system Global positioning system Interferometric synthetic aperture radar kiloannum (thousand years) kilometer last glacial maximum Light detection and ranging meter Million years Matanuska-Susitna Borough MWH Americas,Inc. Probabilistic seismic hazard analysis Roller-compacted concrete Reservoir-triggered seismicity Technical memorandum United States Geological Survey Woodward Clyde Consultants Explanation of Units Measurements in this report were made using the International System of Units (SI),and converted to English system for reference.For the conversions,the measurements reported in the English system were rounded off for simplification purposes.Both sets of numbers are presented for the reader,except in cases of very small numbers that are shown only using SI (i.e.metric). INTERIM DRAFT Page iv 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. EXECUTIVE SUMMARY The proposed Susitna-Watana Dam is a hydroelectric power development project planned for the upper Susitna River under the auspices of the Alaska Energy Authority (AEA)and the regulatory authority (among others)of the Federal Energy Regulatory Commission (FERC).Under subcontract to MWH Americas (MWH),Fugro Consultants,Inc.(FCL)is investigating and evaluating the seismic hazard in support of engineering feasibility,and the licensing effort for the Susitna-Watana Hydroelectric Project. This draft technical memorandum presents part of the continued seismic evaluations associated with the proposed dam,specifically a lineament field evaluation. In 2011,Fugro Consultants,Inc.(FCL)prepared a preliminary seismic hazard source model and probabilistic ground motion assessment based on desktop review of prior studies and recent literature (FCL,2012).Subsequent to the preliminary seismic hazard ground motions assessment,FCL completed lineament mapping based on interpretation of recently acquired,detailed,topographic data (i.e.,INSAR-and LiDAR-derived DEM data).The mapped lineaments were assembled into lineament groups,and evaluated in the office using semi-qualitative criteria to reject or select lineament groups for further investigation during the summer field season of 2013 (TM-8;FCL,2013).In total,22 lineament groups and three broader lineament areas were advanced to the field investigation phase in summer of 2013. The primary objective of the summer 2013 lineament evaluation was to document and interpret available field evidence for the presence or absence of potential shallow crustal seismogenic sources (faults)along features identified through previous lineament mapping,and evaluate the features' significance with respect to Quaternary faulting and their potential as seismic sources of significance to the Susitna-Watana Dam seismic hazard evaluations. The lineaments inspected were assessed based on geomorphological characteristics observed in the field and field geologic relationships around the lineaments.As guidelines for the field teams conducting the evaluation of individual lineament groups,a series of questions were developed as an aid to focus observations made during the field investigation.To evaluate the field data,a set of questions and criteria similar to those used by FCL (2013)for evaluation of the desktop findings were developed.The principal objective of these criteria is to guide judgments regarding the lineaments'origins in order to evaluate their potential association with Quaternary faulting and potential crustal seismogenic sources. The 2013 field activities and lineament evaluations highlighted three topics with broad impacts across several aspects of the lineament evaluations.These topics include:1)insights gained from field investigation and evaluations on the scale and resolution of DEM data,2)identification of the dominant geomorphic processes acting to modify the landscape,and 3)updated regional age estimates for late INTERIM DRAFT Page ES-1 01/20/14 -Zz-ALASKA ENERGY AUTHORITY .AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. Quaternary landscapes and events in south-central Alaska.Interpretations and evaluations of most lineament groups and individual features within these lineament groups are linked to key principles or limitations posed by data or concepts associated with these topics. Synthesis of previous studies and research of Alaskan glacial chronologies coupled with field observations on the type and distribution of glacial constructional and erosion landforms suggests that there are three broad age categories within which the landscape may be viewed.These are,from youngest to oldest:late Holocene,mid-to early Holocene,and post-late Wisconsin period of the late Pleistocene.It was judged that the preponderance of surficial geologic deposits are in the mid-to-early Holocene category,and thus are the limiting age for detecting Quaternary deformation. All lineament groups targeted for 2013 investigation received a low-altitude aerial observation,and ground inspection was completed at selected locations where features of interest were identified and ground access was permitted'.Based on the work to-date and access restrictions,the lineament groups are placed into four categories. e Category I.Lineament groups in category I were not advanced for 2013 field observations (FCL,2013),but where convenient,brief fly-overs in 2013 visually confirmed their placement in category I,with no further work suggested. e Category II includes the majority of the lineament groups and features evaluated in 2013. Lineaments in this category are judged to be 1)dominantly erosional in origin,2)related to rock bedding or jointing,or 3)to a lesser extent,a result of constructional geomorphic processes. This category is subdivided in to categories Ha and IIb.Category Ia lineament groups are those which are not evidently associated with bedrock faults.Category IIb lineament groups that do appear to be associated with bedrock faults (Category IIb).For both categories no further work is suggested. e Category III consists of lineament groups which are unresolved due to unavailable ground access in 2013,and field activities and further evaluation are deferred.This category includes investigation sites most relevant to evaluations of surface faulting for the dam site area and includes the WCC trench T-1 area,Fog Creek area,and dam site and reservoir vicinities. e Category IV includes lineament groups that have defensible justification for consideration or inclusion as crustal seismic sources in an updated seismic source model:lineament group 27 'Ground access was limited to state and federal lands.For lineament features on ANCSA lands,aerial observations were made during fly-overs however,no landings or ground access was undertaken INTERIM DRAFT Page ES-2 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. (Sonona Creek fault)and the Castle Mountain fault extension are the two lineaments in this category.No further field work is suggested. At present,this document is an interim work-in-progress pending further "boots on the ground”access. It is anticipated that right-of-way access will be granted in 2014 to allow further investigation of geologic or geomorphic features at and near the dam site to complete the lineament evaluation,evaluate additional LiDAR data under pending acquisition,as well as address potential for fault rupture at the dam site.Accordingly,this document will be updated and finalized based on completion of the field investigations and evaluation of the remaining features. INTERIM DRAFT Page ES-3 01/20/14 -zZ-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. 1.INTRODUCTION The proposed Susitna-Watana Dam is a hydroelectric power development project planned for the upper Susitna River under the auspices of the Alaska Energy Authority (AEA)and the regulatory authority (among others)of the Federal Energy Regulatory Commission (FERC).The proposed dam would be constructed near about River Mile 184 on the Susitna River,north of the Talkeetna Mountains near the Fog Lakes area.Current concepts envision a RCC dam approximately 715 feet high,impounding a reservoir with a maximum water surface elevation at about 2,050 feet.At this elevation,the dam would impound a reservoir of approximately 5,170,000 acre-feet. MWH Americas (MWH)is the prime contractor providing engineering and geotechnical services to AEA for the project development and submittal of licensing documents to the FERC.Under subcontract to MWH,Fugro Consultants,Inc.(FCL)is investigating and evaluating the seismic hazard aspects in support of engineering feasibility and the licensing effort for the Susitna-Watana Hydroelectric Project. 1.1 Background In 2011,Fugro Consultants,Inc.(FCL)prepared a preliminary seismic hazard source model and ground motion assessment based on a desktop review of prior studies and recent literature (FCL,2012). Subsequent to the preliminary seismic hazard ground motions assessment,FCL interpreted recently acquired,detailed,topographic data (i.e.,INSAR and LiDAR)to examine the regional landscape,vis-a- vis digital elevation models (DEM),for evidence of potential lineaments,faults,or geomorphic landforms suggestive of Quaternary faulting.Limited field ground truthing,including low-altitude fly- overs,was performed in late summer of 2012 to inspect and verify features identified by the desktop- based lineament mapping.The mapped lineaments were assembled into lineament groups (Figure 1-1), and analyzed in the office using semi-qualitative criteria to select lineament groups for further investigation during the summer field season of 2013.This analysis included lineaments identified by WCC (1980,1982)for the two-dam scheme at Devil's Canyon and Watana as originally envisioned in the 1970s and 1980s.In total,22 lineament groups and three broader lineament areas were advanced to field investigation phase in the summer of 2013.The desktop lineament mapping data,analysis,and selection of lineament groups for further investigation is documented in TM-8 (FCL,2013),as is a discussion of the regional geologic map data (e.g.,Figures 1-2A and 1-2B). In June 2013,MWH was informed that AEA would not acquire access to Native Village Corporation (ANSCA)lands in 2013 (Figure 1-3).Principally,this resulted in deferral of field studies and investigations at and near the dam site area to summer of 2014 as field activities were limited to aerial INTERIM DRAFT Page 1 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY ;AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. inspection.However,low-altitude fly-overs were performed,and investigative field tasks for lineament evaluations (e.g.,soil pits)could be conducted on the ground on state and federal lands. This interim technical memorandum presents part of the continued seismic evaluations associated with the proposed dam,specifically lineament field evaluation.At present this document is a work-in- progress pending further ground access for field investigations and mapping.It is anticipated that right- of-way access will be granted in 2014 to allow further investigation of geologic or geomorphic features at and near the dam site to complete the lineament evaluation,as well as to address the potential for fault rupture at or near the dam site.Accordingly,this document will be updated as necessary based on the additional future data acquired.The 2013 lineament evaluation,field observations and judgments of lineament groups,as well as recommendations for potential 2014 geologic evaluation activities to complete the crustal seismic source evaluation are presented herein. 1.2 Scope of Work The scope of work for 2013 FCL investigations is defined under MWH Task Orders T10502190-99468- OM dated March 11,2013 and T10502190-99894-OM dated July 1,2013.In general,the focus of the studies is continuation of the crustal lineament evaluation.Specific technical activities within the scope of work include development of field plans and logistics,health and safety plan update,geologic mapping,seismometer station site characterization through collection of Vs30 measurements of the rock mass,field geologic inspection of lineaments,assessment of the lineament feature origin,analysis of lineaments as potential crustal earthquake sources of project significance,and identifying and developing recommendations for lineament features that warrant additional field geologic characterization to complete the crustal seismic source evaluation.Other activities specified in the task order include review of earthquake monitoring data,interim probabilistic seismic hazard assessment (PSHA)sensitivity analyses,development of seismic design criteria framework,and work planning studies in support of project licensing.Findings related to most of these activities are reported separately and are not described in this technical memorandum. As envisioned originally for the crustal lineament evaluation,the 2013 scope of work included wintertime field geologic mapping and fault evaluation at the dam site,a late springtime geologic reconnaissance of lineaments advanced from the desktop study (FCL,2013),and summertime field investigation of potential crustal seismic sources or fault rupture hazards (e.g.paleoseismic trenching), based on the results of the winter and springtime efforts.Because of the unanticipated field right-of- way access constraints,the full scope of work as originally envisioned was modified to optimize the summer 2013 field season investigation on state and federal lands while ground access to key areas at and near the dam site situated on private lands was resolved. INTERIM DRAFT Page 2 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. This interim technical memorandum presents part of the continued seismic evaluations associated with the proposed dam,specifically lineament field evaluation,and is a work-in-progress pending further ground access for field investigations and mapping.The objectives of this interim draft TM are to:(1) document and interpret available field evidence for the presence or absence of potential shallow crustal seismogenic sources (faults)along features identified through previous lineament mapping;(2)ascribe an origin to the lineaments identified,(3)if considered a fault,evaluate field evidence for late Quaternary faulting;and (4)develop a conceptual geo-chronologic model for Quaternary deposits or surfaces in the study area. INTERIM DRAFT Page 3 of 81 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. 2.APPROACH The approach to the lineament evaluation,in general,consisted of desktop digital terrain mapping and analysis (i.e.,FCL,2013)complemented by field inspection and mapping in the summer of 2013 (this memorandum). The desktop lineament mapping and analysis report (TM-8;FCL,2013)describes the approach for mapping of individual lineaments across the Project area,100 km ( 62 miles)radius from the dam site, and assigning morphologic attributes to the individual lineaments.For that effort,criteria were established to provide a basis for delineating lineament groups (that is,aggregates of individual lineaments)that appear to have sufficiently extensive lateral continuity and geomorphic expression consistent with an origin by tectonic processes (FCL,2013).Additional criteria were developed to exclude lineament groups that were created by erosional or depositional processes (i.e.non-tectonic lineaments),lineament groups that are chiefly related to lithologic controls (i.e.,differential erosion), lineament groups that did not meet length and distance criteria,and lineaments that did not show consistent senses of displacement along strike.For completeness,the criteria used to identify and analyze lineament groups is reviewed below in Section 2.2.In total,22 lineament groups and three broader lineament areas were advanced to further field investigation and evaluation in summer of 2013 (FCL,2013). The 2013 field teams consisted of two,two-person groups and involved visual inspection of landscape and geomorphic features within lineament groups via low-altitude helicopter fly-overs and ground data collection in selected locations where access was permitted.The mapped lineament groups were visually inspected in the field to identify positive evidence for (or against)tectonic deformation of the Quaternary deposits (as present in the field)that may overlie,or project toward,the lineaments.The ground-based geologic data collection included walking of parts of mapped lineaments,photo documentation,exposure and logging of shallow soil pits,local mapping,collection of relevant structural measurements (strike,dip),and comparison of existing geologic mapping to field exposures and findings. Each field team used a ruggedized field laptop computer (Toughbook)with real time GPS tracking and GIS capabilities.The geologic database compiled by FCL during the efforts of FCL (2013)for the seismic studies was loaded onto each Toughbook with LiDAR and INSAR digital elevation and derivative surface models.This approach allowed for:(1)accurately locating position with respect to lineament features in the field in real time,and (2)real-time analyses of the existing geologic mapping and landscape models to the features observed in the field. The helicopter inspection was conducted chiefly with R-44 type aircraft.Other rotary aircraft were used to a lesser extent during the aerial inspection.Each ruggedized field laptop was carried in the helicopter INTERIM DRAFT Page 4 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. with the GPS enabled to record a "track”for each team's course,position,and pattern for each flight (Figure 2-1).Minor satellite signal loss occurred during parts of the field investigation,but was supplemented with redundant auxiliary tracks collected by hand-held GPS units.Hand-held GPS units were primarily used to collect way points at selected locations of the ground investigation.The field tracks document the extent and location of low-altitude inspections,and way points document ground locations relevant to the geologic data collection. Photographs were taken during the low-altitude flyovers and while on the ground,and serve to document the field observations.The photographs were collected with a digital camera whose internal clock was synchronized with the hand-held GPS clock.This allowed geo-referencing of the photographs to the location where the photo was collected,and ensured collected photos were assigned to the correct place,feature,or lineament group.In some instances,inclement weather (rain,clouds) hindered quality of photo documentation.In other instances,glare or distortion from aircraft windows is apparent in the photographs. The lineament groups and larger areas are depicted in detail on a series of strip maps and plates on which relevant field-and office-generated geologic and geomorphic data are compiled and evaluated. Examples of this field data collection and synthesis effort are shown in Figures 2-2,2-3,and 2-4.(The map data are presented in-full in Appendices A and B and each lineament group is described below in Section 4.)The content of the strip maps and plates is customized for each lineament group and only the most the relevant field data and geologic map data are shown alongside the mapped lineaments with the most appropriate base imagery,given the local terrain and features of interest (e.g.,Figure 2-2). Figure 2-3 demonstrates the annotated field photographs that are linked to the maps while Figure 2-4 provides an example of an explanation sheet that accompanies the maps. 2.1 Geospatial Data The primary digital data sets utilized by FCL (2013)for the lineament mapping phase and during the 2013 field work consisted of several high-resolution topographic and aerial imagery datasets (Table 2- 1).Of the available data,the INSAR and LiDAR (Figure 2-5)were the most valuable due to their high resolution and broad coverage of areas of interest.INSAR coverage is complete for the entire region of study interest within about 100 km of the Susitna-Watana dam site as well as a broader region of south- central Alaska.LiDAR coverages are available for much more restricted areas,and near the Susitna- Watana dam site is generally limited to a narrow corridor along the Susitna River (Figure 2-5).Both INSAR and LiDAR can penetrate through vegetation cover to map the ground surface beneath and can be used to create a "bare earth”digital elevation model (DEM)of the landscape. In addition to the elevation data,two imagery datasets covered the study area:1)ortho-imagery (0.3 m) collected as part of the Matanuska-Susitna Borough (MatSu)LiDAR collection project,and 2)regional INTERIM DRAFT Page 5 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Landsat scenes (30 m)(Table 2-1).The MatSu aerial imagery coverage has limited regional extent coincident with the extent of the MatSu LiDAR data (Figure 2-5).Both imagery datasets provide data in the visible spectrum.These imagery datasets were used to provide context and better understand landscape features displayed on the INSAR and LiDAR data and also navigate the terrain during the field work. Table 2-1.Principal Data Sets Utilized During the Lineament Mapping Data Cell Size Year Source . _Data collected by Intermap (50%)and FugroINSARelevationdata(bare earth)5 m ( 16 ft)2010 EarthData.Inc.(FED!)(50%)* MatSu LIDAR elevation data (bare earth)1m ( 3 ft)2011 Matanuska-Susitna Borough*t MatSu aerial imagery 0.3 m ( 1 ft)2010 Matanuska-Susitna Borough*t Landsat satellite imagery 30 m ( 100 ft)2010 NASA/USGSS *Data downloaded from the Geographic Information Network of Alaska (GINA)at the University of Alaska tFor more information see:http://www.matsugov.us/it/201 1-lidar-imagery-project §Downloaded from http://qlovis.usqs.gov/ 2.2.Desktop Approach for Lineament Evaluation 2.2.1 Criteria for Selection of Lineaments Requiring Further Analysis FCL (2013)defined multiple acceptance criteria to serve as a basis for delineating potentially tectonically-relevant lineament groups (Table 2-2).In general,the lineament groups consisted of individual lineaments having consistently similar orientations that when aggregated together as a group, have a relatively appreciable length and which trend across terrain.Several criteria were established to serve as a relatively inclusive basis for delineating lineament groups within the study area.These criteria from FCL (2013)are described below (Table 2-2),and are presented in generally decreasing degree of confidence in lineament delineation as a potential crustal feature. INTERIM DRAFT Page 6 of 81 01/20/14 -z- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Table 2-2.Criteria for Delineating Lineament Groups Criterion Reasoning Lineaments that are expressed in Quaternary deposits,that collectively aggregate to greater than about 10 km ( 6 miles)in length. Quaternary lineaments may strongly represent neotectonism. Lineaments that appear to represent potential extensions or continuations of known Quaternary faults. These lineaments may contribute to additional fault source length in ground motion calculations. Lineaments with possible tectonic geomorphologic evidence that are spatially associated with previously mapped faults or lineaments. Suggestive,but not conclusive,of neotectonism.Association with previously mapped faults or lineaments supports inference of structure. Lineaments with possible tectonic geomorphologic evidence that are not spatially associated with previously mapped faults/lineaments. Suggestive,but not conclusive,of neotectonism. Lineaments that aggregate to greater than 10 km ( 6 miles)in length. Length criterion is based on an approximately minimal structural length for a seismogenic source capable of ground rupture. Lineaments that are within 30 km ( 18 miles)from the proposed site and reservoir,and are greater than 20 km ( 12 miles)in aggregated length. Seismogenic features within 30 km ( 18 miles)of the site may contribute non-trivially to the ground motion calculations. The lineament groups identified through the inclusion criteria were subsequently screened using semi- objective exclusionary criteria (Table 2-3).The semi-objective criteria included length and distance restrictions,and also geologic process restrictions.The screening process thus required an examination of the identified lineament groups to assess the possible genesis of the features.The screening step eliminated lineaments that show strong evidence of being non-tectonic in origin (e.g.erosional, depositional),or those that likely would not appreciably contribute to the seismic hazard at the proposed dam site. INTERIM DRAFT Page 7 of 81 01/20/14 Za SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Table 2-3.Desktop Evaluation Exclusion Criteria Criterion Reasoning Lineament groups that are greater than 100 km ( 62 miles) distance from the proposed dam site,excepting potential extensions of the Castle Mountain fault. Lineaments over 100 km ( 62 miles)distant would have very little contribution in hazard calculations.Potential extensions of the Castle Mountain fault may contribute to hazard calculations. Lineament groups that are greater than 70 km ( 43 miles)distance from the proposed site and less than 40 km ( 25 miles)aggregate length and with no apparent association to previously mapped structures. These lineament groups likely would not appreciably contribute to the hazard calculations,based on the Sonona Creek seismic source contribution in the preliminary PSHA (FCL,2012). Lineament groups that are greater than 30 km ( 18 miles)from the proposed dam site and less than 20 km ( 12 miles)in length are excluded from further analysis,where the group cannot be linked to an adjacent group. Based on the results of the preliminary PSHA (FCL,2012),it is likely that these lineament groups (if seismic sources)will not appreciably contribute to the hazard calculations. Lineament groups whose individual features are dominantly erosional and/or depositional with no apparent association with previously mapped faults or lineaments. Such lineaments are non-tectonic in origin and not considered further. Lineament groups with inconsistent expression of kinematics along strike. Inconsistent,contrasting,or discrepant lineament kinematics indicates low likelihood as a potential seismic source. A second,more subjective,evaluation process (Table 2-4)was applied by FCL (2013)to the remaining lineament groups,based on desktop geological examination of the data compiled on the lineament group strip map.This process served to identify potentially significant lineament groups that would need additional data and evaluation as part of the summer 2013 field studies. INTERIM DRAFT Page 8 of 81 01/20/14 za SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Table 2-4.Criteria for Desktop Geologic Evaluation of Lineament Group Criterion Reasoning Lineaments within groups that appear to have expression in Quaternary units or Quaternary landforms proceed to further analysis. Quaternary-age lineaments may _strongly neotectonism,if not erosional or depositional in origin. represent Lineament groups that transect or cut across different geologic units proceed to further analysis. Lineaments that are traceable across different geologic units imply crustal structure exists,as opposed to lineament genesis from lithology,bedding,or jointing. Lineaments within groups that may be tested for positive evidence of inactivity (e.g.,overlain by Tertiary volcanic units) proceed to further analysis. Determining inactivity via positive evidence will remove lineament group from further study. Lineament groups that demonstrate relative consistency of geomorphic expression and anticipated structural kinematics along strike proceed to further analysis. Consistent expression and structural style suggests a common genesis such as neotectonism because many other processes of formation change along the length of their occurrence. Lineament groups that are explainable in the context of the tectonic model proceed to further analysis. The tectonic model serves as a guide for anticipating orientation and sense of motion with respect to crustal stresses. 2.2.2 Criteria for Evaluation of Lineaments,Summer 2013 Field Investigation The lineaments inspected in the field during summer 2013 were assessed based on geomorphological characteristics observed in the field and geologic relationships around the lineaments.As guidelines for the field teams conducting the field investigation of individual lineament groups,a series of questions were developed prior to the field activities as an aid to focus observations and data collected during the field investigation.The intent was for the field teams to discuss and debate during the process of the lineament field evaluations as an ongoing field methodology to help ensure that field observations were sufficiently complete during the limited time available,often with no opportunities for revisitation. Table 2-5 lists these questions and the reasoning which supported the need for collecting the associated field data in order to assess each lineament in a relatively consistent fashion. INTERIM DRAFT Page 9 of 81 01/20/14 -za- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Table 2-5.Field Team Geologic Data Collection Guidance Field Data Reasoning/Comments Is a previously mapped bedrock fault structure coincident with or near the lineament group? Spatial proximity to or association with a previously mapped fault may support the lineament group having a tectonic origin. Was field evidence of fault structure observed (either directly or indirectly)? Direct evidence:exposure of shear zone or fault contacts observed. Indirect evidence:apparent rock type juxtapositions,alteration zones,color changes. What does the trend of the lineament across the topography imply about the geometry of the potential structure? Topographic expression provides a basis for defining the potential 3D geometry and potential style of faulting or constraints on potential non-tectonic origins. What types of deposits or geomorphic surfaces is the lineament expressed in? Quaternary glacial,lacustrine,alluvial,and colluvial deposits or bedrock units?Are the geomorphic surfaces constructional or erosional? What is the oldest deposit in which the lineament occurs?Age of deposit may constrain age of activity or limit of reasonable hypotheses of origin. What is the youngest deposit in which the lineament occurs?Age of deposit may constrain age of activity or limit of reasonable hypotheses of origin. Do the mapped lineaments transect or cut across different geologic units or landforms? Expression of lineament across multiple units or landforms may indicate continuity of geologic process. What is the scale (magnitude)of expression of the lineaments along strike? Expression that is proportionally consistent across different age portions of the landscape suggests continuity of process. Is the lineament discordant with glacial ice flow directions?Discordance with ice flow direction suggests origins other than ice flow. Is there field evidence that linear strain markers (such as moraine or ridge crests,esker ridges,terrace risers or treads, lake shorelines,drumlins or other ice scour-generated striae) are cross-cut,deformed or displaced?If deformed,what is the amount? Disruption of Quaternary strain markers may suggest a recent tectonic origin. What does the morphology of the lineament imply about the kinematics of a potential fault?What are the apparent structural kinematics needed to produce the morphology of the lineament? Kinematics need to be consistent along strike. To evaluate the field data and guide development of documentation for the evaluation of each lineament group,a set of questions and criteria similar to those used by FCL in TM-8 (FCL,2013)for evaluation of the desktop findings were developed (Table 2-6).In much the same way that the data collection guidelines shown in Table 2-5 were intended to enhance consistency and focus across the range of features visited in the field,the guidance which follows in Table 2-6 is intended to build those observations into a consistent set of discussions for documentation of the evaluation of each lineament group.The principal objective of these criteria is to guide judgments regarding the lineaments'origins in order to evaluate their potential association with Quaternary faulting and crustal seismogenic sources. INTERIM DRAFT Page 10 of 81 01/20/14 -Z- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Table 2-6.Criteria for Evaluation of Field Data Criterion Reasoning Does the lineament show evidence of geomorphic expression in Quaternary deposits or landforms?What is the character of expression? Quaternary-age lineaments may strongly represent neotectonism,if not clearly of erosional or depositional in origin. Does the lineament group transect or cut across different geologic units or landforms? Lineaments that are traceable across different geologic units may indicate through-going crustal structure exists,as opposed to lineament genesis from local lithology,bedding,orjointing. Does the lineament group demonstrate relative consistency of geomorphic expression and apparent structural kinematics along strike? Expression that is proportionally consistent across different age portions of the landscape suggests continuity of process. Consistent expression and structural style suggests a common genesis such as neotectonism because many other processes of formation change along the length of their occurrence. Are the lineaments'apparent origins dominantly erosional and/or depositional?Such lineaments are likely non-tectonic in origin. Are the individual lineaments or lineament groups associated with previously mapped faults? Spatial proximity to or association with a previously mapped fault may support the lineament having a tectonic origin. INTERIM DRAFT Page 11 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. 3.FIELD DATA EVALUATION FRAMEWORK The 2013 field activities and lineament evaluations revealed three topics with broad impacts across several aspects of the lineament evaluations.These topics include:1)insights gained from field investigation and evaluations on the scale and resolution of DEM data,2)identification of the dominant geomorphic processes acting to modify the landscape,and 3)updated regional age estimates for late Quaternary landscapes and events in south-central Alaska.Interpretations and evaluations of most lineament groups and individual features within these lineament groups are linked to key principles or limitations posed by data or concepts associated with these three topics. 3.1 Post-Field Data Evaluation of DEM Data As noted in Section 2.1,two sets of topographic data were used for the desktop lineament mapping: INSAR and LiDAR (FCL,2013).The INSAR (Interferometric Synthetic Aperture Radar)data covered the largest area for the project and has a 5 m ( 16 ft)horizontal cell-size (Table 2-1).The LiDAR,with a 1 m ( 3 ft)horizontal cell-size,captured a smaller aerial extent that chiefly focused on the Susitna River corridor (Figure 2-5).Both INSAR and LiDAR can penetrate through vegetation cover to map the ground surface beneath and can be used to create a "bare earth”model of the landscape. The INSAR-derived DEM data was the basis for mapping lineaments at regional extents (e.g.the 100- km [ 62 miles]radius),and is a significant improvement in accuracy and detail of elevation as compared to any previously available regional data in south-central Alaska,and compared to DEM models derived from typical 1:24,000-scale topographic quadrangles throughout the mainland United States.However,after comparing the elevation model data along mapped lineaments to the geomorphic features observed on the ground during the field work,several trends became apparent.First,for example,what visually appear to be relatively small features on the INSAR data actually are rather large features in the field.Features such as slope breaks that appeared sharp and abrupt on hill shaded maps, generally were found to be larger than expected in overall size and relief with less abrupt and more rounded slope geometries.Considering that the investigation team's objective was to detect and identify potential earthquake-related geomorphic features (i.e.,fault rupture scarps),the INSAR-based lineament mapping (FCL,2013)may have over-mapped features that in hindsight after two weeks of field investigation -likely would not be considered tectonic in origin.Nevertheless,all lineaments were mapped impartially,and subsequently tested via observation and reasoning. Secondly,some relatively small features were observed on the landscape and on the ground during the field investigation which were not captured by the INSAR data,and thus not identified as lineaments in FCL (2013).This condition is challenging to characterize because the ability of the INSAR to image small features seems to be a function of the features'relief relative to that of the landscape (small INTERIM DRAFT Page 12 of 81 01/20/14 -zZ-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. feature in flat terrain vs.small feature in a ravine or valley)and the features'inherent geomorphic expression (steeply sloped margins vs.gently sloped margins and also continuity or length).To mitigate this apparent resolution limitation,derivative surface elevation models from the bare earth model were analyzed during the field investigation using the ruggedized field laptop GIS platform. Slope maps (change of elevation),and slope of slope maps (change of slope),were used to highlight subtle changes in elevation or slope that accentuate features that may be generally non-apparent in traditional hillshade elevation maps.These derivative surface elevation models were locally helpful in identifying smaller landscape features such as solifluction scarps and terraces. Overall,the field investigation highlighted the previously known limitations of the INSAR based lineament mapping,notably that the base resolution of a 5 m ( 16 ft)DEM is still relatively coarse with respect to the scale of geomorphic features that might be expected to be associated with single earthquake surface ruptures.As noted in FCL (2012),surface rupture features associated with the 2002 Susitna Glacier fault rupture are subtle,but recognizable in the 5 m INSAR DEM data.Conversely,the previously mapped lineament along the Talkeetna fault trenched by WCC (1982)and discussed later in Section 4.1,is not resolved on the INSAR DEM,but does represent the type and scale of feature that would be of interest as a potential tectonic feature.When considered together with the role of active surface modification processes (discussed below in Section 3.2),these two features show that while there may be significant limits to the preservation of small tectonic features over time periods of thousands of years due to geomorphic surface modifications,such features can be stable and preserved in the Holocene landscape.Our field observations confirm that this limitation is likely most severe in areas of more irregular and high relief terrain,and somewhat less so in areas with more gentle,rounded, and uniform slopes.In short,the terrain and the style of faulting will together affect how apparent potential fault-derived features will be in the INSAR data. The scale of features mapped in areas where LIDAR DEM data are available is much finer,but no direct comparisons of the field scale of these features have been done to date,as most of the areas in which mapped features of potential interest occur,and where there is overlap of the INSAR and LiDAR data, were not available for ground access in 2013.Direct on-ground comparisons of mapped features in areas with data overlap may provide a basis for specific definition of the overall resolution of scale of features detectable through the mapping on the INSAR and LiDAR DEM data sets. 3.2 Role of Geomorphic Processes for Creating Apparent Lineaments Another insight stemming from the 2013 lineament field investigation is that a preponderance of the individual lineaments mapped within many of the lineament groups are the result of glacial and/or periglacial processes.Therefore,a discussion of the various geomorphic processes and resulting landforms is warranted in order to provide a context for their extensive presence on the landscape,as well as a technical basis for evaluation of lineament groups within the project area.Based on the field INTERIM DRAFT Page 13 of 81 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. observations,the dominant erosional features observed are common in glacial and periglacial environments and include:subglacial (sub-ice)channels carved into rock or soil;solifluction-related scarps and lobes;roche moutonee,drumlins,and nivation-related scarps.The erosion-related landforms tend to produce slope breaks and linear features that are similar in landscape expression to tectonically produced lineaments.These processes are briefly described below. 3.2.1 Subglacial Channels and Basal!Erosional Processes Subglacial erosional processes appear to be significant factors in the origin of many of the larger lineament features identified through the desktop DEM analyses in FCL (2012).Unfortunately,the specific genesis of subglacial erosion that creates subglacial channels (also called meltwater channels)is generally poorly understood because their process of origination cannot be directly observed. Moreover,the classification and nomenclature for describing landforms and origins of various types of subglacial channels is relatively non-uniform and inconsistent,which further confounds clear terminology. In essence,subglacial channels may develop by eroding upward into ice,eroding downward into the underlying substrate,or a combination of both.Channels that erode upward into ice may eventually become plugged with sediment and,when the ice recedes,remain on the landscape as eskers. Subglacial channels that form by eroding downward under the ice into the underlying geologic substrate are relevant to this lineament evaluation because this action produces sub-linear erosional features on the landscape (Figures 3-1 to 3-3).Geomorphic characteristics common to subglacial channels include: an often abrupt beginning or termination in places where normal river channels do not start or end (e.g., across interfluves),uneven longitudinal profiles,channels that tend not to widen downstream,and steep channel side-walls oriented down slopes at a right angle to the contour lines (Gray,2001;Gao,2011). The geomorphic expression usually is a ravine that starts for seemingly no reason and then continues towards the bottom of a valley where it may terminate abruptly.Where the channels have formed in solid rock,the substrate rock typically is deeply incised or gorged,with narrow and steep-sided walls (Figure 3-2). The subglacial channels described above may also be referred to as a tunnel valley.A tunnel valley is a large,long,valley originally cut under the margin of former continental ice sheets (Figure 3-3; Jorgensen and Sandersen,2006;Gao,2011).The processes forming the valleys appear to advantageously occupy pre-existing (open and buried)valleys for the renewed erosion.Thus,old subglacial erosion pathways may have been re-used several times.The Finger Lakes in New York State are attributed to tunnel valley processes (Jorgensen and Sandersen,2006).Tunnel valleys appear in the technical literature under several terms,including tunnel channels,subglacial valleys,iceways,snake coils and linear incisions. INTERIM DRAFT Page 14 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Roche moutonnee (a.k.a.sheepback)landforms result from the passage of glacier ice over bedrock that creates an asymmetric erosional form as a result of abrasion on the up-ice side of the rock and plucking on the down-ice side (Ritter et al.,1995).This process generally produces isolated "knobs”of rock that may protrude through glacial drift or alluvial cover,and appear similar to a tectonically bounded or emplaced sliver because of its generally infrequent occurrence on the landscape. Drumlins form by ice-flow and substrate abrasion or scour,and typically are elongate,linear ridges oriented parallel to the direction of ice flow (Ritter et al.,1995).On a drumlin,the steep side is facing the approaching glacier,rather than trailing it,and thus may appear as an apparent truncation if the slope is appreciably steep. 3.2.2 Solifluction Solifluction (also called gelifluction)is a slow-rate hillslope mass wasting process that commonly occurs in periglacial environments during the thaw (i.e.,summer)season.It is distinct from the frost heave process.(Frost heave is a particle's movement perpendicular to slope because of volumetric ice expansion.)The term solifluction describes the gravity-driven downslope movement of water-saturated unconsolidated surface material (regolith)that flows down slopes of moderate to very low gradient because meltwater saturates the upper layers but cannot penetrate the frozen ground beneath (Bloom, 1988).The process produces arcuate erosional (and scarp-like)features up-slope as well as arcuate lobate constructional landforms on the downslope.The arcuate landforms tend to produce apparent slope breaks on the landscape that may be interpreted as potential fault-related features.In many cases, it appears that solifluction related scarp-like features and slope breaks of sufficient size to be identified and mapped in the INSAR based DEM were included as individual features within the lineament groups.These occurrences are most common in landscapes with more uniform and moderate slopes, where extensive areas of solifluction features have developed.Because of similarities at the outcrop scale of the size,morphology,and continuity of these features to surface rupture features associated with large tectonic earthquakes,evaluation of lineament groups and features in these types of landscapes poses significant challenges and added uncertainty for interpretations. 3.2.3 Other Processes and Landforms Nivation processes are difficult to define because the process includes both physical weathering coupled with hillslope erosion.In general,nivation is the acceleration and/or intensification of ground weathering and erosion associated with patches of snow that persist into the summer season in a periglacial environment (Bloom,1988).Snow patches that persist in sheltered (shaded)positions on hillslopes below the altitude of permanent snow fields may produce nivation depressions or "hollows.” The weathering becomes intensified in the saturated ground beneath a compacted snow patch (i.e.,névé: a young,granular type of snow which has been partially melted,refrozen and compacted yet precedes INTERIM DRAFT Page 15 of 81 01/20/14 -zZ--ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. the form of ice).The saturated snow mass produces a flow of water on the ground surface that erodes particles of soil beneath the snow.In addition,freezing and thawing of the snow mass can impart physical breakdown of soil as well as heave and downslope soil erosion processes. Nivation scarps and related geomorphic features are most common and apparent in the higher elevation portions of the landscape above treeline,most often in portions of valleys most recently occupied by glacial ice.In these areas,low-level aerial and ground observation facilitated differentiation of nivation- related landforms from landforms generated by other processes.Importantly,the identification of lineaments,whether nivation-related or not,in areas most recently occupied by glaciers implies a very young age.Many of the features ultimately interpreted as nivation-related were prominent in the DEM models,but found with field observations to be much larger than credible for features of tectonic origin given their occurrence within the youngest portions of the regional landscape. 3.3.Age Datums and Detectability Limits Understanding the Quaternary geologic history in the Susitna River basin region is relevant to understanding the geomorphic processes,resultant surficial geologic deposits,as well as relationships amongst deposits,both stratigraphically and chronologically.Quaternary stratigraphy and chronology form a basis to establish a geologic datum for evaluating tectonic (fault)activity during the late Quaternary. 3.3.1 Quaternary Geology Model At their maximum extent during the Quaternary,glacial ice caps coalesced and covered essentially the entire 100 km ( 62 miles)radius about the Susitna-Watana dam site (Wahrhaftig,1965;Hamilton, 1994;Kaufman et al.,2011).Even during the late Wisconsin or last glacial maximum (LGM)in south- central Alaska,recent regional compilations (Kaufman et al.,2011)show that the glacial extent was slightly restricted relative to the Quaternary maximum extent,but still only a few relatively high elevation or isolated areas within 100 km ( 62 miles)of the Susitna-Watana dam site remained ice free (Figure 3-4).Most remaining lower elevation areas in that region,such as the northwestern Copper River Basin,were largely occupied by proglacial lakes,confined by ice blockages between the mountain ice caps.In the Susitna-Watana dam site area,prior investigations (e.g.,Acres,1981,1982)document the stratigraphic record left by alternating ice advances and glacial lakes associated with the most recent glaciations. Age control for the late Wisconsin glacial advances in the Susitna-Watana dam region is limited,and largely based on recent cosmogenic dating of moraines and landforms on either side of the Alaska Range,north of Susitna-Watana dam site (Figure 3-4).Most recent age compilations (e.g.,Kaufman et al.,2011;Briner and Kaufman,2008)now suggest that the timing of Oxygen Isotope Stage 2 (LGM) INTERIM DRAFT Page 16 of 81 01/20/14 za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. maximum advances in Alaska may have varied by thousands of years across the state,but retreat from the maximum extent in south-central Alaska likely started about 22 to 20 ka.Ice extent probably remained near the maximum extent for a few thousand years,with several readvances and periods of stabilization through about 15 ka.The last significant readvances of glaciers in the Alaska Range occurred between 14 to 12 ka,and 12 to 11 ka (Briner and Kaufman,2008),followed by rapid deglaciation. Near Anchorage and in the upper Cook Inlet,about 200 km ( 125 miles)to the southwest of the site,the late Wisconsin advance is locally termed the Naptowne,and occurred between about 30 to 11 ka (Reger et al.,2007).During the maximum advance,ice from the Alaska Range flowed south and southeast and filled much of the Cook Inlet at about 23 ka.Ice remained near this limit until about 19 ka,then retreated gradually to less extensive advances or stillstands until about 17 ka,when there was significant retreat.A final re-advance,which built the Elmendorf moraine complex,began after 16 ka,and extended to about 11 ka. For fault and lineament evaluations,the ages for the regional glacial chronology imply that the vast majority of the landscape within about 100 km ( 62 miles)of Susitna-Watana dam site was covered beneath glacial ice or glacial lakes as late as about 15 ka,with a slow reduction in ice and lake extent through 12 to 11 ka.During this later period,significant ice and lakes remained in most of the glaciated valleys within the northern and central Talkeetna Mountains,and potentially included the last glacial advances of the Tsusena and Deadman Creek glacial lobes into the Susitna-Watana dam site vicinity, and intervals of glacial lakes in the Watana Creek area.Thus,geomorphic surfaces on which a record of potential surface faulting might be preserved prior to about 12 to 11 ka within about 100 km ( 62 miles) of the Susitna-Watana dam site were likely limited to isolated high peaks above the ice limits,and small ice-free areas above the limits of glacial lakes.Potential ice free areas during the later stages of the late Wisconsin advance lie mostly east of Watana Creek along either side of the Susitna River,and along the southeastern margin of the Talkeetna Mountains above the limits of Lake Ahtna in the Copper River Basin (Figure 3-4).As ice receded during the late Wisconsin advance,areas near Talkeetna,along the Chulitna River from Susitna River to the Broad Pass area,and the low hills and valleys southwest of the Alaska Range glaciers on Monihan Flats,but northeast of Susitna-Watana dam site may have been ice free closer to 15 ka. Following the last late Wisconsin advances at about 12 to 11 ka,there was rapid deglaciation and retreat of the glaciers of southern Alaska to high altitude limits and positions not far from present glacial extents (e.g.,Reger and Pinney,1997).Moraines and deposits just beyond the limits of current and recently active deposits have ages of less than 2 to 1 ka (e.g.,Dortch et al.,2010a),suggesting glacial extents during the Holocene have remained near present limits.Near the Susitna-Watana dam site,the rapid transition to non-glacial conditions is evidenced by several radiocarbon ages on peats and bog INTERIM DRAFT Page 17 of 81 01/20/14 za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. deposits which began to accumulate in the post-glacial environment and which yield radiocarbon ages ranging up to about 11 to 10 ka (e.g.,WCC,1982;Reger et al.,1990).Radiocarbon ages from the lake deposits in Copper River Basin,suggest final lowering and drainage of the large glacial lake there during the same time period (Williams and Galloway,1986).Thus,beginning around 11 ka,large areas of the formerly ice and glacial lake-covered landscape began to stabilize and present geomorphic surfaces which might record faulting emerged.Published radiocarbon chronologies from archaeological studies indicate that some parts of the Upper Susitna area may have been habitable by 12 ka (Potter, 2008).The upper Susitna basin was first occupied by somewhere between 11.5 and 8 ka (Potter,2008). At least three Holocene tephra units are known to overlie glacial deposits in some areas near the Susitna-Watana dam site.These deposits are thought to have originated from eruptions in the Tordrillo Mountains to the southwest of the Watana site (Riehle et al.,1990).Three tephra units described near the Watana site are reported to be about mid to late Holocene age,based on radiocarbon analyses of 42 samples (Dixon et al.,1983,1985). For fault and lineament evaluations in the Susitna-Watana dam site region,the review of previous studies and research of Alaskan glacial chronologies,coupled with field observations of the type and distribution of glacial constructional and erosion landforms suggests that there are three broad age categories within which the landscape may be viewed.These are,from youngest to oldest:late Holocene,mid-to early Holocene,and post-late Wisconsin period of the late Pleistocene.Geomorphic surfaces and deposits associated with maximum phases of the late Wisconsin glaciation,and older glaciations,were generally either modified or buried by effects of the last phases of late Wisconsin glaciation.Thus,for geomorphic evaluations of the faults and lineaments in the region,these older deposits are generally of limited use because the surface expression of older faulting has been removed. INTERIM DRAFT Page 18 of 81 01/20/14 za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. 4.OBSERVATIONS AND INTERPRETATIONS OF LINEAMENT GROUPS The following section discusses each of the individual lineament groups and larger areas visited during the summer 2013 lineament investigation.The groups and larger areas are depicted in detail on a series of strip maps and plates on which relevant field and office geologic and geomorphic data are compiled and evaluated (Appendix A).The lineament groups identified for summer 2013 field work are shown on Appendix A,Figure AQ.1,and a series of supporting figures'.The larger areas showing the Broad Pass fault,Clearwater Mountains,northeastern Castle Mountain fault,are shown on Plates A-BP,A- CWM,and A-CME,respectively.Appendix B contains a series of figures presenting map and field data for numerous photogeologic lineaments mapped by Reger et al.(1990)on the Healy A-3 Quadrangle (see Figure B-01 and discussion below).The strip maps and plates facilitate discussion and evaluation of the data collected in the field with respect to the features'relevance to the seismic hazard evaluation for the proposed Susitna-Watana dam site and potential needed further study. Lineament Group 1:Observations and Evaluation Lineament group |is an east-northeast-trending group of lineaments defined by a series of aligned, linear to sub-linear drainages and uphill-facing slope breaks,approximately 51 km ( 32 miles)north of the proposed Susitna-Watana dam site (Appendix A,Figures AO.1,and Al.1).Individual mapped lineament feature lengths range from approximately 200 m to 4 km ( 650 feet to 2 miles),with an aggregate length of approximately 20 km ( 12 miles).No previously mapped faults or lineament features coincide with the group (Figure Al.1),and no evidence of fault structure was observed during low-level aerial investigation.Along the eastern portion of the group,the morphology of the lineaments and their very linear trend across the high relief terrain suggests that any potential fault structure that may exist would have a steep dip and apparently north-down,south-up sense of motion.The feature has a similar trend to the relatively proximal Denali fault (Figure AO.1).Discrete lineaments that make up the aggregate group occur in the Cretaceous Kahlitna flysch sequence (map unit KJf,Wilson et al., 1998)and to a lesser extent,Tertiary intrusives of felsic and intermediate composition (map unit Thf). Late Quaternary deposits along the Jack River,of late Wisconsin and post-glacial age intersect the projected trace of the group 1 lineaments near the center of the group 1 ellipse.These late Quaternary deposits show no apparent expression of the lineament (Figures Al.1 and A1.2). 2 Note that for ease of reference,Appendix A figure numbers correspond to lineament group numbers.For example,Figure A1.1 shows the extent of lineament group 1.The content of the strip maps and plates is customized for each lineament group and only the most the relevant geologic data are shown on the most appropriate base imagery,given the local terrain and features of interest.The explanation of symbols and relevant existing geologic mapping shown on the figures has been compiled into a series of explanation sheets (Figures A0.2,A0.3,A0.4,and A0.5)that follow the index map of lineament groups and precedes the figures for lineament group 1. INTERIM DRAFT Page 19 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY ;AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. Observations made during aerial field investigation suggest that the topographic expressions of the lineaments within the Cretaceous flysch (map unit KJf),in the eastern portion of the group,may be erosional features along unmapped bedrock structure,or possibly large sackung features.In either case, the absence of continuity of the individual lineaments from steep bedrock slopes into areas adjacent areas of lower slopes where Quaternary deposits are present is evidence of non-tectonic origin for these features.Although the lineament group has a similar trend to the Denali fault located about 18 km ( 11 miles)to the north,no previously mapped faults or lineament features coincide with the group (Figure Al-1),and no evidence of fault structure was observed during low-level aerial investigation.The lineaments that were identified in the western portion of group 1 are associated with a large,narrow, linear canyon,with no change in rock type or expression across the valley.Additionally,the lineament segments of Group |do not align across the Jack Creek drainage at larger (more detailed)map scales, suggesting the lineament group may represent two shorter sets of unrelated features.Based on the above evidence,the lineaments of group 1 are likely non-tectonic in origin,are judged to be primarily erosional and/or landslide features,and are not considered further. Lineament Group 2:Observations and Evaluation Lineament group 2 is an east-northeast-trending series of aligned,linear drainages,slope-breaks,and V- notched saddles (Figure A2.1)located approximately 46 km ( 29 miles)north-northwest of the proposed Susitna-Watana dam site (Figure A0.1).No previously mapped geologic faults or lineament features coincide with the lineaments of group 2,although the group has a similar trend to the relatively proximal Denali fault (located 25 km [ 15 miles]to the north-northwest).No evidence of fault structure was observed during low-level aerial investigation.Individual features range in length from a few hundred meters to approximately 2 km (<985 feet to 1 miles),with an aggregate length of approximately 12 km ( 7 miles).The youngest unit expressing lineament features are Tertiary volcanic rocks (map unit Tvu),and the oldest unit is the Cretaceous Kahlitna flysch (map unit KJf)sequence (Wilson et al.,1998;Figure A2.1).Individual lineaments within the group have a clear expression in both bedrock units.Mapped Quaternary surficial sediments,fluvial deposits in several unnamed drainages,a glacial moraine,and an alluvial fan deposit show no apparent deflection or deformation where overlying the projected trace of the lineament group (Figures A2.1 and A2.2).Glacial valley orientations are orthogonal,or sub-orthogonal to the lineament group,suggesting that Quaternary glacial processes likely had little role in the formation of the features.From west to east,the mapped linear segments present both down-to-the-north and down-to-the-south apparent senses of vertical deformation with a variable scale of vertical relief ranging from less than 10 m to about 50 m ( 33 to 164 ft). Discrete lineaments within group 2 occur primarily in Tertiary volcanic rocks (map unit Tvu),with one feature showing an apparent expression in both the Tertiary and Cretaceous rocks,and an additional aligned linear drainage expressed in Cretaceous rocks (Figure A2.1).No FCL mapped lineament from group 2 has expression in Quaternary units or Quaternary landforms based on field observations.As INTERIM DRAFT Page 20 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. mapped,the Wilson et al.(1998)map compilation in this area is generalized and does not accurately depict the full extent of Quaternary surficial deposits (map unit Qs)along the position of FCL-mapped lineaments.Field investigation confirmed that Quaternary surficial deposits should be mapped through the floor of the Jack River valley and on both the north and south sides of the linear drainage shown in Figure A2.2 Photograph A)and that much of these deposits consist of till and other glacial deposits, likely of late Wisconsin age.In all instances,lineaments with clear expression in bedrock lose expression at contacts with Quaternary deposits and landforms.In the eastern portion of the lineament group,the lineament appears to consist of erosional scarps and linear drainage sections that follow the course of the Jack River.At a rectilinear bend in the river (near A on Figure A2.2),late Wisconsin glacial deposits in the valley bottom overlie the projected trace of the linear river segment,and did not show any expression indicative of deformation related to faulting.West of the Jack River,the lineament consists of discontinuous,but aligned linear slope breaks in Tertiary volcanic bedrock (map unit Tvu) separately by Quaternary units in which the lineament is not expressed.The western-most of the lineaments extends into KJf (Cretaceous Kahiltna flysch),based on the Wilson (1998)mapping,but is again separated from other lineaments by Quaternary units with no expression of the lineament.The limited and ambiguous expression of lineament features outside of the Tertiary volcanic rocks within the Cretaceous flysch,suggests that the observed trend may represent erosion along internal bedrock structure or features with the Tertiary volcanic rocks,as opposed to a through-going crustal structure. The geomorphic expression of this lineament group presents an inconsistent expression of apparent vertical displacement.Along the trace of this lineament group both down-to-the-north and apparent down-to-the-south sense of displacement is expressed.The case for lateral displacement is unlikely because of the absence of deflected drainages and other features related to lateral deformation (shutter ridges,sag ponds,etc.)along the projection of the lineament trend.Based on the field observations, notably the irregular characteristics of the lineaments along strike,lack of western continuity into the Cretaceous Kahiltna flysch units,and absence of expression in Quaternary units along the feature,the likelihood of a tectonic origin for the lineaments in group 2 is judged to be low and they are not considered further. Lineament Groups 3a &3b:Observations and Evaluation Lineament group 3a is an east-west trending group consisting of a series of linear to sub-linear aligned drainages,approximately 40 km ( 25 miles)northwest of the proposed Susitna-Watana dam site (Figure A3a.1).Lineament group 3b,east of group 3a,consists of east-west trending lineaments manifested by a series of aligned,linear to sub-linear drainages,slope-breaks,and steep V-shaped notched canyons, approximately 27 km ( 17 miles)north-northwest of the proposed dam site (Figure A3b.1). These two groups were considered for evaluation in summer 2013 largely because they share a generally similar orientation/trajectory on the landscape and they are spatially proximal,thus introducing the possibility that groups 3a and 3b could represent a through-going (i.e.linked)structure INTERIM DRAFT Page 21 of 81 01/20/14 -Zz-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401 -TM-012014 Clean,reliable energy for the next 100 years. of appreciable length.In fact,considered separately,group 3a and group 3b would have failed,or nearly failed,the lineament exclusionary criteria (Table 2-3).There are no previously mapped faults that coincide with either group 3a or group 3b lineament,however,each group is depicted (Clautice, 1990;Wilson,2009)with bedrock faults crossing each lineament group at high angles (Figures A3a.1 and A3b.1).The northeast trending fault in group 3b was not observed.The faults bounding Triassic metamorphic rocks (Trnm)in group 3a did appear to bracket rock types based on somewhat different surface textures. The trend of lineaments within group 3a across the topographic contours is linear,and does not follow a pattern expected from a dipping plane intersecting the ground surface.The lineaments are expressed in mapped undifferentiated Quaternary deposits (map unit Qs -likely post glacial age)as short linear gullies tributary to Crooked Creek along the eastern part of group 3a (Figure A3a.2),however no scarp- like feature was observed in the field during low-level aerial investigation.The lineaments also are expressed in Cretaceous Kahiltna flysch sequences (map unit KJf)as a raised ridge with an apparent color contrast on either side of the ridge (Photograph B,Figure A3a.2).However,this observation could not be extended laterally to the west;the adjacent,older,Triassic metamorphic rocks (map unit Trnm)show no expression of faulting.The 3a lineaments cross several different geologic units and landforms,and are largely discordant to the likely ice flow direction.The lineaments'morphology largely are v-shaped notches and slope breaks whose scale is variable along strike of the group.Near the Crooked Creek drainage,the lineaments have both small and moderate magnitude notches.Farther west,and into the Triassic rocks,the notches become relatively larger in magnitude.The magnitude of expression at the west end of group 3a is least of the entire group. The lineaments mapped in Quaternary (post-glacial)deposits along group 3a do not show neotectonic expression or offset.While the group 3a lineaments are mapped across several different geologic units, there is no apparent offset of mapped bedrock contacts along the trend of the lineaments.Most of the lineaments are interpreted to be either erosional in origin or related to slope processes due to their expression as short linear gulleys or presence on slopes where solifluction or nivation processes are dominant.The exception to this is the ridge in the Cretaceous Kahiltna flysch in which field observations found a color contrast (Figure A3a.2)that may be structurally-controlled,or may just as equally be stratigraphically controlled. The lineaments within group 3b are nearly entirely within Eocene granitics (map unit Tegr,Figure A3b.1).The lineaments within group 3b are mapped along the invert of v-shaped notches,and thus the trend of the lineaments across topographic contours is nearly orthogonal.No Quaternary deposits are mapped,but ground-based observations indicate that there are youthful (Holocene)deposits in cirques and drainage valleys,as well as rock glacier deposits (Figure A3b.2).Although these are very young deposits,there are no expression of lineaments in these deposits.The lineaments are somewhat oriented INTERIM DRAFT Page 22 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. parallel to ice flow direction along the eastern part of the group,but are positioned mostly in cirques and near ridgelines.Rock glaciers are present along the western part of group 3b,and interrupt the mapped lineaments without offset or deformation (Photograph D,Figure A3b.2).The morphology of the lineament is inconsistent along strike,showing north-facing slope breaks,south-facing slope breaks,as well as v-shaped notches. The lineaments show an absence of evidence of expression in the Quaternary drainages,and in particular,the toes of rock glaciers where they interrupt the mapped lineaments.While the rock glaciers are likely no older than post-glacial,they may also be as young as early Holocene.Given the relatively large expression of the north-facing slope break along the eastern part of group 3b,it is reasonable to expect some signature in the Quaternary deposits despite their potential youthfulness. Overall,lineaments within groups 3a and 3b are not associated with previously mapped faults,are predominantly erosional in origin,and show no evidence of offsetting Quaternary deposits.When considered individually,there is little evidence to support the lineaments as a fault structure.When considered collectively,there is little similarity in their landscape expression across the two groups to support positive interpretation of a linked,through-going crustal structure.Lineament groups 3a and 3b are interpreted to not represent an active crustal structure and no further work is deemed necessary. Lineament Group 4:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013)and strip maps for this group are not included herein (Figure AO).However,a limited number of low-altitude fly-overs in 2013 appear to confirm the desktop conclusion that the group 4 features are pre-Quaternary.Rock-type contrasts were observed across the previously mapped NE-trending thrust fault but no prominent tectonic geomorphology to suggest Quaternary activity was observed along strike in post-glacial surficial deposits nor in the bedrock. Lineament Group 5:Observations and Evaluation Lineament group 5 is an east-northeast trending lineament group defined by aligned V-shaped troughs, side-hill benches,and slope breaks,approximately 40 km ( 25 miles)west-northwest of the proposed Susitna-Watana dam site,near Chulitna Pass (Figures AS-1.!and A5-1.2).The eastern extent of the lineament group coincides with a previously mapped,unnamed lineament feature (Wilson et al.,2009), however lineament group 5 does not coincide with any previously mapped faults (FCL,2013).Low altitude aerial observation found no evidence for the presence of a fault structure along group 5.Along its eastern extent,the trend of individual lineament groups is generally parallel to ice-flow direction expressed as fluted and grooved topography in a general east-west orientation.The trend of the lineaments across the topography is near straight,implying a vertical to steep geometry of a hypothetical structure.The lineaments primarily are expressed in Cretaceous turbidite rocks of the Kahiltna flysch INTERIM DRAFT Page 23 of 81 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. sequence (map unit KJs)and,to a lesser extent,Tertiary granitics and Quaternary (probable late Wisconsin)glacial sediments.While the lineaments traverse different age rocks and sediments,the lineaments mapped in Quaternary sediments are restricted to likely floodplain or terrace deposits of the Indian River that could be as young as Holocene and coincide with terrace risers (Figure A5-2.2).The magnitude of the lineaments expression along strike is variable,with greater expression in the older bedrock units and substantively less expressed within the Quaternary units.The lineaments within the Quaternary deposits are relatively concordant with the ice-flow direction as expressed in the ice-scoured surfaces.There is no evidence that the ice-scoured surfaces are cross-cut or otherwise offset by the lineaments.Along the eastern extent of the group,the lineaments'morphologic expression as side-hill benches would imply an extensional-type kinematics (i.e.,down-to-the-south);along the western extent the morphologic expression varies as both uphill and downhill facing scarps,linear grooves,and drainages that would imply a translational-type kinematics. Low altitude aerial field observation revealed no evidence of lineament expression within the Quaternary deposits or surfaces.While the lineament group does traverse different geologic units and landforms suggesting a continuity of structure,the lineaments show an inconsistent kinematic expression along strike (i.e.,extensional on the east,translational on the west)within the same rock unit (Cretaceous turbidites;map unit KJs)that tends to not support the presence of a tectonic structure for creating the lineaments.The lineament group is associated with a previously mapped lineament along the eastern extent,however,the lineament does not continue westerly past Indian Creek drainage. Given the above,it is likely that individual lineaments apparent origin is dominantly erosional.Along the western part of the group near Little Coal Creek,field observations indicated that a side-hill bench and linear drainage (Figure A5-2.2)likely are the result of bedded turbidite sediments dipping into the hillslope (Figure A5-1.1),with differential weathering accentuating the erosion features.The lineaments in the Quaternary sediments of Indian River valley appear to be the result of erosion along generally west-flowing creeks that are dissecting the geomorphic surfaces creating apparent scarps in the fluvial deposits.From the above,it is judged that the lineaments along group 5 are the result of bedding orientations in the Cretaceous turbidite units and elsewhere from fluvial or glacial erosion,and do not represent a tectonic fault. Lineament Group 6:Observations and Evaluation The northeast-trending linear drainage of Watana Creek is a prominent landscape feature;this and smaller lineaments along Watana Creek are grouped as Lineament 6 (Figure A6.1).The lineaments primarily define a northeast-trending,linear to sub-linear drainage,approximately 14 km ( 9 miles)east of the proposed Susitna-Watana dam site.Traces of the Talkeetna fault previously-mapped (as concealed and/or inferred)pass within the ellipse defining group 6.In addition,Watana Creek was the target of focused project-specific geologic mapping and data collection by WCC (1980,1982)and Acres (1981,1982).However,the previous studies result in a fair degree of disagreement as to the INTERIM DRAFT Page 24 of 81 01/20/14 za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. (inferred)location and character of the Talkeetna fault in the area of lineament group 6.Importantly, the published map traces (as concealed and/or inferred)are placed along the western upland margin of Watana Creek,and are not shown as crossing or intersecting Watana Creek (Figure A6.1).During multiple low altitude overflights,field evidence of a fault structure was not observed along or in the immediate vicinity of lineament group 6,and no evidence was observed along the projection of the fault trace across Delusion Creek.A shear zone is mapped near the mouth of Watana Creek (Orange line in Acres mapping shown in Figure A6.1),and may coincide with an observed juxtaposition of Triassic basalt and inferred Tertiary sediment (Photograph A in Figure A6.2).However,the trend and extent of the shear zone do not seem to correspond to other map traces of the Talkeetna fault.Because the lineaments are chiefly mapped along Watana Creek itself,as well as linear drainages tributary to the creek,the trend of the lineaments as mapped reveals little about hypothetical fault structure geometries. The lineaments are expressed as linear drainages or erosional gullies oriented sub-orthogonal to the Talkeetna fault trace(s),and principally are developed in late Quaternary glacial drift (till)and glacio- lacustrine (lake)deposits.Lineament group 6 occurs at a high angle to regional ice-flow direction, suggesting that Quaternary glacial processes had little influence on the formation of the feature.The lineaments themselves are thus attributed to surface erosion and drainage development on the Quaternary upland surface,with one exception.A linear feature of about 700 m length ( 2,300 ft)with distinctly positive relief was observed and mapped as a lineament segment near where Watana Creek turns easterly into the uplands.This feature,parallel and nearby to the inferred locations of the Talkeetna fault,was inspected from the air and on the ground,and a shallow test pit was opened to examine the stratigraphy to better understand the origin of the feature (Figures A6.1 and A6.4).The shallow subsurface texture generally was sand with gravel,grading upward into silt,and was interpreted as an esker landform.Tephra deposits (wind-laid volcanic ash)were observed near the top of the pit, and three different tephras could be present.Discussions with project archaeologists and review of published literature indicate that the tephras likely represent the Mt.Hayes,Watana,and possibly the Oshetna tephra deposits (Dixon,1990).It is interpreted that the esker is at least a few to several thousand years old based on the presence of the tephras,but an upper age limit is undetermined at present. There is an appreciable lack of mapped lineaments coincident with the (concealed and/or inferred) locations and orientations of published Talkeetna fault traces,even within LIDAR imagery area.The LiDAR-derived DEM data reveal an absence of scarp-like features along the map traces in Quaternary surfaces (Figure A6.1)that was confirmed during field investigation (Figure A6.2 and A6.3).The INSAR-derived DEM data also reveal an absence of lineaments in the post-glacial valley bottom sediments to the northeast of GPS waypoints 017 and 183.Field observations of Quaternary stratigraphic outcrops along Watana Creek suggest that the contact between the overlying lake and underlying till deposits is planar,unbroken,and apparently untilted (Figure A6.2).A prominent ridge consisting of bedded Tertiary sediments (map unit Tsu)appear as gently northwest-dipping (A6.3). 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This is generally consistent with structural data collected in Oligocene (Tertiary)outcrops along Watana Creek by WCC (1982)that was used as a basis to argue for northeast-southwest compression and related flexural deformation of the Tertiary units.Though gently northwest-dipping,the stratigraphy of the ridge appears undisrupted along its length and provides additional evidence that the Talkeetna fault likely does not run down the Watana Creek canyon.This style of deformation is inconsistent with reverse thrusting along this part of the Talkeenta fault while regional stress field data allows for the potential reactivation of this lineament as a northeast-oriented thrust fault.The lineaments mapped within group 6 are judged to be the result of erosion of tributary drainages and fluvial erosion to create terrace risers along the creeks and are not likely tectonically-related.Further,there is an absence of tectonic geomorphology along the inferred locations of the Talkeetna fault in Quaternary deposits and surfaces present along the uplands adjacent to Watana Creek.However,additional LiDAR data is being collected to provide complete coverage for the area of lineament group 6 and the concealed and/or inferred locations of the mapped Talkeetna thrust fault.Additional future work for lineament group 6 should include review of these new high-resolution data to confirm that the current interpretations are still supported. Lineament Group 7:Observations and Evaluation Lineament group 7 is a northeast-oriented lineament group defined by an aligned series of linear to sub- linear drainages,faceted ridges,and saddles (Figure A7.1),approximately 28 km ( 17 miles)east of the proposed Susitna-Watana dam site (Figure A0.1).Mapped bedrock fault structures are depicted within the lineament group by some,but not all existing maps (FCL,2013).For example,mapping by Kline et al.(1990)shows a shear zone within lineament group 7.One of the bedrock faults juxtaposing Triassic (Nikolai)greenstone (map unit Trn)against Paleozoic volcanic rocks (map unit Pv)was indirectly observed as a color and vegetation change coincident with a topographic notch in the ridgeline (Photograph A,Figure A7.2).These are the oldest rocks within which the lineaments occur.The youngest deposits that the lineaments are mapped in are latest Pleistocene (late Wisconsin?);the lineaments transect young valley floor glacial sediments as well as elevated bedrock ridgelines.The topographic expression of the individual lineaments implies a high angle to near vertical orientation for a fault because they cut steeply across topographic contours.Along the northern part of the group,the lineaments are not mapped nor are expressed in the glacial valleys;along the southern part of the group the lineaments are oriented along the drainage direction toward the Susitna River.Aerial investigation revealed no field evidence that linear strain markers were deformed or displaced,however the glacial sediments are from rock glacier processes,and few older landforms such as moraines,eskers,or terraces were observed along this group.The expression of the lineament is inconsistent along strike with an apparent stronger expression where mapped along fluvial drainages,and no expression in WNW- oriented cirque-floors or valleys.An additional lineament feature less than 2 km [ 1 mile]away from the group 7 also was inspected,although this was not formally included as part of group 7.This feature trends slightly west of north,and is expressed as a large notch near rock glacier deposits.Low altitude INTERIM DRAFT Page 26 of 81 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. fly-overs allowed a visual inspection of the notch that was estimated to be about 15 meters tall ( 50 ft). No corresponding notch or groove was observed in the ridgeline on projection to the north,thus the groove was probably created by non-tectonic surface processes. Lineament group 7 does not show consistent field expression in Quaternary deposits or landforms.The largest magnitude relief along the lineament is along the south-flowing drainages,and relief is not expressed topographically across the WNW trending cirque valley floors.Because the lineament expression in Quaternary deposits is chiefly linear gullies (erosion)with no apparent difference in relief across the gulley,the expression does not suggest either normal or reverse-type faulting.A translational kinematic sense of motion cannot be ruled out;however there is little along-strike expression to assess the sense or magnitude of potential relative lateral motion.There are previously mapped faults along the mapped lineament (Wilson et al.,2009;Figure A7.1).However,there are large scale topographic changes (i.e.reverses)along the length of the fault (and lineament)that leads to an inconsistency in location,magnitude,and type of lineament expression.These inconsistencies,coupled with the fact that the Quaternary deposits in the valley floors are not disrupted,strongly indicates that erosional process of creek incision and downcutting into surface deposits along the south-flowing drainages are likely responsible for creating the mapped lineament feature.Where mapped in bedrock,lineaments of group 7 generally coincide with mapped bedrock structures within fault-line-valleys but lineaments in late Quaternary deposits are inconsistently expressed and likely relate to processes of erosion.No evidence of Quaternary deformation along the mapped lineaments was observed and no further work is deemed necessary. Lineament Group 8:Observations and Evaluation The lineaments of group 8 are north-northwest-oriented features expressed topographically as aligned V-and U-shaped,linear to sub-linear drainages,aligned with several discontinuous slope breaks and linear fronts (Figures A8-1.1 and A8-2.2),approximately 38 km ( 24 miles)west of the proposed dam site (Figure A0.1).The lineament group coincides with a north-trending promontory around which the Susitna River makes a prominent bend in course (Figure A8-1.1).The middle portion of lineament group coincides with an unnamed,inferred fault mapped by Wilson et al.(2009)that juxtaposes Tertiary undivided volcanic rocks (map unit Tvu)against Paleocene granite (map unit Tpgr)and also granodiorite (map unit Tgd)against turbidites of the Kahiltna flysch (unit KJs)(Figure A8-2.1).WCC lineament feature KD5-44 also coincides with lineament group 8 (FCL,2013).WCC described their feature KD5-44 as a linear stream valley north of the Susitna River,and south of the Susitna River as a linear valley (Cheechako Creek and a tributary creek)and "a shallow,broad,linear depression on the upland plateau...”(WCC,1982).No direct evidence of fault exposures were observed during ground and low level aerial investigation but indirect evidence in the form of changes in lithology across the linear valley was observed near the middle of the lineament group (Photograph C,Figure A8-2.2).The linear trend of the lineament group across the terrain suggests any potential fault that may exist has a INTERIM DRAFT Page 27 of 81 01/20/14 -Z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. very steep to near-vertical dip.The lineaments are expressed in ice-scoured bedrock uplands and a thin cover of glacial and colluvial deposits subject to solifluction.The bedrock ranges in age from Cretaceous-Jurassic flysch (map unit KJf)to Tertiary volcanics (map unit Tvu).The glacial deposits are likely latest Pleistocene to early Holocene ( 11 to 12 ka)in age while the colluvium is latest Holocene to modern in age.The mapped lineaments transect across several different bedrock units (Figure A8-1.1 and A8-2.1).The magnitude of expression ranges from none in broad,flat-lying terrain,to 1-to 2-m- high (3-to 6-ft)scarps in solifluction-prone colluvial slopes,to deeply incised linear streams and 50-to 100-m-high ( 164 to 328 ft)linear fronts (Figures A8-2.2 and A8-2.3).The lineament group lies roughly perpendicular to the direction of glacial striae.Glacial striae north of the Susitna River do not appear consistently deformed or displaced across the trend of the lineament and,although the Susitna River does take a tight bend-in-course along the projection of some of the mapped lineaments,several small streams that cross the lineaments near GPS waypoints 177 and 195 are not consistently laterally offset or deflected (Figure A8-2.1).Aerial investigation did reveal the oxidized mafic dike on the northern canyon wall of the Susitna River that WCC (1982)observed projecting across the observed lineament trend but discovered the same ambiguous and poor exposure conditions described by WCC. The 2013 aerial investigation efforts discovered no new evidence to confirm or refute WCC's (1982) interpretation that the dike is not truncated by the linear drainage (FigureA8-2.3);ground access may be required.Based on the preponderance of east-facing bedrock escarpments,the morphology of the lineament group overall suggests down-to-the-east or dip-slip motion on high-angle faults,but a few west-facing escarpments do exist.In addition,mapped fault relations that juxtapose units (Wilson et al., 2009)along the middle of the lineament group are not entirely consistent with the contact of turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs)and Paleocene granite (map unit Tpgr)being apparently undeformed across the northern portion of the lineament (Figure A8.1). Portions of lineament group 8 are expressed in very thin Quaternary (i.e.,latest Holocene)colluvial and glacial deposits that overlie bedrock,but the lineaments are not consistently expressed in Quaternary strain markers (i.e.,stream channels).In two locations,on the north side of Susitna River and along its southern extent,individual lineaments of the group appear to be overprinted by glacial or flood-derived striae (Figure A8-1.1 and A8-2.1).The orthogonal orientation of the lineaments to the regional ice-flow direction suggests that most of the lineament features likely do not result from ice scour or abrasion. However,other ice-related processes such as plucking might explain some of the short lineaments north of the Susitna River where the small east-facing (and up-ice stream-facing)knobs of turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs)might have been preferentially erodible due to the highly bedded nature of the unit.Lineament group 8 does transect different mapped geologic units but does not exhibit relative consistency of geomorphic expression along strike.For example,in the middle of the group,both east-and west-facing topographic scarps in undivided Tertiary volcanics (map unit Tvu) range up to 50 to 200 m high ( 164 to 656 ft)but apparent scarps in thin colluvium overlying Tertiary granodiorite (unit Tgd)near GPS waypoints 177 and 195 are less than several meters high (Figure A8- INTERIM DRAFT Page 28 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. 2.2 and A8-2.3).Furthermore,the lack of spatially-connected and through-going lineaments across the ice-striated terrain north of the Susitna River is inconsistent with the magnitude of expression the deeply-incised linear streams and tall linear fronts to the south.In addition,the apparent structural kinematics (dip-slip)based on mapped contact relations compiled by Wilson et al.(2009)for the middle and southern portion of the group are not consistent with the undeformed contact relations between turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs)and Paleocene granite (map unit Tpgr) near the Susitna River and also the lack of deformation in turbidite rocks (map unit KJs)north of the river.Lineament group 8 is spatially coincident with previously mapped lineaments (feature KD5-44 of WCC (1982))and faults (Wilson et al.,2009)but making kinematic sense of the mapped fault and unit contact relations is challenging.No positive evidence of active tectonism was observed and the discrepancy in magnitude in the apparent tectonic geomorphology along the group is inconsistent with a genesis by active faulting;a fault capable of producing topographic displacement on the order of 50 or more meters ( 164 ft)should leave a more consistent,through-going pattern of deformation on the landscape.Overall,the evidence supports the presence of a fault-line-scarp (an erosional feature aligned with a mapped fault)along the middle and southern portions of group 8 where glacial erosion may have preferentially eroded along pre-existing faults or lithologic contacts. Lineament Group 9:Observations and Evaluation Lineament group 9 consists of north-northwest oriented features expressed principally as a prominent V-shaped linear drainage greater than 5 km ( 3 miles)in length,along with smaller,sub-linear aligned drainages,aligned knobs,and short east-facing slope breaks (Figures A9-1.1 and A9-2.1 through A9- 2.4)approximately 31 km ( 19 miles)west of the proposed dam site (Figure AO.1).The southern portion of the lineament group coincides to an inferred fault mapped by Wilson et al.(2009)that lies within the prominent linear V-shaped drainage and juxtaposes Paleocene granitics (map unit Tpgr) against turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs)(Figure A9-2.1).The lineament group also coincides with WCC fault KC5-5.WCC (1982)described the feature as a linear stream drainage north of the Susitna River and a prominent linear canyon and shallow linear depression south of the Susitna River that is fault-controlled in several locations.Indirect evidence of fault structure was observed along the prominent linear V-shaped drainage in the form of contrasting rock types (Figure A9-2.4).With the exception of the southern end,the strongly linear trend of most of the lineament group implies that any potential tectonic structure would have a steep to near-vertical dip.At the southern end of the lineament,the mapped lineaments that curve around a hill near WCC segment 4 (Figure A9-2.1)suggest that a fault in this area would have a moderate to shallowly west-dipping orientation.Individual lineaments are expressed in several Cretaceous to early Tertiary bedrock units exposed in the glaciated uplands:turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs), Paleocene granitics (map unit Tpgr),and at the contact between units those units where the inferred fault trace is mapped (Wilson et al.,2009).North of the Susitna River,lineaments are expressed as short,discontinuous,and weakly-aligned,bedrock knobs,and in the southernmost portion of the group INTERIM DRAFT Page 29 of 81 01/20/14 -Z-ALASKA ENERGY AUTHORITY ;AEA11-022SUSITNA-WATANA HYDRO 46-1404-TM-012014 Clean,reliable energy for the next 100 years. as 1-to 4-m-high ( 3-to 13 ft),east-facing slope breaks in thin colluvium overlying bedrock.The mapped lineaments do transect mapped bedrock units,but are not expressed in the limited extent of Quaternary surficial deposits present along the group.No lineaments were observed in post-glacial (early Holocene)fluvial deposits within a broad depression (Figure A9-2.1)or across the extent of a post-glacial landslide located in WCC segment 3.The scale of expression of the lineaments is variable along trend.The 1-to 4-m-high ( 3-to 13 ft),east-facing slope breaks in the south contrast with the >300-m-deep ( 985 ft)linear V-shaped canyon,and the absence of any lineaments in above-mentioned late Quaternary deposits.The orthogonal orientation of the lineament group to the regional ice-flow direction (Figures A9-1.1 and A9-2.1)suggests that the lineament group as whole likely does not result from ice-flow or scour,but individual knobs in the north could relate to plucking by flowing ice.No field evidence of consistently deformed linear strain markers was observed along the lineament group during low altitude aerial or ground investigation.A sharp bend in the Susitna River exists where the lineament group projects across the river (Figure A9-1.1)but south of the river lies an apparently undeformed contact between turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs)and Paleocene granitics (map unit Tpgr),while the southern portion of the lineament group corresponds to an inferred fault mapped by Wilson et al.(2009)that juxtaposes those same rock types (Figure A9-2.1). Based on the mapped geologic contacts along the southern portion of the group,the apparent sense of offset is right-lateral with possible unknown oblique component.However,this is kinematically inconsistent with the mapping north of the Susitna River because the mapped contact between Cretaceous Kahiltna flysch (map unit KJs)and Paleocene granitics (map unit Tpgr)is apparently undeformed and undisplaced where the lineament group projects across the contact. WCC's evaluation of their feature KC5-5 led them to recognize four segments of the feature (WCC, 1982)(Figures A9-1.1 and A9-2.1).Segment 1 is the linear drainage that lies north of the Susitna River.WCC acknowledged that the drainage may be fault-controlled but WCC did not observe any evidence that conclusively confirmed or precluded a fault origin (WCC,1982).Low-level aerial investigation revealed that the drainage is only weakly linear and did not reveal any evidence to refute WCC's observations. Segment 2 is the V-shaped linear drainage >5 km ( 3 miles)in length directly south of the Susitna River.Here,WCC observed fault zones via helicopter aerial reconnaissance in three different locations running parallel to the overall lineament orientation.The fault zones are a few inches (few centimeters) to a few feet (few meters)in width,near vertical in orientation,light gray in color,and form sharp, distinct boundaries within intrusive rocks and locally separate intrusive from metamorphic rocks.No evidence to determine the sense of displacement was observed (WCC,1982).These fault zones may be similar to the zones of light-colored,fractured,and highly weathered rock in Cheechako Creek along lineament group 8 observed by both WCC and FCL during aerial inspection.One or more of these fault zone location may lie within the view captured in photograph J of Figure A9-2.4. INTERIM DRAFT Page 30 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Segment 3 is a broad and shallow curvilinear depression in the bedrock upland south of segment 2. Mapping completed by WCC revealed that a contact mapped by Csejtey et al.(1978)between Cretaceous argillite and greywacke metasediments on the west and Tertiary intrusive rocks on the east, which was previously thought to coincide with the depression,is too irregular to match the contact. Rather,WCC describes that the fault zone lies entirely within the Tertiary intrusive rocks (WCC,1982). However,more recent compilations of mapping (i.e.,Wilson et al.,2009)show this area as turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs)(Figure A9-2),suggesting an apparent discrepancy in the understanding of the geologic units.Field investigation in July of 2013 confirmed the presence of granodiorite (presumably equivalent to Paleocene granitics;unit Tpgr)in a nearby drainage previously mapped as exposing turbidite rocks of the Cretaceous Kahiltna flysch (map unit KJs)(Figure A9-2.1 and A9-2.4),confirming the interpretation that contact relations from this ground inspection are more complicated than shown by Wilson et al.(2009). Regardless of the bedrock lithologies present,WCC observed sediments in the broad depression which they interpreted to be approximately 40,000 to 75,000 years in age.Their aerial inspection revealed no evidence of deformation of the sediments and they interpreted that the observed fault zones had not experienced displacement within the last 40,000 years (WCC,1982).Based on an updated view of the Quaternary glacial history of the region (Section 3.3),these sediments are likely much younger,as deglaciation of this area is possibly as young as 15,000 to 11,000 years.Our low-level aerial and ground inspection confirmed the absence of any apparent deformation or lineaments observed by WCC (1982)(Figure A9-2.4). Segment 4 consists of an alignment of east-facing linear bedrock scarps,some of which coincide with the location of several springs (Figures A9-2.2 and A9-2.3).These topographic escarpments are readily apparent in the INSAR data along the southernmost portion of the lineament group (Figure A9-2.1)and are the most suspiciously fault-like geomorphic features in the group.WCC's field investigations suggested that the scarps could relate to differential erosion controlled by jointing but that the scarps are not controlled by lithologic contacts.WCC could not identify direct evidence of faulting along segment 4 of their Fault KC5-5 but did acknowledge the segment could be fault controlled (WCC,1982). Ground access restrictions prevented thorough study of all the features but aerial inspection revealed the lineaments are generally 1-to 4-m-high,east-facing slope breaks that are each several hundred meters or more long (Figures A9-2.2 and A9-2.3).The features align in a subtle curve across the topography, suggesting that any fault here would have a moderate to shallowly west-dipping orientation.Detailed review of the geomorphology along the features revealed apparent morphological and kinematic inconsistencies;in adjacent drainages both left-lateral and right-lateral apparent sense of motion indicators were observed,which is further inconsistent with the apparent west-up/east-down thrust movement suggested by adjacent features along trend and the apparent the west-dipping orientation of the features as they cross topography. INTERIM DRAFT Page 31 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401 -TM-012014 Clean,reliable energy for the next 100 years. After evaluating all four segments of their Fault KC5-5,WCC concluded that together the observed features represented a fault without recent displacement,noting "the absence of any compelling evidence of recent displacement (e.g.,systematic stream drainage offsets,scarps in recent sediments,or offset of youthful geomorphic units)”(WCC,1982;p.4-44).Low altitude aerial and ground inspection in July of 2013 of the lineaments of group 9 revealed similar evidence and concluded that the features are likely a fault-line scarp.For example,no evidence of expression in Quaternary units,landforms,or strain markers was observed.Furthermore,although a rock-type contrast does exist across portions of the lineament,the current mapping compilation may be too simplified and more irregularity of bedrock unit contacts likely exists along the linear V-shaped drainage and mapped fault.Although the lineament group does coincide with a previously mapped fault and also cuts across several bedrock units,the magnitude of expression and apparent sense of deformation observed in the field is inconsistent along trend.Lineament group 9 is interpreted to represent a fault-line scarp and not a Quaternary tectonic feature. Lineament Group 10:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013)that the lineament group is over 70 km ( 44 miles)from the proposed dam site and is less than 40 km ( 25 miles)long (Table 5-2),and likely would not appreciably contribute to the hazard calculations.Strip maps for this group are not included herein (Figure AO)but were presented as part of FCL (2013).During limited flyovers in 2013,no features were observed that suggested a need to revise those conclusions. Lineament Group 11:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013)suggesting that surficial processes are likely exploiting existing topographic position and/or local weaknesses in the underlying Cretaceous Khalinta flysch bedrock to create the lineaments.Strip maps for this group are not included herein (Figure AO)but were presented as part of FCL (2013).Limited overflight of these features in 2013 appears to confirm this conclusion.In addition,the group is greater than 30 km ( 19 miles)from the proposed site and is less than 20 km ( 12 miles)in length (Table 5-2), and likely would not appreciably contribute to the hazard calculations. Lineament Groups 12a &12b:Observations and Evaluation Lineament 12a traverses part of the southeastern-facing Paleozoic volcanic hills in the Fog Creek area, about 14 km ( 9 miles)southeast of the proposed dam site (Figures AO.1 and Al2a.1).Aerial and ground inspection of group 12a confirmed the presence several southeast-facing slope breaks near the lower flanks of the hillside of the northern part of the group (Figure Al2a.2).There are no previously mapped faults within this group;however,field observations of color contrasts within the Paleozoic INTERIM DRAFT Page 32 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. rocks (map unit Pzv)suggest the possible presence of northeast-oriented bedrock structures.No evidence of a fault was observed along the lineament group trend.A prominent notch with an uphill- facing slope break was observed within the Paleozoic rocks along the nose of a ridge (Photograph C, Figure Al2a.2).The topographic expression of this lineament feature on the ridge topography implies a northwest-dipping structure geometry.Bedded rock exposed on the other side of the mountains within the northwest-facing cirque walls appear to have a generally northwest dip and a moderate ( 457) degree dip angle.The topographic expression of the lineaments about 1.2 km ( 3/4 mile)to the north of the notch may allow an inferred northwest-dipping geometry but with a much shallower dip plane as compared to the notch feature;suggesting a substantive change in dip should the lineaments represent a structural fault.The individual lineaments mapped along the north part of the group chiefly are within probable latest Wisconsin-age glacial deposits near the valley margin,and are oriented along the ice flow direction.To the southwest,the lineaments rise in elevation and are mapped in the Paleozoic rocks (map unit Pzv)above the contact with glacial sediments (map unit Qs).There are no lineaments expressed in the Quaternary deposits along about the southern half of group 12a,and there is visual evidence that right-lateral moraine and kame terrace features at the southern end of the group are not offset.The relief of the lineaments along strike is variable,and generally is greater in magnitude within the bedrock than the unconsolidated deposits.However,the morphology of the features is kinematically inconsistent along strike,with south-east facing downhill slope breaks found on the lineaments in the Quaternary deposits,and an uphill facing slope break on the bedrock notch feature. Although the individual lineaments of group 12a are mapped within late Quaternary deposits along the valley margin,there is no expression of deformation or offset of late Wisconsin landforms in kames or delta surfaces within the valley of Fog Creek directly north.Similarly,there is no expression of deformation or offset of late Wisconsin landforms in lateral moraines or delta surfaces within the Clear Valley directly south of group 12a.The individual lineaments appear to traverse both Paleozoic rocks as well as late Quaternary deposits,however,as noted above there is an inconsistent morphologic expression of those features along strike,as well as inconsistent relative structural kinematics (apparent dip,scarp direction)along the lineaments.The slope breaks within the Quaternary sediments along the northern part of the group appear to be a result of solifluction and to a lesser extent,nivation processes, and thus are dominantly erosional in origin.The observation of multiple slope breaks on the hillslope in the vicinity of the mapped lineaments,as well as the general lineament orientation being parallel to ice flow directions,suggests the lineament group was not produced by tectonic processes,rather glacial deposits that are now undergoing solifluction and nivation processes.From these observations and interpretations,it is judged that the lineaments within group 12a are the result of both past glacial processes,ongoing hillslope erosion processes,and potentially bedding relationships within the Paleozoic rocks,and do not represent a tectonic fault. INTERIM DRAFT Page 33 of 81 01/20/14 -za-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Lineament group 12b is approximately 16 km ( 10 miles)southeast of the proposed Susitna-Watana dam site,and is about 2 km ( 1.5 miles)northwest of lineament group 12a and directly west of Mount Watana.Lineaments within group 12b are coincident with an unnamed,kinematically-undefined fault (Clautice,1990)within the Paleozoic Slana Spur volcanic rocks (map unit Pzv)(Figure A12b.1), however no direct or indirect field evidence of the fault was found from low-altitude inspection;the morphologic expression of the feature is incised drainages and a very broad and deep valley within which a small creek now flows (Photograph C,Figure Al2b.2).The trend of the lineament group across topography is essentially linear,implying a vertical geometry that cuts directly across contours.The lineaments are expressed chiefly in Paleozoic rocks,however,a thin cover of Holocene regolith mantles the rocks,consisting of unmapped talus,solifluction of glacial material,colluvium,and alluvium,in which the lineaments also are mapped.The lineaments show no field evidence of offsetting or deforming those sediments.The scale of expression of the lineaments varies along strike:it is rather large at the middle and northern end of the lineament group where it is coincident with an unnamed northeast-flowing drainage;the expression decreases along the southern end of the lineament group. The middle and northern part of the lineament group is oriented parallel to a glacial ice flow from cirques toward the Susitna River.The southern part of the lineament group is less certainly assessed with respect to ice flow because of its topographic position on the landscape.None of the glacial geomorphic surfaces in Fog Creek valley (e.g.eskers,deltas)along the southwestern projection of the lineaments were observed to be offset or deformed,and no evidence of deformation was observed at the Susitna River margin along the northeastern projection.Along the south-center part of the lineament group,a northwest-facing break in slope morphology may suggest reverse-type movement (i.e. northwest vergence),however,the ends of the group do not exhibit any strong kinematic indicators. The lineaments within group 12b did not show field evidence of expression in Quaternary deposits or landforms serving as strain markers,notably along the southwestern projection of the group into Fog Creek valley with late Wisconsin landforms.The lineament is chiefly constrained to within the Paleozoic volcanics (map unit Pzv),and is coincident with the previously mapped fault of Clautice (1990),suggesting a potential structural control and preferential erosion along the pre-existing structure. Alternatively,internal lithologic control on the geomorphic expression of the lineament (e.g.bedding)is plausible given the lack of lineament continuity beyond the Paleozoic rocks.The lineament group appears to have a variable geomorphic expression along strike,has weak kinematic indicators along strike,and has its largest surface expression in drainages flowing away from the area of kinematic indicators.In total,the field observations and data evaluation suggest that glacial and post-glacial fluvial erosional processes are a likely explanation for the origin of the lineament features.Individual lineaments may represent fault-line scarps or fault-line-valleys but due to the lack of expression in Quaternary deposits,the lineament group is not considered a Quaternary tectonic structure and no further work is deemed necessary. INTERIM DRAFT Page 34 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Lineament Group 13:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013).Strip maps for this group are not included herein (Figure AO)but were presented as part of FCL (2013).FCL (2013)interpreted that lineament group 13 was the result of erosion,but also discussed that the lineament group lies greater than 40 km ( 25 miles)distant from the proposed dam site and is less than 20 km ( 12 miles)in aggregate length (Table 5-2)and would therefore likely have limited contribution to the hazard calculations.During limited flyovers,no features were observed that suggested a need to revise those conclusions. Lineament Group 14:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013).Strip maps for this group are not included herein (Figure AO)but were presented as part of FCL (2013).The group is greater than 30 km ( 19 miles)from the site and less than 20 km ( 12 miles)in aggregate length,(Table 5-2)thus meeting lineament exclusion criteria.A limited fly-over in 2013 revealed no features that that suggested a need for additional analysis. Lineament Group 15:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013).Strip maps for this group are not included herein (Figure AQ)but were presented as part of FCL (2013).FCL (2013)excluded the group from further analysis on the basis of its large distance from the proposed damsite ( 43 km [ 27 miles])and short aggregate length ( 6 km [ 4 miles])(Table 5-2).A limited fly-over in 2013 revealed no features that that suggested a need for additional analysis. Lineament Group 16:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013).Strip maps for this group are not included herein (Figure AQ)but were presented as part of FCL (2013).This group is sub-orthogonal to the map trace of the Talkeetna fault (Csejtey,1978;Wilson et al.,2009),directly north of the WCC trench T-2 site (Figures 2-1 and 5-3).The group was excluded from further analysis on basis on its significant distance to the proposed damsite ( 60 km [ 37 miles]) and relatively short aggregate length ( 19 km [ 12 miles])(Table 5-2).During limited flyovers,no features were observed that suggested a need for additional analysis. Groups 17a,17b,&17c:Observations and Evaluation Lineament group 17a is a north-northwest trending lineament,approximately 24 km ( 15 miles)west of the proposed Susitna-Watana dam site (Figure AO.1).Lineament group 17b is a north-northwest trending lineament group,approximately 36 km ( 22 miles)southwest of the proposed Susitna-Watana dam site.Lineament group 17c is approximately 45 km ( 28 miles)south-southwest of the proposed INTERIM DRAFT Page 35 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401 -TM-012014 Clean,reliable energy for the next 100 years. Susitna-Watana dam site,and is the southernmost extent of lineament the 17a,17b,and 17c series (Figures AQ.1 1).Lineament group 17a is not coincident with previously mapped faults,however,the southerly extent of 17b and parts of 17c are (Figure Al7b.1 and Al7c.1).Wilson (2009)depicts a lineament coincident with 17a and another coincident with 17b.Although aerial field inspection did not find evidence to directly confirm the presence of a fault within group 17b and 17c,contrasting rock types and units were observed in the field in general consistency with previous geologic mapping, allowing the possibility of a bedrock fault structure along these groups. Lineaments within group 17a are mapped along a northerly segment of the Susitna River,a north- trending canyon tributary,and in the Quaternary deposits south of the canyon (Figure Al7a.1).No evidence of a fault was observed at the northern end of the lineament group along the south-facing wall of the Susitna River,nor along strike to the north.Low altitude aerial field inspection revealed that the lineaments in Quaternary deposits at the south end of group 17a do not show scarp-like morphologies; rather one is a discordant,small,creek drainage and the other appears to be a depositional contact of likely late Holocene grassy swale (bog)sediments against a near-surface ice-sculpted bedrock buttress (Figure Al7a.2).Lineament group 17a is somewhat off-trend of lineament groups 8 and 9,and also appears to follow a bedrock jointing pattern that is expressed on the landscape.Based on the absence of compelling evidence for Quaternary tectonism,lineament group 17a is judged to not represent a tectonic fault. As noted above,lineaments within the group 17b are somewhat coincident with previously published inferred faults and lineaments.Aerial field inspection indicated that the morphologic break in slope along the FCL-mapped lineaments at the base of the uplands near the western margin of the valley is not as sharp and abrupt in the field as implied on the INSAR-derived DEM.The most prominent morphologic feature is actually a narrow drainage that is fed by a perched lake;review of USGS topographic maps confirmed this linear feature as a creek.The trend of the lineaments across topographic contours is straight,but also parallel to contour because it is in the valley bottom;this would imply either a vertical or horizontal hypothetical fault dip geometry.The lineaments are chiefly mapped in thin glacial-derived sediments that primarily reflect erosion by small creek drainage,and are probably Holocene age.Near the south end of group 17b,the lineaments are mapped as extending out of the glacial deposits and traversing Tertiary volcanics (map unit Tvu)and Paleozoic volcaniclastic rocks of the Slana Spur formation (map unit Pzv)(Figure A17b.2)directly north of the Talkeetna River. Field investigation found no direct evidence of a fault along this trend.The lineaments appear to coincide with the trend of glacial ice flow directions that were valley parallel.The southeasterly oriented inferred fault of Csejtey (1974)also was not confirmed in the field;this area appears to be sculpted bedrock knolls that have been slightly dissected and mantled by a thin veneer of youthful glacial deposits (Figure Al7b.2).South of the Talkeetna River,the southern part of group 17b coincides with a short inferred fault of Wilson (2009).Low altitude fly-overs of this area discovered a INTERIM DRAFT Page 36 of 81 01/20/14 za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. positive relief "mole track-like”features present on the ground along the FCL-mapped lineament. Ground inspection resulted in the conclusion that the feature in fact is a pro-talus rampart;a geomorphic feature constructed by talus collecting in a snow covered field that results in talus deposition a short distance away from the base of the slope (Figure A17b.3).The ground inspection supports the interpretation that glacial ice was present in the valley by the observation of an out-of-place glacial erratic.Although there may be a bedrock structure along part of this group that separates Paleozoic (map unit Pzv)and Mesozoic rocks (map unit Tvu),lineament group 17b is judged to be created at the local scale by fluvial erosion as well as in part by glacial ice erosion of the linear valley and periglacial processes. Along part of its northern and southern ends,lineament group 17c is partially coincident with faults previously mapped by Wilson (2009),although none are recognized by Csejtey (1974)and Clautice (1990).None of the faults depicted on Wilson (2009)are shown extending across or displacing Quaternary glacial or moraine deposits.No evidence was found during low altitude aerial field investigation to confirm the northern (dashed and inferred)previously mapped fault in group 17c.Near the southern end of 17c,the depicted rock juxtaposition between units Tertiary volcanic rocks (map unit Tvu)and Eocene mafic volcanic rocks (map unit Tem)(i.e.bedrock fault)was not lithologically well expressed in the field with apparently similar bedded volcanic rocks exposed on either side of the canyon walls (Figure Al7c.1),and the presence of the previously mapped fault is unconfirmed.The lineament trends across topography irrespective of contours in steep terrain,suggesting a near vertical geometry for a hypothetical structure.The lineaments are mapped across Tertiary volcanic rocks as well as in young (likely Holocene)rock glacier deposits;the expression within the rock glacier deposits correspond to relatively deep drainages eroded into the rock glacier deposits (Figure Al7c.2).The scale of the lineaments'expression along strike varies;along the north end of group 17c cirque ridges that are traversed by previously mapped structure are not offset and little relief is expressed topographically. Along the middle of the group the lineaments are expressed as ridgeline saddles with adjacent ridge peaks standing about 75 meters ( 246 ft)above the saddle whereas on the INSAR DEM the lineaments are attributed as linear v-shaped troughs.Along the south end of lineament group 17c,the relief along the lineament in the Quaternary rock glaciers is lesser than the middle part of the group,however,the relief in the rock glacier drainage is about 25 meters ( 82 ft);much larger than would be expected for a relatively low-slip rate fault structure in young post-glacial deposits.While the presence of a bedrock fault cannot be ruled out along lineament group 17c,it is judged that the mapped lineament is the result of erosion into the rock glacier deposit. Lineament groups 17a,17b,and 17c are each independently judged as formed by erosional processes (fluvial and/or glacial)as described above,based on field observations and interpretations.Collectively, these groups do not form a continuous geologic structure based on an absence of faults observed INTERIM DRAFT Page 37 of 81 01/20/14 -Z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. (directly or indirectly)in the field,and the inconsistent and variable geomorphic expression of the lineaments in the landscape along 17a,17b,and 17c as a whole. Lineament Group 18:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013)which concluded that the group's large distance to the proposed damsite and short overall length (Table 5-2)would likely not appreciably contribute to the hazard calculations.Strip maps for this group are not included herein (Figure AO)but were presented as part of FCL (2013). Lineament Group 19:Observations and Evaluation Lineament group 19 is a semi-arcuate,northeast-trending group of linear features that is nearly 44 km ( 27 miles)long,located approximately 54 km ( 34 miles)southeast of the proposed Susitna-Watana dam site (Figure AO.1).This feature is defined by a series of aligned,gently-sloping linear range-fronts, slope breaks,linear valleys,and a few aligned saddles (Figures A19-1.1,A19-2.1,and A19-3.1). Existing geologic mapping (Wilson et al.,2009;Csejtey et al.,1978)suggests that this lineament group may represent a bedrock contact zone between various Jurassic age bedrock units (mostly Trondhjemite {map unit Jtr]vs.a migmatite border zone of granodiorite [map unit Jpmu]).An inferred fault mapped by Clautice (1990)lies east of the aligned features along a parallel orientation and nearly converges with the lineament group near the northern projection of the lineament (Figures A19-1.1,A19-2.1,and A19- 3.1).Indirect evidence of a fault structure was observed in the southwestern portion of the lineament where apparent rock type contrasts were observed via aerial inspection across an alignment of linear drainages (Figures A19-1.2 and A19-1.3).The trend of this rock type contrast/rock contact across the topography is very linear,suggesting that any tectonic feature present would have a near-vertical to steeply-dipping orientation.The features making up lineament group 19 are expressed in bedrock valleys,bedrock plateaus,valley-margin glacial deposits,and colluvial deposits.The ages of deposits in which lineament features are expressed ranges from the Jurassic age bedrock exposed in the linear valleys shown in Figures A19-1.2 and A19-1.3 to thin colluvial deposits of latest Holocene age.Low- level aerial inspection revealed that the lineaments of group 19 do transect several different geologic units and landforms,but are not present in the post-glacial (Holocene)alluvium of the Goose Creek or adjacent drainages (Figure A19-2.1).The magnitude of expression of the lineaments ranges from 10- m-high ( 33 ft)downhill-facing slope breaks in glacial deposits of the Black River to gently sloping 125-m-high ( 410 ft)(Photograph A,Figure A19-2.2;Photograph A,Figure A19-3.2)bedrock escarpments.The lineament group is roughly parallel to glacial ice flow directions in the Black River canyon and spatially coincident with left-lateral ice margins as mapped by Williams and Galloway (1986)(Figures A19-1.1,A19-2.1,and A19-3.1).Field inspection did not reveal any displaced or deformed linear strain markers along the lineament.The morphology of the lineament and its expression in the landscape suggests that,if it were a tectonic fault,it would be a strike-slip fault. INTERIM DRAFT Page 38 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Low altitude aerial observations showed variable evidence of lineament expression within the Quaternary deposits along lineament group 19.Lineaments are expressed in the glacial deposits of the Black River,but not in Holocene age rock glacier and glacial moraine deposits at the head of Kosina Creek (Photographs E and F,Figure A19-1.3),nor in the Holocene-age deposits of the Goose Creek adjacent drainages (Figure A19-2.1).(The lineaments in the glacial deposits of the Black River valley occur parallel to the ice-flow direction and their geomorphic position high on the left side of the valley suggests that the lineaments are most likely left lateral moraine or kame terraces.)The large magnitude of relief across the lineaments in the northeastern portion is inconsistent with the apparent lack of topographic offset across the lineaments in the southwest portion of the group.Specifically,the surfaces of the exceptionally planar bedrock plateau across which the aligned linear valleys run (Figure A19-1.1)show no evidence of the vertical displacement apparent along the lineament group to the northeast.This inconsistency in relief does not support the existence of a tectonic structure along lineament group 19.Bedrock exposures observed during ground inspection in creeks along the lineament showed evidence of pervasive jointing (Photograph C,Figure A19-3.2)which is the likely genesis of the linear troughs and swales at the northeast-most portion of the group (Photograph D). Lateral ice margins mapped by Williams and Galloway (1986)coincide with many of the mapped lineaments (Figures A19-2.1 and A19-3.1),providing a non-tectonic origin alternative.In addition,a series of sub-ice fluvial channels located just north of Goose Creek (Photograph B,Figure A19-3.1) cross the lineament and do not appear to be displaced.For these reasons,lineament group 19 is not interpreted to be the result of Quaternary tectonic faulting;a fault or bedrock contact may exist in the southwest portion of the group,but there is no direct evidence of Quaternary tectonic activity anywhere within the group.It is judged that lineament group 19 is a result of a combination of bedrock jointing and glacial and post-glacial erosion processes,and does not represent at Quaternary fault. Lineament Group 20:Observations and Evaluation Lineament group 20 is a northeast-trending lineament group defined by a series of sub-linear,aligned drainages,saddles,broad U-shaped troughs,and V-notched linear canyons expressed in an area of gently rolling hills and terrain of relatively modest-relief (Figures A20.1,A20.2,A20.3,and A20.4), approximately 94 km ( 58 miles)southeast of the proposed Susitna-Watana dam site (Figure A0.1). Some of the lineaments in this group coincide with mapped,unnamed faults with apparent vertical throw (Grantz,1960)that lie along the northeastern projection of the Castle Mountain fault (Figure AO.1,Plate A-CME).Early mapping by Grantz (1960)shows stratigraphic offsets within Tertiary (Eocene)units as well as between Tertiary (Eocene),Cretaceous,and Jurassic age rocks.However, more modern compilations (Wilson et al.,1998)show the same faults juxtaposing Jurassic-age sedimentary rocks against one another as well as Jurassic sedimentary rock units against Tertiary sedimentary units,suggesting a revised understanding of the geologic units with further study.No direct evidence of any of the mapped faults was apparent in the field during aerial or ground inspection but indirect evidence in the form of apparent rock type contrasts across mapped faults was observed INTERIM DRAFT Page 39 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY .AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. near GPS way point 018 and locations to the southwest of GPS way point 018 (Figure A20.1).The trend of the lineaments across topography is very linear,suggesting any potential fault structures would be steeply dipping.Grantz's (1960)map unit Jns (Jurassic sandstone)is the oldest unit in which the linear drainages and aligned saddles occur in while the youngest map unit to express lineaments is Eocene fluviatile conglomerate and coaly sandstone (map unit Tf)(Figure A20.1).Very few Quaternary units were observed during field investigation of this group;colluvium is relatively thin and thin alluvial deposits are restricted to narrow watercourses.The area appears to be a region of erosional or residual terrane with gentle slopes with relatively non-resistant bedrock and few solifluction features. None of the mapped lineaments are concordant with glacial ice-flow directions;there is no field evidence of erosion from glacial ice within the area of the lineament group 20 (Figure A20.5)although the presence of glacial lake sediments and glacial erratics suggests the presence of glacial lakes (Figure A20.1).The magnitude of expression of the lineaments is not consistent along trend.For example,the mapped lineaments often alternate between weakly expressed and subtle slope breaks and broad troughs and deep and well-defined linear valleys.A prime example is the U-shaped swale shown in photographs A and B of Figure A20.1 which is not matched by similar features along trend to the southwest (Photograph C). Based on the bedrock map units alone,a short fault mapped by Grantz (1960)as running through the middle of the lineament group 20 ellipse and which is mapped as displacing Eocene fluviatile conglomerate and coaly sandstone (map unit Tf)in a down-to-the-southeast sense.GPS way point 001 lies on this fault.(Wilson et al.'s (1998)compilation of the area does not include this fault,but whether this difference is due to the regional scale of their compilation,or the discovery of additional evidence to refute the fault's existence is unknown.Consequently,review of the original mapping is warranted.) As noted above,a mapped lineament feature is spatially associated with this fault where the fault passes through a saddle but the lineament is not consistently expressed along trend.Specifically,a prominent linear ridge and the geologic unit contacts within it are not obviously displaced (Photograph C)and the southeast-flowing stream valley to the north also does not express the lineament.Close inspection of the INSAR-derived DEM revealed that no separation of geologic units may exist across the fault (Figure A20.6).Grantz (1960)mapped an apparent 100 feet ( 33 m)offset in the Tf-Jns contact but a detailed slope map of the area apparently shows the basal contact of Tf with the underlying Jns in a different position than depicted by Grantz and that does not suggest any offset.Southeast of the mapped fault, Grantz's (1960)Tf-Jns contact is approximately 100 feet too low on the hillside and northwest of the fault the contact is 100 feet too high elevation. The prominent swale coinciding with the mapped fault may have a genesis related to spillways and wave-cut benches developed during the presence of an ice-marginal glacial lake.Glacial meltwater was likely impounded by the left lateral moraines of the Little Nelchina ice lobe to the east and by the ice in Daisy Creek to the north (Figure A20.5).Ground investigation discovered a presumably ice-rafted INTERIM DRAFT Page 40 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. granitic glacial erratic in terrain mapped as Jurassic sedimentary rocks (unit Jnbc)at an elevation of 3925 feet (at GPS waypoint 018 on Figure A20.1),about 100 feet higher in elevation than the swale shown in Photographs A and B of Figure A20.2.Williams and Galloway (1980)show a spillway transecting part of lineament group 20 at similar elevations that would have sent water over a drainage divide to Fourth of July Creek (Figure A20.5).Development of a similar spillway could be the genesis of the swale shown in Photograph A.In addition,several planar and horizontal benches at similar elevations may indicate the presence of a relatively long-lived lake,but could also relate to differential erodibility of the nearly horizontal stratigraphy in the area. In summary,some of the individual lineaments along the northwestern margin of group 20 do appear to coincide with previously mapped bedrock faults and are likely fault-line scarps developed along bedrock faults,but the remaining lineaments are interpreted to be the result of erosion and not tectonically-related.Low-level aerial and ground inspection did not reveal any evidence for Quaternary faulting along the mapped lineaments or previously mapped faults.However,the validity of some of the faults is in question when evaluated with modern high-resolution elevation data.The mapped lineaments are not consistently expressed across the landscape and nearly all are spatially associated with erosional features.For the above reasons,no further work for lineament group 20 is deemed necessary. Lineament Group 21a:Observations and Evaluation Lineament group 21a is a northwest-trending small group of lineaments expressed as weakly aligned features within a terminal moraine complex,and a few topographic slope breaks and linear drainages (Figures A2la.1 and A21a.2),approximately 41 km ( 25 miles)northeast of the proposed Susitna- Watana dam site (Plate 1).No previously mapped fault or lineament feature coincides with the orientation of the lineament group and no direct evidence of fault structure was observed during low- level aerial investigation.However,the Mesozoic-age Honolulu thrust fault (Csejety,1961)does cut across the lineament group but does not align or coincide with any mapped lineaments.The weakly linear alignment of lineaments across the relatively low-relief terrain (Figure A21a.1)does not constrain the geometry or kinematics of any potential tectonic structure.Lineament group 21a lies entirely with glaciated terrain at the confluence of possibly four different ice streams (Figure A21a.2)and although Cretaceous flysch is mapped nearby (Csejtey et al.,1992;Wilson et al.2009),field inspection confirmed that most of the area has either a surficial cover of glacial moraine and/or glacial lake deposits from a series of glacial lakes (Reger et al.,1990).The youngest deposits containing lineaments are likely late Holocene linear streams while the oldest surficial deposits in which lineaments are expressed are likely latest Pleistocene glacial deposits (Reger et al.,1990).The lineaments do not cut across different age deposits or landforms;they lie almost entirely within the Quaternary deposits in the valley bottoms.Aside from a 120-meter-tall rock-cored drumlin,the lineaments all have a relatively consistent magnitude expression of <15 meters tall and are both parallel and discordant with ice flow INTERIM DRAFT Page 41 of 81 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO |AEA11-022 16-1401 -TM-012014 Clean,reliable energy for the next 100 years. directions.The most prominent lineaments are three lineaments that trend highly obliquely to the rest of the group and which have morphology and position suggestive of being either a terminal moraine ridge from northwest flowing ice or an esker (Figure A21a.2).No field evidence of displaced or deformed terrace risers or moraine ridges was observed along the trend of the lineaments. Several lines of evidence point to a non-tectonic origin for the lineaments in group 21a.Although expressed in Quaternary deposits and of a scale consistent with a low slip-rate fault,the lineaments of group 21a do not traverse across portions of the landscape of different ages which would help support the existence of through-going tectonic structure.The apparent origins of the lineaments are both constructional (terminal moraine complex and eskers)and erosional (linear streams and short slope breaks in dissected glacial moraine ridges).In addition,part of the importance of group 2la as a potential tectonic structure is the group's spatial proximity and along-trend parallel orientation with group 21b,for which a non-tectonic explanation is likely (see below).Overall,the lineaments of group 2la are few in number,weakly expressed,weakly aligned,and do not coincide with a previously mapped structure.These factors,and the recent dominance of both active and stagnant ice processes in the area,point to a non-tectonic,glacial origin for the lineaments of group 21a and the lineaments are not considered further. Lineament Group 21b:Observations and Evaluation Lineament group 21b is a northwest trending group of lineaments expressed as a series of linear slope breaks and aligned linear drainages (Figure A21b.1)located approximately 43 km ( 27 miles)north- northeast of the proposed Susitna-Watana dam site.Lineament group 21a is separated from group 21b by about 5 km ( 3 miles).The only previously mapped fault or lineament feature that coincides with lineament group 21b is a photographic lineament mapped by Reger et al.(1990)that is discussed below and shown on Figure B-15.No fault exposures were observed during aerial and ground field investigation along lineament group 21b.The portion of the lineament group located west of Butte Creek climbs east-sloping terrain in a straight-line manner (Figure A21b.1)that suggests any potential tectonic structure would have a steep to near vertical dip and strong lateral kinematics.The lineaments of group 21b occur as downhill-facing slope breaks in mapped Quaternary glacial deposits (unit Qdt3 of Smith et al.(1988))and as linear streams and gulleys eroded into Cretaceous flysch,and to a lesser extent,Cretaceous granite (Csejtey et al.,1992;Wilson et al.,2009).Map unit Qdt3 is considered to be of late Wisconsin age (11,800 to 25,000 year B.P.)(Smith et al.,1988).The mapped lineaments coincide with a concealed bedrock contact between units Ks (schist)and Kph (phyllite)of Smith et al. (1988)but cut across the map unit contacts of Wilson et al.(1998)(Figure A21b.1).Low-level aerial and ground inspection revealed the scale of the lineaments ranges from 2-to 4-m-high slope breaks (Photograph A,Figure A21b.2)to 5-to 10-m-deep linear stream channels.The lineament group is oriented perpendicular to the ice flow directions within the Butte Creek valley. INTERIM DRAFT Page 42 of 81 01/20/14 za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Field investigation did confirm the expression of the 3-km-long,downhill-facing slope break in Quaternary glacial deposits (Photograph A,Figure A21b.2)but did not reveal any exposures of the spatially-coincident concealed schist-phyllite contact mapped by Smith (1988).Inspection of the stream banks and terrace risers located to the west along the trend of the feature did not reveal any displaced terrace risers or surfaces (Figure A21b.3).Exposures in the left bank of Butte Creek at GPS waypoint 009 consisted of east-southeast striking,vertically-dipping phyllite which coincide with the projection of a lineament formed by a short,low-relief downhill-facing slope break (small arrows in Photograph A,Figure A21b.2)on the adjacent strath terrace surface.More resistant,sandy beds within the phyllite are interpreted to form the short slope break along the margin of the strath terrace and serve as an analogy for the much larger lineament located upslope.For example,rather than a being formed by a tectonic fault,the 3-km-long lineament mapped from INSAR data most likely relates to the rock type contrasts mapped by Smith et al.(1988)where higher grade (and more resistant)schist lies upslope of the slightly lower grade (and less resistant)phyllite and is overlain by a thin veneer of Quaternary glacial deposits.The linear streams and gulleys to the west of Butte Creek are therefore interpreted to be serendipitously-aligned erosion features.Alternatively,the reconnaissance mapping compiled by Wilson et al.(2009)for this area may be inaccurate,and the contact relations shown by the more detailed mapping of Smith et al.(1988)may continue westward,controlling the drainage patterns to produce linear streams along the strike direction of the phyllite.In either case,the lineaments of Group 21a are judged to be non-tectonic in origin and likely relate to differential erosion along depositional contacts within bedded metasedimentary rocks. Lineament Group 22:Observations and Evaluation Lineament group 22 is a northwest-trending group of lineaments defined chiefly as a series of aligned, linear V-shaped troughs and slope breaks (Figure A22),approximately 27 km ( 17 miles)northwest of the proposed Susitna-Watana dam site (Plate 1,Figure AO.1).Group 22 spatially coincides with several northwest-trending photogeologic lineaments discussed below as features 7,8,and 9 in the section on Reger et al.'s (1990)northwest-trending photogeologic lineaments of the Healy A-3 quadrangle.These features are depicted as extending across Quaternary glacial sediments as well Tertiary and Cretaceous intrusives that have variable strikes and dips.The lineaments are mapped in Reger et al.'s (1990)till of late Wisconsin age (unit Qd3;9,500 to 25,000 years old)(Reger Public Data file 90-1),and are expressed in the field as linear erosional gullies.The geomorphic features east of Deadman Creek are smaller and less prominent in Mesozoic and Tertiary rocks as compared to those in Cretaceous rocks that are west of the creek,indicating an inconsistent scale of expression along strike (Figure A22.1).No field evidence of a fault was found during low-level aerial inspection,and much of the hillsides appear to be influenced by solifluction processes (Figure A22.2).The trend of the lineament on the landscape would suggest a hypothetical steeply-dipping geometry because the lineaments trend at high angles across contours.Along Deadman Creek,the lineaments are nearly orthogonal to the ice flow direction INTERIM DRAFT Page 43 of 81 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. (Reger et al.,1990,sheet B),and no offsets in the lateral moraines were observed.Along the far western part of the lineament group,the lineaments are parallel to the ice flow direction. The lineaments of group 22 show a dearth of expression in Quaternary deposits,other than being associated with two linear drainages.While the lineaments transect several different geologic units, suggesting some continuity,we find that the magnitude of expression along strike is quite variable supporting an erosional genesis to the lineaments.The absence of substantive Quaternary lineaments further supports an erosional origin.Because of its geomorphic expression as linear drainages,there is insufficient landform information to assess potential kinematics (e.g.,uphill facing scarp).Because there is no fault previously mapped along this group and no evidence of a fault was observed,coupled with the field observations of hillslope processes as well as a distinct lack of faulting expression in the late Wisconsin glacial deposits,it is judged that lineament group 22 is not a fault. Lineament Group 23:Observations and Evaluation Lineament group 23 is an arcing group of roughly east-west-trending lineaments defined by a series of aligned slope-breaks,low mounds,and short linear ridges (Figure A23.1),approximately 62 km ( 39 miles)southeast of the proposed Susitna-Watana dam site.The features along the lineament trend occur entirely within mapped Quaternary glacial and lake deposits of the Copper River Basin (Williams and Galloway,1986;Wilson et al.,2009).Potential ages for these deposits range from mid to late Pleistocene_for the glacial till deposits to latest Pleistocene_for the glacial lake deposits (Williams and Galloway,1986).The lineaments do not coincide with any previously mapped faults or lineaments (FCL,2013)and low altitude aerial inspection did not reveal any direct evidence of tectonic structures anywhere along the lineament,including in the near-vertical cut banks of Tyone Creek.The aligned slope-breaks,low mounds,and short linear ridges that make up the lineament group are of mostly broad and low relief,ranging in height from approximately 30 m high ( 100 ft)in the west to 10 to 15 m high in the center and east portions.The orientation of the mapped lineaments is parallel to several north- south oriented drumlins mapped by Williams and Galloway (1986),and perpendicular to regional ice- flow directions,but parallel to and locally coincident with terminal moraine crests. Several pieces of evidence beyond the spatial coincidence with the terminal Tysus Moraines of Williams and Galloway (1986)point to a non-tectonic explanation for lineament group 23.For example,no direct evidence of tectonic structures was observed during very low altitude aerial inspection,including in key exposures where the lineament alignment crosses Tyone Creek.The arcing alignment and the consistently low relief morphology of the aligned slope-breaks,low mounds,and short linear ridges does appear similar to a terminal moraine complex.The positive relief of these features suggests constructional or depositional geomorphic processes,rather than tectonic processes, may have played a role in their formation and their subtle expression could derive from being obscured by overlying glacial lake deposits.For example,the lineament group lies within published glacial lake INTERIM DRAFT Page 44 of 81 01/20/14 -z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. extents and elevations in the Copper Basin for lake elevations of 975 m,914 m ,800 m,and partly for the 775 m lake level (Kaufmann et al.,2011),suggesting Quaternary lake glacial processes may have influenced the formation of these features.The discordance of the lineaments located east of Tyone Creek with the orientation of terminal moraine ridges mapped by Williams and Galloway (1986)may result from differences in the scale and quality of the aerial photography used by Williams and Galloway (1986)compared to modern hi-resolution INSAR data.For example,the discordance could be the result of receding lake shorelines being interpreted as terminal moraines.Overall,the preponderance of evidence described above points to a genesis via glacial processes for the lineaments of group 23,and does not support a tectonic genesis.It is judged that lineament group 23 does not represent a tectonic fault,and no further work is recommended for lineament group 23. Lineament Group 24:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013).Strip maps for this group are not included herein (Figure AO)but were presented as part of FCL (2013).The lineament group is short ( 15 km [ 9 miles])and lies a great distance from the damsite ( 120 km [ 75 miles]),and likely would not appreciably contribute to the hazard calculations (FCL, 2013). Lineament Group 25:Observations and Evaluation This lineament group was not advanced for field work in 2013 based on the desktop analysis of FCL (2013).Strip maps for this group are not included herein (Figure AO)but were presented as part of FCL (2013).The lineament group was interpreted to be the result of erosional and depositional processes (FCL,2013),chiefly the apparent alignment of several large,curvilinear glacial valleys.During limited flyovers,no features were observed that suggested a need to revise those conclusions. Lineament Group 26:Observations and Evaluation Lineament group 26 is a northwest-trending lineament group expressed as a series of aligned slope- breaks,U-shaped troughs,and linear drainage segments (Figure A26.1),approximately 2 km ( 1 miles) west of the proposed Susitna-Watana dam site (Figure A0O.1).Much of the lineament follows an unnamed tributary to the Susitna River that lies directly west of Tsusena Creek.Previously mapped bedrock structures,lineaments,or faults are not coincident with or near this lineament group.Similarly, field evidence of fault structures were not observed along this lineament group during low altitude aerial inspection.The trend of the lineaments across topography implies a hypothetical near vertically- oriented geometry because the lineaments cut across topographic contours at high angles.South of the Susitna River,the lineaments are mapped in glacially-sculpted terrain that shows geomorphic landforms indicative of stagnant ice (e.g.eskers).The thickness of unconsolidated deposits on the south side of the river seems to be relatively thin.At the confluence of the Susitna River with Tsusena Creek,the INTERIM DRAFT Page 45 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. lineament is mapped across Quaternary till deposits that overlie bedrock.North of the Susitna River, the lineaments principally are mapped in a linear drainage in whose upper banks are exposures of till that overlies lacustrine and fluvial deposits.The lineaments are mapped as cutting across Tertiary volcanics and intrusives as well as Quaternary sediment,however field observations did not find evidence to confirm presence of a lineament(s)expression in the bedrock or sediment.The scale of the expression of the lineaments along strike is variable,with little to no apparent relief across lineaments on the south side of the river.North of the Susitna River,the lineaments are depicted along a deeply incised canyon.The lineament group is relatively discordant with the ice flow direction,however,an esker deposit on the south side of the river trends oblique to the lineaments and showed no evidence of being offset or deformed based on low-altitude flyovers (Figure A26.2).Assessment of kinematics of the lineament morphology is indeterminate because there a near absence of geomorphic expression of tectonic-related features. The lineament group does not show evidence of expression in late Quaternary units or landforms, including the till deposits at the confluence of the Tsusena Creek and Susitna Rivers.The till that seems to overlie the lake deposits along the upper banks of the unnamed drainage also appears to have a horizontal basal contact (Figure A26.2).Most clearly,the esker landform on the south side of the Susitna River appears to be continuous where it extends across the mapped lineament,indicating no deformation since its emplacement.While the lineament group is mapped across different geologic units,there is very little consistency of expression north of the Susitna River as compared to the south. North of the river,the lineaments appear to be dominantly erosional based on their mapped position at the bottom of a sub-linear canyon.South of the river,the lineaments that are mapped largely follow ice- flow directions.The few that are not concordant with ice-flow direction seem to be related to near- surface bedrock that is expressed as drumlin-like landform features.Because of the absences of previously mapped structures or faults,the lack of field evidence of faults,and the apparent positive evidence for non-faulting or displacement vis-a-vis the undeformed esker deposit (>11 ka in age),it is preliminarily judged that the lineament group is erosional in origin and likely does not represent a fault structure.However,ground access for this lineament group was restricted during the 2013 field inspection,and due to the close spatial proximity to the dam site,this lineament group warrants additional study to confirm the absence of bedrock structure along these features. Lineament Group 27:Observations and Evaluation Lineament group 27 is a northeast-trending series of aligned lakes and subtle topographic troughs/swales that project towards a large and linear U-shaped valley (Figures A27-1.1 through A27- 3.1),approximately 80 km ( 50 miles)southeast of the proposed Susitna-Watana dam site (Figure AO.1).This group is expressed in mapped Quaternary sediments within the Copper River Basin and partially coincides with the mapped Sonona Creek fault (Williams and Galloway,1986;Wilson et al., 2009),although no fault exposures were directly observed in the field during aerial and ground INTERIM DRAFT Page 46 of 81 01/20/14 -Za-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. reconnaissance.The geometry of any potential tectonic structure is difficult to resolve with certainty because the linear trend of the lineament across the very low relief (i.e.,basically flat)portion of the Copper River Basin could result from several fault geometries.The lineament is expressed in late Quaternary glacial drift and glacial lake deposits as a series of aligned lakes,linear lakes and swales, vegetation lineaments,low-relief ( 2-m-high)ridges,all of which project toward a |km right stream deflection in Tyone Creek (Figures A27-3.1 and A27-3.2).These lineament features were not mapped throughout all the Tolson Creek Moraine complex of Williams and Galloway (1986)but do exist in the glacial lake deposits (and underlying basal till under the center of the ice lobe?)located to the east. Williams and Galloway's (1986)depiction of the Sonona Creek fault is somewhat equivocal regarding the constraining age of potential faulting;they show the fault as truncating,cutting across,and also terminating into different ridges of the Tolson Creek moraine complex.The magnitude of lineaments' expression is relatively consistent along strike as shallow, 2-to 3-m-deep lakes and 2-m-high linear ridges,but the apparent sense of displacement is not consistent.In some locations (Photograph D, Figure A27-3.2)the apparent sense of displacement is south-down/north-up,whereas elsewhere the apparent displacement is south-up/north-down,and at other locations there is no discrete topographic expression of any displacement.The orientation of the lineament group is roughly perpendicular to the northwest-flowing ice in the Copper River Basin,but parallel to ice flowing down a northeast-trending segment of the Oshetna River Valley.No observations of displaced linear strain markers such as moraine ridges or terrace risers were found during low-level and ground investigation or from desktop analysis of the INSAR data.This suggests that the 1 km ( 0.6 miles)of apparent right-lateral stream deflection cannot be due to lateral fault motion,but it does not eliminate the possibility of stream deflection due to damming or diversion by a south-facing topographic scarp created by a north- up/south-down sense of vertical movement. Field investigation revealed that the very few lineaments mapped in the western half of the group within the broad glacially-sculpted Oshetna River valley (Figures A27-1.1 and A27-2.1)are either rock or drift drumlins or coincide with ice-marginal features such as kame terraces,and are not likely tectonically related.The most prominently expressed features of group 27 are located in the eastern portion of the group amongst features that appear to be derived from stagnant ice (Figure A27-3.1)and coincide with the mapped Sonona Creek fault,but these aligned lakes,linear lakes and swales,and vegetation lineaments do not appear to transect across features of different ages.Specifically,ground investigation and aerial inspection of the Tolson Creek moraines did not reveal any lateral or vertical deformation along the projection of the mapped fault-only the presumably younger areas of ice-related deposition contained lineaments.The expression of lineaments in a portion of the landscape judged to be the youngest,and the absence of observed deformation (lateral or vertical)in the adjacent Tolson Creek Moraines,which are older,is inconsistent with an origin by faulting.(If the youngest portions of the landscape express prominent tectonic geomorphology,the older portions would likely also show evidence of recent tectonic activity too.)However,the lineament group's orientation does align with an INTERIM DRAFT Page 47 of 81 01/20/14 -za-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. apparent regional structural grain in the landscape,based on the orientation of the Castle Mountain fault 30 km to the south.Field investigation did not reveal any definitive evidence to strongly refute nor strongly support the presence of the mapped portion of the Sonona Creek fault and a late Pleistocene/early Holocene earthquake event cannot be refuted. The initial Susitna-Watana PSHA (FCL,2012)included the Sonona Creek fault as a seismic source based on the mapping of Williams and Galloway (1986)that depicts a late Quaternary faulted moraine. The aerial and ground field observations from this study did not verify this feature,however,the field data are not sufficiently detailed or extensive to preclude the potential of a latest Pleistocene to early Holocene co-seismic surface rupture.This would require developing a new detailed map along the Sonona Creek fault trace and confirmation of the relative age relationships of the presumed unfaulted deposits in that area.The Sonona Creek fault was not a significant contributing seismic source in the FCL (2012)PSHA evaluation due to its low slip rate and distance ( 70 km)from the Watana site. Based on the 2013 field observations,the Sonona Creek fault should likely be retained in the seismic source model,but with an updated source characterization which considers a weighted non-tectonic interpretation of this lineament suggested by the new field observations.Reasons for maintaining this feature in the seismic source model are:(1)it is depicted on a previous publication as a late Quaternary fault,and,(2)the present study scope does not provide sufficient field evidence to positively refute its existence.In the absence of further field studies of the Sonona Creek fault,inclusion of a non-tectonic alternative for this fault would encompass a broad range of alternative interpretations within the crustal source model.No further field studies of the Sonona Creek fault or features in lineament group 27 for the Watana dam seismic hazard evaluation are recommended. Broad Pass Area Faults:Observations and Evaluation The Broad Pass area includes,for this investigation,the northeast-trending northwest-dipping thrust fault previously mapped by Csejtey (1961),approximately 56 km ( 35 miles)northwest of the proposed Susitna-Watana dam site,along the western extent of the Chulitna River valley (Plate Al);as well as other bedrock faults mapped within and near the Chulitna valley (e.g.,Honolulu thrust fault of Csejtey (1961));and most recently several northeast-southwest oriented faults depicted by Wilson et al., (1998)).Faults oriented approximately northeast-southwest in this area are likely favorably oriented for (re)-activation in the existing crustal stress field near the Denali fault.A strong fabric of northeast- trending glacial features characterizes the geomorphology in the Chulitna valley,with numerous landforms such as drumlins,and glacial striae occurring throughout the valley.Existing geologic mapping (Wilson et al.,1998)depicts pre-Quaternary faults that apparently place Paleozoic and Mesozoic rocks against each other,or Paleozoic and Mesozoic rocks against Tertiary sedimentary rock units.These older rocks are in turn overlain by Quaternary glacial and fluvial sediments that are no older than late Wisconsin age. INTERIM DRAFT Page 48 of 81 01/20/14 -Zz-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Several locations were investigated as part of the assessment of previously mapped faults in the Chulitna River valley (Plate A-BP).Faults mapped as bounding Tertiary units could not be confirmed due to lack of exposure (e.g.,Figure A-BP.1).A ground traverse was made orthogonal to the mapped fault and no exposures were present and a fault was not observed during the hike.Low altitude fly- overs of the partly-forested,partly-wetland surface of the Chulitna valley found no evidence of Quaternary faulting,and the surficial geomorphology observed was uninterrupted and undeformed. Exposures of Quaternary terrace units exposed along the western bank of the West Fork of the Chulitna River appear to be chiefly fluvial in origin and show lenticular beds that are not entirely planar in geometry.On the east side of the West Fork of the Chulitna River,an important outcrop exposes late Quaternary till that unconformably overlies Tertiary sediments with an apparently horizontal basal contact geometry for the length of the exposure (Figure A-BP.1).Similar contact relations and horizontal geometries were observed in the East Fork Chulitna River and several tributaries.This observation argues that the till deposit has not experienced tectonic deformation since its emplacement, supporting an interpretation of no late Quaternary or post-glacial faulting. Other locations within the Chulitna River valley were visually inspected (Plate A-BP;Figures A-BP.2 and A-BP.3).Field investigation found no evidence to directly confirm the faults as mapped.In all instances,late Quaternary cover overlying the fault appeared undisturbed and not offset.Based on the extensive glacial ice features that are prevalent in the valley,the late Quaternary deposits and landforms are probably from the last glacial maximum.The lineaments mapped within the Chulitna River valley are oriented along the direction of ice flow,and generally are located along the margins of geomorphic features (e.g.drumlins,kettle edges)that are genetically related to glacial flow and related processes. Thus,none of the lineaments mapped in this area are considered tectonic in origin.The field evidence did not directly confirm the previously mapped pre-Quaternary faults,nor did it confirm faulting of Tertiary deposits at locations inspected.However,observations of field exposures and late Quaternary surficial deposits showed no evidence of faulting. Clearwater Mountains:Observations and Evaluation FCL (2013)identified the Clearwater Mountains as an area of interest because the western extent of the Broxson Gulch fault lies within the Clearwater Mountains,and was inferred as Quaternary-active by Nokleberg et al.(1994).Conceptually,the region could be analogous to the area around the Susitna Glacier fault,where a WSW-trending fault splays from the Denali fault and results in southward- directed uplift on a north-dipping fault.West-southwest trending fault splays may be favorably oriented for (re)-activation within the existing crustal stress field and if active would potentially provide a structural connection between the Denali fault and the Talkeetna thrust fault.In order to better understand the potential genesis of the Clearwater Mountains and potential connections between the Broxson Gulch fault and Talkeetna thrust fault,Plate A-CWM displays the area surrounding the INTERIM DRAFT Page 49 of 81 01/20/14 -Zz-ALASKA ENERGY AUTHORITY ;AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. Clearwater Mountains.The potential junction of the Broxson Gulch fault and Talkeetna thrust faults lies approximately 83 km ( 52 miles)northeast of the proposed dam site. Several different iterations of geologic mapping exist for the area of the southern Clearwater Mountains and these data are described in detail by FCL (2013).For the purposes of the current discussion,it is sufficient to reiterate that three maps in particular demonstrate the range of depictions of the faults in the area:Smith (1981),Silberling at al.(1981),and Csejtey et al.(1992).Importantly,the three maps show different configurations for the potential junction of the Broxson Gulch,Black Creek,and Talkeetna thrust faults in the Pass Creek area (Plate A-CWM).Smith et al.(1981)show the Talkeetna thrust fault as a continuation of the Broxson Gulch fault,which together truncate the Black Creek fault.Silberling et al.(1981)also show the Talkeetna thrust fault as a continuation of the Broxson Gulch fault but do not present mapping of the Black Creek fault.In contrast,Csejtey et al.(1992)shows the Broxson Gulch fault continuing westward as the Black Creek fault and the Broxson-Black Creek fault system as truncating the Talkeetna thrust fault.Based on their own work,and upon review of previous work, including the work of Nokleberg et al.(1994),O'Neill et al.(2001)conclude that the Black Creek/Broxson Gulch fault truncates the Talkeetna thrust fault,and that the Broxson Gulch fault and Talkeetna thrust faults are not kinematically or structurally related. Based on the results of FCL (2013),two specific areas within the Clearwater Mountains were deemed candidates for field inspection (Plate A-CWM):1)the junction area of the Talkeetna thrust,Broxson Gulch thrust,and Black Creek faults (lineament group CMW1)and,2)a collection of lineaments on the south side of the Clearwater Mountains (lineament group CMW2). Lineament group CWM1 does contain a few lineaments that lie proximal to mapped faults in the saddle between the Windy Creek and South Fork Pass Creek valleys (Plate A-CWM,Figure A-CWM.1)and in other locations along the Black Creek fault (Plate A-CWM).In the saddle between the Windy Creek and South Fork Pass Creek valleys,the trend of most mapped lineaments across the terrain was somewhat inconclusive while the trends of others suggested the potential geometry of fault structures would be steeply dipping.Indirect evidence of fault structure was observed in several locations in the high elevation bedrock terrain above the valley floor in the form of contrasting rock-type juxtapositions (Figure A-CWM.1 and A-CWM.2)that corroborate the general locations of the mapped faults.The FCL-mapped lineaments are expressed as linear gullies and streams in both late Cretaceous to early Jurassic bedrock and glacial deposits,broad and shallow U-shaped linear troughs in glacial deposits,and locally as side-hill benches within latest Pleistocene glacial deposits on the margins of the valleys.The lineaments do not appear to cut across different geologic units and have a consistent magnitude of expression.The lineaments are both discordant and concordant with glacial ice-flow directions;some lineaments may be expressing the ice-limit elevations at the bedrock-glacial moraine contact (Figure A- CWM.1).No field evidence of deformed Quaternary-age linear strain markers along the trend of INTERIM DRAFT Page 50 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. mapped lineaments or faults was observed during aerial inspection.Furthermore,no evidence of through-going tectonic geomorphology was observed along the mapped lineaments in the saddle between the Windy Creek and South Fork Pass Creek valleys,nor any expression of deformation in the Quaternary sediments of the north-trending glaciated valleys across which the Black Creek fault cuts (Figure A-CWM.2). The FCL-mapped lineaments in the area of group CWM2 do not coincide with previously mapped faults,lie at elevations below the maximum ice elevation,and are oriented mostly parallel to the direction of ice flow (Plate A-CWM).The lineaments are expressed as side-hill benches within Quaternary glacial deposits (and spatially coincide locally with kame terraces)(Figure A-CWM.3)and as downhill-facing scarps in areas subject to solifluction.The magnitude of expression varies from relatively broad side-hill benches 10s of meters wide and 100s of meters long to smaller topographic scarps with only a few meters of relief that are difficult to trace laterally in thick vegetation.Extensive low-level and ground investigation revealed that the lineaments are not laterally continuous across different geologic units or landforms;eskers and post-glacial alluvial fans are not apparently deformed along the projection of the lineaments (Figure A-CWM.3).No evidence of displaced or deformed linear strain markers was observed. In summary,some mapped lineaments mapped by FCL (2013)in the central Clearwater Mountains area coincide with previously mapped bedrock faults but no evidence of deformed or displaced Quaternary deposits was observed.No field evidence of Quaternary activity along the mapped traces of the Talkeetna thrust,westward extension of the Broxson Gulch,or Black,Creek faults was observed and consequently the specific geometries and contact relationships between these three faults were not evaluated in the field.The lineaments mapped along the southern slopes of the Clearwater Mountains are interpreted to be of non-tectonic origin.The geomorphology on the southern slopes of the Clearwater Mountains is heavily influenced by glacial processes and the presence of left-lateral moraine deposits.Field investigation did not reveal any through-going and laterally continuous aggregations of individual lineaments or tilted tectonic markers (such as shorelines or terraces)at the southern foot of the mountains that could be definitively linked to a tectonic origin.Post-glacial landforms and deposits did not express any lineaments and appear undeformed. Castle Mountain Fault Extension:Observations and Evaluation The Castle Mountain fault is a Quaternary seismogenic structure,as well as a major structural boundary which was included as a seismic source in the initial Watana Dam PSHA evaluation (FCL,2012).The eastern extent of the Castle Mountain fault,as mapped in the Alaska Quaternary fault and fold database (i.e.,Koehler et al.,2012),bifurcates to the east toward the Copper basin,ending in two splays (Plate A-CME).The northern splay ends at an unnamed glacial valley west of Caribou Creek;and the southern splay ends at the confluence of Billy Creek,and the larger Caribou Creek drainage.Northeast INTERIM DRAFT Page 51 of 81 01/20/14 -zZ-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. of the mapped end of the southern splay of the Castle Mountain fault,along Billy Creek,a group of lineaments projects to the northeast along a trend similar to the Castle Mountain fault (Plate A-CME). Lineament features aligned with the Castle Mountain fault could potentially increase the overall rupture length of the fault,and may extend slightly closer to the Watana dam site than previously mapped. Field evidence for faulting observed during low altitude aerial and ground inspection included:apparent bedrock type juxtapositions,bedrock color change associated with alteration zones,and deformation of bedrock units.All apparent evidence was observed in bedrock and no linear expression or evidence of faulting was observed in Quaternary deposits,although Quaternary deposits were scarce.The mostly straight to overall gently arcuate trend of the lineaments across high-relief mountainous terrain occur within a swath of parallel to sub-parallel features.The landscape in this swath exhibits a clear northeast-trending structural grain which suggests a steeply dipping structure(s)within a zone of deformation.To the southwest,the lineaments coalesce and join the right-lateral Castle Mountain fault. Considering the oblique orientation of these faults to the east-west trending right-lateral Castle Mountain fault system,the kinematics of these features can be implied as being right-lateral oblique with a larger vertical component than lateral.Observed lineament features occur in multiple bedrock lithologies,including:the Jurassic Talkeetna (Jtk),the undivided Chinitna and Tuxedni formations (Jtxc),and Naknek formations (Jn),Cretaceous Matanuska Formation (Km),Tertiary age Chickaloon formation (Tch)and undifferentiated Tertiary volcanic rocks (Tvu)(Plate A-CME).These features are only expressed in upland bedrock terrain and slopes and do not occur in alluvial deposits or glacial landforms.The orientation of these lineaments is perpendicular to regional ice-flow direction.It is unlikely that glacial processes played a major role in the formation of these lineaments. Quaternary deposits in the vicinity of the Castle Mountain fault extension lineament group have limited spatial coverage and most commonly occur as fluvial deposits found within in narrow canyons.Bubb Creek,Flume Creek,Greta Creek,and other unnamed drainages intersect,and are nearly orthogonal to, the lineament alignment and mapped features of Csejtey et al.(1978).Each waterway is relatively narrow with little to no Quaternary deposits.The Little Nelchina River valley is a broad glacial valley, and it provides the best exposure of continuous,flat-lying,and undeformed Quaternary terraces across the lineaments and mapped features.The scale of aligned features such as saddles,linear U-and V- shaped valleys,side-hill benches and breaks-in-slope remain consistent along strike and across variable terrain.Although a core group of lineaments within this group coincide with mapped faults,others do not.The mapped lineaments that do not coincide with previously mapped faults are attributed to be linear drainages (erosion features)and lineaments related to structural grain of the bedrock (lithologic control).The fault-related lineaments appear to be related to the Castle Mountain-Caribou fault systems of late Cenozoic age (Csejtey et al.,1978).Because of limited exposure of Quaternary deposits and the segmented and splayed characteristics of the mapped faults in this area,it is difficult to declare that all segments of this fault exhibit no Quaternary activity.No definitive evidence was encountered that INTERIM DRAFT Page 52 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014Clean,reliable energy for the next 100 years. precludes a scenario where this segment of aligned features ruptures as an extension of the Castle Mountain fault.If the group of aligned features acts as an extension of the Castle Mountain fault,the group of features could extend the fault by approximately 21 km ( 13 miles)to the northeast of the current mapped extent of the fault as shown in Koehler et al.(2012).Based on the observations that these features are clearly related to faulting of late Cenozoic age,we suggest adding this segment of fault-related features to the crustal seismic source model as a northeast extension of the Castle Mountain fault rupture scenario. North-South Features near Talkeetna River-Susitna River Confluence:Observations and Evaluation This area was not advanced for field work in 2013 based on the desktop analysis of FCL (2013)on the basis of the features'large distance (i.e.,>70 km [>40 miles])to the proposed dam site and their poor expression in the surrounding Quaternary sediments and Tertiary granodiorite outcrops as manifested in the INSAR data.This group was not visited during the 2013 field inspections and no observations were made that suggested a need for additional analysis.A plate showing available geologic data for this group is not included herein but was presented as part of FCL (2013). Photogeologic Lineaments Mapped by Reger et al.(1990)in the Healy A-3 Quadrangle In addition to investigation of the lineaments mapped by FCL (2013),lineaments appearing in Reger et al.(1990)were also evaluated in the field.In their study,Reger et al.(1990)mapped geologic units, glacial features,glacial lake shorelines,faults and lineaments within the extent of the Healy A-3 quadrangle.These features are presented in several thematic map sheets and described in the associated report.In the report,Reger et al.(1990)mention that "several photogeologic lineaments transect or offset moraines...”and are "likely candidates for active faults.”Reger et al.(1990)describe one specific lineament as intersecting an east facing cirque in the headwaters of Butte Creek and being coincident with an offset cirque floor.Three lineament groups mapped by FCL (2013)and evaluated as part of this study (groups 21a,21b,and 22)fully or partly overlap the Reger et al.(1990)map area (Figure B-01). None of the features identified in these three lineament group areas are interpreted to be associated with late Quaternary faulting.However,closer examination of the Reger et al.(1990)map showed a number of locations where the map depicted faults and solid lines either through or extending into Quaternary units.Based on these observations and the statements in the associated text,the features shown on the Reger et al.(1990)map were highlighted for further field review. Lineaments and faults appearing in Reger et al.,(1990),Sheet 1 of 2,were digitized as shapefile lines at a scale of 1:63,360,or better,and attributed appropriately.The locations where these lineaments and faults were mapped across or extended into Quaternary units were identified,saved as shapefile points and given a feature number (Figure B-01).The line and point shapefiles were loaded into an ArcGIS- enabled ruggedized field laptop with real-time GPS tracking.Field investigation of each feature was INTERIM DRAFT Page 53 of 81 01/20/14 za ALASKA ENERGY AUTHORITY .AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. conducted via helicopter overflight with limited ground inspection,using the evaluation process described in Section 2 and Section 3 above.Discussion of these features follows below,but due to the large number of features shown by Reger et al.(1990),figures presenting the map and field data for the features are presented as Appendix B. Feature 1: Feature 1 is a northeast trending photo-lineament mapped over orthogneiss and migmatite (TKgm) bedrock in its central and northern portions.The southern portion of the lineament is mapped over Quaternary age landslide (Qct)and rock glacier (Qcg)deposits in a narrow south facing cirque (Figure B-02).Low altitude aerial inspection of this location revealed that the mapped trace of the lineament is coincident with a linear alignment formed by the toe of a rock glacier advancing downslope from the eastern cirque wall.The lineament is enhanced because it is in close proximity,and parallel to,the axial drainage channel.Additionally,the lineament is absent in the Quaternary sediments on the valley floor of the down-drainage intersecting valley.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 2: Feature 2 is a northwest trending photo-lineament mapped over a quartz monzonite gneiss (TKqmg)and paragneiss (TKpng)bedrock ridge.The lineament is terminated in Wisconsin age till (Qd3)at its northwest extent (Figure B-03).The mapped trace of the feature overlies obliquely oriented linear glacial striations within the bedrock.Low altitude aerial inspection revealed no clear linear expression in the terrain with the same orientation as the mapped trace of Feature 2.Quaternary deposits at the northwest and southeast extent of this feature were visually inspected,and no evidence of linear expression was observed.Field observations and existing data indicate that this feature is likely non- tectonic in origin. Feature 3: Feature 3 is a west-northwest trending photo-lineament mapped across Wisconsin age till (Qd3), moraine (Qm3),and abandoned meltwater channel alluvium (Qac)deposits (Figure B-04).Low altitude aerial inspection revealed that this feature correlates with linear expressions related to glacial features rather than tectonic features.The western and central segments of this lineament are coincident with two prominent breaks-in-slope on the northeastern margin of a U-shaped glacial valley.The eastern portion of the feature is coincident with a linear to semi-arcuate moraine.In addition,the lineament has no expression within the Qac deposits near the center of the mapped trace.Field observations and existing data indicate that this feature is likely non-tectonic in origin. INTERIM DRAFT Page 54 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014Clean,reliable energy for the next 100 years. Features 4 &5: Features 4 and 5 are mapped as sub-parallel northwest striking faults across a broad Kahiltna Terrace argillite,sandstone,and siltstone (JKs)bedrock ridge (Figure B-05).Both of these faults are depicted as intersecting Wisconsin age till (Qd3)deposits on the flanks of the ridge.A clear expression of these faults was not observed in the bedrock during low altitude aerial inspection.In addition,the Quaternary (Qd3)deposits were observed to have no linear expression or fault related deformation.Lacking evidence of Quaternary age deformation,these features are not considered to be active structures. Feature 6: Feature 6 is an arcing north-northwest trending photo-lineament mapped across granodiorite (Tgdf) bedrock and Quaternary age paludal (Qs)and Wisconsin age till (Qd3)deposits (Figure B-06).The central portion of the mapped lineament correlates to a prominent break in slope and juxtaposing bedrock and Quaternary deposits.The northern extent of the lineament is expressed by a subtle west facing slope and linear valley.The southern extent is mapped over the crest of a bedrock knob and has no clear expression.Low altitude aerial inspection revealed that this lineament exhibits an opposite sense of vertical displacement in the north (apparent down-to-the-west)compared to the middle and southern segments (apparent down-to-the-east),an unlikely combination of geomorphic expressions for a tectonic feature with vertical displacement.Geomorphic expression indicative of oblique or strike-slip faulting was not observed.Additionally,this lineament has no expression within Quaternary deposits. Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 7: Feature 7 is a sinuous east-northeast trending photo-lineament mapped over quartz monzonite gneiss (TKqmg),quartz monzonite (Tqm)bedrock,and Wisconsin age till (Qd3)deposits (Figure B-07a/b).A pegmatite vein is mapped,unbroken,across this feature at its intersection with the Feature 8 lineament. Low altitude aerial inspection revealed that linear expression within the Quaternary deposits was observed to be a linear drainage (western segment)and an alignment of solufluction lobes (eastern segment).In aggregate,this lineament is a collection of aligned and unrelated non-tectonic features: linear drainages,linear erosional features,and aligned solufluction lobes.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 8: Feature 8 is a slightly arcing west-northwest trending photo-lineament mapped over a quartz monzonite gneiss (TKqmg)bedrock ridge and Wisconsin age till (Qd3)deposits (Figure B-07a/b).The mapped trace of Feature 8 intersects Feature 7 on the eastern flank of the bedrock ridge.On the western side of the ridge,the feature intersects the northern extent of a mapped fault that has no expression in Quaternary deposits.Two pegmatite veins are mapped unbroken across this feature.This lineament is INTERIM DRAFT Page 55 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. made prominent by a very large southwest facing topographic scarp along a linear drainage on the west side of the ridge,and a linear drainage on the eastern side of the bedrock ridge.Low altitude aerial observations revealed that the topographic scarp is approximately 10-20m in height and likely an erosional feature related to solifluction.The scarp has a limited extent and is not expressed in any other bedrock segment or Quaternary deposit along Feature 8.Field observations and existing data indicate that this feature is likely non-tectonic in origin. The western portion of this mapped feature (from the fault intersection to the west)corresponds with the FCL mapped lineaments of lineament group 22 discussed above. Feature 9: Feature 9 is a northwest trending photo-lineament that is mapped over Wisconsin age till (Qd3),alluvial fan (Qaf),and moraine (Qm3)deposits (Figure B-08).The eastern portion of this lineament is the same feature as the lineaments included in FCL lineament group 22 discussed above.Low-altitude aerial inspection revealed that feature is formed by an alignment of non-tectonic glacial features:linear moraine,solufluction features,and glacial striations in the bedrock on the valley margin slopes.At one location near the center of its mapped trace,the lineament is overprinted with a Quaternary age alluvial fan.No trace of the lineament was observed within the alluvial fan deposit.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 10: Feature 10 is a long ( 10.5-km)north-northwest trending photo-lineament mapped over quartz monzonite (Tqm)and granite (Tgr)bedrock,and Wisconsin age till (Qd3)and alluvium (Qa)deposits (Figure B-09a/b).Low altitude aerial inspection showed that the lineament is mostly composed of linear drainages,linear moraines,and breaks in slope.The breaks in slope in the north and south display an opposite sense of displacement (down-to-the-east)than the middle slope (down-to-the-west), an argument against a through-going,tectonic feature with vertical displacement.Geomorphic features indicative of oblique or strike-slip faulting were not observed.Alluvial deposits within the intersecting glacial valley (southern portion of the trace)and the glaciated plain (mid to northern segment of the trace)show no clear evidence of linear expression.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 11: Feature 11 is a northwest trending photo-lineament mapped over granite (Tgr)and quartz monzonite (Tqm)bedrock and over Wisconsin age till (Qd3)and Quaternary landslide (Qct)and rock glacier (Qcg) deposits (Figure B-10).Observations made during low altitude aerial inspection showed that the mapped trace of this lineament is coincident with an alignment of moraine crests and linear erosion INTERIM DRAFT Page 56 of 81 01/20/14 -Z-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. features.The lineament was not observed in any of the intersecting Quaternary deposits.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 12: Feature 12 is an east-northeast trending photo-lineament mapped in Quartz Monzonite (Tqm)bedrock and Quaternary age rock glacier (Qcg)deposits (Figure B-10).The western and central segments of this lineament are coincident with linear drainages (erosion features).In its eastern extent,the mapped trace of the lineament is coincident with the linear flank of a rock glacier over an older rock glacier. Observations from low altitude aerial inspection and existing data indicate that this feature is likely non- tectonic in origin. Feature 13: Feature 13 is a north-northwest trending fault mapped in Basalt,Rhyolite,and Agglomerate (Tvfa) bedrock and terminates at Quaternary age rock glacier (Qcg)and Quaternary landslide (Qct)deposits (Figure B-11a).The mapped trace is intermittent within the Quaternary deposits,and dike swarms (Tgr- d)are mapped unbroken across the project path of this feature.Observations from low altitude aerial inspection showed no expression of faulting within Quaternary deposits.Lacking evidence of Quaternary age deformation,these features are not considered to be active structures. Feature 14: Feature 14 is a north-northwest trending photo-lineament mapped in Basalt,Rhyolite,and Agglomerate (Tvfa)bedrock and Quaternary age landslide (Qct)and rock glacier (Qcg)deposits (Figure B-]1a).This feature is along strike with,and appears to be mapped as a possible northern extension of,the Feature 13 fault.This lineament is formed by a linear drainage within a rock glacier in a narrow,south facing, cirque and an aligned saddle.Low altitude aerial inspection observed no evidence for faulting along this linear alignment.Field observations and existing data indicate that this feature is likely non- tectonic in origin. Feature 15: Feature 15 is a north-northwest trending fault mapped in Basalt,Rhyolite,and Agglomerate (Tvfa) bedrock and Quaternary glacial till (Qd)deposits (Figure B-1la).Low altitude aerial inspection observed the fault in bedrock outcrops on the mountain slopes and through a saddle.No expression of the fault or fault related deformation was observed in Quaternary (Qd)deposits in the valley floor or in an overlying rock glacier.Lacking evidence of Quaternary age deformation,these features are not considered to be active structures. INTERIM DRAFT Page 57 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Feature 16: Feature 16 is a northwest trending fault juxtaposing Tertiary Quartz Monzonite (Tqm)against Cretaceous Kahiltna Terrane Argillite,Sandstone,and Siltstone (KJs)bedrock and over Quaternary landslide (Qct)and till (Qd)deposits (Figure B-11a/b).This fault is along strike with,and north of,the Feature 15 fault.The two features are separated by a glacial valley.Low altitude aerial and ground inspection observed evidence of faulting in bedrock at a ridgeline saddle near photograph location C, confirming the presence of the fault along the mapped trace.The Quaternary deposits (Qct,Qd)on the floor and lower flank of the glacial valley were observed,and no linear expression or evidence of tectonic deformation was observed.Lacking evidence of Quaternary age deformation,this feature is not considered to be an active structure. Feature 17: Feature 17 is a northeast trending photo-lineament mapped in Kahiltna Terraine Argellite,Sandstone, and Siltstone (KJs)bedrock and across Quaternary landslide (Qct)and an unlabeled unit (late Wisconsin till and/or moraine?)(Figure B-12a/b).The mapped trace of the lineament crosses the till and moraine(?)deposits,however no clear through-going linear expression was observed during low altitude aerial inspection.The mapped trace is most likely defining aligned and subtle slopes and drainages within the Quaternary deposit.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 18: Feature 18 is a northwest trending photo-lineament mapped in Kahiltna Terraine argellite,sandstone, siltstone (KJs)bedrock and Wisconsin age till (Qd3),and an unlabeled unit (late Wisconsin till and/or moraine?)(Figure B-12a/b).The mapped trace of the lineament is coincident with a topographic break- in-slope (apparent down-to-northeast)in bedrock.This lineament is parallel/sub-parallel,and along strike to the northwest,to a (down-to-northeast)normal fault mapped by Reger et al (1990).The two features are separated by a northeast trending glaciated valley.Low altitude aerial inspection observed an apparent fault exposure in bedrock at a topographic break-in-slope along the ridgeline.This evidence indicates that this lineament is likely a continuation of the fault trace mapped to the southeast.The Quaternary deposits between Features 18 and 20 were inspected and found to be undeformed and lacking any linear expression.Lacking evidence of Quaternary age deformation,this feature is not considered to be an active structure. Feature 19: Feature 19 is a northeast tending photo-lineament mapped in unlabeled unit (late Wisconsin till and moraine?)(Figure B-12a/b).Low altitude aerial inspection showed that the mapped linear trace correlates with a vegetated linear drainage.The lineament is made more prominent by the color INTERIM DRAFT Page 58 of 81 01/20/14 Za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. contract between the vegetation and the surrounding rocky ground surface.Observed to be an erosional feature,this lineament is likely non-tectonic in origin and not considered further. Feature 20: Feature 20 is a northwest striking photo-lineament mapped across orthogneiss and migmatite (TKgm) bedrock and Quaternary age undifferentiated colluvium (Qc)deposits (Figure B-12a/b).Low altitude aerial inspection confirmed that the mapped linear trace correlates with a linear drainage and has expression only in bedrock.No linear expression was observed in Quaternary deposits along the projected path of the feature.Lacking evidence of Quaternary age deformation,this feature is not considered to be an active structure. Features 21: Feature 21 is a northwest trending photo-lineament mapped over quartz monzonite (Tqm)bedrock and morainal deposits of Late Wisconsin age (Qm3)(Figure B-13).Low altitude aerial inspection showed that this lineament is composed of a collection of aligned features.The northern and central segments of this feature are a bedrock ridge crest leading to a linear drainage.The southern extent,in Quaternary deposits,was observed to be the crest of a debris flow levee which bounds the linear drainage.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 22: Feature 22 is an east-northeast trending photo-lineament mapped within a deposit of colluviated till of Illinoian age ( 120 to 170 ka)(Figure B-14a).Low altitude aerial reconnaissance observed no clearly defined linear expression to correlate with the mapped lineament.It is likely that the mapped trace represents a color contract created by glacial till along the crest of a low-relief ridge separating two drainages.Field observations and existing data indicate that this feature is likely non-tectonic in origin Feature 23: Feature 23 is an east-northeast trending photo lineament mapped across paragneiss (TKpgn)bedrock and morainal deposits of late Wisconsin age (Qm3),and till of Illinoian age (Qd2)(Figure B-14a/b). This lineament is to the east of,and along strike with,Feature 22.The two features are separated by a broad landscape mantled with Qd2.Low altitude aerial inspection observed that the mapped trace of the lineament correlates with topographic scarps and linear solifluction features.Along strike,the topographic scarps were observed to express opposing expressions of vertical displacement (down-to- northwest and down-to-southeast),an unlikely combination of geomorphic expressions for a through- going tectonic feature with vertical displacement.Geomorphic expression indicative of strike-slip or oblique faulting was not observed.No linear expression or scarps were observed within the intersecting INTERIM DRAFT Page 59 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Quaternary deposits.Field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 24: Feature 24 is a northwest trending photo-lineament mapped in paragneiss (TKpng)bedrock for most of its length except for the northern extent where it is mapped within Quaternary age talus (Qct)deposits (Figure B-15).Reger et al.(1990)describes this lineament as one which corresponds to an offset in the floor of an east-facing cirque,the floor of which is mapped as Tkpgn.Low altitude aerial inspection of the lineament revealed that in bedrock the mapped trace consists of an alignment of variably-scaled, linear swales more likely related to glaciation rather than active tectonics.In the Quaternary deposits, the lineament corresponds to a linear drainage.Scarps and vertical displacement were not observed in the cirque floor described by Reger et al.(1990)and no evidence of tectonic origin was noted for this feature.Field observations and existing data indicate that this feature is likely non-tectonic in origin Feature 25: Feature 25 is an angled northwest trending photo-lineament.The lineament is mapped over paragneiss (TKpgn)bedrock and late Wisconsin age till (Qd3)(Figure B-15).Low altitude aerial inspection revealed that the mapped trace is coincident with a shallow linear drainage that is highlighted by an apparent vegetation color contrast.Being an erosional feature,these field observations and existing data indicate that this feature is likely non-tectonic in origin. Feature 26: Feature 26 is an east-to-west trending photo lineament mapped over bedrock for its entire trace except for the far western end (Figure B-16).At this location,it is mapped over Quaternary age talus deposits before it terminates against a bedrock knob in the center of the cirque.Visual inspection of the lineament via low altitude aerial inspection revealed no clear linear trace through the talus deposits. Within the cirque,the only along-strike linear trend is attributed to a linear drainage incised into bedrock. Feature 27: Feature 27 is an east-to-west trending photo-lineament mapped over paragneiss (TKpgn)bedrock in its middle portion and Quaternary talus (Qct)deposits on its eastern and western extents (Figure B-16). Within bedrock,no continuous linear features were observed that correspond with the mapped trace of Feature 27.Within Quaternary talus,the only linear expressions observed via low altitude aerial inspection were related to linear drainages.Field observations and existing data indicate that this feature is likely non-tectonic in origin. INTERIM DRAFT Page 60 of 81 01/20/14 Za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Feature 28: Feature 28 is a north-northwest trending photo-lineament mapped over orthogneiss and migmatite (TKgm)bedrock and Quaternary age colluviated till (Qdc3)(Figure B-17).During low altitude aerial inspection,the feature was observed to be characterized by a shallow linear trough oriented at an oblique angle to linear solifluction features and moraines,possibly indicating that this feature is related to bedrock structure.However,it has no expression in overlying Quaternary deposits or within adjacent Quaternary till deposit to the southeast.Lacking evidence of Quaternary age deformation,this feature is not considered to be an active structure. Summary of Reger et al.(1990)Lineaments This study evaluated 28 locations where photo-lineaments and faults,appearing in Reger et al.,(1990) Map I,intersect Quaternary deposits to determine if any of these features display morphology indicative of post-glacial surface rupture and faulting.The aerial reconnaissance of these 28 features did not identify evidence of post-glacial surface rupture associated with these features.The prominence of these features on some aerial photography,linear traces,and local topographic expression can be explained through juxtaposition of different rock types with physical or erosional contrasts,linear erosion features along existing bedrock structures or down slopes,linear features associated with glacial landforms such as moraines and eskers.In addition to the visual inspection of these features,Dr.Reger was contacted,and through personal communication (Reger,2013),commented that he does not believe that any linear features identified in Reger et al.,(1990),Map |are related to active faulting.This study also judges that Reger et al.(1990)lineaments are not the result of late Quaternary faulting. 4.1.Discussion of the Talkeetna Fault Trench Locations of WCC (1982) The Talkeetna fault was characterized as a major tectonic feature near the Watana dam site by WCC (1982)although no evidence of Quaternary faulting was located during their investigations.FCL (2012, 2013)reached similar conclusions,based on the initial literature review for seismic source characterization (FCL,2012)and subsequently based on lineament mapping using LiDAR and INSAR derived DEM's (FCL,2013).The WCC (1982)investigations included paleoseismic trenching at two locations along the Talkeetna fault.As part of the 2013 field evaluation,aerial inspection and focused review of the INSAR data for those sites was conducted.Two trenches were excavated along parts of the Talkeetna fault:trench T-1 and trench T-2.Trench T-1 is located directly southwest of the Fog Lakes,and lies about 15 km from the proposed dam site (Figures 5-1 and 5-2).Trench T-2 is located much farther to the southwest,about 65 km from the proposed dam site,and is slightly west of the confluence of the Talkeetna River and Iron Creek (Figure 4-3). Low altitude aerial inspection was performed near the WCC trench T-1 site along the map trace of the Talkeetna fault,to confirm the location of the trench and observe the geology and geomorphology in the INTERIM DRAFT Page 61 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. area (Figure 4-1).Ground access was not available during the 2013 summer season.From the air,the slightly west of north-facing break-in-slope is a geomorphic feature that would expected from a potential southeast-dipping,reverse to oblique-slip fault (Figure 4-1).From subsurface excavations, WCC (1982)concluded that the exposures in trench T-1 were not faulted,and the slope break "scarp”is related to the melting edge of a late Wisconsin ice margin.This scarp trenched by WCC (1982)is relatively unique compared to the other lineaments inspected during the summer 2013 field investigations and it is reasonable that this location was selected by WCC for paleoseismic investigation.However,this scarp is not readily discernible on the INSAR DEM (Figure 4-2),and thus was not captured by the lineament mapping.This area lies south of the existing detailed LIDAR data extent along the Susitna River,and additional LiDAR coverage in this area is necessary to inspect and interpret features that could be related to the scarp at the WCC T-1 trench site that are not readily apparent on the INSAR data. A brief aerial inspection of the WCC paleoseismic trench T-2 area was performed to confirm,as best as practical,the location of the excavation,and observe the geology and geomorphology at the location (Figure 4-3).No distinct features were associated with the excavation site (e.g.tree lines,backfill mounds),so the exact trench spot was only approximately located.In general,there are linear topographic grooves along the mapped location of the Talkeetna fault.In this area,the fault juxtaposes Cretaceous sedimentary rocks (map unit KJs)on the northwest against Paleozoic volcanic rocks on the southeast.The northeast projection of the fault is shown as terminating at a hill composed of intrusive Tertiary volcanics (map unit Tvu)that were dated at slightly older than 50 ma (Csejtey,1978).WCC (1982)observed that these volcanic rocks have not been displaced.Our field inspection confirms the conclusion that the volcanic rocks show no evidence of displacement (Figure 4-3),suggesting that the fault,at least in this part of the study area,shows no evidence of movement post volcanic emplacement (early Eocene). INTERIM DRAFT Page 62 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014Clean,reliable energy for the next 100 years. 5.SUMMARY OF FINDINGS The purpose of the lineament mapping and evaluation is two-fold:(1)to identify potential seismic sources (i.e.,crustal faults)that could appreciably contribute to the seismic hazard at the proposed hydroelectric project and affect dam design;and (2)to identify faults and assess their potential for surface fault rupture at or near the proposed dam site area.However,because of unanticipated lack of ground access to private land (e.g.,ANCSA)in 2013 (Figure 1-3),not all planned activities were completed during the summer field season.Certain parts of select lineament groups and features in the dam site area will need to be investigated and evaluated to complete this study and to reduce remaining uncertainties. All lineament groups targeted for 2013 field work received a low-altitude aerial observation,and ground inspection was completed at selected locations (i.e.state and federal lands)where features of interest were identified and ground access was permitted.Based on the work to date and the current access restrictions,the lineament groups are placed into four categories: e Lineament groups in category I were not advanced for 2013 field observations (FCL,2013),but where convenient,brief fly-overs in 2013 were performed to visually confirm their placement in category I,with no further work suggested. e Category II includes the majority of the lineament groups and features evaluated in 2013. Lineaments in this category are judged to be 1)dominantly erosional in origin,2)related to rock bedding or jointing,or 3)to a lesser extent,a result of constructional geomorphic processes. This category is subdivided in to categories Ila and IIb.Category IIa lineament groups are those which are not evidently associated with bedrock faults.Category IIb lineament groups that do appear to be associated with bedrock faults (Category IIb).For both categories no further work is suggested. e Category III consists of lineaments which are presently unresolved due to unavailable ground access in 2013,and for which field activities and further evaluation are deferred.This category includes investigation sites most relevant to evaluations of surface faulting in the dam site area and includes the WCC trench T-1 area,Fog Creek area,and dam site and reservoir vicinities. e Category IV includes lineament groups that have defensible justification for consideration or inclusion as crustal seismic sources in an updated seismic source model.No further field work is suggested. INTERIM DRAFT Page 63 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. The overall evaluation and grouping of the lineament groups and features are summarized in Table 5-1 below.Category I includes several lineament groups not advanced for further study based primarily on distance from the site considerations derived from the evaluations in FCL (2012,2013).Table 5-2 presents a summary of lineament data,observations,and evaluations from the detailed discussions in Section 4.0. Table 5-1.Summary of Lineament Groups and Areas Category Category Description Lineament Groups Lineament groups that were not advanced for field investigation in 2013 |4,10,11,13,14,15,16,18,24,25, |based on FCL (2013)desktop evaluations.Most were not inspected during |North-South Features near Talkeetna 2013 field activities.River-Susitna River Confluence Lineament groups evaluated during 2013 field studies,and judged to be non-tectonic (dominantly erosional,depositional,or jointing/bedding in ]1,2,3a,3b,5,12a,17a,21a,21b,22, origin).No further work is recommended for evaluation as potential crustal |23,select Reger et al.(1990)features seismic sources. lla Lineament groups evaluated during 2013 field studies,and also judged to be of non-tectonic origin,but which appear to be spatially associated with IIb previously mapped bedrock faults.No evidence of Quaternary faulting was observed,and no further work is recommended for evaluation as potential crustal seismic sources 7,8,9,12b,17b,17c,19,20,Broad Pass area,Clearwater Mountains area,select Reger et al.(1990) features i Lineament groups or other areas unresolved due to unavailable ground |6,26,WCC T-1 area,Fog Creek area, access in 2013.Field activities and further evaluation are deferred.dam site and reservoir vicinities IV Lineament groups that have defensible justification for consideration or 27 (Sonona Creek fault),Castle inclusion as crustal seismic sources in an updated seismic source model.Mountain extension Many of the lineament groups visited in 2013 are judged to be dominantly erosional in origin,or to a lesser extent,related to rock bedding or jointing,are not evidently associated with tectonic faults,and are thus assigned to Category Ila (Table 5-1).These include features in lineament groups 1,2,3a,3b,5, 12a,17a,21a,21b,22,and 23.Most of the Reger et al.(1990)photolineament features fall in Category IIa as well.A second set of lineament groups do appear to be coincident with previously mapped pre- Quaternary (i.e.bedrock)faults,but are also interpreted as erosional in origin as no evidence was found for offset or deformation of Quaternary deposits or surfaces.These are assigned to Category IIb,and include lineament groups 7,8,9,12b,17b,17c,19,20,the remaining Reger et al.(1990)features, lineaments in the Broad Pass area,and lineaments in the Clearwater Mountains area. Category III features are those that remain relatively unresolved because of the unanticipated lack of access during the summer 2013 field season.This category includes lineament group 6,lineament INTERIM DRAFT Page 64 of 81 01/20/14 Zz ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. group 26,as well as WCC T-1 area,Fog Creek area,dam site area and reservoir vicinities.The Category III features are discussed further in Section 5.1. Category IV lineaments have defensible justification for consideration or inclusion as crustal seismic sources in an updated seismic source model,and consist of lineament group 27 (Sonona Creek fault) and lineaments of the Castle Mountain extension. Part of lineament group 27 is shown on previously published maps as offsetting Quaternary moraine landforms (i.e.Sonona Creek fault;Figure A27-3.1)and this relationship could not be confirmed nor refuted during aerial and ground field inspection.However,field investigation showed no justification for laterally extending the fault farther than already mapped.Because the Sonona Creek fault was previously included in the preliminary PSHA as a seismic source (FCL,2012),and did not result in significant contributions to the seismic hazard at the Watana site due to its low slip rate and distance from the site ( 70 km),there is little value for further field investigation of this lineament group.Based on the new field data,the updated seismic source characterization for the Sonona Creek fault should include an alternative evaluation in which the Sonona Creek fault is considered non-tectonic in order to fully represent the potential uncertainty associated with this fault. The Castle Mountain extension area includes several lineaments along mapped bedrock structures which appear to constitute a northeastern extension of this known Holocene active fault (Koehler et al.,2012). While Quaternary deposits of appreciable extent and age along these lineaments are lacking,the sharpness of geomorphic expression within the bedrock units was notable.Based on these two observations,it is prudent to consider the lineaments as part of the Holocene-active fault system,and include this within the alternatives considered for an updated crustal seismic source model.Castle Mountain fault provided modest contributions to the total hazard for the Watana site (FCL,2012),and extension of the Castle Mountain system to the northeast would increase the total fault length of this system and result in minor reduction in the closest distance to the Watana site ( 100 km in FCL,2012). Based on the results from this study,an updated seismic source characterization might consider alternative seismic source models which include potential northeastern extensions of the Castle Mountain fault. 5.1 Unresolved Lineaments and Areas The unanticipated lack of ground access in certain areas has resulted in a number of potential seismically significant features that remain to be fully addressed during the future studies.These features are shown in Table 5-1 as Category III,and mostly relate to features along the projection of the map trace of the Talkeetna fault,and features identified in areas proximal to the dam site and reservoir vicinity. INTERIM DRAFT Page 65 of 81 01/20/14 -Zz-ALASKA ENERGY AUTHORITY .AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. Lineament group 6 ( 14 km [ 9 miles]from the dam site)and the WCC trench T-1 site are along the projection of the map trace of the Talkeetna fault,and ground access was unavailable for the T-1 site area as well as the southern part of lineament group 6 near the Susitna River.To facilitate a thorough investigation of these areas,new additional LiDAR data should be acquired for as an expansion to the existing project LIDAR coverage.Review and interpretation of the LIDAR data will further assist in the evaluation of landscape expression of the Talkeetna fault along lineament group 6 and the WCC T-1 area,and provide a platform for closing the gap on the remaining uncertainties of this mapped fault. This would include evaluation of features in the Fog Creek area,mid-way between lineament group 6 and the WCC T-1 area,where key bedrock outcrops mapped by Acres (1982)appear to define limits on the Talkeetna fault trace. Based on the work to date,lineament group 26 (2 km [ 1 miles]from the dam site)appears to be of erosional origin and not associated with bedrock faults.However,based on its proximity to the dam site,coupled with the lack of access to potentially important stratigraphic exposures in the vicinity of Tsusena Creek,lineament group 26 has been assigned to category III. Evaluation of the dam site area for potential surface faulting and studies on the reservoir area were not able to be accomplished during the summer 2013 season,and remain to be investigated as access becomes available.For evaluation of potential surface faulting at the dam site and near the reservoir,a key issue is the underlying resolution of the lineament mapping observations from the INSAR and LiDAR DEM data.As noted in Section 3.1 and the individual feature discussions in Section 4,many of the features mapped on the INSAR base map are of a scale larger than would be expected to be associated with low-to moderately-active tectonic features.One aspect of the evaluations of lineaments near the dam site that will be needed for future studies will be more direct on-ground comparisons of the scales of features mapped,and not mapped,on the LiDAR and INSAR DEM datasets in areas where they overlap.These comparisons would be most useful in the areas nearby the dam site and reservoir, along the Talkeetna fault,and in areas such as Fog Creek,and near the WCC T-1 trench site lineament. Such on-ground comparisons would provide a direct basis for evaluation of the resolution of the INSAR and LIDAR DEM data for detection of potential lineaments and tectonic features in key areas near the dam site.The acquisition of additional LIDAR data and geologic mapping on the existing and new LiDAR base maps will be useful to completing this assessment. INTERIM DRAFT Page 66 of 81 01/20/14 -wO ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Table 5-2.Lineament Data Summarized from Section 4.0 .Approximate Approximate :Group Previously Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary Interpretations Lineament Number Mapped?Sitet (km)(km)Category Late Quaternary deposits along the Jack River,of late Wisconsin and post-The absence of continuity of the individual lineaments from steep bedrock glacial age intersect the projected trace of the group 1 lineaments near the slopes into areas adjacent areas of lower slopes where Quaternary deposits are {N 51 20 center of the group 4 ellipse.These late Quaternary deposits show no present is evidence of non-tectonic origin for these features.The lineaments of Ila apparent expression of the lineament.No evidence of fault structure was group 1 are likely non-tectonic in origin,are judged to be primarily erosional observed during low-level aerial inspection.and/or landslide features. Mapped Quaternary surficial sediments,fluvial deposits in several unnamed Based on the irregular apparent throw of the lineaments along strike,lack of drainages,a glacial moraine,and an alluvial fan deposit show no apparent western continuity into the Cretaceous Kahiltna flysch,and absence of deflection or deformation where overlying the projected trace of the lineament |expression in Quaternary units along the feature,the likelihood of a tectonic 2 N -46 12 group.In all instances,lineaments with clear expression in bedrock lose origin for the lineaments in group 2 is judged to be low.The limited and lla expression at contacts with Quaternary deposits and landforms.ambiguous expression of lineament features outside of the Tertiary volcanic rocks within the Cretaceous flysch,suggests that the observed trend may represent erosion along internal bedrock structure. The lineaments mapped in Quaternary (post-glacial)deposits along group 3a_'|Lineaments within groups 3a and 3b are not associated with previously mapped do not show neotectonic expression or offset.While the group 3a lineaments faults,are predominantly erosional in origin,and show no evidence of offsetting 39 N _40 42 are mapped across several different geologic units,they appear erosional in Quaternary deposits.When considered individually,there is little evidence to llaorigin.The exception to this is the ridge in the Cretaceous Kahiltna flysch in support the lineaments as a fault structure.When considered collectively,there which field observations found a color contrast (Figure A3a.2)that may be is little similarity in their landscape expression across the two groups to support structurally-controlled,or may just as equally be stratigraphically controlled.positive interpretation of a linked,through-going crustal structure. No Quaternary deposits are previously mapped,but ground-based inspection |Lineaments within groups 3a and 3b are not associated with previously mapped indicate that there are youthful (Holocene)deposits in cirques and drainage faults,are predominantly erosional in origin,and show no evidence of offsetting 3p N _97 19 valleys,as well as rock glacier deposits.Although these are very young Quaternary deposits.When considered individually,there is little evidence to lladeposits,there are no expression of lineaments in these deposits.The support the lineaments as a fault structure.When considered collectively,there morphology of the lineament is inconsistent along strike,showing north-facing |is little similarity in their landscape expression across the two groups to support slope breaks,south-facing slope breaks,as well as v-shaped notches.positive interpretation of a linked,through-going crustal structure. This lineament group was not advanced for field work in 2013 based on the A limited number of low-altitude fly-overs in 2013 appear to confirm the desktop Unnamed fault of Wilson et al desktop analysis of FCL (2013)conclusion that the group 4 features are pre-Quaternary.Rock-type contrasts4Y(2009) '23 11 were observed across the previously mapped NE-trending thrust fault but no l prominent tectonic geomorphology to suggest Quaternary activity was observed along strike in post-glacial surficial deposits nor in the bedrock. Along its eastern extent,the trend of individual lineament groups is generally While the lineament group does traverse different geologic units and landforms parallel to ice-flow direction expressed as fluted and grooved topography ina |suggesting a continuity of structure,the lineaments show an inconsistent general east-west orientation.There is no evidence that the ice-scoured kinematic expression along strike within the same rock unit (Cretaceous Partial coincidence with an surfaces are cross-cut or otherwise offset by the lineaments.Along the turbidites)that tends to not support the presence of a tectonic structure for 5 Y unnamed lineament of Wilson et al.40 23 eastern extent of the group,the lineaments'morphologic expression as side-creating the lineaments.It is judged that the lineaments along group 5 are the lla (2009)hill benches would imply an extensional-type kinematics (i.e.,down-to-the-result of bedding orientations in the Cretaceous turbidite units and elsewhere south);along the western extent the morphologic expression varies as both from fluvial or glacial erosion,and do not represent a tectonic fault uphill and downhill facing scarps,linear grooves,and drainages that would imply a translational-type kinematics. INTERIM DRAFT Page 67 of 81 01/20/14 -z- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Previousl Approximate Approximate LineamentGroupreviousySourceofPreviousMappingDistancetoDam|Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary Interpretations C menNumberMapped?Sitet (km)(km)ategory Previous studies result in a fair degree of disagreement as to the location and |The lineaments mapped within group 6 are judged to be the result of erosion ofcharacterofthe(inferred)Talkeetna fault in the area of lineament group 6.tributary drainages and fluvial erosion to create terrace risers along the creeks Field evidence of a fault structure was not observed along or in the immediate |and are not likely tectonically-related.Further,there is an absence of vicinity of lineament group 6,and no evidence was observed along the expression of the Talkeetna fault in Quaternary deposits and surfaces present Talkeetna thrust fault of Csejtey et projection of the fault trace and Delusion Creek.The lineaments are expressed |along the uplands adjacent to Watana Creek.However,additional LIDAR data 6 Y al.(1978);WCC,(1982);and Wilson 14 17 as linear drainages or erosional gullies oriented sub-orthogonal to the is being collected to provide complete coverage for the area of lineament group Ill et al.(2009)Talkeetna fault trace(s),and principally are developed in late Quaternary 6 and the mapped Talkeetna thrust fault.Additional future work for lineament glacial drift (till)and glacio-lacustrine (lake)deposits.Field observations of group 6 should include review of these new high-resolution data to confirm that Quaternary stratigraphic outcrops along Watana Creek suggest that the the current interpretations are still supported. contact between the overlying lake and underlying till deposits is planar, unbroken,and apparently untilted. Unnamed shear zone of Wilson et The lineaments transect young valley floor glacial sediments as well as The geomorphic inconsistencies,coupled with the fact that the Quaternary al.(2009),a mapped thrust fault elevated bedrock ridgelines.There was no field evidence that linear strain deposits in the valley floors are not disrupted,strongly indicates that erosional(Tuer an d Smith.1974:Belkman markers were deformed or displaced,however the glacial sediments are from |process of creek incision and downcutting into surface deposits along the 7 Y et al.1975 Kacha doorian and 28 47 rock glacier processes,and few older landforms were observed along this south-flowing drainages are likely responsible for creating the lineaments.IIbMoore1979:and Clautice,1990)group.The expression of the lineament is inconsistent along strike with an Lineaments of group 7 generally coincide with mapped bedrock structures d 'rth ast-tren din anticline apparent stronger expression where mapped along fluvial drainages,and no within fault-line-valleys but lineaments in late Quaternary deposits areandanorinewe8expressioninWNW-oriented cirque-floors or valleys.inconsistently expressed and likely relate to processes of erosion.No evidenceaxisCsejteyetal.(1978)of Quaternary deformation was observed. The lineaments are expressed in ice-scoured bedrock uplands and a thin Lineament group 8 does not exhibit relative consistency of geomorphic cover of glacial and colluvial deposits subject to solifluction.Glacial striae expression along strike.The apparent structural kinematics (dip-slip)based on Coincidence with feature KD5-44 of north of the Susitna River do not appear consistently deformed or displaced mapped contact relations (Wilson et al.,2009)for the middle and southern WCC (1982);Partial coincidence across the trend of the lineament and several small streams that cross the portion of the group are not consistent with the undeformed contact relations8YwithanunnamedfaultofWilsonet3826lineamentsarenotconsistentlylaterallyoffsetordeflected.Aerial inspection between turbidite rocks of the Cretaceous and Paleocene rocks near the lb 1 (2009)did reveal the oxidized mafic dike on the northern canyon wall of the Susitna Susitna River,and also the lack of deformation in turbidite rocks north of theal.(River that WCC (1982)observed projecting across the observed lineament river.The evidence supports the origin as a fault-line-scarp (an erosional trend but discovered the same ambiguous and poor exposure conditions feature aligned with a mapped bedrock fault). described by WCC. The mapped lineaments transect mapped bedrock units,but are not Based on the mapped geologic contacts along the southern portion of the expressed in the limited extent of Quaternary surficial deposits present along group,the apparent sense of offset is right-lateral with possible unknown Coincidence with feature KC5-5 of the group.No lineaments were observed in early Holocene fluvial deposits oblique component.This is kinematically inconsistent with the mapping north of WCC (1982);Partial coincidence within a broad depression or across the extent of a post-glacial landslide.the Susitna River because the mapped the contact there between Cretaceous 9 Y with an unnamed lineament and an 31 24 Although a rock-type contrast does exist across portions of the lineament,the |Kahiltna and Paleocene granitics is apparently undeformed and undisplaced \Ib unnamed fault of Wilson et al.current mapping compilation may be too simplified and more irregularity of where the lineament group projects across the contact.No evidence of (2009)bedrock unit contacts likely exists.The magnitude of expression and apparent |expression in Quaternary units,landforms,or strain markers was observed. sense of deformation observed in the field is inconsistent along lineament Lineament group 9 is interpreted to represent a fault-line scarp and not a group trend.Quaternary tectonic feature. This lineament group was not advanced for field work in 2013 based on the During limited flyovers,no features were observed that suggested a need to 40 N _70 97 desktop analysis of FCL (2013)that the lineament group is over 70 km ( 44 revise those conclusions.|miles)from the proposed dam site and less than 40 km ( 25 miles)long,and likely would not appreciably contribute to the hazard calculations. Coincidence with an unnamed This lineament group was not advanced for field work in 2013 based on the Limited overflight of these features in 2013 appears to confirm this conclusion. 11 Y lineament and an unnamed fault of 40 48 desktop analysis of FCL (2013)suggesting that surficial processes are likely In addition,the group is greater than 30 km ( 19 miles)from the proposed site Wilson et al.(2009)exploiting existing topographic position and/or local weaknesses in the and is less than 20 km ( 12 miles)in length,and likely would not appreciably 'underlying Cretaceous Khalinta flysch bedrock to create the lineaments.contribute to the hazard calculations. INTERIM DRAFT Page 68 of 81 01/20/14 za ALASKA ENERGY AUTHORITY .AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. G Previousl Approximate Approximate Lineamentrouprevious'y Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary InterpretationsNumberMapped?Sitet (km)(km)Category The individual lineaments mapped along the north part of the group chiefly are |There are no lineaments expressed in the Quaternary deposits along about the within probable latest Wisconsin-age glacial deposits near the valley margin,southern half of group 12a,and there is visual evidence that right-lateral and are oriented along the ice flow direction.A prominent notch with an uphill-|moraine and kame terrace features at the southern end of the group are notfacingslopebreakwasobservedwithinthePaleozoicrocksalongthenoseof|offset.There is no expression of deformation or offset of late Wisconsin aridge.The topographic expression of this lineament feature on the ridge landforms in kames or delta surfaces within the valley of Fog Creek directly 42a N _14 42 topography implies a northwest-dipping structure geometry,similar to bedded {north.Multiple slope breaks on the hillslope in the vicinity of the mapped ilarockexposedontheothersideofthemountains.The morphology of the lineaments,as well as the lineament orientation parallel to ice flow directions, features is kinematically inconsistent along strike,with south-east facing suggests the lineament group was produced by glacial deposits that are now downhill slope breaks found on the lineaments in the Quaternary deposits,and |undergoing solifluction and nivation processes.It is judged that the lineaments an uphill facing slope break on the bedrock notch feature.within group 12a are the result of both past glacial processes,ongoing hillslope erosion processes,and potentially bedding relationships within the Paleozoic rocks,and do not represent a tectonic fault. The lineaments are expressed chiefly in Paleozoic rocks,however,a thin The lineament is chiefly constrained to within the Paleozoic rocks,and is cover of Holocene regolith mantles the rocks.The morphologic expression of |coincident with the previously mapped bedrock fault,suggesting a potentialthefeatureisinciseddrainagesandaverybroadanddeepvalleywithinwhich|structural control and preferential erosion along a pre-existing weakness. a small creek now flows.None of the glacial geomorphic surfaces in Fog Internal lithologic control on the geomorphic expression of the lineament also is ;Creek valley (e.g.eskers,deltas)along the southwestern projection of the plausible given the lack of lineament continuity beyond the Paleozoic rocks.12b Y Unnamed fault of Clautice,(1990)6 "lineaments were observed to be offset or deformed,and no evidence of The evaluation suggests that glacial and post-glacial fluvial erosional processes ilo deformation was observed at the Susitna River margin along the northeastern |are a likely explanation for the origin of the lineament features.Individual projection.The lineament group appears to have a variable geomorphic lineaments may represent fault-line scarps or fault-line-valleys,but due to the expression along strike,has weak kinematic indicators along strike.lack of expression in Quaternary deposits,the lineament group is not considered a Quaternary tectonic structure. This lineament group was not advanced for field work in 2013 based on the During limited flyovers,no features were observed that suggested a need to 43 Y Coincidence with unnamed fault of 67 15 desktop analysis of FCL (2013).Also,because of the large distance from the |revise the conclusions of FCL (2013).|Wilson et al.(2009)site,the group would therefore likely have limited contribution to the hazard calculations. This lineament group was not advanced for field work in 2013 based on the A limited fly-over revealed no features that that suggested a need for additional 44 Y Coincidence with unnamed fault of 62 48 desktop analysis of FCL (2013).The group is greater than 30 km ( 19 miles)analysis. Wilson et al.(2009)from the site and less than 20 km ( 12 miles)in aggregate length,thus meeting lineament exclusion criteria. ;This lineament group was not advanced for field work in 2013 based on the During limited flyovers,no features were observed that suggested a need for 45 Y Coincidence with unnamed fault of 43 6 desktop analysis of FCL (2013)due to its large distance from the proposed additional analysis.|Wilson et al.(2009)damsite ( 43 km [ 27 miles])and short aggregate length ( 6 km [ 4 miles)). Partial coincidence with an This lineament group was not advanced for field work in 2013 based on the During limited flyovers,no features were observed that suggested a need for 16 Y unnamed lineament of Wilson et al 60 19 desktop analysis of FCL (2013).The group was excluded from further analysis |additional analysis.(2009)'on basis on its significant distance to the proposed damsite ( 60 km [ 37 miles])and relatively short aggregate length ( 19 km [ 12 miles]). Field investigation revealed that the lineaments in Quaternary deposits at the Lineament group 17a appears to follow a bedrock jointing pattern that is Unnamed lineament of Wilson et al south end of group 17a do not show scarp-like morphologies;rather one is a expressed on landscape,and potentially enhanced by fluvial erosion.Based on 17a Y (2009) ,24 11 small,discordant,creek drainage and the other appears to be a depositional the absence of compelling evidence for Quaternary tectonism,lineament group Ila contact of likely late Holocene grassy swale (bog)sediments against a near-17a is judged to not represent a tectonic fault.: surface ice-sculpted bedrock buttress. INTERIM DRAFT Page 69 of 81 01/20/14 -za- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 G Previousl Approximate Approximate Lineamentrouprevious'y Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary Interpretations n Number Mapped?Sitet (km)(km)Category The most prominent morphologic expression of the lineaments is a narrow The ground inspection supports the interpretation that glacial ice was present in Unnamed lineament of Wilson et al.creek drainage that is fed by a perched lake.The lineaments appear to the valley.Although there may be a bedrock structure along part of this group 17b Y (2009);and dashed fault of Csejtey 30 20 coincide with the trend of glacial ice flow directions that were valley parallel.that separates Paleozoic and Mesozoic rocks,lineament group 17b is judged to IIb (1974)No direct evidence of a fault along this trend was found in the field.be created at the local scale by fluvial erosion as well as in part by glacial ice erosion of the linear valley and periglacial processes. The lineaments are mapped across Tertiary volcanic rocks as well as in young |Along the south end of 17c group the relief along the lineament in the (likely Holocene)rock glacier deposits;the expression within the rock glacier Quaternary rock glaciers is lesser than the middle part of the group,however, Unnamed fault of Wilson et al deposits correspond to relatively deep drainages eroded into the rock glacier the relief in the rock glacier drainage is about 25 meters ( 82 ft);much larger 17c Y (2009) ,45 8 deposits.None of the faults depicted on Wilson (2009)are shown extending than would be expected for a relatively low-slip rate fault structure in young Ilb across or displacing Quaternary glacial or moraine deposits.post-glacial deposits.While the presence of a bedrock fault cannot be ruled out along lineament group 17c,it is judged that the mapped lineament is the result of erosion into the rock glacier deposit. This lineament group was not advanced for field work in 2013 based on the This group was not visited during the 2013 field inspections and no Partial coincidence with two desktop analysis of FCL (2013)which concluded that the group's large observations were made that suggested a need for additional analysis. 18 Y unnamed faults of Wilson et al.52 10 distance to the proposed damsite and short overall length would likely not | (1998)appreciably contribute to the hazard calculations. The lineaments of group 19 transect several different geologic units and The large magnitude of relief across the lineaments in the northeastern portion landforms,but are not present in the post-glacial alluvium of Goose Creek or is inconsistent with the apparent lack of topographic offset across the adjacent drainages.The magnitude of expression of the lineaments ranges lineaments in the southwest portion of the group.Specifically,the surfaces of Partial coincidence with unnamed from 10-m-high ( 33 ft)downhill-facing slope breaks in glacial deposits of the |the exceptionally planar bedrock plateau across which the aligned linear valleys19YfaultofClautice(1990)54 44 Black River to gently sloping 125-m-high ( 410 ft)bedrock escarpments.run show no evidence of the vertical displacement apparent along the lineament Itb Bedrock exposures in creeks along the lineament showed evidence of group.It is judged that lineament group 19 is a result of a combination of pervasive jointing.The lineament group is roughly parallel to glacial ice flow bedrock jointing and glacial and post-glacial erosion processes,and does not directions in the Black River canyon and spatially coincident with left-lateral ice |represent at Quaternary fault. margins. No direct evidence of any of the mapped faults was apparent in the field but Low-level aerial and ground inspection did not reveal any evidence for Partial coincidence with unnamed indirect evidence in the form of apparent rock type contrasts across mapped Quaternary faulting along the mapped lineaments or previously mapped faults. 70 Y |fault of Wilson et al.(2009)94 14 fault traces.There is no field evidence of erosion from glacial ice within the Some of the individual lineaments along the northwestern margin of group 20 {Ibnormallaut0' 60 area of the lineament group.The mapped lineaments often alternate between |do appear to coincide with previously mapped bedrock faults and are likelyandfaultmappedbyGrantz(1960)weakly expressed and subtle slope breaks and broad troughs and deep and fault-line scarps developed along bedrock faults,but the remaining lineaments well-defined linear valleys.are interpreted to be the result of erosion and not tectonically-related. Lineament group 21a lies entirely with glaciated terrain at the confluence of The lineaments of group 21a do not transect portions of the landscape of possibly four different ice streams.Field inspection confirmed that most of the |different ages which challenges the existence of through-going tectonicareahaseitherasurficialcoverofglacialmoraineand/or glacial lake deposits |structure.The apparent origins of the lineaments are both constructional from a series of glacial lakes.No field evidence of displaced or deformed (terminal moraine complex and eskers)and erosional (linear streams and short21aN-40 12 co _a nan :Hlaterracerisersormoraineridgeswasobservedalongthetrendoftheslopebreaksindissectedglacialmoraineridges.Limited and poor expression lineaments.The lineaments of group 21a are few in number,weakly of lineaments coupled with both active and stagnant ice processes in the area, expressed,weakly aligned,and do not coincide with a previously mapped point to a non-tectonic glacial origin for the lineaments of group 21a. structure. INTERIM DRAFT Page 70 of 81 01/20/14 -za- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 G Previousl Approximate Approximate LineamentroupreviousYSourceofPreviousMappingDistancetoDam{Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary InterpretationsNumberMapped?Sitet (km)(km)Category The lineaments occur as downhill-facing slope breaks in mapped Quaternary Field investigation did confirm the expression of the 3-km-long,downhill-facing glacial deposits (unit Qdts of Smith et al.(1988))and as linear streams and slope break in Quaternary glacial deposits but did not reveal any exposures of gulleys eroded into Cretaceous flysch,and to a lesser extent,Cretaceous the spatially-coincident concealed schist-phyllite contact mapped by Smith Coincides with a photographic granite.Map unit Qdts is considered to be of late Wisconsin age (11,800 to (1988).The group 21b lineament most likely relates to the rock type contrasts 21b N lineament mapped by Reger et al.42 12 25,000 year B.P.).The lineament group is oriented perpendicular to the ice mapped by Smith et al.(1988)where higher grade (and more resistant)schist lla (1990)flow directions within the Butte Creek valley.Inspection of the stream banks lies upslope of the slightly lower grade (and less resistant)phyllite and is and terrace risers located to the west along the trend of the feature did not overlain by a thin veneer of Quaternary glacial deposits.The lineaments of reveal any displaced terrace risers or surfaces.Group 21a are judged to be non-tectonic in origin and likely relate to differential erosion along depositional contacts within bedded metasedimentary rocks. The lineaments are mapped in Reger et al.'s till of late Wisconsin age (unit The lineaments of group 22 show a dearth of expression in Quaternary Qd3;9,500 to 25,000 years old)(Reger Public Data file 90-1),and are deposits,other than being associated with two linear drainages.While the Spatially coincides with several expressed in the field as linear erosional gullies.Much of the hillsides appear |lineaments transect several different geologic units,suggesting some lateral 29 N northwest-trending photogeologic 97 17 to be influenced by solifluction processes.Along Deadman Creek,the extent,we find that the magnitude of expression along strike is highly variable.lla lineaments from Reger et al.(1990)lineaments are nearly orthogonal to the ice flow direction,and no offsets in the |Because there is no fault previously mapped along this group and no evidence ,lateral moraines were observed.of a fault was observed,coupled with the field observations of solifluction processes as well as a distinct lack of faulting expression in the late Wisconsin glacial deposits,it is judged that lineament group 22 is not a fault. The features along the lineament trend occur entirely within mapped The arcing alignment and the consistently low relief morphology of the aligned Quaternary glacial and lake deposits of the Copper River Basin.The slope-breaks,low mounds,and short linear ridges does appear similar to a lineaments do not coincide with any previously mapped faults or lineaments terminal moraine complex.The positive relief of these features suggests (FCL,2013)and low-level aerial inspection did not reveal any direct evidence |constructional or depositional geomorphic processes,rather than via tectonic 23 N --62 17 of tectonic structures anywhere along the lineament,including in the near-processes,may have played a role in their formation.The lineament group lies lla vertical cut banks of Tyone Creek.The orientation of the mapped lineaments is }|within published glacial lake extents and elevations in the Copper Basin.Theparalleltoseveralnorth-south oriented drumlins,and perpendicular to regional |evidence points to a genesis via glacial processes,and does not support a ice-flow directions,but parallel to and locally coincident with terminal moraine tectonic genesis.It is judged that lineament group 23 does not represent a crests tectonic fault. This lineament group was not advanced for field work in 2013 based on the This group was not visited during the 2013 field inspections and no oA Y Partial coincidence with lineament of 120 44 desktop analysis of FCL (2013)that the lineament group is short ( 15 km [ 9 |observations were made that suggested a need for additional analysis. Wilson et al.(2009)miles])and lies a great distance from the damsite ( 120 km [ 75 miles]),and likely would not appreciably contribute to the hazard calculations. This lineament group was not advanced for field work in 2013 based on the During limited flyovers,no features were observed that suggested a need to desktop analysis of FCL (2013).The lineament group was interpreted to be revise those conclusions.25 N -23 32 .«a:.|the result of erosional and depositional processes,chiefly the apparent alignment of several large,curvilinear glacial valleys. Neither direct nor indirect field evidence of fault structures were observed An esker landform on the south side of the Susitna River appears to be along this lineament group.South of the Susitna River,the lineaments are continuous where it extends across the mapped lineament,indicating no mapped in glacially-sculpted terrain that shows geomorphic landforms deformation since its emplacement.Because of the absences of previously indicative of stagnant ice.North of the Susitna River,the lineaments principally |mapped structures or faults,the lack of field evidence of faults,and thearemappedinalineardrainageinwhoseupperbanksareexposuresoftillapparentpositiveevidencefornon-faulting or displacement vis-a-vis the 26 N -16 13 that overlies lacustrine and fluvial deposits.The lineament group is relatively undeformed esker deposit (>11 ka in age),it is judged that the lineament group Ill discordant with the ice flow direction.Assessment of kinematics of the is erosional in origin and does not represent a fault structure.However,ground lineament morphology is indeterminate because there a near absence of access for this lineament group was restricted during the 2013 field geomorphic expression of tectonic-related features.investigations,and due to the close spatial proximity to the dam site,this lineament group warrants additional study to confirm the absence of bedrock structure along these features. INTERIM DRAFT Page 71 of 81 01/20/14 -a- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 G Previous!Approximate Approximate Lineamentrouprevious'y Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary InterpretationsNumberMapped?Sitet (km)(km)Category The lineament is expressed in late Quatermary glacial drift and glacial lake The expression of lineaments in a portion of the landscape judged to be the deposits as a series of aligned lakes,linear lakes and swales,vegetation youngest,and the absence of observed deformation (lateral or vertical)in the lineaments,low-relief ( 2-m-high)ridges,but the apparent sense of adjacent Tolson Creek Moraines,which are older,is inconsistent with an origin Coincidence with Sonona Creek displacement is not consistent along the lineament group.Williams and by faulting.Field investigation did not reveal any definitive evidence to strongly 27 Y fault mapped by Williams and 62 50 Galloway's (1986)depict the Sonona Creek fault as truncating,cutting across,|refute nor strongly support the presence of the mapped portion of the Sonona IV Galloway (1986)and also terminating into different ridges of the Tolson Creek moraine Creek fault.The field observations from this study favor a non-tectonic complex.Ground investigation and aerial inspection of the Tolson Creek interpretation for this feature,but are not sufficiently strong to rule out the moraines did not reveal perceptible lateral or vertical deformation along the potential of late Quaternary faulting. projection of the mapped fault Astrong fabric of northeast-trending glacial features characterizes the Low altitude fly-overs of the partly-fcrested,partly-wetland surface of the geomorphology in the Chulitna Valley,with numerous landforms such as Chulitna valley found no evidence of Quaternary faulting,and the surficial drumlins,and glacial striae occurring throughout the valley.Existing geologic |geology and geomorphology observed was uninterrupted and undeformed.This Coincidence with dashed faults mapping depicts pre-Quaternary faults that apparently place Paleozoic and argues that the deposit has not experienced tectonic deformation since its Broad Pass Y mapped by Csejtey (1961)and 56 Several;various Mesozoic rocks against each other,or Paleozoic and Mesozoic rocks against |emplacement,supporting an interpretation of no late Quaternary or post-glacial IIbFaultAreaWilsonetal.(1998)lengths Tertiary sedimentary rock units.These older rocks are in turn overlain by faulting.The lineaments mapped within the Chulitna River valley are oriented 'Quaternary glacial and fluvial sediments that are no older than late Wisconsin |along the direction of ice flow,and generally are located along the margins of age.Several locations were investigated as part of the assessment of geomorphic features (e.g.drumlins,kettle edges)that are genetically related to previously mapped faults in the Chulitna River valley.Faults mapped as glacial flow and related processes.Thus,none of the lineaments mapped in bounding Tertiary units could not be confirmed due to lack of exposure.this area are considered tectonic in origin. The lineaments are both discordant and concordant with glacial ice-flow Indirect evidence of fault structure was observed in several locations within the directions;some lineaments may be expressing the ice-limit elevations at the |core of the Clearwater Mountains in the high elevation bedrock terrain above bedrock-g!acial moraine contact.No field evidence of deformed Quaternary-the valley floor in the form of contrasting rock-type juxtapositions that .. ;age linear strain markers along the trend of mapped lineaments or faults was corroborate the general locations of the mapped faults.No field evidence ofClearwaterCoincidencewithfaultsmappedby:Several:various |observed.Field investigation did not reveal any through-going and laterally Quaternary activity along the mapped traces of the Talkeetna thrust,westward Mtns Area Y Smith oe en at 00 63 lengths continuous aggregations of individual lineaments or tilted tectonic markers extension of the Broxson Gulch,or Black Creek faults was observed.Ib (1981),and Csejtey et al.(1992)(such as shorelines or terraces)at the southern foot of the mountains that The lineaments mapped along the southern slopes of the Clearwater Mountainscouldbedefinitivelylinkedtoatectonicorigin.Post-glacial landforms and do not coincide with previously mapped faults and are interpreted to be of non-deposits did not express any lineaments and appear undeformed.tectonic origin,and likely is originated by glacial processes and the morphology of left-lateral moraine deposits. Field evidence for faulting observed during low-level aerial inspection includes:|Although a core group of lineaments within this group coincide with mapped apparent bedrock type juxtapositions,bedrock color change associated with faults,others do not.The mapped lineaments that do not coincide with alteration zones,and deformation of bedrock units.All apparent evidence was |previously mapped faults are attributed to be linear drainages (erosion features) observed in bedrock and no linear expression or evidence of faulting was and lineaments related to structural grain of the bedrock (lithologic control).No observed in Quaternary deposits,although Quaternary deposits were scarce.|definitive evidence was encountered that precludes a scenario where this The Castle Mountain fault is a Quaternary deposits in the vicinity of the Castle Mountain fault extension segment of aligned features ruptures as an extension of the Castle MountainCastleMinYQuaternaryseismogenicstructure10021lineamentgrouphavelimitedspatialcoverageandmostcommonlyoccurasfault.If the group of aligned features acts as an extension of the Castle IV extension (Koehler et al.,2012)fluvial deposits found within in narrow canyons.Because of the limited Mountain fault,it could extend the fault by approximately 21 km ( 13 miles)to exposure of the Quaternary deposits and the segmented and splayed the northeast of the current mapped extent of the fault as shown in Koehler et characteristics of the mapped faults in this area,it is difficult to declare that all |al.(2012).Based on the observations that these features are clearly related to segments of this fault exhibit no Quaternary activity.faulting of late Cenozoic age,we suggest adding this segment of fault-related features to the crustal seismic source model as a northeast extension of the Castle Mountain fault rupture scenario. INTERIM DRAFT Page 72 of 81 01/20/14 -y . SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 G Previous!Approximate Approximate Lineamentrouprevious'y Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary InterpretationsNumberMapped?.CategorySitet(km)(km) North-South This area was not advanced for field work in 2013 based on the desktop This group was not visited during the 2013 field inspections and no Features near Unnamed.normal faults are analysis of FCL (2013)on the basis of the features'large distance (i.e.,>70 observations were made that suggested a need for additional analysis. Talkeetna Y identified in revious mapping b 85 43 km [>40 miles])to the proposed dam site and their poor expression in the River-Susitna Wis on etal 1998,0008)9 °Y surrounding Quaternary sediments and Tertiary granodiorite outcrops as River ,manifested in the INSAR data. Confluence Reger''s (1990)Photogeologic Lineament Features Reger,1990,Geologic Map of the At its southern extent,this lineament is mapped across Quaternary age This linear feature is coincident with the linear toe of a rock glacier advancing Healy A-3 Quadrangle,Alaska.landslide (Qct)and rock glacier (Qcg)deposits within a narrow south facing downslope from the eastern cirque wall.The linear trace through the Alaska Division of Geological and 20 225 cirque.On the ground,this lineament is expressed as a mild inflection in the Quaternary deposits shows no evidence of being caused by a tectonic feature.IR1YGeophysicalSurveys,Public Data 'slope angle.Down drainage,to the south,the lineament has no expression in a File 90-1 sheet 1 of 2 the valley floor sediments. Reger,1990,Geologic Map of the A northwest trending photo-lineament mapped over a quartz monzonite gneiss |It appears likely that the lineament represents a collection of small and Healy A-3 Quadrangle,Alaska.(TKqmg)and paragneiss (TKpng)bedrock ridge and terminated in Wisconsin unrelated linear features such as:vegetation lineaments,glacial features, Alaska Division of Geological and age till (Qd3)at its northwest extent.The mapped trace of the feature overlies |joints/bedding rather than having a tectonic origin. .;obliquely oriented linear glacial striations within the bedrock.No clear linearR2YGeophysicalnePublicData26'expression with the same orientation as the mapped lineament was observed lla File 90-1 sheet 1 of 2 in the terrain.Quaternary deposits at the northwest and southeast extent of the mapped lineament were visually inspected,and no linear expression was observed. Reger,1990,Geologic Map of the A west-northwest trending photo-lineament mapped across Wisconsin age till |The mapped lineament is expressed by two prominent slope breaks and a Healy A-3 Quadrangle,Alaska.(Qd3),moraine (Qm3),and abandoned meltwater channel alluvium (Qac)linear trace coincident with a moraine crest.This evidence indicates that the Alaska Division of Geological and deposits.The western and central segments of this lineament are coincident mapped trace correlates with glacial features and is likely non-tectonic in origin. R3 Y ..25 3 with two prominent breaks-in-slope on the northeastern margin of a U-shaped llaGeophysicalSurveys,Public Data ;.rr aL ok ;glacial valley.The eastern portion of the feature is coincident with a linear toFile90-1 sheet 1 of 2 semi-arcuate moraine.The lineament has no expression within the Qac deposits near the center of the mapped trace. Reger,1990,Geologic Map of the A clear expression of these sub-parallel faults was not observed in the bedrock |Lacking evidence of Quaternary age deformation,these features are not Healy A-3 Quadrangle,Alaska.during low altitude aerial inspection.Intersecting Quaternary (Qd3)deposits considered to be active structures. R4&R5 Y Alaska Division of Geological and 28 4 were observed to have no linear expression or fault related deformation.lla Geophysical Surveys,Public Data File 90-1 sheet 4 of 2 Reger,1990,Geologic Map of the The central portion of the lineament correlates to a prominent break in slope The inconsistent expression of apparent vertical displacement along the Healy A-3 Quadrangle,Alaska.and juxtaposing bedrock and Quaternary deposits (apparent down-to-east).mapped trace and a lack of geomorphic expression indicative of strike-slip R6 Y Alaska Division of Geological and 34 45 The northern extent of the lineament is expressed by a subtle west facing faulting suggest that a tectonic origin is highly unlikely.This lineament appears lla Geophysical Surveys,Public Data slope and linear valley.The southern extent is mapped over the crest of a to represent a collection of unrelated features.;pny YS,bedrock knob and exhibits an apparent down-to-east sense of motion.NoFile90-1 sheet 1 of 2 expression of the lineament was observed within Quaternary deposits. INTERIM DRAFT Page 73 of 81 01/20/14 -Za- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 G Previous|Approximate Approximate LineamentN'be Mapped?Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary Interpretations Cateaoumberapped:Sitet (km)(km)gory Reger,1990,Geologic Map of the A sinuous east-northeast trending photo-lineament mapped over quartz In aggregate this lineament is a collection of aligned and unrelated non-tectonic Healy A-3 Quadrangle,Alaska.monzonite gneiss (TKqmg),quartz monzonite (Tqm)bedrock and Wisconsin features:linear drainages,linear erosional features,and aligned solifluction R7 Y Alaska Division of Geological and o7 5 age till (Ge3)deposi.A pegmatite vein sapped,unproken,across this lobes.tla Geophysical Surveys,Public Data eature at Its intersection with the Feature ineament.inear expression ;4 sheet 4 of 2 within the Quaternary deposits was observed to be a linear drainage (westernFile90-1 sheet 1 0 segment)and an alignment of solufluction lobes (eastern segment) Reger,1990,Geologic Map of the Aslightly arcing west-northwest trending photo-lineament mapped over a Low altitude aerial observations revealed that the topographic scarp is Healy A-3 Quadrangle,Alaska.quartz monzonite gneiss (TKqmg)bedrock ridge and Wisconsin age till (Qd3)]approximately 10-20m in height and likely an erosional feature related to Alaska Division of Geological and deposits.On the western side of the ridge,the feature intersects the northern |solifluction.The scarp has a limited extent and is not expressed in any other RB Y Geophysical Surveys,Public Data 99 5 extent of a mapped fault that has no expression in Quaternary deposits.Two bedrock segment or Quaternary deposit along Feature 8.lla File 90-1 sheet 1 of 2 mappe pegmatite veins are mapped,unbroken,across this feature.Thislineamentismadeprominentbyaverylargesouthwestfacingtopographic scarp along a linear drainage on the west side of the ridge,and a linear drainage on the eastern side of the bedrock ridge Reger,1990,Geologic Map of the A northwest trending photo-lineament that is mapped over Wisconsin age till The lineament is created by an alignment of non-tectonic glacial features:a Healy A-3 Quadrangle,Alaska.(Qd3),alluvial fan (Qaf),and moraine (Qm3)deposits.The feature is linear moraine,solifluction features,and glacial striations in bedrock and along Rg Y Alaska Division of Geological and 99 575 coincident with numerous glacial related features.At one location near the the valley margin.lla Geophysical Surveys,Public Data center of its mapped trace,the lineament is overprinted with a Quaternary age ; ,alluvial fan.No trace of the lineament was observed within the alluvial fanFile90-1 sheet 1 of 2 deposit. Reger,1990,Geologic Map of the The lineament is mostly composed of linear drainages,linear moraines,and The opposing sense of apparent vertical displacement along the trace of the Healy A-3 Quadrangle,Alaska.breaks in slope.The breaks in slope in the north and south display an opposite |fault and lack of geomorphic indicators for strike-slip faulting is an argument Alaska Division of Geological and sense of displacement (down to east)than the middle slope (down to west).against this feature having a tectonic origin.The mapped trace appears to R10 Y Geophysical Surveys,Public Data 26 10.5 Geomorphic features indicative of oblique or strike-slip faulting were not depict a linear alignment of unrelated non-tectonics features.Ila F pny 4 of 2 observed.Alluvial deposits within of the intersecting glacial valley (southernile90-1 sheet 1.0 portion of the trace)and the glaciated plain (mid to northern segment of the trace)show no clear evidence of linear expression. Reger,1990,Geologic Map of the Observations made during low altitude aerial inspection showed that the This lineament represents the alignment of glacial features.g Healy A-3 Quadrangle,Alaska.mapped trace of this lineament is coincident with an alignment of moraine R411 Y Alaska Division of Geological and 32 3.25 crests and linear erosion features.The lineament was not observed in any of lla Geophysical Surveys,Public Data the intersecting Quaternary deposits File 90-1 sheet 1 of 2 Reger,1990,Geologic Map of the The western and central segments of this lineament are coincident with linear |This lineament represents both erosional and glacial features. Healy A-3 Quadrangle,Alaska.drainages (erosion features).In its eastern extent,the mapped trace of the R412 Y Alaska Division of Geological and 34 4.25 Hneament is coincident with the linear flank of a rock glacier over an older rock lla Geophysical Surveys,Public Data glacier. File 90-1 sheet 1 of 2 Reger,1990,Geologic Map of the A north-northwest trending fault mapped in Basalt,Rhyolite,and Agglomerate j Lacking evidence of Quaternary age deformation,this feature is not considered Healy A-3 Quadrangle.Alaska.(Tvfa)bedrock and terminates at Quaternary age rock glacier (Qcg)and to be a Quaternary structure.yA-3Q gle,;an R13 Y Alaska Division of Geological and 37 0.25 Quaternary landslide (Qct)deposits.Dike swarms (Tgr-d)are mapped across lla Geophysical Surveys,Public Data the project path of this feature,unbroken.Observations from low altitude ,aerial inspection showed no expression of faulting within Quaternary depositsFile90-1 sheet 1 of 2 INTERIM DRAFT Page 74 of 81 01/20/14 -za- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Grou Previously ..Approximate Approximate LineamentNHeMapped?*Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary Interpretations Cateaoumberapped:Sitet (km)(km)gory Reger,1990,Geologic Map of the Anorth-northwest trending photo-lineament mapped in Basalt,Rhyolite,and Field observations indicate that this feature is a linear drainage and is erosional Healy A-3 Quadrangle,Alaska.Agglomerate (Tvfa)bedrock and Quaternary age landslide (Qct)and rock in origin. Alaska Division of Geological and glacier (Qcg)deposits.This feature is along strike with,and it appears to be R14 Y Geophysical Surveys,Public Data 38 1 mapped as a possible northern extension of the Feature 13 fault.This lla ,lineament is formed by a linear drainage within a rock glacier in a narrow,File 90-1 sheet 1 of 2 south facing,cirque and an aligned saddle.Low altitude aerial inspection observed no evidence for faulting along this linear alignment Reger,1990,Geologic Map of the A north-northwest trending fault mapped in Basalt,Rhyolite,and Agglomerate |Lacking evidence of Quaternary age deformation,this feature is not considered Healy A-3 Quadrangle,Alaska.(Tvfa)bedrock and Quaternary glacial till (Qd)deposits.Low altitude aerial to be an Quaternary structure. R15 Y Alaska Division of Geological and 39 15 inspection observed the fault in bedrock outcrops on the mountain slopes and lla Geophysical Surveys,Public Data through a saddle.No expression of the fault or fault related deformation was ;observed in Quaternary (Qd)deposits in the valley floor or in an overlying rockFile90-1 sheet 1 of 2 glacier. Reger,1990,Geologic Map of the A northwest trending fault juxtaposing Tertiary Quartz Monzonite (Tqm)Lacking evidence of Quaternary age deformation,this feature is not considered Healy A-3 Quadrangle,Alaska.against Cretaceous Kahiltna Terraine Argellite,Sandstone,and Siltstone (KJs)}to be a Quaternary structure. Alaska Division of Geological and bedrock and over Quaternary landslide (Qct)and till (Qd)deposits.This fault is Geophysical Surveys,Public Data along strike with,and north of,the Feature 15 fault.The two features are R16 Y File 90-1 sheet 4 of >42 0.75 separated by a glacial valley.Low altitude aerial inspection observed evidence lla.'of faulting in bedrock at a ridgeline saddle near the center of the lineament, confirming the presence of the fault along the mapped trace.The Quaternary deposits (Qct,Qd)on the floor of the glacial valley and lower flanking slopes were observed,and no linear expression or evidence of tectonic deformation was observed. Reger,1990,Geologic Map of the A northeast trending photo-lineament mapped in Kahiltna Terraine Argeliite,The mapped trace is coincident with,and most likely defining aligned and subtle Healy A-3 Quadrangle,Alaska.Sandstone,and Siltstone (KJs)bedrock and across Quaternary landslide (Qct)|slope inflections and linear drainage channels within the Quaternary deposits. R17 Y Alaska Division of Geological and 42 295 and unlabeled (till and/or moraine?)quaternary deposits.The mapped trace of }The field observations found no evidence to support a tectonic origin for this tla Geophysical Surveys,Public Data ,the lineament crosses the till and moraine(?)deposits;however no clear feature. ,through-going linear expression was observed during low altitude aerialFile90-1 sheet 1 of 2 inspection. Reger,1990,Geologic Map of the A northwest trending photo-lineament mapped in Kahiltna Terraine argellite,Evidence indicates that this lineament is likely a continuation of the bedrock Healy A-3 Quadrangle,Alaska.sandstone,and siltstone (KJs)bedrock and Wisconsin age till (Qd3),and _fault trace mapped to the southeast.However,lacking evidence of Quaternary Alaska Division of Geological and unlabeled (till and moraine?)deposits.The mapped trace of the lineamentis |age deformation,this feature is not considered to be an active structure. Geophysical Surveys,Public Data coincident with a topographic break-in-slope (apparent down-to-northeast)in ; 'bedrock.This lineament is parallel/sub-parallel,and along strike to the R18 Y File 90-1 sheet 1 of 2 42 0.5 northwest,to a (down-to-northeast)normal fault mapped by Reger et al lla (1990).The two features are separated by a northeast trending glaciated valley.Low altitude aerial inspection observed an apparent fault exposure,in bedrock,at a topographic break-in-slope along the ridgeline.Quaternary deposits between Features 18 and 20 were inspected and found to be undeformed and lacking any linear expression. Reger,1990,Geologic Map of the A northeast tending photo-lineament mapped in unlabeled.Quaternary (till and |Observed to be an erosional feature this lineament is likely non-tectonic in origin Healy A-3 Quadrangle,Alaska.moraine?)deposits.Low altitude aerial inspection showed that the mapped and not considered further. R19 Y Alaska Division of Geological and 43 1 linear trace correlates with a vegetated linear drainage.The lineament is made lla Geophysical Surveys,Public Data more arding rock grou oer contract between the vegetation and thesurroundingrockygroundsurface.File 90-1 sheet1 of 2 INTERIM DRAFT Page 75 of 81 01/20/14 --za- SUSITNA-WATANA HYDRO Clean,reliable energy for the next 100 years. ALASKA ENERGY AUTHORITY AEA11-022 16-1401-TM-012014 Group Number Previously Mapped?*Source of Previous Mapping Approximate Distance to Dam Sitet (km) Approximate Length of Group (km) 2013 Lineament Summary Observations 2013 Lineament Summary Interpretations Lineament Category R20 Reger,1990,Geologic Map of the Healy A-3 Quadrangle,Alaska. Alaska Division of Geological and Geophysical Surveys,Public Data File 90-1 sheet 1 of 2 44 A northwest striking photo-lineament mapped across orthogneiss and migmatite (TKgm)bedrock and Quaternary age undifferentiated colluvium (Qc) deposits.Low altitude aerial inspection confirmed that the mapped linear trace correlates with a linear drainage and has expression only in bedrock.No linear expression was observed in Quaternary deposits along the projected path of the feature. Observed to be an erosional feature this lineament is not considered further. lla R21 Reger,1990,Geologic Map of the Healy A-3 Quadrangle,Alaska. Alaska Division of Geological and Geophysical Surveys,Public Data File 90-1 sheet 1 of 2 38 2.29 A northwest trending photo-lineament mapped over quartz monzonite (Tqm) bedrock and morainal deposits of Late Wisconsin age (Qm3).Low altitude aerial inspection showed that this lineament is composed of a collection of aligned feature.The northern and central segments of this feature are a bedrock ridge crest leading to a linear drainage.The southern extent,in Quaternary deposits,was observed to be the crest of a debris flow levee which bounds the linear drainage This lineament represents a collection of aligned,non-tectonic features and is not considered further. lla R22 Reger,1990,Geologic Map of the Healy A-3 Quadrangle,Alaska. Alaska Division of Geological and Geophysical Surveys,Public Data File 90-1 sheet 1 of 2 45 0.75 An east-northeast trending photo-lineament mapped within a deposit of colluviated till of Illinoian age.Low altitude aerial inspection observed no clearly defined linear expression to correlate with the mapped lineament. it is likely that the mapped trace represents a color contrast created by glacial till along the crest of a low-relief ridge separating two drainages.Likely non- tectonic in origin this feature is not considered further.lla R23 Reger,1990,Geologic Map of the Healy A-3 Quadrangle,Alaska. Alaska Division of Geological and Geophysical Surveys,Public Data File 90-1 sheet1 of 2 46 3.75 An east-northeast trending photo lineament mapped across paragneiss (TKpgn)bedrock and morainal deposits of late Wisconsin age (Qm3),and til! of Illinoian age (Qd2.Low altitude aerial inspection observed that the mapped trace of the lineament correlates with topographic scarps and linear solifluction features.Along strike,the topographic scarps were observed to express an opposing sense of vertical displacement (down-to-northwest and down-to- southeast).Geomorphic expression indicative of strike-slip or oblique faulting was not observed.No linear expression or scarps were observed within the intersecting Quaternary deposits. The geomorphic expression of this lineament is composed of an unlikely combination of features to support a through-going tectonic structure with vertical displacement,and it lacks geomorphic expression to support strike-slip faulting. This lineament appears to be a collection of coincidentally aligned linear features and caused by solifluction and erosion. lla R24 Reger,1990,Geologic Map of the Healy A-3 Quadrangle,Alaska. Alaska Division of Geological and Geophysical Surveys,Public Data File 90-1 sheet1 of 2 44 A northwest trending photo-lineament mapped in paragneiss (TKpng)bedrock for most of its length except for the northern extent where it is mapped within Quaternary age talus (Qct)deposits in an east-facing cirque.Low altitude aerial inspection of the lineament revealed that in bedrock the mapped trace consists of an alignment of variably-scaled,linear swales.In the Quaternary deposits the lineament corresponds to a linear drainage.Scarps and vertical displacement were not observed in the cirque floor described by Reger et al. (1990)and no evidence of tectonic origin was noted for this feature. This lineament represents a collection of aligned non-tectonic features.The linear swales appear to be glacial in origin,and other segments of this lineament are formed by a linear drainage (erosional feature). lla R25 Reger,1990,Geologic Map of the Healy A-3 Quadrangle,Alaska. Alaska Division of Geological and Geophysical Surveys,Public Data File 90-1 sheet 1 of 2 43 1.25 An angled northwest trending photo-lineament.The lineament is mapped over paragneiss (TKpgn)bedrock and late Wisconsin age till (Qd3).Low altitude aerial inspection revealed that the mapped trace is coincident with a shallow linear drainage that is highlighted by an apparent vegetation color contrast. Being an erosional feature,these field observations indicate that this feature is likely non-tectonic in origin. lla INTERIM DRAFT Page 76 of 81 01/20/14 -o .ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO 16-1401 Aero eo14 Clean,reliable energy for the next 100 years. -." Grou Previously .P Approximate Approximate LineamentNneMapped?*Source of Previous Mapping Distance to Dam |Length of Group 2013 Lineament Summary Observations 2013 Lineament Summary Interpretations Cateaoumberpped:Sitet (km)(km)gory Reger,1990,Geologic Map of the An east-to-west trending photo lineament mapped over bedrock for its entire Within the cirque the only along-strike linear trend is attributed to a linear Healy A-3 Quadrangle,Alaska.trace except for the far western end.At this location it is mapped over a drainage incised into bedrock.The mapped trace appears to represent an RIG Y Alaska Division of Geological and M4 3.25 Quaternary age talus deposits before it is terminated against a bedrock knob -_|erosional feature and is not considered further.lla Geophysical Surveys,Public Data in the center of the cirque.Visual inspection of the lineament revealed no clear ; ,linear trace through the talus deposits.File 90-1 sheet 4 of 2 Reger,1990,Geologic Map of the An east-to-west trending photo-lineament mapped over paragneiss (TKpgn)The only linear expression observed in the vicinity of the mapped trace was a Healy A-3 Quadrangle,Alaska.bedrock in its middle portion and Quaternary talus (Qct)deposits on its eastern |linear drainage (erosional feature)and non-tectonic in origin.This feature is not ROT Y Alaska Division of Geological and 40 2 and western extents.Within bedrock,no continuous linear features were considered further.lla Geophysical Surveys,Public Data observed that correspond with the mapped trace of Feature 27.Within Qct,the File 90-1 sheet 1 of >only observed linear expressions were related to linear drainages. Reger,1990,Geologic Map of the A north-northwest trending photo-lineament mapped over orthogneiss and Lacking evidence of Quaternary deformation,this feature is not considered to Healy A-3 Quadrangle,Alaska.migmatite (TKgm)bedrock and Quaternary age colluviated till (Qdc3).During be an active structure. Alaska Division of Geological and low altitude aerial inspection the feature was observed to be characterized by R28 Y Geophysical Surveys,Public Data 39 2.5 a shallow liner trough oriented at an obliqulique angle to linear solufluction llaFil30heet4H>features and moraines,possibly indicating that this feature is related tone-l_sneet '0 bedrock structure.However,it has no expression in overlying Quaternary deposits or within adjacent Quaternary till deposit to the southeast. Notes:*Y =yes,N =no. {Distance value represents the approximate distance to the portion of the lineament group nearest to the dam. INTERIM DRAFT Page 77 of 81 01/20/14 Za ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014Clean,reliable energy for the next 100 years. 6.REFERENCES Acres,(1981),Susitna Hydroelectric Project,1980-1981 Geotechnical Report,Volume 1,unpublished consultant's report prepared by Acres for Alaska Power Authority,288 p. Acres,(1982),Susitna Hydroelectric Project,1982 Supplement to the 1980-1981 Geotechnical Report, Volume 2,unpublished consultant's report prepared by Acres for Alaska Power Authority,dated December 1982,236 p.and 250 pp of Appendices. Bruen,M.,(1981),Personal Communication,Project Geologist for the Susitna Hydroelectric Project, Acres American,Inc.,Anchorage,Alaska,in Woodward-Clyde Consultants (WCC),(1982), Subtasks 4.09 through 4.15,Final Report on Seismic Studies for Susitna Hydroelectric Project. Clautice,K.H.,(1990),Geologic map of the Valdez Creek mining district:Alaska Division of Geological &Geophysical Surveys Public Data File 90-30,1 sheet,scale 1:250,000. Clautice,K.,Newberry,R.,Pinney,D.,Gage,B.,Harris,E.,Liss,S.,Miller,M.,Reifunstuhl,R., Clough,J.,(2001),Geologic map of the Chulitna Region,Southcentral Alaska;scale 1:63,360, Alaska Division of Geological and Geophysical Surveys Report of Investigations 2001-1b. Csejtey,B.,(1974),Geologic map of a part of the Talkeetna Mountains (A-5,C-4)quadrangle, Talkeetna Mountains,Alaska;United States Geological Survey Open File Map 74-147. Csejtey,B.,Nelson,W.,Jones,D.,Silberling,N.,Dean,R.,Morris,M.,Lanphere,M.,Smith,J.,andSilberman,M.,(1978),Reconnaissance geologic map and geochronology,Talkeetna Mountains quadrangle,northern part of Anchorage quadrangle,and southwest corner of Healy Quadrangle, Alaska;U.S.Geological Survey Open File Report 78-558-A,62 p.,1 plate. Csejtey,B.,Mullen,M.W.,Cox,D.P.,and Stricker,G.D.,(1992),Geology and geochronology of the Healy quadrangle,south-central Alaska:U.S.Geological Survey Miscellaneous Investigations Series Map I-1961,63 p.,2 plates,scales 1:250,000,1:360,000. Dixon,E.J.,Smith,G.S,,King,M.L.,and Romick,J.D.,(1983),Final Report 1982 field season,Sub- task 7.06:Cultural Resources Survey for the Susitna Hydroelectric project.University of Alaska Museum,361 p. Dixon,E.J.,Smith,G.S.,Andrefsky,W.,Saleeby,B.M.,and Utermohle,C.J.(1985),Cultural Resources Investigation for the Susitna Hydroelectric project 1979 -1985,Volume 1,Chapters 1-10,Appendix A.University of Alaska Museum,587 p. INTERIM DRAFT Page 78 of 81 01/20/14 -za-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Dortch,J.M.,Owen,L.A.,Caffee,M.W.,Brease,P.,2010a.Late Quaternary glaciation and equilibrium line altitude variations of the McKinley River region,central Alaska Range.Boreas 39,233- 246. Dortch,J.,Owen,L.,Caffee,M.,Li,D.,Lowell,T.,2010b.Beryllium-10 surface exposure dating of glacial successions in the central Alaska Range.J.Quatern.Sci.25,1259-1269. Fugro Consultants,Inc.,(FCL),(2012),Seismic Hazard Characterization and Ground Motion Analyses for the Susitna-Watana Dam Site Area,unpublished consultant's report prepared for Alaska Energy Authority as NTP 6 Seismic Studies Technical Memorandum No.4,Dated February 24, 2012,146 pages and 4 Appendices. Fugro Consultants,Inc.,(FCL),(2013),Lineament Mapping and Analysis for the Susitna-Watana Dam Site,unpublished consultant's report prepared for Alaska Energy Authority as NTP 11, Technical Memorandum No.8,Dated March 27,2013,61 pages plus figures,plates,and 1 appendix. Gao,C.,(2011),Buried bedrock valleys and glacial and subglacial meltwater erosion in southern Ontario,Canada.Canadian Journal of Earth Science,v.48,p801-818;doi:10.1139/E10-104 Grantz,A.,(1960),Geologic map of Talkeetna Mountains (A-2)quadrangle,Alaska and the contiguous area to the north and northwest;scale 1:48,000.United States Geological Survey Miscellaneous Geologic Investigations Map I-313. Gray,H.H.,(2001),Subglacial meltwater channels (Nye channels or N-channels)in sandstone at Hindostan Falls,Martin County,Indiana;Proceedings of the Indiana Academy of Science,v. 110,pages 1-8. Hamilton,T.D.,(1994),Late Cenozoic Glaciation of Alaska,in Plafker,G.,and Berg,H.C.,eds.,The Geology of North America,Vol.G-1,Chapter 27:The Geology of Alaska,pp.813-844.The Geological Society of America,Boulder,Colorado. Jorgensen,F,and Sandersen,P.B.E.,(2006),Buried and open tunnel valleys in Denmark-erosion beneath multiple ice sheets,Quaternary Science Reviews 25 (11-12):1339-136. doi:10.1016/j.quascirev.2005.11.006. Kaufman,D.,Young,N.,Briner,J.,Manley,W.,(2011),Alaska Palaeo-Glacier Atlas (Version 2);in Ehlers,J.,P.L.Gibbard,and P.D.Hughes (eds),Quaternary Glaciations -Extent and Chronology -A Closer Look.Developments in Quaternary Science,Vol.15,pp.427-445. Elsevier,Amsterdam.ISBN:978-0-444-53447-7 INTERIM DRAFT Page 79 of 81 01/20/14 -Zz-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014Clean,reliable energy for the next 100 years. Kline,J.T.,Bundtzen,T.K.,and Smith,T.E.,1990,Preliminary bedrock geologic map of the Talkeetna Mountains D-2 Quadrangle,Alaska:Alaska Division of Geological &Geophysical Surveys Public Data File 90-24,13 p.,1 sheet,scale 1:63,360. Koehler,R.D.,Farrell,R.,Burns,P.,and Combellick,R.A.,(2012),Quaternary faults and folds in Alaska:A digital database,31 p.,1 sheet,scale 1:3,700,000 Nokleberg,W.J.,Plafker,George,and Wilson,F.H.,(1994),Geology of south-central Alaska,in Plafker,George,and Berg,H.C.,eds.,The geology of Alaska,v.G-1 of The geology of North America:Boulder,Colo.,Geological Society of America,p.311-366. O'Neill,J.M.,Ridgway,K.D.,and Eastham,K.R.(2001).Mesozoic Sedimentation and Deformation Along the Talkeetna Thrust Fault,South-Central Alaska-New Insights and Their Regional Tectonic Significance.Studies by the US Geological Survey in Alaska,U.S.Geological Survey Professional Paper 1678,pp.83-92. Potter,B.A.,(2008),Radiocarbon chronology of Central Alaska:Technological continuity and economic change;Radiocarbon,v.50,no.2,p181-204 Reger,R.,Bundtzen,T.,and Smith,T.,(1990),Geologic map of the Healy A-3 quadrangle,Alaska; scale 1:63,360;Alaska Division of Geological and Geophysical Surveys Public data file 90-1. Reger,R.D.,and Pinney,D.S.,(1997),Last major glaciation of Kenai Lowland,in Karl,S.M.,Vaughn, N.R.,and Ryherd,T.J.,eds.,1997 guide to the geology of the Kenai Peninsula,Alaska: Anchorage,Alaska Geological Society,p.54-67. Reger,R.D.,(2013)"Talkeetna/Healy faulting and mapping,”Written communication to Dean Ostenaa, 15 August 2013,Email. Riehle,J.R.,Bowers,P.M.,and Ager,T.A.,(1990),The Hayes tephra deposits,and upper Holocene marker horizon in south-central Alaska;Quaternary Research 33,pp.276-290. Ritter,D.F.,Kochel,R.C.,Miller,J.R.,(1995),Process Geomorphology,third ed.,Dubuque,Iowa,Wm. C.Brown Publishers,546 p. Sherrod,B.,Brocher,T.,Weaver,C.,Bucknam,R.,Blakely,R.,Kelsey,H.,Nelson,ALR.,and Haugerud,R.,(2004),Holocene fault scarps near Tacoma,Washington,USA:Geology,v.32, p.9-12,doi:10.1130/G19914.1. INTERIM DRAFT Page 80 of 81 01/20/14 -zZ-ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDRO AEA11-022 16-1401-TM-012014 Clean,reliable energy for the next 100 years. Silberling,N.J.,Richter,D.H.,Jones,D.L.,and Coney,P.J.,(1981),Geologic map of the bedrock part of the Healy A-1 quadrangle south of the Talkeetna-Broxson Gulch fault system,Clearwater Mountains,Alaska:U.S.Geological Survey Open-File Report 81-1288,scale 1:63,360. Smith,T.E.,(1981),Geology of the Clearwater Mountains,south-central Alaska:Alaska Division of Geological and Geophysical Surveys Geologic Report 60,69 p.,scale 1:36,360. Smith,T.,Albanese,M.,Kline,G.,(1988),Geologic map of the Healy A-2 quadrangle,Alaska Division of Geological and Geophysical Surveys Professional Report 95.Scale 1:63,360 Wahrhaftig,C.,(1965),Physiographic Divisions of Alaska:A classification and brief description with a discussion of high-latitude physiographic processes.U.S.Geological Survey Professional Paper 482. Williams,J.R.,Galloway,J.P.,(1986).Map of western Copper River basin,Alaska,showing lake sediments and shorelines,glacial moraines,and location of stratigraphic sections and radiocarbon-dated samples.U.S.Geological Survey Open File Report 86-390,30 p.,|sheet, scale 1:250,000. Wilson,F.H.,Dover,J.H.,Bradley,D.C.,Weber,F.R.,Bundtzen,T.K.,and Haeussler,P.J.,(1998), Geologic map of central (interior)Alaska:U.S.Geological Survey Open-File Report 98-0133-B, 63 p.,3 sheets. Wilson,F.H.,Hults,C.P.,Schmoll,H.R.,Haeussler,P.J.,Schmidt,J.M.,Yehle,L.A.and Labay K.A., (2009),Preliminary Geologic Map of the Cook Inlet Region,Alaska U.S.Geological Survey Open-File Report 2009-1108,54 p.,2 sheets. Woodward-Clyde Consultants (WCC),(1980),Interim Report on Seismic Studies for Susitna Hydroelectric Project.Prepared for Acres American Inc. Woodward-Clyde Consultants (WCC),(1982),Subtasks 4.09 through 4.15,Final Report on Seismic Studies for Susitna Hydroelectric Project. INTERIM DRAFT Page 81 of 81 01/20/14 -Zz-ALASKA ENERGY AUTHORITY AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. Figures FIGURE 1-1 DRAFT Explanation No field work planned in 2013 based line where inferred (Alaska Division of -_on results of TM-8 (FCL,2013) Proposed Watana site Geological and Geophysical Surveys, moderately constrained,short dashed 2012) constrained,long dashed line where on results of TM-8 (FCL,2013) ------Quaternary fault,solid where well _Field work planned in 2013 based * SUSITNA-WATANA HYDROELECTRIC PROJECT LOCATION MAP 146°0'W JEN STATE OF ALASKA ALASKA ENERGY AUTHORITY +400KS\- "_Le pae__12/02/13 =nsionyLvCastle,-Mtn-exte 150°0'W €bZ0'ZL paylpow 'g19Z Jeqo}9O poday juawesulT6gL Peyseiy 006812 62 portDecember2013,modified12.04.132189_LineamentRe79_218900_Alaska149°30'0"W 149°0'0"W 148°30'0"W 148°0'0"W 147°30'0"W Rae Ss Qs {Healy 250k quad Talkeetna Mtns 250k quad 'Qs63°0'0"N62°30'0"Na:.2 2 ;on es ae aS , Geology from Wilson et al.,1998 (USGS Open-file Report 98-133 Healy and Talkeetna Mountains 250,000 quadrangles) See Figure 1-2B for map legend DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREfeosALASKAENERGYAUTHORITY{=ALASKA SITE REGION GEOLOGY FROM TM-8 1-2A @=->ENERGY AUTHORITY Be ue pae_12/04/13 1189_LineamentRe;79_218900_AlaskaportDecember2013,modified12.04.13"ig .Ice fields or glaciers QUATERNARY DESPOSITS Qs |Surfical deposits,undifferentiated TERTIARY ROCKS Sedimentary Rocks Tsu |Sedimentary rocks,unidivided Tn |Nenana Gravel Tcb |Coal-bearing rocks Tfv |Fluviatile sedimentary rocks and subordinate volcanic rocksaaeli Igneous Rocks Volcanic and Hypabyssal Rocks Tvu j Tertiary volcanic rocks,undivided Thf_j Hypabyssal felsic and intermediate intrusions Hypabyssal mafic intrusions Intrusive Rocks Granite and volcanic rocks,undivided EOCENE Tegr|Granite and granodiorite PALEOCENE Granitic rocks TERTIARY AND/OR CRETACEOUS Igneous Rocks Intrusive RocksJ2GOEE TKg]}Granitic rocks tI Kad)Granodiorite,tonalite and monzonitedikes,and stocks Metamorphic Rocks [TKgg|Gneissose granitic rocks UNDIVIDED MESOZOIC ROCKS METAMORPHIC ROCKS Mzsa)Schist and amphibolite Mzpcal Phyllite,pelitic schist,calc-schist,and"-- amphibolite of the McClaren metamorphic belt Geology from Wilson et al.,1998 (USGS Open-file Report 98-133) CRETACEOUS Melange _Kmar;Melanges of the Alaska Range [TrSl Limestone blocks Igneous Rocks Volcanic and hypabyssal rocks'Ksva|Andesite subvolcanic rocks Intrusive Rocks 'Kgu}Granitic rocks Kgk/Keq Granitic rocks younger than 85 Ma Ultramafic rocks CRETACEOUS AND/OR JURASSIC Sedimentary Rocks KJsj Argillite,chert,sandstone,and limestone |KJf |Kahiltna flysch sequence |KJcg|Conglomerate,sandstone,siltstone,shale, and volcanic rocks JURASSIC Igneous Rocks Mafic and ultramafic rocks Alaska-Aleutian Range and Chitina Valley batholiths,undifferentiated Metamorphic Rocks JPauq Uranatina metaplutonic complex Sedimentary Rocks Trl Limestone and marble Talkeetna Formation TRIASSIC Sedimentary Rocks .Trcs]Calcareous sedimentary rocks(Tres] Kamishak limestone Plutonic Rocks Gabbro,diabase,and metagabbro Volcanic Rocks Col Nikolai Greenstone and related similar rocks Metamorphic Rocks ,trnm}Metavoicanics and associated metasedimentary rocks MESOZOIC AND PALEOZOIC Assemblages and Sequences 'JTrsuj Red and brown sedimentary rocks and basalt Crystal tuff,argillite,chert,graywacke, and limestone Red beds [TrDv]Volcanic and sedimentary rocks Serpentinite,basalt,chert and gabbro PALEOZOIC Assemblages and Sequences (Skolai Group) Eagle Creek Formation |Pzv |Station Creek and Slana Spur Fm., and equivalent rocks Pat Teteina Volcanics Jpmu/JpamPPast Streina metamorphic complex rootJPzmb,Marble --Stratigraphic contact -Shoreline or riverbank woerenmnae Ice contact (glacier limit) ----Lineament ---Fault -certain ---Fault -approximate ----Fault -inferred seennane Fault -concealed -4-«.Thrust fault -certain «4.Thrust fault -approximate --4-Thrust fault -inferred --4..-4 Thrust fault -concealed DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREporALASKAENERGYAUTHORITYSITEREGION3":«_- Seen 8 «=ALASKA GEOLOGY LEGEND e pate 12/04/13_@&-ENERGY AUTHORITY portOctober2013,modified12.02.132189_LineamentRe;79_218900_Alaska150'PO'W 148°0'W DENALI '"4 Explanation Lineament Groups pate__12.02.13 /=ALASKA@&-_ENERGY AUTHORITY AND LINEAMENT GROUPS GE No field work planned in 2013 based on results of TM-8 (FCL,2013) J my -Field work planned in 2013 7s]based on results of TM-8 on (FCL,2013) -aes Land Ownership _[|Denali National Park a [Denali State Park f.87 |_|Notidentified .ANCSA Corporation land w -C Alaska Mental Health Land Trust 12 [J Alaska Railroad Corporation land «[_2Paxson|8 -Federal land Za/|Municipal land i) |Native allotment i \]()pivate tanPSi)|state tanaCyQXsStateland -navigable waterway [---]University land _N !Bureau of Land Management =.7 Fish and Wildlife Service .Cc]Forest Service ::National Park Service 4 Gemaign, LJ e s s i z,2 wr 8 DRAFT ara STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURETALASKAENERGYAUTHORITYLANDOWNERSHIP4 189LineamentRe79_218900_Alaska_|portOctober2013,modified12.02.13400000 Metskee0 40 mi oO Telechm 2"- 0 20 km do 450000 ral € Coordinates on NAD83 UTM 6 North. Elevation from INSAR data and USGS SRTM data. 550000a,a rr aot gi fis a7gor'ee i Z -See olen-)y 600000 SL SyoyaaedeSecAN :aS ont 2 vad :J .* tag OP A ;sh Fee bel SOD ey i ep ae Brehm ;sh OAGE ST ; rin abet he"at 4 "a.[7 MM maeestaanPo|co ae eme,ee fy :?a .Ye :week Pe |anndieaeaefeooyhseOS-aed (oe of Ff eo;r wid 8 a ae-oa. :. 3 e be : . : :at ne -- "4%To he veOPsegFIto t +on,AesSgeewit me, od @ =a}-4 ay §L = Explanation Quaternary fault,solid where well constrained,long dash where moderately constrained,short dash where inferred (Koehler et al., 2012) *Proposed Watana site 3 GPS Tracks 3 (by reconnaissance date) ia -7/11/2013 --7/19/2013 mm 7/12/2013,oe 7/21/2013 --7/13/2013 --7/22/2013 --7/14/2013 ---7/23/2013 -7/15/2013 -7/24/2013 vom 7/16/2013 -9/4/2013 -7/17/2013 -9/5/2013 -7/18/2013 o 8 2 3 8 8 oO 8 DRAFT pate_12/02/13 />ENERGY AUTHORITY STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREfoareALASKAENERGYAUTHORITY ;<_2013 GPS TRACKS - -<=ALASKA a 79_218900_Alaska_410000 ” 7 a ye *,iahegameUne¢"'fi .V on -7020000Wet t nn MS Aye, te eas wesr7 *a 415000 "!i aclinnas+b Jre.wig ue Aewee. 420000 70200007020000.,>NY =mn.60.8 atthe Gia seek mee_-or - ---_ee rev? %189LineamentReportOctober2013,modified01.06.14- nN aa :| 425000 To ee 7020000410000 415000 420000 425000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Geology by Wilson et al.,1998 STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREtearALASKAENERGYAUTHORITYEXAMPLEOFbeeoef=ALASKA LINEAMENT GROUP 2-2 pate 01/06/14 @=-ENERGY AUTHORITY MAP DATA 79_218900_Alaska189LineamentReportOctober2013,modified01.06.14A) B) Location of Location of Photograph C Photograph B View looking northeast from location A towards the confluence of the Jack River and the East Fork Jack River.Arrows point along the alignment of mapped lineaments. Note absence of linear expression in Quaternary deposits. Location of Location of Photograph A Photograph C View looking southwest from location B along alignment of linear features.Arrows indicate the alignment of the mapped lineaments. View looking southwest from location C at a detailed view of aligned uphill-facing scarps.Note Thf contact is up-slope from the scarp in the distance. Date 01/06/14 DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREALASKAENERGYAUTHORITYEXAMPLEOF=ALASKA LINEAMENT GROUP 2-3/qe ENERGY AUTHORITY PHOTOGRAPHS Attributes of lineaments mapped by FCL (2013)that apply to all figures and plates in Appendix A Reconnaissance (INSAR) 1-6 -.---10 eevee TI -----8 Detail (LIDAR) soe.-10 @eeeee 77 meee 8688 Lineament Groups 1-5 Lineament group mapped for this study coinciding with previously mapped fault or lineament No previously mapped fault or lineament coincides with lineament group Attribute Cross Section Morphology”Description Examples Linear break-in-slope bisecting a planar surface Uphill-or downhill-facing scarps, ateral moraines or kame deposits along lateral margins of valley glaciers sxrrnatn189_LineamentReportOctober2013,modified01.06.1479_218900_Alaska_F2 )Y)Abrupt changes in slope adjacent |Linear range fronts,faceted ridges,sea level while stagnant ice was still in valley bottom.,pon to otherwise relatively horizontal terrace risers,steep downstream heal orannnlenainiaienan ena ain naies(and planar)surfaces faces of rouche mountonees eve : y 9 1 has deepened its canyon. Bottom deposits of last regional lake Delta of glacial lake,including those of modern glacial A ;;;Overprint denoting drape of bottom deposits over lakes such as Tazlina Lake.Linear U-shaped trough Glacial valleys,ice-scoured flutes,drift and thick lake sediments that persisted in 3 flood-scoured flutes,Copper River drainage basin from just beforePPmg :ju :Linear or drumlinoid feature,due to ice scour,direction ofdepositionofOldManmorainestoatimewhenicemovementindicatedbyarrow.glaciers had retreated to within 16 to 24 km of present glaciers:older than 13,000 years. 4 +Linear V-shaped trough Active stream channels eause :;;;;'Spillway for glacial meltwater,including that stored inVsuseeeslargeglaciallakes. 5 p77 Linear ridges Drumlins,water-scoured terrain,Contact between map units where not glacial boundary,g eskers most commonly between different levels of lake deposits. .... D .6 n/a A series of aligned features Could include attributes #1 -5 AYA Active (?)fault,lower Sonona Creek,offsetting (also 77)above and/or aligned saddles,tonal U unconsolidated deposits. lineaments,etc. 66 n/a Data artifacts Linear seams between data sets collected on different dates 88 n/a A series of aligned features,Could include features with A Location of selected erratic boulders,mountain topwhicharetoosmalltoindividually|attributes #1-5 above and/or erratic stones transported by glaciers,e.g.Sheep map at the given scale aligned saddles,tonal lineaments,Mountain;many occurrences on mountains lower than etc.1829 m not shown. 99 n/a A line which encloses a broad An area of jointing or of glacialexpanseoffeaturesallhavingthe|striae all having the same,parallel same orientation orientation DRAFT 10 n/a Anthropogenic lineaments Roads,rail roads,power lines and aro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE other linear clearings,etc.orn ALASKA ENERGY AUTHORITY EXAMPLE OF a Notes:*Arrow points to location of the mapped feature.nate 01/06/41 4 /=ALASKA STRIP MAPS EXPLANATION Geologic Units Bottom deposits of 914 -975 m lake Overprint denoting glacial drift that is mantled by bottom sediments of glacial lake that extended to 914 -975 m abovemodern sea level,largely confined to middle Susitna valley,above ice dam below Fog Lake (off map)and apparently bounded on east and south side by glacier ice.Does not cover late(st)Wisconsin (last major)morainal systems.No shoreline features are mapped. Bottom deposits intermediate (777 -747)lake Overprint denoting bottom deposits of a local lake that covered melting glacier ice between Tyone Lake and Lake Louise,apparently behind Tyone Spillway,and drained as the elevation of the spillway was cut down from 777 m to 747 m above L\AA Explanation for relevant geologic units of Williams and Galloway (1986)shown on Figure A20.5 and A23.1 Symbols Location and letter designation of radiocarbon-dated stratigraphic section in accompanying text. Ice boundary,morainal ridge,kame terrace,delta,or other ice contact feature marking edge of glacier:hachures toward glacier. Shoreline of regional lake:mapped for the lake in Copper River basin where at 747 m (maximum elevation);the elevation to which Tyone Spillway was eroded,and successively lower levels in the northern part of area between 747 m and 701 m above sea level.Lesser recessional shorelines mapped by Nichols and Yehle (1969)not shown. Upper limit of post-glacial (Holocene,in part)shoreline of 39_LineamentRe79_218900_Aiaska_RiportOctober2013,modoified01.06.14150°0'W 149°0'W 148°0'W 147°0'W 146°0'W Petersville' g ia Trapper Creek a Anderson]ve.es aa.fy Le ee-*BlgiDeltar ..-i64°0'NFort Gresive.Deltanag) adoee,i,a"rite! fe ™.63°0'New. : in fet goes Lake wy "CG Chase Louise |= :.Ley tay ned 7 "Talkeetna "i=7 ee OF ao t een my Tolsona::ee en 7 : pewiPmeTSoa A ."FypoetEVESoeLANeyAMendeltna:a fseeaeyYo.fez -4N ':,wo-_7 fe 'e . Base data from ASTER Global Digital Elevation Model (ASTER GDEM is a product of METI and NASA) Explanation Extent of Extent of LiDAR Data Note:Extent of Landsat imagery and INSAR data AreaA ASTER GDEM elevation data ; Area B are greater than the area shown 0 20 mi Area C in figure.L-! Anes i"0 40 km -----_Area DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURETrALASKAENERGYAUTHORITYwed=ALASKA EXTENT OF GEOSPATIAL DATA 2-5 date'_01/06/14 =ENERGY AUTHORITY portOctober2013,modified10.18.1379218900Alaska_Railbelt/2189_LineamentRea 59ynGa£:tes'rhiWeseay™From http:/Avww.landforms.ca/cairngarms/meltwater%20channels.htm,last accessed 1 October,2013. These sub-ice channels are cut through interfluves,seen as notches on the skyline. Date 10/18/13 STATE OF ALASKA ALASKA ENERGY AUTHORITY =ALASKA qe ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT SUB-ICE CHANNELS CUT THROUGH INTERFLUVES,SCOTLAND AND EXAMPLE SUB-ICE CHANNEL MORPHOLOGY FIGURE 3-1 79218900Alaska_Railbelt/2189_LineamentReportOctober2013,modified10.18.13Source:http://www.graenslandet.se/en/traces-of-the-ice-age/meltwater-ridges-meltwater-channels-or-glacial-grooves Sub-ice channels at Grévelsjon. DRAFT Date / STATE OF ALASKA ALASKA ENERGY AUTHORITY =ALASKA@&-ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT EXAMPLE SUB-ICE CHANNELS,GREENLAND FIGURE 3-2 79218900AlaskaRailbelt/2189_LineamentRey|portOctober2013,modified10.18.13=m4EsseBaeNtseN,: |ORS ay"Ef Bead e503 White arrows denote locations of linear to sub-linear incised creeks that enter at high angles to Seneca Valley and Lake. DRAFT cro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE ;juerRa ALASKA ENERGY AUTHORITY re <-_.>i /=ALASKA SUB-ICE CHANNELS,FINGER LAKES,NEW YORK 3-3 pate 10/18/13_@=-ENERGY AUTHORITY to 16.7444 79_218900_Alaska_s.cme.2189_LineamentReportOctober2013,modified12.02.13146°0'W 63°0'N62°0'NExplanation Alaska Paleo-Glacier Atlas v.2 Data (Kaufman et al.,2011) Limit of late Wisconsin glaciers Cosmogenic Exposure Sample Locations e Dortch et al.,2010a 6)Dortch et al.,2010b i)Matmon et al.,2006 Glacial Lake Elevation Extents (meters) 800 m 975m ------Quaternary fault,solid where well constrained,long dashed line where moderately constrained,short dashed line where inferred (Alaska Division of Geological and Geophysical Surveys, 2012) Oate DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREaeAeAAIA.LATE WISCONSIN GLACIAL LIMITSi[<7)/==>ALASKA AND AGE CONTROL 3-4 12/02/13 @=->ENERGY AUTHORITY 410000 412000 414000 416000 69540006 , i en Location of Wwcc '..YeayeeteAFfin'+same',.oeLat.sou:.:fetaicf}"wt.Seaameota.x.STH, * te £ INSAR 2010 (m) 1271 669 6954000'Shaded relief with color-ramped DEM fro al On ot nouns: m 5-meter INSAR data,2010 aaa aS ©aad 6954000port,modified12.02.13189LineamentRey_; -arene 4Pepe disc "ge Rohe"ey O ar.iertd44,4 >ery s Pafriefpod TeFanetRSsa.i -_5are°? ; "osaeeFY_S \"Location'of4Sne 79_218900_Alaska_|410000 Slope map from 5-meter INSAR data,2010 Talkeetna fault traces in top panel: A Csejtey et al.,1978 B WCC report,1982 C Wilson et al.,2009 412000 fests 416000 6954000Lane oate_12/02/13 STATE OF ALASKA ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT WCC TRENCH T-1 LOCATION MAP FIGURE 4-1 189_LineamentRe79_218900_Alaska_|portOctober2013,modified102513View of WCC T-1 location (marked by tree line),looking slightly east of south. C) View of WCC T-1 looking southwest.Note how th Very low altitude view of tree line tha +.oeew set set feature in mid-background. D) a eya ee aaaeet2Fale t corresponds to backfilled Trench T-1,with scarp-like View of WCC T-1 looking northeast.expression of the scarp feature dies out along the DRAFT projected trend of the feature.aro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE :ALASKA ENERGY AUTHORITY ; :PHOTOGRAPHS OF WCCarf=ALASKA TRENCH T-1 SITE 4-2=<- pate_10/17/13 >ENERGY AUTHORITY 2189_LineamentRe;79_218900_AlaskiportOctober2013,modified102513eee btSS«teniaeooarMionesie}.ae oe,eR View looking north-northeast along trend of mapped Talkeetna fault trace with unfaulted volcanic intrusives (Tvu)in the background. 365000 368000 371000 374000 365000 368000 371000 7 * wel a :aad y\oy”--.ee >”y ;-Tt :iz we y-BLe /tee ]oe,ee itaae at 454):A 2 4e on meee Gere,#ten Loe)yan es ON pe IP Bae a A an ,oe ad,if pee nena eo:oe .r "/eae FYFoa BEaaTgdaPP.be "om : yp -oat *_/"a i A aan .4 ' t .Talkeetna fault 4 7 :location +/ 3 ; we (Csejtey,1978)we owe oo -j KJs J.ee Seobee.-+brent .|3 5 i s 5 Pea el N io :2 ube,a ry 34 - :ee , ,+pa OF #4 ai eS getpeaom<8 Ne ah Wt h TrnceFeRaa&,Fee vor Ayench T2we4Sk>So ea FM PALin'tae /;mye mieted re yer vee.Wh hoaaaaanSehe.ca od fe S.we,oa .\we oS atm .f . .Qat o.2 .ah,ge . com,.re a eo mannee_4 eo "f we =. , ef ao se va .V/,_>ated .4 gt .wel :a 4,7 aw A,DFaaeveser}”Oe le gael : 'a a .p a :.N nef ey.. . wf :é ..\a Jae aeaePiea-;aeons D fo,oan oo #a :qalkeetna River LL NYfowage'R vel .¢IV EL for oy my a ygetind l rae|ee eee oaameaegullasinayaeotteinane"lg Se 7)ane8a:a ae!*. cl er mL aa a Root ,te By'.sf?|.a ae yf ae wa : .. «em wee-2 for”_f » TrPavs pa?,D..fteTgdae4-7)ar a L 69280006925000Geology from Wilson et al.,2009 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation. DRAFT Lae pae_10/18/13 STATE OF ALASKA ALASKA ENERGY AUTHORITY =ALASKA @z__>ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT MAPS AND PHOTOGRAPHS OF WCC TRENCH T-2 AREA FIGURE 4-3 za ALASKA ENERGY AUTHORITY ;AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. Appendix A: Strip Maps and Photographic Documentation of Lineament Data Presented in FCL (2013) |portOctober2013,modified12.16.13189_LineamentRe;79_218900_Alaska_|150°0'W 148°0'W 146°0'W moderately constrained,short dash =ae weethlealy KX.oS, Explanation fo 7 ae ------Quaternary fault,solid where well vrs po ea constrained,long dash whereOarth:we tie.l.we where inferred (Koehler et al.,2012) Extent of stripmap tile;figure number indicated Field work planned in 2013 based on results of TM-8 (FCL,2013) mx”No field work planned in 2013 basedonresultsofTM-8 (FCL,2013) *Proposed Watana site Lineament Groups and Corresponding Figures Lineament Group Appendix A Figure Number 1 A1.1,A1.2 2 A2.1,A2.2 3a A3a.1,A3a.2 3b A3b.1,A3b.2 z 4 None,see TM-8 (FCL,2013) 9 5 A5-1.1,A5-2.1,A5-2.2 Laer ANI SS 6 AG.1,A6.2,A6.3,A6.4 SE 7 ATA,A7.2aa2,8 A8-1.1,A8-2.1,A8-2.2,A8-2.3 .A i Vey 5 ee 9 AQ-1.1,A9-2.1,A9-2.2,A9-2.3, at eo.)pep ee A9-2.4 ELA,a ae ge :or yenges tate 10 None,see TM-8 (FCL,2013) b :+”-*11 None,see TM-8 (FCL,2013) B<ema.re .12a A12a.1,12a.2 SS 'c 12b A12b.1,12b.2 13 None,see TM-8 (FCL,2013) oa .14 None,see TM-8 (FCL,2013) oP .(15 None,see TM-8 (FCL,2013) :16 None,see TM-8 (FCL,2013) 17a A17a.1,A17a.2 17b A17b.1,A17b.2,A17b.3 17¢A17c.1,A17c.2 ;yuo ri Yas / 18 None,see TM-8 (FCL,2013) Talkeeta =oe ;:el ,; "1 . : :19 A19-1.1,A19-1.2,A19-1.3, _"waa :, Lo gps A19-2.1,A19-2.2,A19.3-1,A19-3.2 20 A20.1,A20.2,A20.3,A20.4, A20.5,A20.6 21a A21a.1,A21a.2 21b A21b.1,A21b.2,A21b.3 22 A22.1,A22.2 23 A23.1 z 24 None,see TM-8 (FCL,2013) =25 None,see TM-8 (FCL,2013) ©26 A26.1,A26.2 27 A27-1.1,A27-2.1,A27-3.1,A27-3.2 Broad Pass area|Plate A-BP,A-BP.1,A-BP.2,A-BP.3 Castle Mtn.fault |Plate A-CME,A-CME.1,A-CME.2 extension Clearwater Mtns.|Plate A-CWM,A-CWM.1,A-CWM.2, area A-CWM.3 DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREtorALASKAENERGYAUTHORITYSonwceuand{=ALASKA STRIP MAP TILE AND PLATE INDEX A0.1 pate_12/16/13 @E->ENERGY AUTHORITY 79218900_Alaska_|189_LineamentReportOctober2013,modified01.06.14This explanation applies to all figures and plates in Appendix A. Geologic Units from OFR 09-1108 (Wilson et al.,2009) rene Water,ice field,or glacier Unconsolidated Deposits Qs _|Surficial deposits,undivided Qat .Alluvium along major rivers andweedoeinterraces (¢|Landslide and colluvial deposits Qm_,Glacial deposits,undivided Qhg |Young moraine deposits Major moraine and kame deposits 'Qge |Glacioalluvium| Qgo ;Outwash in plains,valley train,=="and fans Qge Glacioestuarine deposits Sedimentary Rocks Tsu.Sedimentary rocks,undivided "Tkn_|Kenai Group,undivided ami Tts |Tsadaka Formation Teh |Chickaloon formation Km |Matanuska formation Turbiditic sedimentary rocks of the Kahiltna flysch sequence Undivided Chinitna and Tuxedni formations In |Naknek Formation,undivideded Jtk ]Talkeetna Formation,undivided _STrim |Limestone and Marble ;Pe 1 Eagle Creek Formation,marineargilliteandlimestone Note:For full explanation of geologic units see USGS OFR 09-1108 and USGS OFR 98-133. Igneous Rocks Volcanic and Hypabyssal Rocks ;Tvu |Tertiary volcanic rocks,undivided Tfv /Felsic volcanic and sub-volcanic rocks i Mafic volcanic rocks |Dikes and sills Nikolai Greenstone and related rocks Slana Spur Formation,volcaniclastic rocks Pat |Station Creek Formation andesitic= yoleanic rocks Plutonic Rocks Ti Intrusive rocks,undivided Toegr |Granitic rocks Tpgr ;Granitic rocks of Paleocene age "Tga |Biotite-hornblende-granodiorite -TKg |Granitic rocks,undivided 7 reTKgd1|Granodioritic rocks Kgd;Granodiorite Jtr |Trondhjemite Jqm |Granodiorite and quartz monzonite Melange and Metamorphic Rocks "TKgg |Gneiss "Jpmu Plutonic and metamorphic rocks,----undifferentiated JPam|Amphibolite _JPmb|Marble -Trnm |Metabasalt and slate TrPavs.Basaltic to andesitic metavolcanic Seemed FOCKS PPast |Metamorphosed Skolai Group Geologic Units from OFR 98-133 (Wilson et al.,1998) Ice fields or glaciers Water Surficial deposits,undifferentiated Tertiary volcanic rocks,undividedei 4=-=Hypoabyssal felsic and intermediate intrusions Granitic and volcanic rocks,undivided i Tegr |Granite and granodiorite fee.Mzpca/Phyllite,pelitic schist,calc-schist,and amphiboliteoftheMacLarenmetamorphicbelt 'Kgu }Granitic rocks |KJf |Kahiltna flysch sequencey :Tres |Calcareous sedimentary rocks :Trnm j}Metavolcanic and associated metasedimentary rocks Tectonic Features from WCC report (WCC,1982) Detailed feature,from site-specific maps Regional feature,from small-scale maps For completeness,features from both regional and detailed scale Faults Compiled by FCL (Wilson et al.,1998;Wilson et al.,2009;Williams and Galloway,1986;Clautice, 1990;Clautice,2001;Csejtey,1978;Kachadoorian, 1979;Smith,1988) ---Fault,approximate -'--Fault,inferred or queried Fault,certain seececee Fault,concealed --&-High-angle reverse fault,approximate --4 High-angle reverse fault,certain -4---High-angle reverse fault,concealed -4 -?--High-angle reverse fault,inferred or queried -+-Thrust fault,approximate -4-A Thrust fault,certain 4---Thrust fault,concealed Lineament Hydrographic Features from National Hydrography Dataset,2000,1:24,000 scale Stream Ice mass figures have been included.The location of regional features may not always be accurate and the detailed features may be limited to the extent shown on original figures. es Location of trench T-2(shown on Figures A14 and A16) [|Lake or pond Other Items Location of photograph taken during 2013 field reconnaissance,labeled with photo ID and showing view direction Date 01/06/14 /=ALASKA@=-ENERGY AUTHORITY 1 OF4 1160 =GPS waypoint GPS track line,July 2013 STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREfourALASKAENERGYAUTHORITY =3 STRIP MAPS EXPLANATION AO.2 Attributes of lineaments mapped by FCL (2013)that apply to all figures and plates in Appendix A Reconnaissance (INSAR) 1-65 -.-.-10 eooevee TI -----8 Detail (LIDAR) .-.-.-10 eeeee 77 ---88 Lineament Groups 1-5 Lineament group mapped for this study coinciding with previously mapped fault or lineament No previously mapped fault or lineament coincides with lineament group Attribute Cross Section Morphology”Description Examples Linear break-in-slope bisecting a planar surface Uphill-or downhill-facing scarps, ateral moraines or kame deposits along lateral margins of valley glaciers portOctober2013,modified01.06.14189_LineamentRe2 )AF Abrupt changes in slope adjacent |Linear range fronts,faceted ridges,oon \Ge to otherwise relatively horizontal terrace risers,steep downstream y (and planar)surfaces faces of rouche mountonees )Linear U-shaped trough Glacial valleys,ice-scoured flutes, 3 J flood-scoured flutes, 4 v Linear V-shaped trough Active stream channels 5 p77 Linear ridaes Drumlins,water-scoured terrain,g eskers 6 n/a A series of aligned features Could include attributes #1 -5 (also 77)above and/or aligned saddles,tonal lineaments,etc. 66 n/a Data artifacts Linear seams between data sets collected on different dates 88 n/a A series of aligned features,Could include features with which are too small to individually |attributes #1-5 above and/or map at the given scale |aligned saddles,tonal lineaments, etc. 99 n/a A line which encloses a broad An area of jointing or of glacialexpanseoffeaturesallhavingthe|striae all having the same,parallel same orientation orientation 10 n/a Anthropogenic lineaments Roads,rail roads,power lines and other linear clearings,etc.79_218900_Alaska_FNotes:*Arrow points to location of the mapped feature.xLnBgAn»Geologic Units Bottom deposits of 914 -975 m lake Overprint denoting glacial drift that is mantled by LA AA bottom sediments of glacial lake that extended to 914 -975 m abovemodern sea level,largely confined to middle Susitna valley,above ice dam below Fog Lake (off map)and apparently bounded on east and south side by glacier ice.Does not cover late(st)Wisconsin (last major)morainal systems.No shoreline features are mapped. Bottom deposits intermediate (777 -747)lake Overprint denoting bottom deposits of a local lake that covered melting glacier ice between Tyone Lake and Lake Louise,apparently behind Tyone Spillway,and drained as the elevation of the spillway was cut down from 777 m to 747 m above sea level while stagnant ice was still in valley bottom. Bottom deposits of last regional lake Overprint denoting drape of bottom deposits over drift and thick lake sediments that persisted in Copper River drainage basin from just before deposition of Old Man moraines to a time when glaciers had retreated to within 16 to 24 km of present glaciers:older than 13,000 years. Explanation for relevant geologic units of Williams and Galloway (1986)shown on Figure A20.5 and A23.1 Symbols Location and letter designation of radiocarbon-dated stratigraphic section in accompanying text. Ice boundary,morainal ridge,kame terrace,delta,or other ice contact feature marking edge of glacier:hachures toward glacier. Shoreline of regional lake:mapped for the lake in Copper River basin where at 747 m (maximum elevation);the elevation to which Tyone Spillway was eroded,and successively lower levels in the northern part of area between 747 m and 701 m above sea level.Lesser recessional shorelines mapped by Nichols and Yehle (1969)not shown. Upper limit of post-glacial (Holocene,in part)shoreline of Tazlina Lake from elevation 564 m down to present lake level 544 m caused by lowering of lake as Tazlina River has deepened its canyon. Delta of glacial lake,including those of modern glacial lakes such as Tazlina Lake. Linear or drumlinoid feature,due to ice scour,direction of ice movement indicated by arrow. Spillway for glacial meltwater,including that stored in large glacial lakes. Contact between map units where not glacial boundary, most commonly between different levels of lake deposits. Date D 4yAL Active (?)fault,lower Sonona Creek,offsettinguUunconsolidateddeposits. *Location of selected erratic boulders,mountain top erratic stones transported by glaciers,e.g.Sheep Mountain;many occurrences on mountains lower than 1829 m not shown. DRAFT aro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE :THOR!tT :Aen eAOY NY STRIP MAPS EXPLANATION 103 01/06/14 =ALASKA@@__>ENERGY AUTHORITY 2 OF4 189_LineamentRe79_218900_Alaska_|portOctober2013,modified10.18.13Explanation for relevant geologic units of Smith et al.(1988)shown on Figure A21b.1 he Kp 35 Modified from UNCONSOLIDATED DEPOSITS Alluvial deposits FLOODPLAIN ALLUVIUM -Unconsolidated deposits in modern stream drainages.Material ranges from coarse,unsorted gravel in highland valleys to finely bedded silt in large river drainages. Glacial deposits TILL OF LATE WISCONSIN AGE -11,800 to 25,000 yr B.P. TILL OF EARLY WISCONSIN AGE-40,000 to 75,000 yr B.P. SCHIST -Medium-to coarse-grained biotite-plagioclase-quartz schist with local garnet and feldspar porphyroblasts to 0.5 mm.Dominantly gray or brown weathering.Includes local horizons that contain randomly oriented hornblende on foliation surfaces.Stippled pattern near intrusive contacts indicates hornfelsed zone in schist.K-Ar age of 57.2 m.y.was obtained from biotite in this unit in the adjacent Healy A-1 Quadrangle (Smith,1981). PHYLLITE -Silver-gray,biotite-bearing phyllite with biotite porphyroblasts to 2mm long;locally calcareous.Minor compositional banding with more quartzose layers parallel to foliation.Biotite yielded K-Ar age of 53 +1.6 m.y. (loc.3 on map;Turner and Smith,1974).Grades into ampbibole-bearing phyllite (Khp)unit. AMPHIBOLE-BEARING PHYLLITE -Medium to dark gray spotted phyllite with planar laminations.Spotted with porphyroblastic biotite.Interlayered with beds that contain randomly oriented amphibole on foliation surfaces. Amphibole prisms commonly 0.5 to 3 mm long.K-Ar age of actinolitic hornblende from this unit in Healy A-i Quadrangle is 64.1 m-y.(Smith,1981). MAP SYMBOLS Contact -dashed where approximately located ;dotted where concealed;queried where inferred High-angle fault -dashed where approximately located;dotted where concealed;queried where inferred.D,downthrown side; U,upthrown side Thrust fault -dashed where approximately located.Sawteeth on upper plate.Arrow indicates dip of fault Lineament -inferred from aerial photographs,may represent fault selected portion of Smith et al.(1988)explanation Explanation for relevant geologic units of Reger (1990)shown on Figure A21a.2 -T rT 3 rTnTTw wo www GLACIAL LIMITS Glaciation of unassigned age,dashed where discontinuosly mapped Glaciation of Illinoian age,dashed where discontinuously mapped Glaciation of late Wisconsin age,dashed where discontinuously mapped Glaciation of Holocene age,dashed where discontinuously mapped OTHER FEATURES Prominent meltwater drainage channel Radiocarbon sample locality PROMINENT WAVE-CUT SCARPS 3,700-ft (1,120-m)lake,dashed where discontinuously mapped,dots on descending scarp 3,650-ft (1,110-m)lake,dashed where discontinuously mapped,open triangles point down descending scarp 3,400-ft (1,030-m)lake,dashed where discontinuously mapped,solid triangles point down descending scarp AREAS INUNDATED BY GLACIER-DAMMED LAKES 3,700-ft (1,120-m)lake 3,650-ft (1,110-m)lake 3,400-ft (1,030-m)lake Explanation for relevant geologic units and features from Acres,1982 shown on Figure A6.1 --Contact 4-Thrust fault --Shear QUATERNARY Ice disintegration deposits Til Outwash Alluvium,alluvial terraces and fans TERTIARY Conglomerate,sandstonesuandclaystone MESOZOIC TRIASSIC Basaltic metavolcanic rocks, metabasalt and slate /=ALASKApate_10/18/13 @&-ENERGY AUTHORITY 3 OF4 DRAFT aro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREPoere|ALASKAENERGY AUTHORITY STRIP MAPS EXPLANATION A04 79_218900_Alaska_!189_LineamentReportOctober2013,modified10.18.13PleistoceneandRecentEoceneUpperCretaceous(?)rc LowerCretaceousL Bar beneath letter symbol indicates map units identified on aerial]photographs or from distant views (Tf,Qd,etc.) Explanation for relevant geologic units of Grantz (1960)shown on Figure A20.1 Explanation Geologic Units UNCONFORMITY f Jnbs Jns Jnbsm Jnc >?Zne$s uns Jnbe Naknek formation Jnbs and Jibsm,biotitic sandstone and siltstone with coqui-QUATERNARYnoid bedg Jns,siltstone and shale with limestone concretions; Tt Fluviatile conglomerate and coaly sandstone Qrg Qal Qtc Qis Rock Alluvial Talus and Landslide glaciers deposits colluvium deposits QgdQgQgo q Qd Glacial deposits Surficial de- Qg,moraine,outwash,and proglacial posits,un-: lake deposits differenti-;Qad,proglaciel lake delta deposits ated !Qg0,stratified gravel,probably outwash | deposits older than the last major | glaciation J - UNTONFORMITY UNCONFORMITY Km Matanuska formation(?) Siltstone and shale Kee Cobble conglomerate ; UNCONFORMITY(?) WESTERN PART OF AREA EASTERN PART OF AREA > Ke i Calcareous sandstone, siltstone,and claystone Kn Knu Nelchina limestone \Caleareous sandstone, A calcarenite siltstone,and claystone Ks Sandstone,locally conglom- eratic and coquinoid to west,siltstone and clay- stone d P,CRETACEOUSJnbec,cobble and bould.ngl ate at base of formation;Jnc,cobble cnd bould.gl ate above base of formation UpperJurassicUNCONFORMITY Jcsl Jcs Chinitna formation Jesl,siltstone and shale with limestone concretions; q Jcs,sandstone and siltstoneTERTIARY Js Sandstone Sandstone,siltstone,and conglomerate with fossil wood frag- ments,and many mollusk shells in some beds.Equivalent L to,or oniy slightly older than JcsMiddleorUpperJurassic UNCONFORMITY vt Tuxedni formation Sandstore with calcareous concretions and some siltstone and shaleMiddleJurassic UNCONFORMITY Jtk Talkeetna formation Lavas and pyroclastic rocks of intermediate composition,sand- stone,and argillite,all dominantly marine.Sedimentary rocks become dominant in upper part of the formationLowerJurassic Lineaments,Faults,Contacts, Synclines,and Anticlines eecee --Anticline,dashed where approximate,dotted where concealed Contact;solid where certain,dashed and queried where uncertain Fault;solid where certain,dashed and queried where uncertain,dotted where concealed ---Lineament,approximate -Syncline,approximate JURASSICDRAFT rerBieoeogSelpate10/18/13 ALASKA ENERGY AUTHORITY / STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT STRIP MAP EXPLANATION 4 OF 4 FIGURE A0.5=ALASKA@E->ENERGY AUTHORITY 79218900_Alaska_f189LineamentReportOctober2013,modified10.18.13410000 7020000415000 ee joes 4ied--Laeaacall 415000 raren 2vomsbptreaeeeSSNywegertyNad 420000 425000 420000 ee .4 peminy yetwe8wos8oooO f CN Oo Pn 7020000"rary al.a)nr re _*a -.ca =aa ° "4 J s . .ee :.'os "3 eReste$2 in ttt tientiseme teSinum:7 --.SS tenet edt ond 425000 PE ns N \'as..Sos .ad ':"os j 'a ; rom te -f :-¥'i fe .aos 'eos 'aSeneeQs.CoE KENoF.St ee et :ONy-q -"y we =Fa aaa .'-}4 #iN,? aren i : - }eienn ioe aa"a- 410000 415000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Geology by Wilson et al.,1998 425000 7020000DRAFT Date Lae 10/18/13 STATE OF ALASKA ALASKA ENERGY AUTHORITY /=ALASKA@&->ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT LINEAMENT GROUP 1 MAP DATA FIGURE A1.1 2189LineamentReportOctober2013,modified10.18.1379218900_Alaska_A) Location of Location of Photograph C Photograph B View looking northeast from location A towards the confluence of the Jack River and View looking southwest from location C at a detailed view of aligned uphill-facing the East Fork Jack River.Arrows point along the alignment of mapped lineaments.scarps.Note Thf contact is up-slope from the scarp in the distance. Note absence of linear expression in Quaternary deposits. B) Location of Location of Photograph A Photograph C DRAFT View looking southwest from location B along alignment of linear features.Arrowsindicatethealignmentofthemappedlineaments.cro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE Py eget ALASKA ENERGY AUTHORITY woe >LINEAMENT GROUP 1Sect{=ALASKA PHOTOGRAPHS A1.2 pate 10/18/13 @-ENERGY AUTHORITY portOctober2013,modified10.18.13189_LineamentRe,79_218900_Alaska70100007010000400000 405000 410000 415000 a* 43i€LYaetaees400000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Geology by Wilson et al.,1998. 2 8 is} P=) ia *=%'.id ; 2 +> ' .[ie "way DER "Pf it ped "4atic,a eg OF weaeaeaemewea1=aal *way 4 ut all iadan__f a ee y tat,NG anf ae i b Ane a3iaete\at 7?in i ;ineooae.MO canes! fio””kif "og .;=ae cae 5 28 rs) 5 i Y8.7 405000 410000 415000 DRAFT wor3 Lice gal Date 10/18/13 STATE OF ALASKA ALASKA ENERGY AUTHORITY @@_>ENERGY AUTHORITY/=ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT LINEAMENT GROUP 2 MAP DATA FIGURE A2.1 79218900_Alaskarauve/2189LineamentReportOctober2013,modified12.16.13fen eS se ee 3s ::-__2 Yu em Os wef tees Sg.mem oktbaaSw>» "o%(¥end Ce s ; . a etCeesSeee4'aan SRN oe lcawee .ce -7 qe a Fe oe a ad Photograph taken from location A looking east-northeast.Arrows show the alignment of FCL-mapped lineament.Note lack of apparent deformation in bedrock exposure along Jack River.OaaeWBEphitetepate 12/16/13 @=-ENERGY AUTHORITY MAP DATAAND PHOTOGRAPH DRAFT LASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE'.-_-LINEAMENT GROUP 2 A202=ALASKA . portOctober2013,modified10.18.13189_LineamentRe79_218900_Alaska_70000006995000700000069950001 f)'raeWear,ae Crean 385000 rr ES guetta 395000 400000390000 70000006995000400000 .°70000006995000380000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation. 2.Geology by Wilson et al.,1998. 390000 DRAFT aro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREtTALASKAENERGYAUTHORITYLINEAMENTGROUP3aA3ata/.7)ALASKA MAP DATA pate_10/18/13 @&__ENERGY AUTHORITY 189LineamentReportOctober2013.modified10.18.1379218900Alaska|B) View looking east at likely solifluction-related scarps on hillside that correspond with mapped lineaments.Large arrows point along lineaments.aii'z-esSei)'''44ehgDwnay-aapheweyOey ar fad ey View looking west along 3a lineament expressed as sharp ridge within Kahlitna flysch (KJf).Apparent color change and topographic expression may suggest a geologic eredeeict Q surface.sf 2880ft MSL W View looking east past ridge,with unfaulted Quaternary sediments in the foreground and far distances. structure,however,none were previously mapped.The feature may be a result of DRAFT weathering because of lithologic change within the flysch.STATE OF ALASKA SUSITNA.WATANA HYDROELECTRIC PROJECT FIGUREMlespatiaheALASKAENERGYAUTHORITYAer=<LINEAMENT GROUP 3afone/=ALASKA PHOTOGRAPHS A3a.2 pate __10/18/13 @@-ENERGY AUTHORITY portOctober2013,modified10.18.13489_LineamentRe;79_218900_Alaska69950006995000--|tod WrereaSo4.-a 415000 + aWSusChia-Creck 4 \69950006995000Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation. 2.Geology by Wilson et al.,1998. 405000 pate_10/18/13 ALASKA ENERGY AUTHORITY / STATE OF ALASKA =>ALASKA @=-ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT LINEAMENT GROUP 3b MAP DATA FIGURE A3b.1 189LineamentReportOctober2013,modified10181379218900AlaskaA) C) ee ars711512013 9:31:36 AM (-8.0 hrs)Dir=W Lat=6 ae oolweeS Gow we acPaeawnytaa}oe ee >ee:Pi neath'oeagOemeeweennw">ae”. 7 em wre A we atehSThae ets re esfo Boe net Same: View looking west along lineament 3b projection.South-facing escarpment indicates a reversal in kinematic morphology. woe Escarpment ASOEAS."of PhotographA ra q .e.:+_ rin NPra2-2 .%.a ae *a at on wooraLceny-cana kilt ern *.oe no 2 ot woe ay . aridom = £aan PEC CET ee aN 0 oe ere Mines:Wty Nene eee ad 9:49:28 AM (-8.0 hrs)Dir=ESE Lat=63.07086 Lon=!148.76224 Alt=4604ft MSL WGS 1984 View looking east along lower talus scree field that shows decreasing relief at west end of lineament 3b. View looking west along lineament 3b projection.Holocene rock glaciers are not offset,and lineament is expressed as a linear valley.DRAFT creo ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE eerg LINEAMENT GROUP 3boe/=ALASKA PHOTOGRAPHS A3b.2 pate _10/18/13 @@->ENERGY AUTHORITY 279_218900_Alas1/2189LineamentReportOctober2013,modified10.18.13355000 365000 370000 neld 6975000T ”” cg bone,:ay °Seas on aaoeToorce 6975000360000 365000 6975000T T 1 6975000355000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Geology by Wilson et al.,2009. 360000 365000 370000 DRAFT Tr ALASKA ENERGY AUTHORITY SUSTTINASAATANA PNDROELECTING PROWECT FIGURE ceca d LINEAMENT GROUP 5 ABA|JES ALASKA | Oate __10/18/13 f=@=--ENERGY AUTHORITY MAP DATA /2189_LineamentRe79_218900_AlaskportOctober2013,modified10.18.13365000 370000 375000 380000 385000 T or sedeeclian Alida 3 TE ar -_.5 ipa”,aGoforthoo z.ar)t aaa iar.we 4 "none f'oe 7,: Qg an le Lo A C:wll \og -- a -¢rf \"S,a cad *a =|a cS Vd\!pt oan fy$:hePyseego™}------.a 'fe -"-eo = .+.>i Qg '< ,] - .5 i,omen,Chulitna on ee_Byvo\:,Pass Pe gen as}- ."aVagus-a ' .evasere*pres , a . . +4 ,os ™'et Ssfa)'orn38ahie.J2oPenatneS3>?}o A A "7"a ? "ra "a"KJs oA oa ca iaa}9 ..eo ..an "pre Pre'Uden *ae 385000 69750006975000Date 10/18/13 /@&-ENERGY AUTHORITY MAP DATA 0 a | 365000 370000 375000 380000 385000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Geology by Wilson et al.,2009.'osre ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE y =ALASKA LINEAMENT GROUP 5 A5-2.1i«<_A 189LineamentReportOctober2013.modified10.18.1379218900Alaska|A) Side hill bench .oo View looking west at eastern part of apparent side hill bench. View of linear gullies developed on bedrock slope. Mapped lineament approximately shown. :"ROS ne Ah arc we2GayERateaTBteThea)Dir=W Lat=62 89503 Lon=-149.35411 Ait=3105ft MSL WGS 1984 B) oe Rave *.Sn ae a eeoa2a ree ue i'caincid ry View of drainage with mapped lineament approximately shown. PHOTOGRAPHS/=ALASKApate__10/18/43_@--ENERGY AUTHORITY DRAFT ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURELINEAMENTGROUP5A5-2.2 189_LineamentRe79_218900_Alaska_FportOctober2013,modified10.18.13435000435000435000 6975000 440000 6980000 od.sion,(Scano)|ialactaE Location of esker and Photograph J F * =. "te."=Ve ¥-,:RELL.",ny -eid gl and4 440000 445000 4500006980000K NESGeesartetok a Vem a cha awae "Sa 1 tw JPaur'=: ws «=ae 450000Sax Zé we 69800006965000 440000 6970000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation. 2.Data frame has been rotated 45°east of north. 3.Geology from Acres,1982 (top)and by Wilson et al.,2009 (bottom) 6975000 DRAF =|fusre STATE BGY AUTHO TY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGU RE ALASKA ENER RI a i ae ALASKA LINEAMENT GROUP 6 AG.1ae=<MAP DATA pate_10/18/13 @@ >ENERGY AUTHORITY 79_218900_Alaska_f189LineamentReportOctober2013,modified10.18.13of Talkeetna fault,map trace,ae "So.AgUF eh mG seaeeclocation| pe BO :" * a .3 a se «7 F Ff ery : : ' a Ksae:ay seteate Ta Seas nts Hey Hare peste .;Miva "Saye ean STL ERS:ST atshe ittemas yi ewesseeiJ"fd 4 ey:ym meaE &x oe See Oey te!oe bad!vee a vy Beat sever te u,es SS;red *?iy ot *Cony ee *naar eT Cs CL ORN/CHESseg wey a etyhoraySAEpegMtEN.an :.4,e 'we .Biel gts we .AS "od "heaecarerJPeaeaSeePaeae.4,"tea revoy"4 ay BY ted See,asp.Ep,"atePAEADirheHFeraieelsOe'putib¥i)SF.ar;4nehatetaleit-ewwer,:Fteesaoo2.do7H,wTx2weat.oeTeetepanneaeOFadView looking east at apparent flat-lying contact between Quaternary lake sediments (above)and Quaternary till (below).Arrows point to contact.w®.aeerrsSM7/19/2013 4:29:10 PM (-8.0 hrs)Dir=E Lat=62.84423 Lon=-148.23722 Alt=1627ft MSL WGS 1984 Sb ee a OF ASN *Bae ae PEE |ee ph pea ae ae ayLNggte.osoroeanoowenwvhabonWest"antereair}syay,iaeaneat|Ya,oe75eeke's"ea re:atasina.2MaView looking east along lower river bank at apparent alternation zone distinguished by color contrast,possible juxtaposition of Triassic metabasalts and undifferentiated Tertiary sediments.This location is east of the mapped projections of the Talkeetna fault. D) View looking west at projected trace of Talkeetna fault whose ground sxpression is absent in a surface. AgneoaietensnetiietjelseMLTETR...msstilestal aciihint Vag 5 KeWWREISee NSinciting>> peASanathSisk4WRENSteaya\rnatsAieavevkBenesOAGNG? VCR,:uy ns vee "es "=*et ane 7 aren AE AOL SETIICCERED Ln Line -ont See ta ape TIT .aie *s prom a sweet -:meting alti .ste reais rmeoatewosneTaeeatByWageianmesmaressag7 Reais taalwebbylSeiAcwif,ahTAN DRAFT Date Groffee| =a me 8ere| 10/18/13 STATE OF ALASKA ALASKA ENERGY AUTHORITY =ALASKA @@=-ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT LINEAMENT GROUP 6 PHOTOGRAPHS FIGURE A6.2 79218900Alaskaf189_LineamentReportOctober2013,modified10.18.13E) G) .a aan ne !eon fe .Ped as ;nor!v-3 'joe ae }?ante an-mt le we Dee aE ft.A tn.'-.@ val 'ow en rf . Bayh Seg WR Cat .ths cake Ae .area.wa ee ,.a)vif °. .wehyyetekSoALGofgaelog':.awn . rary heenSrPuenparesSRaeyana!Bebe eeneate w/e had Ava ae aD 40}Bs}us 'i ¥A i View looking south at erosion-resistant ridge of Tertiary sediments whose beds dip gently to the northwest but appear undisrupted. a . {Approximate . P |location of...3s Ly OE: {'Talkeetna fault Joes ye SS map trace *°7 a ay ph,a os Caan Oe a nat j a: pn ere:%4 7 DMS ARES wae a 'ome .rye ". .:4 th : View looking north-northeast past ridge,with flat and apparently undisturbed Quaternary sediments in the background.menSr=®Aheefeeye. View looking west at apparently northwest-dipping beds in Tertiary sediments, relatively consistent with northwest dips measured by WCC (1982)in Tertiary sediments along west bank Watana Creek. H) View looking west at bedded (lake?)stratigraphy exposed in eroding bluff.Beds appear relatively horizontal,but may have a sense of non-planar geometry because of semi-circular outcrop.Note fallen trees that indicate erosion/slope movement. DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT plese ALASKA ENERGY AUTHORITY FIGURE A ear LINEAMENT GROUP62.4 <_re =ALASKA PHOTOGRAPHS A6.3 date _10/18/13 @=->ENERGY AUTHORITY 189LineamentReportOctober2013,modified10.18.1379_218900_Alaska_|;we : 4 a?ae,'+.€OF rp LLL ©a oy FP eemEneOoPea,'.-t7 ped can .ae '4 aReadoknaagatetehOyloys”:©ese 2 ot on ru -!wm,a aeeer ae ae Vie ye ae tis.eh;ore Mah ane 0]ONE 2S ,77 en arapom,wegen ;,a or eg ioe View looking north at linear esker nearly coincident with map projection of Talkeetna fault. i 4 Be a a,”eTay View looking at shallow soil pit dug in esker crest.Upper black,gray,and reddish soil layers are Holocene tephras.Scale is in centimeters;the upper 45 centimeters of the pit are in view. DRAFT Gro ALASKA ENTE RGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT Wey -_LINEAMENT GROUP 6aS{=ALASKA PHOTOGRAPHS pate 10/18/13 @&->ENERGY AUTHORITY FIGURE A6.4 189_LineamentReportOctober2013,modified12.16.1379_218900_Alaska_F445000 6970000 6965000450000 6975000 455000 6980000 an 445000> :eo eenye.be LAD 4 tee ea ..mes l¢eee :: aoe,eee 3 to fe eeege .4 eRe ve.Eyasaif¢AS-”f4Loy,7anig}afTy 9 UAE Bg.<3 "sci \A SFsty SERRE.aey el a engi N mot:Ryace aHeOS maeo4,af7IWer.]"|Iy"}y¢ttqh.i)LdA460000See Tey *yteed |6980000" ™6965000445000C=aa 460000Shat4Nene way ene eee 7.aneH08CORPPESFEgyReswon4ea ain 6980000450000 6965000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation. 2.Data frame has been rotated 45°east of north. 455000 6970000 460000 6975000 DRAFT STATE OF ALASKAwerALASKAENERGYAUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologic map by Kline et al.,1990.Scan 3 .ALASKA LINEAMENT GROUP 7 A71 12/16/13 /MAP DATApate_12/16/13 _@&-ENERGY AUTHORITY 489LineamentReportOctober2013,modified10.18.1379218900Alaska|A)™" =ry --"e .ae »yer Pa ah =oss 4 oe :ee .tty"it a aoa.rr . -Soy aw « -1,aoptyVieDs. aan 7 *al .*.Po .a os fen .a ds * .oS 7 7 ! ..*rine ee ee .we BO eeda5'J Hoe lhe ce 4 i¢\4 Ad Fy . . *wt cre ut =+ty ."we .\' -.aa st Te «** :.ie arr aan esoof" oe -¥Ste :a \ '.adam.CAs es » .ae 4 ws -at ttt ..&3. >.5 ao J - £"*at Vw.. -.*° .as 'nan'os Te,3 .''Po ret .wk ,'id -ot ane -NX...'e .: 7 - .. - ,% jta:ip :aev * .Ne , ' .7%:eenePea aoeae a View looking up-valley at incised drainage that coincides with mapped lineament and previously mapped fault. B) -_ ehororesMakentesrers View looking west down-v alley at apparent undeformed glacial sediments. View looking down-valley from the top of the drainage seen in Photograph C.DRAFT Date 10/18/13 ALASKA ENERGY AUTHORITY / STATE OF ALASKA =ALASKA =ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT LINEAMENT GROUP 7 PHOTOGRAPHS FIGURE A7.2 '189_LineamentReportOctober2013,modified10.18.1379218900Alaska6975000 6970000 385000 6965000 6960000 T To 380000385000y 'Glacial striae continue .°Ne *éeross ligeament group *' ¢Updetonned 385000. ..aan 1 6975000 6970000 6965000 380000 6960000 Notes:1.See Figures AO.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Data frame has been rotated 75°west of north.cro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geology by Wilson et al.,2009.re ALASKA ENERGY AUTHORITY LINEAMENT GROUP 8 AB-1.4{=ALASKA MAP DATADate10/1 8/13 @=-ENERGY AUTHORITY 6965000 6960000 6955000 T 390000 6950000 6945000 79_218900_Alaska_F189_LineamentReportOctober2013,modified10.18.1338500069650003800003850006965000380000yO ST 7 TyTs Sn ne nedoodeet'.?. Yd treed,Oe |,vs'Pedro exposed iin these drainages 'is not{Sbviously faulted and streamsryfatconsistentlydeflectedacrosslineament'see sty)F.ha 390000380000 6960000 6955000 : 6950000 390000380000 6960000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation. 2.Data frame has been rotated 75°west of north. 3.Geology by Wilson et al.,2009. 6955000 =ALASKA oate_10/18/13 /=ENERGY AUTHORITY MAP DATA 6945000 385000 DRAFT cro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGU RE :ALASKA ENERGY AUTHORITYPere LINEAMENT GROUP 8 AB-2.1 189LineamentReportOctober2013.modified10.18.13A)B) baw,+oe oo *es =ee ee mnaa2TL te,-wy MP pew,o”* 7,i « *. a estypert a oe . 7 oe:- "emeee_7/21/2013 10:39:57 AM (8.0 hrs)Lat=62.68974 Lon=-149.23619 Alt=1355m MSL WGS 1984 o-_ View looking north at middle portion of lineament group 8 along mapped inferred fault. Brackets show position of fault but note that no geomorphic expression of faulting is readily apparent. D) a , ::-_F013 10:43:28 AM (-8.0 hrs)Lat=62.74463 Lon=-149.27271 Alt=1470m MSL WGS 1984 - View looking south opposite that shown in Photograph B above.Mapped fault runs 7)ote Sea .:*esaysDey Skea--7/21/2013 10:40:55 AM (-8.0 rs)Lat=62.70957 Lon=-149.23899SEI MSL WGS 1984 = Close up view of saddle area shownin Photograph A.Brackets,again,show position of fault but note that no geomorphic expression of faulting is readily apparent. aaa ies>4seiSatie eons 7/15/2013 3:18:27 PM (-8.0 hrs)Lat=62.73436 Lon=-149.25245 Alt=4209ft MSL WGS 1984 79_218900_Alaska_!View looking north down the prominent,deeply incised linear drainage.Mapped fault runs between large arrows.between large arrows.Note presence of many solifluction scarps in the landscape.DRAFT cro ALAS KENE SGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE Wome y <_LINEAMENT GROUP 8 A822at=<_ALASKA PHOTOGRAPHS , vate 10/18/13 >ENERGY AUTHORITY 189.LineamentReportOctober2013,modified10.18.1379218900Alaska_I"oa et a enmre <P Ee Died ee IS Sg eT meeniaegl oe °* bgtae oot!LF. '-®o fon f TA le eg 8D Lee?att ita rae ¥Ap etd +Laefeeure:a WerteV4cp!AY vLYieeeie}re 2”uaepey"a4 '+e rb3; ia”DaeAPSashe, ve cSaan:peeks;mynySe»,<aAk,7eeotgh2we,Tidfeaha ' *--- View looking north at north (right)bank of Susitna River showing oxidized mafic dike interpreted by WCC (1982)to not be truncated by the linear drainage. Tey oa."Steuiuvela2wheae3ooweBrus: So es .Me,. arPnSEE car3 Vy L View looking west directly towards 1-to 2-m-high east-facing scarps shown in Photographs F and H.Large arrow points along mapped lineament. F) H) ;nai ae i 4 .Sal a a .7 tn =" =.7 ...ion wt _™.*iinet aguas Pe 7” a7 aan ne -.3 'we mg::.te nn wr ee mes -™*L ..wae oa=se mer TT Des4=at 2 yooie ww eae f SSlitting)eee eeeaeay|a errant im ahesYeWie,LPtaba eeepeeaeZAG ae Ay714519013 2-98-50 PM 80 hre)|atzA?FAA1 D ant.149 99347 Alt=34N7A MS!WS 19084 View looking north along 1-to 2-m-high east-facing scarps along southern portion of lineament group 8.Large arrows point along mapped lineament.Note the presence of solifluction lobes with an alcove or recession in between them that create an irregular and curving topographic scarp. p - pas.-non .: peek St eee |_'No expresssion of lineament__Seay:eo eae -.eeasbaie.a La readily apparent along strike es Nee SL Se A Us "Holocene alluvial fan.-.terrace.a Rheem ©24 Hy tay Fy *iehectare)mw - eer n qweeMssicreBeeyeaes points along lineament position and trend.DRAFT ero ALASKAENIE SGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE ghee4 =_LINEAMENT GROUP 8 A8-2.3ne/=ALASKA PHOTOGRAPHSdate10/18/13_@-ENERGY AUTHORITY 79_218900_Alaska_R89LineamentReportOctober2013,modified10.18.136980000 390000 6975000 6970000 6965000 :aa Ea :-._6960000 ."a5¢:Sos ,+ ->7 y!."y *. *:.>-im 3 .; . S.,wy oN OO \nn foes ee a :"f .:*™' S .{.4 '**ete N }'$./+dy *] Ss »):i * . .J,4 Cy i 'f A a rt '14 *LA a é at '|\ y *x 7 a4 . 2 ,1 3 ™y :a."7 a :}./ =ate 7 -"{t 5 t :;. 2 Jnr:Aa wait i Le _') 8 oat Spee Bek Fe ag ey gy : ee Sn 2 A oS ag WEEE ery yg 5 ,.\DS.went,Gennes J ALE EE : . Sg 4 Loo;;/ ."<8 *.yma g me |ud,a re a °i 2°9M Ge we Bal ma ",. 5 ' a ae i j ae A , '-y a eo hl OVE ph le e 'wr te .a Ye Bt AS 'ro Fey .\ws -3 .t.j »é i ,oO Vi Poy)ty a bere oO . -Peeg :[";Vy 4 }. A atyes i3 6975000 ae "3 j a ee 2 ae :3 6980000385000390000.sieneeal -:ss,1 6975000 6970000 385000 6965000 6960000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Data frame has been rotated 75°west of north.aro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologic map by Wilson et al.,2009.er ALASKA ENERGY AUTHORITYaALASKA LINEAMENT GROUP 9 A9-1.1.{=MAP DATA pate 10/18/13 @&-ENERGY AUTHORITY 6965000 6960000 395000 'type contrasts 390000.;ae vs,x ' ;}'''/ORSON Yep eee oherser4'On DL ETOR Beale =]TTP Ney /oo ws aa Ea Saat aoe |NG ... «va! _oo et cS rar,hn!er : oa a Gos ; Granodiorite -f »OO y :'- exposed in ay ou drainage SQLs 6955000 6950000 MW Y "ae T 4 ea OF 7h a ”- fon Poe ae 'rad a ;™\'4 ™%7 4 _Pe on 'Ps »a .f *v7 \et,;.y :ee :Es ' "4 a 2 Ney 'on = . ,¢. .7,4 r' .bere --_ rN 5 ©sr vous 7 . 4 'pas !\an »No expression in + '" .Apparent rock a Mey !?a ; oa Quaternary deposits 6945000395000 o a ='"a ae :¢oe ta,x1 nivel id.tins ry ob tte 3 L L ches ae ee sini pet ']6965000 6960000 6955000 Cy! r "y Qs 44aN 3 '© ae \a Tpgr Wee , . : --\° =" o a me,. . .4 ”yy r,te a4 fey ae . :© st -_ OL ®.' SA)et 7oOa. as sare'eeTpegr4ae 8 2 gh -2 3 yf ? =A, 3 NG3_aa 2 ?:i oN,ca3 yt oO . 0 ='anes g ' 5A 7 a .; 5 :_\ o 'LO oO a S35.31 te who |}. 6965000 6960000 6955000 390000 DRAFTa.g Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation.SSeSa°SUSITNA-WATANA HYOROELECTRIC PROJECT <2.Data frame has been rotated 75°west of north.Tere ALASKA ENERGY AUTHORITY FIGURE 8 3.Geology by Wilson et al.,2009.;ALASKA LINEAMENT GROUP 9 A9-2.1 =/==<MAP DATA S,pate_10/18/13 @->ENERGY AUTHORITY 2 79_218900_Alaska489LineamentReportOctober2013,modified10.18.13B) Oras i”44eet wee.rat '7 .eengore -wtEPbeeSppn ieee Ome OggSombee,”weer |ees ae=at * +DY oetiie "ee wees,*SN OM in gett ho a ntoepraterS aa meh EPSLES ng.arate karl'"oe ty Wr ageMe te ememe7/23/2013 2:33:44 PM (8.0 )Lat=62.664 Lon=-149.06521 Alt=3197ft MSL WGS 1984 =-_ The first in a sequence of 5 photographs looking northwest taken along a series of north-trending,east-facing aligned slope breaks in the southernmost portion of lineament group 8.Large arrows point along lineament. eee 8 Seige .i "ee"ono Betas: 7/23/2013 2:33:53 PM (8.0 Lalt-})Lat=62 66629 Lon=-149.06521 Alt=3221ft MSL WGS 1984 -- Photograph 2 of 5 looking northwest.Large arrows point along lineament. C) ”Photograph 33 of 5 looking northwest.Large arrowspoint along lineament. Date 10/18/13 DRAFT ALASKA ENE SGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT F IG U RE =LINEAMENT GROUP 9 9.2.2=ALASKA : @=-ENERGY AUTHORITY PHOTOGRAPHS 489_LineamentReportOctober2013,modified10.18.1379218900_Alaska_|oify''oot,,FETPyifyi?itaAaaPhotograph 4 of 5 with view looking northwest.Large aarrows point along lineaments. F) -niaal ene,ate)_0kSEwefoteeoeae "wetSNeieaterrereaoewoeaweTine,cE ant pi ae ,P*seeI4°batons apes tf ater 6TrafewSsLtrhoaagaeadeinateal4wee:eteisSREPreeS"r% -7/12/2013 5:36:45 PM 3.0 heyLat=62 67228 Lon=-149.07273 pen MSL woe rie View looking north from location F.Geologist at base of east-facing break-in-slope is 170 cm tall. --7/23/2013 2:34:37 PM (-8 0 hrs}Lat=62 67675 Lon=-149 07441:Alt=3243ft MSL WGS 1984 -- Photograph 5 of 5 with view looking northwest.Note that lineament expression has died out and brackets bound the location of its projection. 4 oopr.+theaeaitaalavy'"wyTey.tithateal e AFybo ei ae!.a,aceeetra1,e eeeRRS Shed.fgoe7/1 2/2013 5:25:22 PM (-8.0 hrs)Lat=62.67732 Lon=-149.07774 Alt=3098f MSL WGS 1984 =-- View looking almost 180 degrees from that shown in Photograph D.Large arrows point along lineaments. DRAFT cro ALASKAENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 2 LINEAMENT GROUP 9 9.2.3ns/==<ALASKA PHOTOGRAPHS vate 10/18/13 >ENERGY AUTHORITY 79_218900_Aiaska|189_LineamentReportOctober2013,modified10.18.13H) t we e®teat '. a'tone ae "vanes er ie ' 4 wie ;\ *_-ire i vt e ';™'' ?ait .a ' - .* .we é+ot wigs ->a,, - _ -_ oe)-:;-”- ne tN a oe : .me .°.eh Oe -=ae ”e+:°come ee ee oo oa arr Soa Teg TeHetwe Had--7/23/2013 2:30:58 PM (-8.0 hrs)Lat=62.69581 Lon=-149.11298 Alt=3404f MSL WGS 1984 -- View looking south from location |across area within WCC's segment 3.Note the lack of expression of any lineaments in the broad depression. wa ee 4 le -: a ame,99 feet cal tt iotSalarmalas'CheeNy:oom ;4%:AAO GEN TreyDraetsFy : 29 eee acs y j :-*'a ¢' a S | oie ===7/23/2013 2:27:19 PM (-8.0 hrs)Lat=62.78284 Lon=-149.15009 Alt=2881ft MSL WGS 1984 -- Exposures of widespread granodiorite in unnamed creek near GPS waypoint 176 View looking northeast at right wall of linear v-shaped canyon.Large arrows point in terrain mapped as flysch (map unit KJs)by Wilson et al.(2009).The geologist along apparent bedrock type contrast. is approximately 175 cm tall.DRAFT ALASKA ENE BGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE A9-2.4LINEAMENTGROUP9-_/=ALASKA PHOTOGRAPHS Date _10/18/1 @=-ENERGY AUTHORITY 189_LineamentReportOctober2013,modified10.18.1379_218900_Alaska_F41500069450004150006945000415000 420000 6955000 425000 430000 6960000TIT7AT,Nao ee r ae Hy |ee : Pe :.B,Myo.es ".Lo a es en al ."pe .'*.y Oe ae raraars "Mae :-4 oo #ed 5 aeeeegpPgLaewRFM:=aot .{; "#wena'.nea -Pays *43oeSolAoPaTiarejobieeSPmb*.?8 YF Lace en |-EMD >oa " _{2*»1 =G Raat We Pad é + '-a i:ana id vtBOROTe!.re cPayf°e a ate "a a f .Fa \e my i :{*. Fond =2 :aaa ra +mee -'6 4 * P *wet i ue F ¢*7 .''\. 7 Te e+7 3°; i - ise .ron.%o .J °-ee,ane a a Pzv ood tee ,Pe '-ao :g L -._a - :'4_7 ae ae os |Sea :3&0 we os mate llaaoF -.ne '-JPmb -48aQc\eines ee ea en i an te \-ees oe oe /-oo ei oN aie a ie toe ew -.Fae ram,a rd" oe #'woe atte:a Tae /eee .-.__*ee =,2m we,:°Neeee|s a lhe cs '.¢Z ;"#4 ae os)b ;>kk >:x7 Tr :,» s eee gyte ncenooo="e >Pep.-é LopMaley-ye mn .a -°Pe ee x .:},-e Jf »-.eae n 12a -_-;.ee ee : -Se aha Pad An we.? : - ™,ot eee ee ,. .=Tgp ee «.:7 a ae L -<C),_-Se ee .en eee”Qs a'Qs ae °_--*ill a ee 'Fog Creek .*my - ;<°ane ee _--" *-eee a .- ._een aa sl aa oll Sino 7 oe ee ae ™ ». .eal ad ”te -nagPalioa [ee ./we - .Qs -oes &.”oo,{wm ia - :' .4,* .ay f wate ae nine * \pe ET...---Pzv a \-Pzv aaan i oN |Pry : ”_P,{7 _ \ [-"yo ,i "EN {:ve /Pzv Noor -,'aate.Of es and -fh nt ee L .!_-_|i Ne' 6945000 425000 435000 6955000 br *¥'T > oe &1 a yO .ae \N .?LY oOo QOQ w iF vt fo] QQ QaoOo oO oOo L r.: --\-2,- 1 miA,_-™--_!nm LI -+ --é, 6945000 420000 425000 6950000 430000 435000 6955000 Not 1.See Fi AO.2,A0.3,A0.4 dA0.5 f |ti DRAFT otes:1.See Figures A0.2,A0.3,A0.4,an 5 for explanation.-a2.Data frame has been rotated 30°east of north."fuare ALASKA ENERGY AUTH ORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologic map by Wilson et al.,2009.Ar Ya)ALASKA LINEAMENT GROUP 12a A12a.1 3)/-MAP DATAvate10/18/13 @-ENERGY AUTHORITY 79_218900_Alaska_I4189LineamentReportOctober2013.modified10.18.13C) View looking northeasterly along lineaments.Arrows point along trend and position of lineaments. wea --sh pee eset we weReemg 9wm*|rereenenateShs< te ete ;Mah ES eee S gy :°RE 6 Sa eet Pek*:42yaty ha He ST ogo f'todo Ng Stee Plaats See yA View looking at notch in bedrock with expression of apparent northwesterly dip. B) z c i t 3:25:34 PM (-8.0 hrs)Dir=SW La 21 Alt=4117ft View of lineaments expressed in Quaternary sediment. ot ae e-y toe a at acod4cf 's,ceSane asnyianvatThee; y 3 LINEAMENT GROUP 12A =3 <=a /<_ALASKA PHOTOGRAPHSdate_10/18/13_@=-)ENERGY AUTHORITY STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREwereALASKAENERGYAUTHORITY A12a.2 189_LineamentReportOctober2013,modified10.18.1379_218900_Alaska_F430000 6960000 435000 440000 4450006965000 696500045000069550006960000450000 6965000peer4500006955000 $3 ;-.in : 430000 435000 6955000 440000 / 445000 450000 @ Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation.DRAFT 2.Data frame has been rotated 20°east of north.STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologic map by Clautice et al.,2009.er ALASKA ENERGY AUTHORITYved=ALASKA LINEAMENT GROUP 12b A12b.1 rote/t3 /A S MAP DATA Date_IVITOllo __@&=-ENERGY AUTHORITY 189_LineamentReportOctober2013,modified10.18.1379218900_Alaska_!A) C) ve,ene ho n Th Seas :ea RoninSeleorSo22YeegFS View looking northeast at erosional break-in-slope mapped as an individual lineament. Feature is absent in the background along projection of strike. linear valley and drainage.Underfit creek in deep linear valley suggests landform created by sub-ice channel meltwater. B) D) Approximate location ofCoPhotograph A View looking southwest down-valley along lineament geomorphically expressed as linear valley. Very little alluvium has accumulated in the drainage,and glacially sculpted bedrock is shallow. View northerly down-valley along lineaments geomorphically expressed as linear drainage. Thin cover of unconsolidated surficial sediment mantles the Paleozoic rocks. Date DRAFT cra ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE a "3 a ALASKA LINEAMENT GROUP 12b A12b2/@&-_ENERGY AUTHORITY PHOTOGRAPHS |...-..189_LineamentReportOctober2013,modified10.18.1379218900Alaska6970000 6965000 6960000 oT vO F TIT 6955000 6950000 tl 2 Sad ewe =4 na a:yet Bd on |"'.. Boye -oa ory,be 'e be,eo |ee Vy ,,\Loa :N.'th 4 a 4 aa ' i 'y (No deflections_in drainagesaefe 400000400000duingkaPakem Ice Scour; grooves * é 8 B co] v g ld /|.if is \0 tkm BRO Ay ="x /TN /--_4ron)7 INS wre AN 7 .. HUN Gh OA:-/-:ft |ee a ee g 6970000 6965000 6960000 6955000 6950000 B Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Data frame has been rotated 90°west of north.-fusra ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geology by Wilson et al.,2009.oe _LINEAMENT GROUP 17aes/=ALASKA MAP DATA Atza.4 date 10/18/13 @-ENERGY AUTHORITY 189LineamentReportOctober2013,modified10.18.1379218900_Alaska_|A) be wee stadia de veins Pe -Ne wt ey,Bile a .; woes drafaiCofelgeeala ae:°°4 = - aa 7 iyeWeek an xtane " 7/15/2013 4:42:28 PM (-8.0 hrs)Dir=SE Lat=62.76989 Lon=-148.99521 Alt=3102ft MSL WGS 1984 View looking south at linear canyon that is tributary to the Susitna River.Canyon bottom and creek drainage have sinuosity not apparent at smaller scales. B) pe NR RRR ET .rn 'VEE a, fp ibe MET ty_'ately eo 1 Si ial SLT een yy 7 ae - >3 ",ey by 7 ayre4';aNEPAiFy;.7 oerantaeie4t.thee eu:ad AAG wo-4ue \.wotaui¥,Ln + Ye ae 1%Rama5sANLAsyaoatWee View looking north-northeast at creek in boggy (Holocene)drainage.Lineament is expressed as a depositional contact along the shallow bedrock knoll. bate 10/18/43 /=ALASKA@@-ENERGY AUTHORITY PHOTOGRAPHS DRAFT cra S SNE SGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE Py peveesieters ALASKA ENFee LINEAMENT GROUP 17a AM17a2 79_218900_Alaska_|189_LineamentReportOctober2013,modified10.18.136950000 T 69400006945000405000 6950000F6935000 6930000 400000o- 6935000 error,No evidence was#4*found to support faulting ¢Fo."otofriveralluvium. .an ne) Appaisit map aiSnise,8 405000i ._™ ¢ w / y ""A .ya v bd .i '\ s*.L .oy . .¢69500004000004050006945000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Data frame has been rotated 75°west of north. i 6930000 3.Geology by Csejtey (1974),Talkeetna Mountains,Figure 4 (top) and Wilson et al.,2009 (bottom). 6935000 400000 DRAFT Tear ALASKA ENERGY AUTHORITY 1 NEAME wT GROUP 47b FIGURE Lee A17b.1«=>ALASKA Date 10/18/13 @=-_>ENERGY AUTHORITY MAP DATA 79218900Alaska189LineamentReportOctober2013,modified10.18.13B) View looking westerly at break-in-slope at base of hillside and undulating glacially- eroded bedrock knobs in foreground. 7117/2013 3:02:42 PM (-8.0 hrs)Dir=SSE Lat=62.55119 Lon=-148.89916 Alt=3222ft MSL WGS 1984 View looking south southwest at lake margin of glacial valley.Lineament was mapped at base of slope, and is not expressed as a scarp-type feature.Apparent colluvium along projection of lineament does not appear offset. C) 7117/2013 3:03:39 PM (-8.0 hrs)Dir=ESE Lat=62.5489 Lon=-148.90173 Alt=3230ft MSL WGS 1984 View looking south southeast along glacially-sculpted terrain along which Csejtey (1974)has inferred a fault within the glacial sediment that mantles the bedrock knolls (Figure A17b.1). Ed /=ALASKASeo pate 10/18/13 @&--ENERGY AUTHORITY PHOTOGRAPHS DRAFT cra ALASKA ENTERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE sO LINEAMENT GROUP 17b A17b.2 D) View looking south along southern extent of group 17b,along which an inferred bedrock fault is mapped by Wilson (2009).Photographs B and C 189LineamentReportOctober2013.modified10.18.1379_218900_Alaska_Iare adjacent to lake. cad*wo .To weg a gee ere:ant 2 ee 'otpeeeealS pik meat ae So ey:Veeeg?ans ss re a F Ta ae bgtcitiSeeieCeaaefeeoGiFeREert'Say : "x sh eB A -oN B doers 21S A!id*vy 3 "A Ss lateral distance between base of slope to crest of rampart.Geologist for scale is about 180 cm tall. mpart v3 Ba,A Pro-talus rampart constructed from blocky,frost-shattered volcanic rocks. Photograph is centered on more sub-rounded glacial erratic (granitic) that is not similar to any of the local hillside lithologies.Field notebook is 19 cm tall. DRAFT cro ALASKA ENIE RGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE ae =AA LINEAMENT GROUP 17b At7b3{=A SKA PHOTOGRAPHS , vate 10/18/13 @@=-->ENERGY AUTHORITY 2189_LineamentReportOctober2013,modified10.18.1379_218900_Alaska6930000 6925000 410000 6920000OTSPOTR |ioeeeweldWefLe.| Me .-we .'a 6915000 '405000Nel a.yeehexeyFf:"Ny Uo ,a a yy sel ihe N yQED ,°Sepiely,Ye UfMl;hs,es1Nd:f,ygoN Uyite.| '.:te,rr 4 ane!ce Owe See Te a eee \,SOs S Pa vo ree |a a 4A ieenina? a x N\Lii.9),eTes .6910000a.Se,ee S10 i a tw o-rd ar »Pm ae aN "°3'wt Gg a an j wos a s) _v.-Tem fs oa ¢,mY Se ;3 ree ye.'y '\S-:one aie \TrPavs,' le emepeoe oY °,H we -{")y :\\e@''|TT ee '¢ ;'an,'i)4s i aan &,o 4 'q 1 x \@eeeoe ".@ i @.a men,ve «4 i «?XN \2 Map i Nee OS AYO NS |->FA,Pan\"Sp MeNageNSMIA'|- §'Ee]2 a \\..oy ';. y sh q!vA Ys \\-4 *.:ar,fe re \". | *:ye".a t if >mn *%*fa .«"\-oD.x »4 a .wh,hy my ,poe wy aAN8myaoreVousORBe.'SN TrPavs:8 ki dale a RG rer Ae Serene Fa\ae eetnN ee . 400000 6925000 6920000 405000 6915000 6910000 DRAFT Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Data frame has been rotated 70°west of north.fuera ALAS ee Oras ity SUSITWA-WATAWA HYDROELECTRIC PROMEGT FIGURE 3.Geology by Wilson et al.,2009.::Bod =-LINEAMENT GROUP 17c M71eeaeendlone10/18/13_/=<ALASKA MAP DATA 189LineamentReportOctober2013.modified10.18.1379218900_AlaskaRass wdtootaptsCae -a : ;Toa aieae:=A,i a peers _pees eae vee .'ne weLyee¢ly go at ofeGoe|ss seitann aii View looking southeasterly at lineament expressed at erosional drainage cutting through the likely Holocene rock glacier deposit. View looking northwesterly (opposite that in Photograph A)at lineament expressed as erosional drainage cutting through the likely Holocene rock glacier deposit. View looking southeasterly at lineament expressed as likely Holocene rock glacier deposit contacting the valley floor. Date _10/18/13 @=--ENERGY AUTHORITY PHOTOGRAPHS DRAFT cRo ALASKE ENTERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE a =ALASKA LINEAMENT GROUP 17c A17¢.2= portOctober2013,modified10.18.1339_LineamentRe79_218900_Alaska_Ri6910000 69050006920000 450000 6905000 QZ Black Lake 45500069200008 8 8 % 440000 6905000 445000 6910000 450000 6915000 455000 3 DRAFT Notes:1.See Figures A0.2,A0.3,AOd.4,and AO.5 for explanation.STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 2.Data frame has been rotated 45°east of north.Ta ALASKA ENERGY AUTHORITY 3.Geologic map from Wilson et al.,2009.Bek <LINEAMENT GROUP 19 A19-1.1oate_10/18/13 _=ALASKA MAP DATA 79218900AlaskaI189LineamentReportOctober2013,modified10.18.13A) Drainage shown . in Photograph B >atpeeataSSreontsotaaoo ity x a re resistant rock,type (craggy outcropme.eG AES,&p38 ere Photograph taken from location A looking southwest along apparent rock type contrast (contact?)and towards mapped lineaments in steep-walled,v-shaped, linear drainage.Arrows point along apparent contact between less-resistant rock on the north and more resistant and craggy outcrops on the south. Drainage shown in PhotographmeeerreFutLLatenw +e &.acm.OMSeH es ay a,7. Photograph taken from location B looking west along mapped lineaments and apparent rock contact in steep-walled,v-shaped,linear drainages. DRAFT Photograph taken from location C looking west at head of steep-walled,v-shaped,cro STATE OF ALASKA SUSITNA.WATANA HYDROELECTRIC PROJECT FIGURE linear drainage where mapped lineaments correspond to apparent rock contact.tbaaet Aan eee AIA LINEAMENT GROUP 19ee!/=>ALASKA PHOTOGRAPHS A19-1.2 pate 10/18/13_@=-ENERGY AUTHORITY 189_LineamentReportOctober2013,modified10.18.1379218900Alaska|Photograph looking northeast from location D along the western continuation of the apparent rock type contrast shown in Photographs A,B,and C.Arrows point along apparent contact. ti SY eeteo -S a =. ..F Naot 41 *"a ..ra * ly ww +d _-.oa "4oeee - a ace Nt P mo ,het yee saeNaw.a 7 Ae Dee FEEICSwe..Pee oD aCe eS Otacylameaana:ee By =als LG ATTICT)eee ..\OO Wee ay ..Cy pew ;woes .;on .bal toySEDYCOMOocSaas. ee ONmcsCOCULUCS(Re alrbogeAGATA,|OraeeCSis >.Ce ae Reh ee*weg a.ae SO meal,Sa wey eee}cm ye *.-""TRAY ET teh garceeereyoungerdiac "4 ,:Te 7 wel, .a -en -an ares wi ;wties©Are aan -,ig 3:ns x ,mn nsreSAY:Mees be Sx maakt!eo :ations ACtiVe rock,glaciet Marame ie te PS coy,®2 EEE *m ek ft ?- Sate we : ; ae ' -S .riche.+ ha oat Loe ee i ae Mil 3 a :i Hato SI em i,SeeGOeesee- -:ee."a ast "a a» Photograph looking northwest from location F showing apparently undeformed rock glacier and/or glacial deposits along strike of the mapped lineaments and apparent rock contact shown in Photographs A through D. . , ; 4 wR fe 3 ee nit Paes Photograph from location E looking southwest down the ridgeline shown in Photo- graph D.View is 180 degrees from that in Photograph D.Note presence of rock glacier and glacial deposits in valley bottom.Arrows point along apparent contact. PHOTOGRAPHSpate_10/18/13 @&-->ENERGY AUTHORITY DRAFT cro ALASKA ENTERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE Soe =ALASKA LINEAMENT GROUP 19 A19-13 portOctober2013,modified10.18.13189_LineamentRe79_218900_Alaska_F6925000 455000 6930000 460000 6935000 r r _l 69200006935000465000450000Linear suet*.,win Photograph B |\>. See,"AN ai ie cal.7 ::Location of sinuous sub-ice §Ne *channel in Photograph B 465000 T 6930000 -T 69200006935000465000Sub-ice fluvial channels 450000nreccansaeeeessenensceens *tesceesnes : t=km 4 h \! N -vv | a ;0 imi - 455000 6920000 460000 6925000 465000 6930000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation.DRAFT 2.Data frame has been rotated 45°east of north.STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE3.Geologic map in top panel by Williams and Galloway,1986 To ALASKA ENERGY AUTHORITY LINEAMENT GROUP 19ietal.,2009 See od <_A19-2.1andbottompanelbyWilsonm{=ALASKA MAP DATAdate_10/18/13 @&__>ENERGY AUTHORITY 79_218900_Alaska_R:39_LineamentReportOctober2013,modified10.18.13A) C) 7 .A,ancirthationt te s miele,.cee --Fa NS te eee mares 2 Tex Se TE ee atm Pa .ie LD -. ne ein ,t60 Z seesRicee ale ae Photograph taken from location A looking west.Arrows point along trend of mapped lineaments along southwest-facing aligned break-in-slope.Note the rounded and subdued nature of break-in-slope.Relief across break-in-slope is 125 m. yr weeson: B) - ma . . "oe . Linear sub-ice annels . not large enough features to be seen on INSAR data. DRAFT lineaments.Arrows point along trend of lineament group 19.Note absence of a STATE OF ALASKA SUSITNVA WATANAHYDROFLFCTRICPROMGT FIGUREexpressionoflineamentswithinthelandscapeacrosstheGooseCreekportionoflomoAeseeeROYNAIA.LINEAMENT GROUP 19 19.0.2thelineamentgroup.-x-{=ALASKA PHOTOGRAPHS " date 10/18/13_@=-->ENERGY AUTHORITY portOctober2013,modified10.18.132189_LineamentRe79_218900_Alaska_6935000 460000 6940000 465000 6945000 470000 é f/f TY T 6930000J"/*pms=)46000069450004750006935000 470000 69300004600006940000 475000 T ¥69450006930000 465000 Notes:1.See Figures AO.2,A0.3,A0.4,and A0.5 for explanation. 2.Data frame has been rotated 45°east of north. 3.Geologic map in top panel by Williams and Galloway,1986 and bottom panel by Wilson et al.,2009 6935000 470000 6940000 475000 DRAFT ar STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREferALASKAENERGYAUTHORITYeeLINEAMENTGROUP19A19-3.1 pate_10/18/13__/=ALASKA@z_>ENERGY AUTHORITY MAP DATA 489LineamentReportOctober2013,modified10.18.1379_218900_Alaska_!A) EFweg.(gh ee ag nd Photograph looking north-northeast from location A along the east-facing break-in-slope that defines the northeast portion of LG 19.Arrows point along alignment of mapped lineaments. eee an*. ”red ree oe i 'oS.Oe:ares i oa ee«wo .*-eae *¥ate Photograph looking south-southwest from location C at widely spaced,near vertical,well-developed joints in trondhjemite (aka tonalite)bedrock.Joint spacing is 1 to 1.5 meters.Predominant orientations ofjoints are 042/80SE, 012/85SE,and 082/85SE but other orientations exist.Joint faces have clean surfaces with relief of minerals of 1 to 3mm.No gouge or mineralization observed on joint surfaces,nor any sense of movement indicators (striae or mullions). B)4680006940000al pert es©amasgermraee)Me, -Sgat <<="oe,i bd an asMyTine?WR*baer?erage v7 iNecrseesovZs ee?way aft pas Ree EO aly fF are"den be er?Eg mb $e wn Merle .ne my "Can PS:2 ety Be Ie,ctRE :=fom b eee ess<we Fapomers,«vee OT ee ee etemaxtd eS cinnteliies 7.ny - channels.Arrows point along the trend of mapped lineaments that make up group 19. 466000 6942000 468000 Ct .Elevation from -2010 InSAR data (meters) '1269 me ee i.; 903 os ° -482 vr 8 4d o oO ..eee ed . nm aN ,of 470000 Detailed DEM showing orthogonal joint sets at northeast end of group 19. DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREAbepetaeALASKAENERGYAUTHORITYLINEAMENTGROUP19BOG[_<)-a =ALASKA PHOTOGRAPHS A19-3.2 date 10/18/13 @&-ENERGY AUTHORITY 189_LineamentReportOctober2013,modified10.18.1379_218900_Alaska_!6895000 480000 63900000 485000 T.?iyar 2!an oRE tOXsdis 6905000 490000 6910000 495000 =-rrad H PSTN Pon EK,-7 Uf {{ \a py cma? 'rememTAMLocationofgranitic\\BS exoe'glacial erratic!)|WA?(fee oOa*\OPN is ' .Fe NSpoteee 6910000480000na (I -ternn UtneaVNhoe PR LORE Ne™=)Leone &a 6895000 490000 eal J "T6890000 4800006890000=° ..a >:-:2AApparentrock S .ae hs)2 _f .+type contrasts ” j ae i ; '_o Ne 2 we + ° 4 X < . 7,rr 4 as "a -« a - - 0 1km j |Ll | ||| 0 1 mi y .--L 6890000 485000 6895000 490000 6900000 495000 6905000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Data frame has been rotated 45°east of north.-fusra ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologic map from Grantz,1960.FABe 3 <|A KA LINEAMENT GROUP 20 A20.1 pate _10/18/13 /=ALASKA MAP DATA 189LineamentReportOctober2013,modified10.18.1379_218900_AlaskaRELALAgegetsae (ne ;2TeeseGTNEYate Photograph looking northeast from location A.Photograph looking west-southwest from location B.Geologist standing in 3-to 6-m deep- and 30-m-wide swale.Swale only exists in saddle;it does not continue down either side of saddle. C)Location of straight-line projection of mapped fault shown in Figure A20.1 (upper panel) aera eee"NCE Noemie macy eo _ a . emgage'. 'et a eeloars..toe ys weet ey nea -'a .pag oe 2 ORs ee yaa.ead be 'toad,. . vm ree .:act or ie 'isnyOePeeMartS'sae:ae Bowes Photograph looking southwest from location C.Basal contact shown by arrows.Note that base of contact is not apparently deformed along projection of fault and that no expression of faulting in valley bottom is apparent. STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT uso ALASKA ENERGY AUTHORITYeG_LINEAMENT GROUP 20aa/=-_ALASKA PHOTOGRAPHSDate_10/18/13 =>ENERGY AUTHORITY FIGURE A20.2 189_LineamentReportOctober2013,modied10.18.1379218900Alaska_FG)D) os Photograph looking north from location G along mapped fault of Grantz (1960).Arrows point to approximate location of mapped fault.Note absence of apparent geomorphic expression fault. E)F) _- Arrows show location of FCL mapped lineament (shallow U-shaped swale).Note no apparent deformation of white-bedded sediments (glacial lake sediments)along line of Tf. a Photograph looking northwest from location F. .i .STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREprojectionoflineament.,juSra ALASKA ENERGY AUTHORITYWeg=LINEAMENT GROUP 20 A203a{=ALASKA PHOTOGRAPHS : vate _10/18/13 @&-ENERGY AUTHORITY 189LineamentReportOctober2013,modoified10.18.1379_218900_Alaska_|H) Wevei ite on owe -s ae :hon Legere Lae more .we ae ret yg toe =Deen irs.smattinatt tn,5 Photograph looking north-northeast from location H along queried mapped fault ofGrantz(1960)that lies outside of lineament group.Note absence of fault expression. aheS aS Photograph looking north-northeast from location |along queried mapped fault of Grantz (1960)that lies outside of lineament group.Note absence of fault expression. pai |=ALASKADate10/18/13_@=-ENERGY AUTHORITY PHOTOGRAPHS DRAFT ALASKA ENTE SGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 'LINEAMENT GROUP 20 A20.4 portOctober2013,modified10.18.13189_LineamentRe,79_218900_Alaska_F460000 470000 69100006890000490000 §00000 510000 8 8 a © ,Fourth of_!July Creek” Pa ”ae i .ne)foe oy : ' é poe 2 6 -oO pp .Staqnent 6 | Explanation ».Drainage divide”:Little Nelchin 200 Glacial drift mantled by glacial lake +)me ved sediments from 914-975 meter lake oo rr GraniticSeGas.glacial . iocarbon sam yea,OG i g A AA Location of radiocarbon sample Pe!_etratic g at "©'ot 8 >&R ©\*;-wo :aN eo /;"os =Ice boundary (morainal ridge,kame ane aed =i «.?a '. , Ss : 2wrace,dee)maring eae o el tabi ake So Zedglacierg'. *sediments .'"ae ae 4 . noe ry ots ' hy,of ale . Linear or drumlinoid feature from ice ons --)-scour.Direction of ice movement .yy bits5indicatedbyarrowOD"Gy,Castle Mtn.-°°°Gz,_--- --.extension - teataaee Spillway for glacial meltwater,_.lineament groupLoyincludingthatstoredinlargeglacial'wee me 3 -phagretet lakes --N\3o *oO CD Lineament group -os r L =5 -.-; . ° are . =.r =.po Be Gettgrek get ae an a ae ' .",ae x 4 .' a -a oo ',ae *;sO oe 2 A a ocet a Poe :ae 'mr,Tee f cd .eA ;.i ae eer'r had ae i '.ores ,a .a fo.-oe wt wee -- Dat loo ate aay Oe rarer Pam ae a £an ov | 460000 470000 490000 500000 510000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation.DRAFT 2.Geologic map from Williams and Galloway,1986.STMT OP ALASKA SOOO ENOnn SURESpeeALASKAENERGYAUTHORITY pate 10/18/13_@=->ENERGY AUTHORITY eG =<LINEAMENT GROUP 20--{=ALASKA WILLIAMS AND GALLOWAY MAP (1986)A20.5 portOctober2013,modified10.18.13189_LineamentRe79_218900_Alaska_'484000 6898000 486000 6900000 6896000484000488000 6902000 490000 Q8 Ss o> oO ae eee,,a No afparent oo ;.4 kdisruptign ofan,_- «©\.'contacts4Ed”ste a &:x v.. ,\-bo . ;aan ee -|p Prominent --_,yg\,break-in-slope vig ow i} ;defines contact fF j x .=P.SiP-é =:ot Pe * !between /If and Jns \|noth ae_aa Maen.Pe res Gree 486000 wy -188000.____6898000 6900000 492000 rs as --=,oN Note ger :.a ,F " ..&:.%tw :ia e a ie ee ;ae 3 a has :age he - ¢ee ?awF3:eget - 'ie <aa aPoWRowNe2arae7:; -a J "0,;.Nae u f :Ee._s "ys a Ge :a 7,«*Gontact appears.hs -.",:.t., ,Le .0 be mappedreaeieeoord..mm 8 toohigh®.J!ae ee ae |ERS .&.5 j ,&\Da ('dl oof,'if Siawataanadl.f t oO "et 4 'f :©}.AS 'te we "fr,¥.ts * }oO *=v8 *Ne 20 |}Sr,'\ge o%5 J 'd 'rs ,cS _i é Pe Qe . F ™KE %' .Ee 7 ¥ i .'Pama \\\eo \Contact'appears to \be mapped 8 . ,io too low 3 ]j : 486000 6896000 6898000 490000 6900000 492000 |:DRAFTNotes:1.See Figures A0.2,AO.3,A0.4,and A0.5 for explanation.SIND OP ALAS Sn2.Data frame has been rotated 45°east of north.fore ALASKA ENERGY AUTHORITY FIGURE 3.Base map is slopeshade derived from INSAR data..e_LINEAMENT GROUP 20PPee/_-ALASKA MAP DATA A20.6 pate 10/18/13 @=->ENERGY AUTHORITY 89_LineamentReportOctober2013,modified10.18.1379_218900_Alaska_F7010000701500070100007015000435000 7010000 440000 T "7 ws ieaaal,oF!fo:D i ,,©Oty adcetbtabgagofiS 4idow7¢.. . ae ,Linéar ridge ; ee :fo (terminal moraine?)4 vA)4 ; wo -Pn pe ae ae *:eat , ™we 'Qa}.a .oe }aAvay)° _Ww,ee ,Pn ,aiaQ°a : <". 0 LOY °;arwoOotyMerSOoSaaeetaeoePeigrwefhwtJD. you geo?"4 -a 2 ff -¥. ° .14;4 Mey,UP ve =7 Py \Z 3 . +;yg ".2 $a .'a ewe re a oo af is Be,; Sy4,re)re TY.:Esker complex 7 Linear stream/iS tk ts fd a fe us ' .o swaleANYfaawin/:\4ne'}'oo a D>wo ;é Y :$a ' Ps'»'7 fe,i '"4 y a ; 8 ; ;woe ¢\a,7 moraine complex-° 'rN Shee OL Efe OM gt 7%.gh ' aN '-_--mn yw aes iooet hl a "eer mee)a 430000 7005000 435000 ys a 7 TSN ecw neers 177(Ss .oy \: fo] QQQQo R | '1imiA f fooa.ad __f 1 Ma43000070050004350004400007000000445000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Data frame has been rotated 30°west of north.peore ALASKA ENE RGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geology by Wilson et al.,1998..3 LINEAMENT GROUP 21a A21a1 coe 10/18/13 J=EAASKIA@@-_>ENERGY AUTHORITY MAP DATA 189_LineamentRe;79_218900_Aiaska_FportOctober2013,modified10.18.1342000070200004150007015000A)!Linear (terminal moraine?)ridge okspolBrushkanaC1 _?, ealtn sssaeeesgTe.2 OgAsNeSeae es +veraneDanecasanalBaTic x om Sob,and ' Ly 4 »oe See i 'Zaft te, 7/13/2013 3:49°14 PM (-8.0 hrs)Lat=63.15827 Lon=- View looking north across Brushkana Creek along north-trending linear ridge and roughly linear stream.Arrows point along alignment of ridges interpreted to be terminal moraine from northeasterly flowing ice. Po oy B) "53:07 PM (8.0 hrs)Lat=63 View looking northwest across western portion of lineament group 21a towards approximately 120-meter-tall rock-cored drumlin.View is looking up the Brushkana Creek valley.Note lack of obvious expression of mapped lineaments in the foreground. CVygss ae enPPHtfsyereYefierekefs.a ay : te Ls 415000 25000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation. 2.Data frame has been rotated 30°west of north. 3.Photointerpretive map of glacial extents by Reger,1990. 4.indicates ice flow direction. 7010000 420000 7005000 430000 ora aed |2.2/"; |_18 '\i pee " "y 1 awe{| ,y,mes ' s _2b y es Ta a .SSR,oy £8anheWTBAo7arr 'porn em "}SA,4 ".</f__3 7:gl os fs 7 :. > . : -4 ';?.r 'pr ly i”wee vd test:«4 ae)-ley 3 743 ws "oa i 4: " .Ls,x,@,a o 10\dW ),ae "ene rn 482-S !z oO 435000 440000 445000 450000 6990000 ° DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREfeos?ALASKA ENERGY AUTHORITY LINEAMENT GROUP 21a*:,A21a.2eae{=ALASKA MAP DATAAND PHOTOGRAPHSoate_10/18/13 _@=-ENERGY AUTHORITY 70050004400007005000440000189LineamentReportOctober2013.modified10.18.1379218900_Alaska|445000 7005000 450000 455000 7000000 460000 ae.-jingament 'coincides\ "a maaeconcealed contactofv..between Ks and 'Kph'Mee,6995000460000Ala Jae=.hs ;-3_yn aan ''. >ysabye!. 4 -.4 ey.i ey .AP 2, L .t°4 Sagas eo °° myth 6 on , "”ae.. fp Vv 440000 Qs ES cwntanl cemes .ayME AsoButteCreep6995000460000N ae.:PIN!adfvAyoIFN'MzpcL|7 "tL:S\N 1 £pc44000070000004450004500006995000455000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Data frame has been rotated 25°west of north.cra ALASKe ENE CRSA ORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Map in top panel from Smith et al.,1988.thoes Pe :=) 4.Geology in bottom panel from Wilson et al.,1998 -_tw)ALASKA LINEAMENT GROUP 211b A21b.1pate10/18/13_@x-ENERGY AUTHORITY MAP DATA 79218900Alaska_F189LineamentReportOctober2013,modified10.18.13INSAR and mapped by Fugro (2013).Field reconaissance revealed smaller lineament (not visible in INSAR data)lies along the small arrows and projects toward the vertically-dipping bedrock exposed in the creek bank shown in Photograph B. An P 4 ” Overview of east-southeast striking,vertically-dipping phyllite exposures located at GPS waypoint 009. or Da ae fet:eres thio=:me vineg : : -Sy ats -6s re ping phyllite. medium sand.Thick,resistant beds,such as this,are interpreted to create the lineament shown by small arrows in Photograph A above.Geologist for scale.DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREMybesteALASKAENERGYAUTHORITYLINEAMENTGROUP24bBgta)aaa =<_-ALASKA A21b.2 bate 10/18/13 @=-ENERGY AUTHORITY PHOTOGRAPHS 79218900_Alaska_F189_LineamentReportOctober2013,modified10.18.13E)F) vee os 7 ie el er eeee"ec,* 4 : o ed weno SSS Be S23 eeeTengealae.Peden rey+Ae”->4 Photograph taken from location E looking east-southeast along trend of FCL mapped lineament (shown Photograph taken from location F looking west along trend of FCL mapped lineament to west of Butte Creek. by arrows).Note absence of any apparent deformation in surficial deposits or in terrace riser on left bank of Note no apparent deformation in right bank of stream or any expression of faulting in broad,flat terrace Butte Creek.surface mapped as Qdt3 by Smith et al.(1988). DRAFT scr ALASKA ENIE SGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE =A21b.3<_LINEAMENT GROUP 21b oae _10/18/13 /<-ALASKA PHOTOGRAPHS 79_218900_Alaska_|189_LineamentReportOctober2013,modified10.18.13430000430000435000 6995000 . 450000 Cee ot oF ey30-kme a 54Dwan,up;rya4?Soei6985000450000* Note that left-lateral moraines are not deformed along projection of mapped lineament seth x-Tegr0 \tes.ole | Seismograph .> *station-ey geetaot msad om %.LZ Pp EEE OFSh(a 4 ace ate KguOPaeenggermete $:» oF xPa 6985000450000430000 6990000 ; Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation. 2.Data frame has been rotated 30°west of north. 3.Geologic map by Reger et al.,1990 (top)and by Wilson et al.,1998 (bottom) 435000 440000 6985000 445000 DRAFT TorePaee| vate_10/18/13 STATE OF ALASKA ALASKA ENERGY AUTHORITY =>ALASKA @Ez--ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT LINEAMENT GROUP 22 MAP DATA FIGURE A22.1 79218900_Alaska_!189LineamentReportOctober2013.modified10.18.13A) C) View looking north-northeast up the Deadman Creek valley.Note the numerous downhill-facing solifluction scarps.Large arrows point along mapped lineaments. aFY View looking north at deep drainages whose margins coincide with nivation terraces and hollows.The large size of these drainages is inconsistent with the weakly expressed lineaments located east of Deadman Creek.Such deeply incised drainages are interpreted to be a result of sub-ice erosion. B) D) a ae,be.Yu.#er thew©EE Sa Rabe tes ON,SEL)-148 30468 Alt=4058R MSL WGS 1984 --and View looking north-northwest up-valley along the margin of the left-lateral moraine and kame terrace complex.No lineaments were observed cutting these deposits. ie°ae =(Tye Ta Salo DRAFT GRo ALASKD ENIERGY A THORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE sn G =ALA LINEAMENT GROUP 22 A0294{=A SKA PHOTOGRAPHS : pate 10/18/13 @=-ENERGY AUTHORITY portOctober2013,modified10.18.13'2189_LineamentRe,79_218900_Alaska485000 6945000 490000 4800006945000mradiusve"70%a 495000 6940000 500000 6935000490000 6935000 48000069450007qi500000'§Elevation from InSAR,2010 (meters)3 843 SiLfé oO pevencar”g 634 oe L a ”4 mi A _. (Le L L 480000 6940000 485000 490000 6935000 495000 Notes:1.See Figures A0.2,A0.3,A0.4,and AO.5 for explanation.DRAFT 2.Data frame has been rotated 25°west of north.foaro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologi in top panel by Williams and Galloway,1986.:ALASKA ENERGY AUTHORITYeologicmapIntoppanelby¥og =ALASKA LINEAMENT GROUP 23 A23.1<-MAP DATAoate_10/18/13 @=-ENERGY AUTHORITY 78_218900_Alaska_Ri39LineamentReportOctober2013,modified10.18.13415000 6975000 420000 4100006970000 6965000 425000 ,x T *en fi 7 me re vi ar oe } 7 / .2aa.¢; t2%Sim"WAT &.Se os ee neAskeeedye+elitiniy45 y 3 4a '"a e we "é ,4 ae a a:"gy "f ' .pos 425000Se abet 4100006975000 410000 Notes:1.See Figures A0.2,A0.3,A0.4,and AQ.5 for explanation. 6970000 4250006960000 420000 2.Data frame has been rotated 55°west of north.aro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE . KAE AUT 3.Geology by Wilson et al.,2009.re AS "ALA wa LINEAMENT GROUP 26 26.4/=ALASKA MAP DATA date_10/18/13 @@__->ENERGY AUTHORITY 79_218900_Alaska_!489LineamentReportOctober2013,modified10.18.13A) eeeoneal 2 «.rd a Lg Ra.eet ne ate pan red rer fren o.eA x -oft q..te et PP e ts »wo a mtn:mo .a Ca aniaaalettofANeeaeStee7AeneaTTome>were Ce eee©Se :emer ;is oe va Bosak gt ”Som +ore ,a Getse ¢ioe4weap View looking southeast at esker landform that projects across mapped lineaments and appears undeformed or offset. Rea .4 7 4 3 -mene omens "|ap tone Syscoe_«.rr ae.Wtied :.,a we chetpeakbe-ee fe Le >a tocar 4 rd eeCaeTepoem.atehe;ern eeaNSetSoeaeee"f-»her PL wert.3.Se seg B.i5 +wR:'wnale baron 8.Sie Ts whaegereeg)we Makes se ST eeeISLEEweOeaTre;rt wy TyertfSeesler7>"yy a WtMLSayoepeeaeZ.¥sap Nes Biene€sa we Vee ie ndt pT.re *Mey ag RS PyLovake®ae ref reas .ha Bepor® et eg fe " . .4 "4 rd :3 : a i Py =i % ao i Lae eee eS me ee) View looking southeast at exposure in left bank of unnamed drainage creek where till apparently overlies lake sediments and fluvial washout gravel.The lenticular beds in the fluvial gravel appear horizontal but are not laterally extensive. B) 'wot . . -- bedrock * View looking northwest at layered bedrock (on left)with apparently undisrupted horizontally-bedded till (on right). D) Agbn "ES LEay>weaiiBS: Close up view of exposure shown in Photograph (B).Note the apparently sub- horizontal basal contact between overlying till and underlying lacustrine deposits. Note sediments on the left of the image are influenced by landslide processes and not in-place locally.DRAFT STATE OF ALASKA Vers ALASKA ENERGY AUTHORITY--i |7 ALASKApate10/18/13 @=->ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT LINEAMENT GROUP 26 PHOTOGRAPHS FIGURE A26.2 '189_LineamentRe79_218900_AlaskaportOctober2013,modified10.18.136910000 455000 460000 6915000 465000 470000 6920000 nae "y T 7 7 T 7 -r T -.r > . | Q8 a Be -te - Th . .ao PsN,*Elevation from 3 , .too.e 7 |INSAR 2010 (m)g 4 7 ° mo -1723lr =. ,.wo. . *p04 4 ° 2s .8 'wo.5 a I ° 470000 475000 -. 8 3 Ay oO .-ae.n ieee i we 3 3B +fo]QB o 8 3 ae \7 =ah L !$ 6905000 460000 465000 6910000 470000 475000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Data frame has been rotated 30°east of north.'fears ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologic map by Williams and Galloway,1986 (top)and E =<LINEAMENT GROUP 27 A27-1.1byWilsonetal.,2009 (bottom).eee =<ALASKA MAP D : pate_10/18/13 ATA@=-ENERGY AUTHORITY 79_218900_Alaska_R89.LineamentReportOctober2013,modified10.18.13470000470000470000 6920000 480000 485000 rT T TT -<Ir7 , 2 *€ ; ee s t co "Elevation from na INSAR 2010 (m) 2 .:"=1289 %J fo] 3 & v 8 N3 'aol 4 "sa”Pa Li 475000 6915000 485000 }/T a }, er /eA \].a L-4 _ ; -. ane / A 2 8 g 3co] q 8 , _-" |LV __.Lou 2 475000 6915000 480000 485000 490000 Notes:1.See Figures A0.2,A0.3,A0.4,and A0.5 for explanation.DRAFT 2.Data frame has been rotated 30°east of north.-fuora STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE3.Geologic map by Williams and Galloway,1986 (top)and ALASKA ENERGY AUTHORITY ..: -)LINEAMENT GROUP 27 -by Wilson et al.,2009 (bottom).moa =ALASKA A27-2.1 pate_10/18/13 @z-ENERGY AUTHORITY MAP DATA 89LineamentReportOctober2013,modified10.18.1379_218900_Alaska_R485000 6930000 T - \ ; a Elevation from 485000495000 6935000 INSAR 2010 (m) 962 6925000500000 -LL a 50500069350004850006925000s920000 500000 505000 G/ LL xy of °Ro f)eye 48 e ON.'ee -a/*/) 2 43 3 % .fs 0 2 &://°i 0 1 mi f °1 1 a 490000 6925000 495000 500000 3050000 505000 Notes:1.See Figures A0.2,AO.3,A0.4,and AO.5 for explanation.DRAFT 2.Data frame has been rotated 30°east of north.STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 3.Geologic map by Williams and Galloway,1986 (top)and fosre ALASKA ENERGY AUTHORITY by Wilson et al.,2009 (bottom).Liman ed LINEAMENT GROUP 27 A27-3.1 Date 10/18/13 /=ALASKA@@-_ENERGY AUTHORITY MAP DATA 189LineamentReportOctober2013,modified10.18.1379_218900_Alaska_!A) .te :Pan f fe wg eo on aie eo .alas. View looking west-southwest toward linear alignment of lakes.Arrows point along lineament.Note kettle lake terrain in the foreground. .ae ee | "ya is ttcaeVegettPorAg cul >U8RTanoPreeSwitWyoeaeSoekeROELE :7 Deyrs :«4;Spiescytatet=="*{D)Ge View looking south across strong vegetation lineament associated with a 2-meter-high linear ridge.Note that topographic expression of ridge abruptly dies out and does not continue to the west. B) awewnew"!8 te:sn wy er ge "osi.aire eeoxy2BaeotBASISPanaikee.Tere oe Rye aan) rn ee ie r.,cory By >ere ee dem 7/12/2013 10:06:12 AM (-8.0 hrs)Lat=62.48532 Lon=14 Close up view looking west-southwest along linear alignment of lakes in Photograph A. Arrows point along lineament. D) = .,eae 3 :*fVat35,Se aae ; *yackpeereevee9neaaidoeaeaineay,gene;aDaytaeISaot"7fe."ogoarAaaEaAvewTSSJn2aTan:AndFBayae,ypehaesieeeesootcagereorysmeVESUFbeet3neoils+or:iooaeAsoarestarott -OenoeOIope)tehrik ay 1emmeen7/12/2013 11:05:19 AM (-8.0 hrs)Lat=62.47351 Lon=-147.16072 Alt=2684ft MSL WGS 1984 N SPRLoe\gu \y \Vaa ee dy Seah akan View looking northeast along south side of vegetation lineament and 2-meter-high linear ridge shown in Photograph C.Positive feedback of vegetation growth and organic matter accumulation on the linear ridge may accentuate the apparent relief of the ridge. date 10/18/13_@=->ENERGY AUTHORITY feces LINEAMENT GROUP 27Baad{=ALASKA PHOTOGRAPHS STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREUGROALASKAENERGYAUTHORITY A27-3.2 79_218900_Alaska_|189LineamentReportOctober2013.modified10.18.13C) .aan,5 :ow}ae?itedAae é View looking north at location where mapped fault would traverse across Quaternary sediments. -Quaternary 3;BsheNa nS nee River vet aaaHesForkChulitnereopt s 'est °*Wt ee , a ;;aan Ff a _-.ws _”._---e .phe _.at "- View looking west at exposure along east bank of the West Fork Chulitna River demonstrating Quaternary till overlying Tertiary fluvial sediments. vy a nh Ft he:x a iesiesae 3 RB tart .7/15/2013 12:00:39 PM (-8.0 hrs)Dir=N Lat=63.07953 Lon=-149 59654 Alt=1511ft MSL WGS 1984 View looking north (upstream)along the West Fork Chulitna River valley at exposures described in text and photographs below. fe a”a.os,roy dar.ifhe_'5 .oA NS rr ji ¥) Close up view of exposure shown in Photograph C.Basal contact between overlying till and underlying fluvial deposits appears to be sub-horizontal. PHOTOGRAPHS/=ALASKAoate10/18/13__@=->ENERGY AUTHORITY DRAFT ALAS KA ENTE RGY AUTHO RITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE BROAD PASS AREA A-BP.1 79218900_Alaska_I189_LineamentReportOctober2013,modified10.18.13G) COC Alte. .. sss View looking northeast at subhorizontal contact between till and Tertiary sediments. aye poe.Middig South DOL big 4. View looking south at location where inferred fault would traverse east of railroad tracks.Fault is mapped as juxtaposing Triassic and Cretaceous rocks outcropping in creek behind photograph.No evidence of faulting in Quaternary deposits. LJ Pik aN «4 View looking west at creek exposure along projection of mapped fault that depicts Cretaceous/Tertiary juxtapostion.Undisturbed surfaces support absence of Quaternary faulting.DRAFT Oate GRo ®=all o? a al 10/18/13 ALASKA ENERGY AUTHORITY / STATE OF ALASKA =ALASKA@-_ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT BROAD PASS AREA PHOTOGRAPHS FIGURE A-BP.2 79_218900_Alaska_|489LineamentReportOctober2013,modified10.18.13S Poext aero 3. re ee|"oa ae .us View looking west at creek exposure shown in Photograph H,Figure A-BP.2,showing morphology of Quaternary deposits along strike. J) * Pa a ii. "ae ea an *tg _#.anes ge OO ay ee pee ek ete '°-7 ot an '. wee i 7 Lon .7 - a.es aan sg,ey . 4 'oe wt ; :.¢.po ee i ne -q”we "oe raat a oe we eed ad at *So ae .Telit 8 Regen eete*:a te *ee ie ee=ae ann -=ar)Os!i are aan,a Papeete': coe os ie samy i,wad fi es NY --e "eg men ,j we og -; ;wey a me F :I aoets <rNSBEne4 4 Northern buPebgt:ren eae3hee .-!- ..ya ow =foad aw %7 we eeue.*. ." es wf f 2 'a oy oe ce eae -.ath.o "yy ®arene = .fs roybblegeAeeeeeoeSis...©oh ae we yaa eh Pe ; .bY eS eo,wie Faas View looking east at uninterrupted interfluves in dissected Quaternary glacial drift along with the mapped fault projects.Undisturbed surfaces support absence of Quaternary faulting. DRAFT STATE OF ALASKA pero ALASKA ENERGY AUTHORITYni|7 ALASKApate_10/18/13 @@-ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT BROAD PASS AREA PHOTOGRAPHS FIGURE A-BP.3 489LineamentReportOctober2013,modified10.18.1379218900Alaska|A) View looking northwest at mine site located along apparent rock type contrast and mapped fault.Arrows point along mapped fault. View looking northeast through the broad saddle at the head of the linear drainage shown in Photograph B.Note the absence of any tectonic geomorphic features. fauifmapped-as concealed ae G3SWENe "ah xf a .4 -:.a ee cout re 4 :tye ae 7/13/2013 12:03:22 PM (-8.0 hrs)Lat=63.13207 Lon=-147.13763 Alt=5215ft MSL WGS 1984 --- View looking northeast along linear drainage mapped as a lineament by FCL that coincides with a mapped fault.Another FCL-mapped lineament lies at the subtle break-in-slope and may correspond to the ice limit elevation. D)F ..vw Adami . '. "*i "oe ve ee,ae ot ve .;Se a ;a #7 9 i f o> -eg wot.G ee .oo 4 en oe peo me a"**.ee ' -fas="wn .nt aos Sa ."ae ete a =e vt tL 4 eoe«-ASM So fe x nrxel:.%" -6,¥yg -oe ee *,, ;oo --*%>aw oy wy we,awe t *. . -mes iy a ees we "-a °7 Ae { ee i ; > .wr ae "Se ad Lk - -x lg aaa ve ay -oy ae,".*- et * '. . wow . 1 _SC . yt - 4. . a ”..,. ._ -y=.-.M . a rf +aNq ... >ee .\-.. i Lan on "Vtar'ert .GO Xm ye Oeeeee{-et o we >Ly wp 'e <,ia 4 "wo :'” :ws '*.we &S *. se x,:NAL . -2 i he :' ,q -.'. 7/13/2013 12:06:21 PM (-8.0 hrs)Lat=63.13327 Lon=-147.15043 Alt=4689R MSL WGS 1984 --- View looking northwest at location of FCL-mapped lineaments and mining roads partly shown in Photograph C.Note that FCL-mapped lineaments on the sidehill are not readily apparent and correspond to subtle break-in-slope like that shown in Photograph B.DRAFT :ucro ALAS KA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE ee CLEARWATER MOUNTAINS AREA A-CWM.1/=ALASKADate_10/18/13_@&->ENERGY AUTHORITY PHOTOGRAPHS 79218900Alaska_!189LineamentReportOctober2013,modified10.18.13E) *da. .16 View looking southwest at several rock type contrasts (shown by arrows)that coincide with previously mapped faults. FO wi =r =rom At aedaaaes; . .tee .oa Tos a os,es ea Oey a85.oo ae vo: m=7/13/2013 12:18:01 PM (-8.0 hrs)Lat=63.17161 Lon=-147.20097 Alt=5271ft MSL WGS 1964 === View looking southwest across an FCL-mappped lineament that corresponds to the trace of mapped Black Creek fault marked by a rock contrast.Note that no expression of faulting exists along trend in the glacial sediments of the valley floor. 7143/2013 42-11-19 PM (8 O hrs)Lat=63 17583 Lon=-147 11187 Alt=5214f MSL WGS 1984 View looking south-southwest up glaciated valley that shows no expression of the mapped Black Creek fault that is present in adjacent bedrock ridges. Fault continues westoothroughthesesaddles across the fault.Aerial reconnaissance confirmed the presence of the fault in bedrock ridges to the west and the lack of expression in glacial sediments in adjacent valley bottoms.DRAFT fey |metho |ccnmmennourancmnen |omeeg=< ocd A-CWM.2pate10/18/13_-_ALASKA PHOTOGRAPHS 79218900Alaska_|189LineamentReportOctober2013,modified10.18.13pery,f adPeersto8-595,"oPaae eeebehMre Overview looking west along mapped FCL-mapped lineaments that coincide with left-lateral moraines and kame terraces.The lineaments are interrupted by an alluvial fan and esker complex.Large arrows point along the mapped lineaments. Soa nee "lt &ee ah:a.'sy t} rae |"ft ws!>py.es Lat=63.05515 Lon=-147.37086 A Close-up view looking west along FCL-mapped lineaments. we ,we aa . He giagtigttd isaereOES MF gateSeesDEGUsateeBR0rivameeoiteanEewes.dpagsosSeeet . >ss.:a?wo Close-up view looking east along FCL-mapped lineaments. date 10/18/13_@=->ENERGY AUTHORITY DRAFT cRo ALA SKAENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE Pe =ALAS CLEARWATER MOUNTAINS AREAert=ALASKA PHOTOGRAPHS A-CWM.3 489LineamentReportOctober2013,modified10.18.1379218900_Alaska_|C) View looking southwest from location A,nearly along-strike with Csejtey et al.(1978) mapped faults.Note clear expression of linear features on bedrock landscape and absence of linear expression in Quaternary deposits. Notched ,Mae citesbgSOOESSor1eeaMSSad,Jas eens'pweriede §etos,wea jaPEELTDde WEAN gh eee Fhe eedtinswoepicohegegtae¢CP pee tk Mirktts in ie eens al EppeseS Signe ah pe af:*Se Tey ory 'a Feng 1ca4ieMesite*(4 a ate pe ay Latin e by ee Cs View looking southwest from location C.Note alignment of features over mapped trace of fault. B) Location of Location of Photograph A Photograph C ©Apparently deformed aaaaeneLekzveCollars}and aerate aa sehr.mans ant?T2201 View looking northeast from location B nearly along-strike with Csejtey et al.(1978) mapped fault.The mapped fault segment projects through the vertical beds observed in the outcrop towards photograph location C.Note apparent undeformed hillslope and Quaternary deposits over projected trace of fault. aS 2 oR ha es"te syCie att tiaeTe :he , .oy awe #ie as "swhedOREYLaasogeeCREEate ees 3 crate er a han ead ne a by SAO ESfoe.ER ee rae RSETn an ReReSEEsreionasndru65eAbasteaSEWCEToewsoe View looking northeast from location D along-strike with a Csejtey et al.(1978) mapped fault.A wide zone of deformation is expressed as vertical bedding exposed in outcrops.Note alignment of the break-in-slope on ridge crest,linear drainage,and the deformation zone. pate __10/18/13 @&-ENERGY AUTHORITY DRAFT cro ALASKA ENTE CGY AUTHORITY .SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE Bg =<_CASTLE MOUNTAIN EXTENSION AREA A-CME.1{=ALASKA PHOTOGRAPHS ' 79218900_Alaska_|189_LineamentReportOctober2013,modified10.18.13w.4,4446AASt1B5nMSEWS1004 View looking northwest from location E at faulted Jurassic units.The fault occupies the linear valley then climbs the hill-slope where it correlates with a clear break-in-slope on the ridge crest. F) sic bedrock and coincides with a break-in-slope on each ridge crest. Date DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREJ-NT ALA.CASTLE MOUNTAIN EXTENSION AREAEassond=ALASKA A-CME.2 10/18/13 /=>ENERGY AUTHORITY PHOTOGRAPHS Zz ALASKA ENERGY AUTHORITY -AEA11-022SUSITNA-WATANA HYDRO 46-1401-TM-012014 Clean,reliable energy for the next 100 years. Appendix B: Strip Maps and Photographic Documentation of Lineament Data for Lineaments Mapped by Reger et al.(1990) 2189_LineamentReportOctober2013,modified12.19.1379_218900_Alaska_|148°30'0"W 148°20'0"W 148°10'0"W 148°0'O"W ow Explanation Feature Appendix B ee adie]Number Figure Number Pa sae hy .4)Feature ID ;BOD LPF 5 GPS track 2 B-03 fm A ans 3 B-04 .i No previously mapped fault or 4 B-05 ar A lineament coincides with 5 B-05 fo MAGE lineament group 6 B-06 f 6 ,7 B-07a,B-07b 7 . Features (Reger et al.,1990)8 B-07a,B-07b :,iis ===:Photo lineament 9 B-08 i 10 B-09a,B-09b .tf al mamas Fault (dashed where inferred)11 B-10 3 FH Of:12 B-10 ne Se HF 13 B-i1a .14 B-i1a C7.15 B-11a,B-11b a 16 B-11a,B-11b fi,17 B-12a 18 B-12a,B-12b :.PIS 19 B-12a,B-12b q,5 20 B-12a,B-12b .5,21 B-13 Te -3 22 B-14a,B-14b '%y 23 B-14a,B-14b 24 B-15 D 25 B-15 A 26 B-16 if 27 B-16 fe ;I as on - |F Pe x fe hank nee- f ee*aree BA 'ay , =."TaD aw im od sae 7D”¢£3,ais_.4 STATE OF ALASKA SUSITNA-WAT, fuses ALASKA ENERGY AUTHORITY ms v UINEAMENTS FIGURE ree |[)Semeccaisd =ALASKA REGER ETAL.(1990)B-01 pate 12/19/13 @=--)ENERGY AUTHORITY 189LineamentReportOctober2013,modified10.18.1379_218900_Alaska_!View looking northeast from location A.Arrows show location of mapped trace of lineament. =, ASS a eS Oe plot SAGsSe TOR View looking southwest from location B.Arrows sho lineament.Note the semi-linear and lobate toe of talus deposit. w the location of 0 0.25 0.5 mi :|qt L |DRAFT i 0.25 0.5 km :ucao ALASKA ENTE RGY AUTHORITY ocaaaasTURE 4 PROJECT FIGURE Bod =ALASKA LINEAMENTS ANALYSIS B-02 bate 10/18/13 @=->ENERGY AUTHORITY REGER ET AL.(1990) 79218900Alaska_|189LineamentReportOctober2013,modified10.10.13aa enan ifeetrridgeNote absence of continuous lineament across projected trace. omaeeeSh, View looking northwest from location A.Arrows and brackets show projected trace of lineament. B)- :vommt -o asSeeeegy21. .."Penen-.%2 se so. 0 ,View looking southeast from location B.Arrows and brackets show projected trace of lineament.0.25 0.5 mi ;..ee . ae ee 1 Note lack of deformation or lineament trace in foreground within Quaternary deposits. PTTItTyiitit [ 0 0.25 05km DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREersALASKAENERGYAUTHORITYFEATURE2 Bog <<)|ae -|A\KA LINEAMENTS ANALYSIS B-03pate_10/18/13 /=ALASKITY REGER ETAL.(1990) 189LineamentReportOctober201,modified10.18.1379_218900_Alaska|Udeteman ¢ragkeia rayiviees ra Mea eae View looking northwest from location A.Arrows show the projected trace of lineament.Note absence of lineament or deformation in Quaternary deposits. >,a . one . a 4 "pres a %. .s .can S07 >prea '.' ..' ,ee 2 aca ta eS "ey a r ,Sy View looking southeast from location B.Arrows show the projected trace of lineament.Note absence of lineament or deformationin Quaternary deposits. 0 0.25 0.5 mi DRAFT poe a ee Taran oRTRC TOT FIGURE ae =ALASKA LINEAMENTS ANALYSIS B-04 pate 10/18/13 @=->ENERGY AUTHORITY REGER ETAL.(1990) 189LineamentReportOctober2013,modified10.18.1379218900Alaska|wero me ee eee es,ae oe OS SarPPITSO0VEN38-98 AMES 0 hes)Dire EE at=6 0008 View looking southeast from location A.Arrows show the projected traces of Features 4 and 5.Note Toie'4e 37814 AS46568 MSEWGS-aa™ absence of lineament or deformation in Quaternary deposits in foreground. of discernable lineament along mapped trace. eS Men comme waa aeTeegameREeneineeee Tee ene teearofief..yoo.a,nce > ae a a eraeaSeeyere .ET Meg DRAFT 0 0.25 0.5 mi \|;|cro STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE 1 TT eos ALASKA ENERGY AUTHORITY FEATURES 4 AND 5 0 0.25 0.5 km bad {=ALASKA LINEAMENTS ANALYSIS B-05 pate 10/18/13 @=-ENERGY AUTHORITY REGER ETAL.(1990) 79_218900_Alaska_|189LineamentReportOctober2013,modified10.18.13ye\*»iiaitYnSas--a NAAgd,Seow oO"%rtakarre ::ae .. +PROT OPH ANTE OE BEM Untnled BaF Ae eamttds OFCSF Aaa IGR WSL WACS ae re . Quaternary deposits. View looking northwest from location A. Arrows and brackets show the projected trace of mapped lineament.Note absence of lineament or deformation in Quaternary deposits. View looking northwest from location B. Arrows show the projected trace of lineament. View looking west from location C.Brackets indicate the projected trace of lineament. Note absence of lineament or deformation in Date DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE :ALASKA ENERGY AUTHORITY FEATURE 6Bed=ALASKA LINEAMENTS ANALYSIS B-06 10/18/13 />ENERGY AUTHORITY REGER ETAL.(1990) 2189LineamentReportOctober2013,modified10.18.1379218900Alaska.« .me neg,.wFIT3I0"Bp Aine Pee PORtESS 6 OF PUC AA View looking northeast at lineaments 7 and 8 from photograph location A. linear series of unrelated features. DRAFT STATE OF ALASKA SUSITNA-WATANA HYOROELECTRIC PROJECT FIGUREeesALASKAENERGYAUTHORITYFEATURES7AND8zd=ALASKA LINEAMENTS ANALYSIS B-07a pate 10/18/13 @&--ENERGY AUTHORITY REGER ETAL.(1990) 79218900Alaska2189LineamentReportOctober2013,modified10.18.13C) View looking southwest at lineaments 7 and 8 from photograph location C.wRee SY!Sk tee ree ees 3,¢.'<r Sh eas "2 .eae seo aw ,Paka ree tee .4 'mn 7/1;PE 5:07:28 PM (8.0 hrs)Dir=NE Lat=63.05043 Lon=-148.28834 At=3812ft MSL ies 1984 » View looking northeast at lineament 7 from photograph location D. REGER ETAL.(1990) DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREAhrobatsnteALASKAENERGYAUTHORITYFEATURES7AND8Pod=ALASKA LINEAMENTS ANALYSIS B-07b date 10/18/13_@@-ENERGY AUTHORITY portOctober2013,modified10.18.132189_LineamentRePe,"a career alAeina eeSeashnADMcocod6eNIWVYCe *Fs oeOFaNyePAPetere-8 STe View looking north from location A.Arrows show projected trace of Feature 9 lineament.Note lineament is overprinted with Quaternary alluvial fan deposit.79_218900_AtaskaDRAFT 0.5 1 mi -were ALASKA ENE SGY AUTHORITY seeATURE 9 PROJECT FIGURE ee {=ALASKA LINEAMENTS ANALYSIS B-08 date _10/18/13 @@--ENERGY AUTHORITY REGER ETAL.(1990) 2189LineamentReportOctober2013,modified10.18.1379218900AlaskaLAneAhaha{IView looking north from location A.Arrows and brackets show the projected trace of lineament. DRAFT 0 STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREar7.|ees ALASKA ENERGY AUTHORITY FEATURE 10 0 05 1km ae f=ALASKA LINEAMENTS ANALYSIS B-09a pate _10/18/13 @@-ENERGY AUTHORITY REGER ETAL.(1990): 79_218900_Alaska_2189_LineamentReportOctober2013,modified10.18.13»caves¢teea aa: ve, "Wa niNog.¥.yeaNz,:2k SWF otNT5Lames07664Lon=148 36397 ANCA 7EGR MISE WOS.b4 eeeeee View looking south from photograph location B.Arrows show the projected trace of lineament.In Qd3 (till)the lineament is coincident with linear drainage in till deposit.Note absence of lineament in Qa deposit. * C)or -Maar TTSase stamens CE LE BLOTS SI0FS FDO.x p View looking south from photograph location C.Arrows show the projected trace of lineament. Note lineament is coincident with a linear drainage in this view. See aiwe.,et *T+.Tt -tal Myetaeeaeeeeeeeerrr?By t .|dt FG Pa EAS SONG KISDEOAIOR WOSIRE ae View looking south from location C.Brackets show the projected trace of lineament. DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREeesALASKAENERGYAUTHORITYFEATURE10Ed/=ALASKA LINEAMENTS ANALYSIS B-09b pate __10/18/13 @=-->ENERGY AUTHORITY REGER ET AL.(1990) 79218900_Alaska_2189LineamentReportOctober2013,modified10.18.13(HEALYA-4)%Lineament not observed in Qua |eposit +ternary ta us depe as 7, Soir |ES.8,""erteetohesogereteteSegeroeoyengOsees View looking west from location A.Brackets show projected trace of Feature 12 lineament.Note the trace of the lineament is a collection of unrelated features rather than a through-going feature. DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREr[oes ALASKA ENERGY AUTHORITY FEATURES 11 AND 12ee{=ALASKA LINEAMENTS ANALYSIS B-10 pate 10/18/13 @=-ENERGY AUTHORITY REGER ETAL.(1990) 189_LineamentReportOctober2013.modified10.18.13ene eye oe 7 <*enBSPOSSPERIZOeh!2 gt: View looking north-northwest from location A.The bracket indicates the projected path of Feature 13 fault.Arrows show the projected trace of Feature 14 lineament.Note absence of evidence of fault under bracket in Quaternary deposits. f Projected pain5i»z ry an ae wee -ae e ee cem.,IRS ae perey Feature 15 fault.Note absence of evidence of fault under bracket in Quaternary deposits.79218900_Alaska_|DRAFT cra ALASKA ENIE RGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE Ered FEATURES 13,14,15 AND 16Ed=ALASKA LINEAMENTS ANALYSIS B-11a pate 10/18/13 @=--_)ENERGY AUTHORITY REGER ETAL.(1990) 189LineamentReportOctober2013,modified10.18.1379218900_Alaska_|15 and 16 faults.Note absence of linear expression in valley floor within Quaternary deposits. DRAFT ALASKRENE RGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE FEATURE 13,14,15,AND 16{=ALASKA LINEAMENTS ANALYSIS B-11b vate _10/18/13__@=--ENERGY AUTHORITY REGER ETAL.(1990) 2189LineamentReportOctober2013,modified10.18.1379218900Alaska_AT a ee- asLs aNeee.aepproximaternortheasteragaaions=Pees terminus of lineament ”:oN .ae diadatIeo#radiFUSEEoTphets - Moe: 5 ve fr . °Ae -w "Looe . Tee OS .£oy! po pom es :é 7S.:-- a '5 .a caren .:x ros .F ;os - .fo,peepee eget agape:(gw vay ee eeieORDROPEoFOSeLOPE£EBS4OF70 Ree 48.4007 AR View looking southeast from photograph location B.Arrows and brackets indicated the projected trace of lineaments 18,19,and 20. DRAFT 0 0.5 1 mi cro ALASKA ENE RGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE|[1 4 ]My eee FEATURES 17,18,19,AND 20:oe ge Coad =ALASKA LINEAMENTS ANALYSIS B-12a cate 10/18/13_@&-ENERGY AUTHORITY REGER ETAL.(1990) 79_218900Alaska..-._ .'2189_LineamentReponOctober2013,modified10.18.13a a:we SQ tet2kgeB a Shea othe!,View looking northwest from photograph location E.Arrows show the mapped trace of Feature 20 lineament.Note mapped trace of Feature 20 is coincident with linear drainage. View looking northwest from photograph location D.Arrows show the mapped trace of Features 18 LN EES NE wewae:We atc xe,seinpde Sestin lated,Wot ian, and 19.Note absence of lineaments or apparent deformation in Quaternary deposits between brackets in lower middle portion of photograph. DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREALASKAENERGYAUTHORITYFEATURES17.18.19.20=ALASKA LINEAMENTS ANALYSIS B-12b vate _10/18/13 @=--ENERGY AUTHORITY REGER ETAL.(1990) 79218900Alaska_|189_LineamentReportOctober2013.modified10.18.13+SS A ee atsRaeBa”4|yes,+ ae teRoa the projected path of Feature 21 lineament. View looking northwest from photograph location A.Arrows indicate of Feature 21 lineament. DRAFT Gea |ALASKAENERGY AUTHORITY cana eraial FIGURE [=)=ALASKA LINEAMENTS ANALYSIS B-13 pate _10/18/13_@&=-ENERGY AUTHORITY REGER ETAL.(1990) .wu .-'2489_LineamentReportOctober2013,modified10.18.131 mi 79_218900_AlaskaB) e .:: .7 okaPgsye_wae ys naeBeseMEME4THMSEWGS-8i Pa Ags oo. te Nee ee RTI ae OEame:fk SVE ae Aj View looking west from photograph location A.Brackets show the projected trace of Feature 22. Note the absence of a continuous lineament along the projected trace and exposed till on low relief ridge crest between drainages. View looking east from photograph location B.Arrows and brackets indicate the projected path of Feature 22 lineament.Note change in apparent vertical displacement. DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE*aM ALASKA ENERGY AUTHORITY FEATURES 22 AND 23{=ALASKA LINEAMENTS ANALYSIS B-14a pate _10/18/13 @&--ENERGY AUTHORITY REGER ETAL.(1990) View looking west from photograph location C.Arrows show the projected trace of the Feature 22 lineament.Note linear expression is coincident with solufluction lobes and not continuous. D) on.easPearson -nsscarp View looking west from photograph location C.Arrows show the projected trace of the Feature 22 lineament.Note topographic scarp in Photograph D is not proportional to minor scarps associated with solufluction in Photograph C.{2189_LineamentReportOctober2013,modified10.18.1379218900AlaskaDRAFT fuses ALASKA ENERGY AUTHORITY "FEATURES 22"AND 23.FIGURE Ed {=Al A SKA LINEAMENTS ANALYSIS B-14b pate 10/18/13 =ENERGY AUTHORITY REGER ETAL.(1990) 79_218900_Alaska_|189_LineamentReportOctober2013,modified10.18.13Se ee ae a >Pea aaePeateOeToru at rom vie ea Oi ns -aeDsaaoa1GBS 24 lineament. View looking west from photograph location C.Arrows indicate the projected path of the Feature DRAFT ALASKA ENERGY AUTHORITY SUSITNA-WATANA HYDROELECTRIC PROJECT FIGURE FEATURES 24 AND 25/=ALASKA LINEAMENTS ANALYSIS B-15 pate __10/18/13 @&-ENERGY AUTHORITY REGER ETAL.(1990) 79_218900_Alask1t/2189_LineamentReportOctober2013,modified10.18.13..a heey puyie eo Sey5SEEMSBEEPEIES Arrows show the projected trace of Features 26 and View looking east from photogra Sif CoG)eaefetSoodCo 'aS oe,.a a oant Leavu:Les x £wore thai nas SasiphlocationB.Arrows and brackets indicate the projected path of Feature 26 and 27 lineaments.Note the absence of a continuous and clear lineament along 0 05 1mi projected traces. |:Ht L |D RAFT 0 0-5 tkm peers ALASKA ENERGY AUTHORITY "FEATURES 26"AND 27.FIGURE ae =>ALASKA LINEAMENTS ANALYSIS B-16 vate __10/18/13_@&-ENERGY AUTHORITY REGER ETAL.(1990) 79218900Alaska_Railbeit/2189LineamentReportOctober2013,modified10.18.13at:Bs View looking west-northwest from photograph location A.Arrows show mapped trace of Feature 28. Note lineament corresponds to subtle linear trough and linear vegetation trend. 0.5 mi Note absence of linear expression in Quaternary deposits. DRAFT STATE OF ALASKA SUSITNA-WATANA HYDROELECTRIC PROJECT FIGUREfusesALASKAENERGYAUTHORITYFEATURE28oe/=ALASKA LINEAMENTS ANALYSIS B-17 pate 10/18/13 @->ENERGY AUTHORITY REGER ETAL.(1990)