HomeMy WebLinkAboutBradley Lake Subbottom Profiling 1986,,~
r
./
BRA
082
FINAL REPORT
Alaska Power Authority
LIBRARY COPY
SUBBOTTOM PROFILING INVESTIGATIONS
HYDROELECTRIC POWER PROJECT
Submitted to:
BRADLEY LAKE
HOMER, AK
Rand M Consultants, Inc.
5024 Cordova
PO Box 6087
Anchorage, AK 99502
Ocean Surveys, Inc.
100 East Water St.
Wilmington, CA 90744
30 April 1986
TABLE OF CONTENTS
1.0 INTRODUCTION •••••• 1
2.0 INSTRUMENTATION AND DATA ACQUISITION PROCEDURES 1
2.1 Horizontal and Vertical Control
2.2 Seismic Reflection Profiling
3.0 DATA REDUCTION AND ANALYSIS
3. 1
3 • 2
Trackl ine Reconstruction
Seismic Reflection Data •
4.0 DISCUSSION AND SUMMARY ••••
1
2
4
4
4
5
4.1 Dam Site Investigations • • • • • • • • 5
4.2 Katchemak Delta Investigations • • • . 6
APPENDIX
A-Survey Equipment Specifications
FINAL REPORT
SUBBOTTOM PROFILING INVESTIGATIONS
BRADLEY LAKE HYDROELECTRIC POWER PROJECT
BRADLEY LAKE
HOMER, AK
1.0 INTRODUCTION
Ocean Surveys, Inc. {OSI) conducted a continuous seismic
reflection profiling survey in support of engineering for the
Alaska Power Authority Bradley Lake hydroelectric power
project near Homer, AK. Field operations were conducted
during the period 27-29 August, 1985.
The objective of these investigations was
overburden thickness and to map the bedrock
to delineate
profile along
alignments at several sites including at the diversion tunnel
intake locations. Additional subbottom profiling data were
obtained in the Katchemak delta area as a portion of the
effort to assessment of the thickness and volume of sediment
accumulations at the upper end of Bradley Lake.
During the three-day field period, continuous seismic
reflection data were obtained along more than 10,000 feet of
survey trackline. Approximately 7,000 feet of trackline data
were obtained along a series of five traverses radiating out
from the Katchemak delta shoreline and 3,000 feet of
additional trackline data were obtained along a series of
five traverses in the vicinity of the dam site.
- 1 -
2.0 INSTRUMENTATION AND DATA ACQUISITION PROCEDURES
2.1 Horizontal and Vertical Control
Horizontal and vertical control for this project was provided
by R&M Consultants, Inc., Anchorage, Alaska. In order to
obtain data along the desired traverses, the survey vessel
was "conned" by a theodolite operator in radio communication
with the vessel along each preselected trackline. Location
of the vessel along each traverse was measured at nominal
10-second intervals and simultaneous "fix" marks were placed
on the graphic records to allow correlation with the
positioning data. All distances were measured employing a
Wild Model DI-1000 electronic distance meter (EDM).
Vertical control was provided by referencing all depth and
con t i n u o us ref 1 e c t i on prof i 1 e r me as u rem en t s to the me as u red
lake elevation during the field data acquisition period.
Lake elevation was measured by conventional levelling
techniques from a benchmark located at the northwestern end
of Bradley Lake.
2.2 Seismic Reflection Profiling
Continuous subbottom profiling records were obtained
employing an OS! 300-joule high resolution Boomer system.
The Boomer system is comprised of a compa~t power supply, a
medium energy seismic source, a multi-element hydrophone
array employed to receive the reflected signals and an EG&G
Model 255 engineering recorde~ which allows real-time,
graphical presentation of the seismic reflection data along
each survey line. A specification sheet for the OSI Boomer
and for the EG&G Model 255 engineering recorder is included
in Appendix A.
- 2 -
All normal incidence seismic reflection profiling systems
operate in an essentially identical fashion. A seismic
source (pinger, boomer, sparker, air gun, etc.) is used to
create an intense, shore duration (0.1 3.0 ms) acoustic
pulse (signal) in the water column. This signal propagates
downward to the lake or seafloor where it is partially
reflected at the water-sediment interface while the balace of
the signal continues into the subbottom. As the downward
propagating signal encounters successive interfaces between
materials of differing properties, successive similar partial
reflections occur.
The "interfaces" to which acoustic signals react are defined
primarily by the cross-product of the bulk density and the
compressional wave velocity of each material; a quantity
called the acoustic impedence. As a first approximation, the
percentage of an acoustic signal which is reflected from an
interface is directly proportional to the change in acoustic
impedence across the interface.
For each pulse, the sequence of reflected signals from a
series of interfaces is received on either a single
hydrophone or a multi-element hydrophone array. Received
signals are electronically filtered to remove noise and
harmonics, amplified, and sequentially displayed, trace by
trace on a graphic recorder to yield continuous display
analogous to a geologic cross-section.
however, is time.
The vertical axis,
As discussed above, the reflected signal consists of a
continuous sequence of reflected energy which has a series of
peaks nominally correlative in intensity with the magnitude
of the change in acoustic impedence of the materials on
either side of the interface. The timing of these "peaks" is
also essentially directly proportional to the depth of the
- 3 -
interface, i.e., a reflector at 2t (time) is at 2d (depth).
Admittedly, the above presentation is a simplification and a
number of second, third and nth order effects must be
addressed in a more rigorous treatment of the reflection
process.
Operationally, during data acquisition in support of this
program, the high resolution Boomer system was programmed to
repetatively generate a seismic signal at a 330 millisecond
(ms) interval as the survey vessel traversed each selected
trackline. The reflected signals were displayed on the Model
255 seismic recorder employing a 100 ms sweep rate resulting
in graphic records having a nominal vertical scale of
1" = 30' (29.41') based upon an estimated average
compressional wave sound speed of 5000 ft/sec.
3.0 DATA REDUCTION AND ANALYSIS
3.1 Trackline Reconstruction
Generation of the survey vessel trackline maps required in
support of the subbottom profiling analysis was done by
R&M Consultants. Separate trackline maps at a horizontal
scale of 1'' = 100' and 1" = 300' for the dam site area and
for the Kachemak delta area, respectively, were generated.
3.2 Seismic Reflection Data
The graphic records obtained along each survey trackline were
analyzed to produce a listing of the thickness of overburden,
depth of internal sediment interfaces and the depth to
possible/probable rock along each survey line. The thickness
of the unconsolidated layer(s) and/or the subbottom depth to
the reflector interpreted to represent the top of rock or
- 4 -
( . '
other very dense (hard) material was then plotted as a depth
below the lake bottom at each measurement point to yield the
continuous profiles presented in drawing nos. 85WS511-C47-50.
4.0 DISCUSSION AND SUMMARY
4.1 Dam Site Investigations
Examination of ~ecords obtained on traverses approaching the
diversion tunnel area indicates the bottom is floored with
parallel bedded lacustrine sediments to within approximately
400' of the shoreline. Between 400' and 200', the lake bed
consists of a convoluted mixture of lacustrine sediments and
apparent talus deposits with evident slump features. Water
depth in this zone ranges from 115' to 75 • bel ow 1 ake 1 evel
(BLL). The third zone, from the shoreline out to 200'
consists of a steep (25°-39°) slope covered with 10-25 feet
of overburden inferred to be gravelly sand and/or sandy
gravels.
Records from the survey traverses in the area of the proposed
cofferdam display a similar structure although the nearshore
slope angle is somewhat steeper (35°-40°). As in the
diversion tunnel area, the bedrock surface is overlain by
10-20 feet of unconsolidated material inferred to consist of
coarse sands and gravels.
The third area which was located immediately offshore of the
proposed intake channel location also has a steeply dipping,
thinly covered bedrock surface which descends from the
shoreline to a depth of approximately so· within 175' of the
shoreline. This surface, which has a slope o.f 25°, is
covered with 3' to 10' of unconsolidated material inferred to
consist of sandy gravels and coarser talus.
- 5 -
Cross-sections along the five seismic reflection profiling
traverses from the lower end of Bradley Lake are presented in
OSI drawing nos. 85WS511-C47 and C48.
4.2 Katchemak Delta Investigations
Examination of seismic records obtained fr-om the offshore
area contiguous to the Katchemak delta indicated that the
depth to bedrock is significantly gr-eater along the SSW
portion of the shoreline. Sediment accumulations are also
measurably greater in this location which is near the mouth
of the Katchemak River. Bedrock depths as great as 360'
bel ow 1 ake level and sediment thickness of up to 230'
(assumed sediment velocity of 5000'/second) were observed.
The bedrock p,...ofile, the sequence of deltaic and lacustrine
sediment and the morphology of the submarine delta slope are
presented in drawing 85WS511-C49.
Towards the central portion of the delta, bedrock depths are
shallower ,...anging between 200'-240' (BLL) with maximum values
of 250'-260' at a distance of 1800' off the present
shoreline. Sediment thickness also is decreased averaging
only 100'-150' with a maximum of 210' adjacent to the
shoreline where delta accumulations are greatest. Delta face
slope angles in each of the two areas average 20°-25°. A
cross-section drawing generated from data acquired along
seismic line no. 2A presents a graphical representation of
the submarine delta, the unconsolidated sediments and the
bedrock profile along a traverse oriented perpendicularly to
the shoreline in the central portion of the Katchemak delta
(drawing no. 85WS511-C49).
Continuing to the NNE along the shoreline, bedrock depths
progressively become shallower with values of 130'-180' being
characteristic for the zone out to 1400' from the present
- 6 -
shoreline. Sediment accumulation within this zone are
correspondingly reduced with thicknesses ranging from 35'-80'
except near the delta shoreline where accumulations of
100'-120' exist. Notably, the delta face slope angles also
exhibits a reduced gradient of only 10°-12°. In the zone
immediately beyond the toe of the prograding delta,
moderately common structures with associated prior sediment
slumping, general mass movement of unconsolidated deltaic
deposits and redepositions exist. Continuing offshore,
significant deposition of deltaic sediments can be observed
out to distance of 1500'-2000' from the present shoreline.
Graphical representation of the bedrock structure and
unconsolidated sediment accumulations for the area offshore
of the NNE section of the Katchemak delta is presented in
cross-section drawing no. 85WS511-C50.
- 7 -
""'.,
Ft E T
400 150
r
\
i
~~~---~+---~~~-----~--+--~ O(LE)
,_
w
w
"-
z
:t:
1--a.
'"
50
0 100
400
+
~ti
E 3'\5.62.&..9
3.50
+
300
+ +
'-iNTERMIX[) TALUS AND
LACUSTRIIIE SEDIMENTS
(SANDY SILT AND SILTY CLAY)
+ + + +
POSS ISLE BOULDER
ACCUMULATIONS
PROFILE 7A
DISTANCE IN fEET
250 200
{LE)0,----------+---~----~----------4----------+------
50-l +
>-I "" w
IL.
!;
;': 100--j + n. w
0
150 +
+ +
/
~------7+/'('
INTERMIXED TALUS ANO
SEDIMENTS
+
+
+ + +
_../" \~' +
/ li TALUS (GRAVEL
ANO COBBLES) •\
+ +
+ +
TALUS ACCUMULATIONS
(GRAVEL AND COBBLES)
+
+
+
+
1150
1--w w
"-
z
:I:
f-u. w
Cl
O(LE)
50
,_
w w
IL.
z
100 ;::
150
0..
"' 0
200~-------L-------L------~------~----~ PROFILE 88 _.__ ___ __L ____ _~_ ____ j_200
DISTANCE IN FfE1 "Z 103 3n 4
~[ ~~.3-,J09.6
-t-~----'--~-+-------
1--
w
~50
~
r ,_
a. w
Cl
100
I
150 J
+
GRAVEL
+ + i· +
,.
w
50 ~
100
z
r ,_
"-w
0
--l-----------~-----------L----------~L-----------J_ISO
f-w w
"-
z
r.:
0.
_!!_2:,10:5,,409.7
[ 343," 14.5
150
PROFILE 8A
DISTANCE IN FEET
100 50
N 2,103,,69.2
It 34l,lOO.!~
o
1-J-----___L----1!--·------+---------t-O(LE)
,_
w w
"-
z
:r ,_
~ 2
0. w 20 0
40 40
PROFILE 9
"
NOTES
I-DISTANCES ARE IN FEET MEASURED FROM INNER END
OF PROFILE
2. DEPTHS ARE IN FEET 8£LO~ LAKE LEVEL AND ARE BASED
UPON AN AVERAGE VELOCITY tSPEEO OF SOUNOl OF
5000'/SECONQ. LAKE ELEVATION AT THE TIME OF THE
SURVEY ~AS •1079.0 FEET.
3. COORDINATES ARE IN FEET AND ARE !N THE ALASKA
STATE PLANE COORDINATE SYSTEM.
4. SURVEY VESSEL TRACKLINE RECONSTRUCTION IS BASED
UPON NAVIGATION POSITIONING INFORMATION SUPPLIED BY
R & H CONSULTANTS. INC .. ANCHORAGE. ALASKA.
S. THE INFORMATION PRESENTED ON THIS CHART REPRESENTS
THE RESULT Of A SURVEY PERFORMED BY OCEAN SURVEYS.
INC. ON 27 -29 AUGUST 1985 AND CAN ONLr BE CONSIDERED
AS INDICATING THE CONDITIONS EXISTING AT THAT TINE.
OCEAN SUI=lVEVS, INC. ~ e:J OLD SAYBROOK. CONNECTICUT
PREPAREO P:OR R 6 M CONSULTANTS. INC.
SEISMIC REFLECT19N PROFILE
DAM SITE AREA
PtlOJ MGR'
O.L.BELL
QR.VTEO BY
J~A.OOYLE
BRADLEY LAKE, ALASKA
SUAV€Y QATE SCALE
27 -29·AUG-198 5 AS SHOWN
DATE DWG NO
8 · APRIL-1986 85WS511-C4 7
' /
t
)
)
;,
N 2,102,552.1
E 343,055.31
500 450
I
400
I
350
I
300
I
DISTANCE IN FEET
I 100 50
I ---------i
( (LE)
1-w
w
LL
Z,
J::
1-a..
w
0
100-
NOTES
1. DISTANCES ARE IN FEET MEASURED FROM INNER END
OF PROFILE
+
2. DEPTHS ARE IN FEET BELOW LAKE LEVEL AND ARE BASED
UPON AN AVERAGE VELOCITY (SPEED OF SOUND) OF
5000'/SECONO. LAKE ELEVATION AT THE TIME OF THE
SURVEY WAS +1079.0 FEET.
3. COORDINATES ARE IN FEET AND ARE IN THE ALASKA
STATE PLANE COORDINATE SYSTEM.
4. SURVEY VESSEL TRACKLINE RECONSTRUCTION IS BASED
UPON NAVIGATION POSITIONING INFORMATION SUPPLIED BY
R & M CONSULTANTS. INC., ANCHORAGE. ALASKA.
5. THE INFORMATION PRESENTED ON THIS CHART REPRESENTS
THE RESULT OF A SURVEY PERFORMED BY OCEAN SURVEYS.
INC. ON 27-29 AUGUST 1985 AND CAN ONLY BE CONSIDERED
AS INDICATING THE CONDlTIONS EXISTING AT THAT TIME.
+ + + + +
-
SEDIMENTS
I 1
PROFILE lOB
1-
w
+~ 150
w
u.
I z -
r
1-
"\ ·TALUS (COBBLES l,oo ~ AND GRAVEL)
+
----_J_I50
OCEAN SURVEYS, INC. @ OLD SAYBROOK, CONNECTICUT
PREPARED FOR
R 8 M CONSULTANTS, INC.
SEISMIC REFLECTION PROFILE
DAM SITE AREA
BRADLEY LAKE, ALASKA
PROJ. MGR SURVEY DATE
I D.L.BELL 27 1985
DRAFTED BY DATE
J.A.D:JYLE 8·APRIL·I986
! SCALE
AS SHOWN
I OWG NG I 85WS511-C48
,.
w
I
J
l
:800
~-----·· -----
100-+ t
J8ABU. REDEPOSITED DELTA SLUMP MATERIAL
{PROBABLE St.ND AND SlLTY SAND)
+ + + +
\.e.~ONDED
\EDIME:N1
·t
----1-'""·---.-··· +
....:.----··-··
+
BEDROCK
FACE
+ +
400......t__ r--1 i __ ---··----1 ---_ __]_ __ ···--__ ,_L ____ , ____ L ___ _
>-w
i:'
" ;:
0. w
0
+
zoo
PROFILE I B
DISTANCE IN fEET
1000
I
·---+-----+
+
+ / + +
400 zoo
I I
----'-O(LEI
DELTAIC
.... w
"' ... 100
!:
" ....
0. w
0
_,--,--,--+ . / + ' ...,.__ _ ___}-zo 0
300-L_____·---~~----~
PROFILE 28 ~oo
·'I
~JOTE S
STANCES ARE IN FEET MEASURED FROM INNER END
OF PROFILE
2. DEPTHS ARE IN FEET BELO~ LAKE LEVEL AND ARE BASED
UPON AN AVERAGE VELOCITY (SPEED OF SOUNDI OF
5000'/SECONO. LAKE ELEVATION AI THE TIME OF THE
SURVEY WAS •10/9.0 FE£!.
3. COORDINATES ARE IN FEET AND ARE IN THE ALASKA
STATE PLANE COORDINATE SYSTEM.
4. SURVEY VESSEL TRACKLINE RECONSTRUCTION IS BASED
UPON NAVIGATION POSITIONING INFORMATION SUPPLIED BT
R ~ M CONSUlTANTS. INC. ANCHORAGE. ALASKA.
5. THE INFORMATION PRESENTED ON THIS CHART REPRESENTS
THE RESULT OF A SURYET PERFORMED BY OCEAN SURVEYS.
INC. ON 21 -29 AUGUST 1985 AND CAN ONLY BE CONSIDERED
AS INDICATING THE CONDITIONS EXISTING AI THAI TIM£.
OCEAN SURVEYSJ INC. f!J OSI
OLD SAYBROOK. CONNECTICUT
PRI;PAREQ FOR R ElM CONSULTANTS. INC
SEISMIC REFLECTION PROFILE
KACHEMAK DELTA AREA
~~~~OJ MCR
D.L .SELL
ORAFT£0 BY
J.A.OOYL E
BRADLEY LAKE, ALASKA
SURVEY OAf€
27-29·AUG·I985
CAT£
S·APRIL 19SG
SCALE
AS SHOWN
OWG "f0
8~WS511-C49
I
___1:!_1_..._!.QQ...0~3 ~
( 3~7,!~ DISTANCE IN FEET ~ 2,098,392 .:. 6( 3~9,058 3
>--
w
w
"-
0:
X
>--
Q_
w
0
z61oo I z~ao z2oo :r--I ____ __j_
1600 l.d 00 12po 1000
I j_____ ___l___
400 200
1 J
800 600
_L__ _____ _L_ 18 )0 2 0 00 ____________j I_
(L EIO
100
200
300
400
I
I
----+----!
+ ~ I ~~~ ~ """ ~~~--=-"''
-+----
+ ~ ~'" "" "" """ e; "''; "'" ; --
"" """ """"',"'"' ~, + -"""" "" ~I ~~~~c;~~~ ---'C~~~~,~=~=~~' # ~~-0::c;:3-?~~# ----~~~-~c~c~+ ~ ~~~--~--~---'~ ~: ~--=--=~+~~ ~ ~=<->~ ~--~~~-' ' ' ' . -----------_.---;.. -----+ <---~c-~ -----~-~-:-----~ ~/_, / ---' , +
~~~-+ + -;;:-~ -----____ ,_,, ~~~-~ -/ "'""" + "''""'-,--~ + -----/_/ + ' """'" ./ I ' ~~ + . •
+ + -+ l200
+ + + + + + + + +
w
"-
~
r
>--
Q_
w
0
I ____!_ _ __[__ ___ __ I __
400
PROFILE 5A
NOTES
I. OIS:ANCES ARE IN FEET MEASURED FROM INNER
OF PROfiLE
ENC
2. DEPTHS ARE IN FEET BELO~ LAKE LEVEL AND ARE BASED
UPON AN AVERAGE VELOCITY ISPEEO OF SOUND! OF
5000"/SECONO. LAKE ELEVATION AT THE TIME OF THE
SURVEY ~AS •1079.0 FEET.
3. COORDINATES
STATE PLANE
ARE IN FEET AND ARE IN THE ALASKA
COORDINATE SYSTEM.
4.
5.
SURVEY VESSEL TRACKLINE RECONSTRUCTION IS BASED
UPON NAVIGATION POSITIONING INFORMATION SUPPLIED BY
R & M CONSULTANTS. INC .. ANCHORAGE. ALASKA.
THE INFORMATION PRESENTED ON THIS CHART REPRESENTS
THE RESULT OF A SURVEY PERFORMED BY OCEAN SURVEYS.
INC. ON 27 -29 AUGUST 1985 AND CAN ONLY BE CONSIDERED
AS INDICATING THE CONDITIONS EXISTING AT THAT TIME.
' 051
SUI=IVEVS INC. G::~ilili?~
OLD SAYBROOK, CONNECTICUT
RaM CONSULTANTS, INC.
SEISMIC REFLECTION PROFILE
KACHEMAK DELTA AREA
BRADLEY LAKE, ALASKA
~GR I SuAVE""--
D.L. 8 ~I I
SCALE
AS SHOWN
DWG NO
85WS511-C50
APPENDIX A
SURVEY EQUIPMENT SPECIFICATIONS
I
I
~I •
I
~I
I
--FA+HOME+E-R®Dr 5
DEPTH SOUNDERS
DESCRIPTION
The Raytheon Model DE-7198 Fathometer® ·
Depth Sounder has been designed for use
as a portable survey instrument to provide
accurate, detailed permanent recordings of
underwater topography. Its low power con-
sumption, portability, ease of set-up and
rugged construction make it ideal for use on
small boats.
The complete system consists of a trans-
ducer and recorder. The transducer mount
and rigging are stowed in the recorder case
when not in use. In operation, the trans·
ducer is mounted on the sectional tube
supplied and the tube is then secured to the
side of the boat. When the battery cable has
been connected, the equipment is ready to
operate.
The DE-7198 is advance design equipment
utilizing completely solid state circuitry,
magnetic keying and electronically controlled
stylus speed. The equipment is housed in a
splash-proof aluminum cabinet required for
operation in unprotected locations.
High resolution chart recordings result from a combina-
tion of very narr:ow transducer beamwidth, high sound-
ing rate, fast stylus speed and fast chart paper speed.
The DE-719B's flexibility is increased by a front panel
tide and draft adjustment, speed of sound control and
--
--·. ~ ·•t
. . . ---· --.. ' --:--: -4~.~;::. :
DE-7198 Interior Controls .
'·'
Model DE-1198 Fathometer® Depth Sounder
four paper speeds. Calibration markers. that indicate
phase in use, tide/draft and sound speed compensa·
tion are permanently recorded on the chart for future
reference. Equipment can be adjusted to e ither foot
or metric scale recording . with use of chart paper of
appropriate scale.
FEATURES
• Portable, compact, lightweight
• Calibration marker
• Tide and draft adjustment
• Four selectable chart speeds
• Hinged chart window for running
chart notations
• Fix Marker switch
• Phase Marker
• Remote fix-mark receptacle
• Chart paper speed adjustable by
external control
• May be used with up to 1500 feet of
transducer cable
• Standby switch
• Foot or metric scale calibration
• Available for 12V DC, 115/2.30V AC
'.operation, 50-60Hz
• Plug-in printed circuits
• Magnetic keying
• Belt driven stylus
• New stylus design -long life,
quick replacement
• Completely solid state
RAYTHEON MARINE COMPANY • 6761SLAND POND ROAD • MANCHESTER, N.H. 03103
FATHOMETER® DEPTH SOUNDER
PRODUCT OAT A
-~
DE-7198 SPECIFICATIONS a ~ce:ra :-·f-1r
Depth Range •••.••••••.•.••••••••.••••••••••••• 0.5 5 ,50.105,100-155, 150·205 Fee~i"' r
0.1 6.5, 15-31.5 ,30-41 .5,45-61 .5 Meters (Note 1)
Sounding Rate ................ ~ ~ • • • • • • • • • • • • • • • • • 534 Soundings per minute
Voltage Input •••••••.•••..• •.... • • • • • • • • • • • • • •. • 12 Volts DC (Note 2)
Cu rrent Input ••••.••.••••••••••••••••••.• , • • • • • 2 .5 Amperes
Accuracy • • • • • • • • • • • • • • . • • • . • • • • . • • • • • • • . • • • • • ±0.5%±1" of indica t ed depth
Operating Frequency . . . • • • . . • • • • • • • • . • . • . • • • • • • • • 208 KHz
Tra nsducer • • • • • • • • • • . • . • • • • . • • • • • • • • • • • . • • • • • • Barium titanate -model 200T5HAD
i C.;~·· · ··~ ....... Optional model 7245A
-1 ..
I
I
Trarlsduce'r 'Beimwidth . • • • • . . • . . • • . . . . . • . . . . . . • . • • 8° at the ha lf power points
t Chart Paper Speed ••••••.••.••••...••.•.•.•.•• ~ :. · 1, 2,*3, 4 inches per minut e
-. ·.·~ i"'t.ft ~ ... -'·.• (' \ ''· _·, 4'~: •·. •·,, [' 7'',•J_>L-r_l..,~'.<~~ -I
' .. ~, , "":'l'lrt ~"~ktJ· ..... · .·. . . .. •. -~~-~ ...... , ... _,,. ... ~ .. ~ •..... ·'. _ ·r' .... ..:. •ncn~-ll~i:OU':lm~It
\... ...L.l_ __ d A· }p • :. t 1 ~ . .;t ··II\ ~ : 1 H iid. JaJ,.. I ..... _-..'~... dl) 18" ...-· ~.. neciQl'· et u n•ons · ~-.... -~ . ': ..• ·. _.. .• • •.•• :':"'. ~; ·: • • •.••••. "' e.11 .. to""' Uuhf!!l .. an e -
· --· · Width 1-5·3/8"
:·~' ·: -~· }ltiJ-.;.;..W ·:.tk':~ ~1!;, 11
;;". • .
1/ . •.· . • •· ·~,: ~:0.·~ .. ~-·-;.¥~1. -~~:_'L.Luc·.·.__·_~-~-~-jd. ~-~gg~ i~1ti lbs_ •
·I
. r \ • 'ij . ~· 81'1''t ·,• ~ .~ • M • .. •., •,,. • .\,,,, •, •,,, •,,."',;,,,. • W!fiii\).~t ii<JMI v.· ··~
,. . ' . ,, ReeorciJr onty '-3Sibs. '· : .· . ' .
··;h, Tide and Draft Adfustrnent: A minus 5 t o plus .4d f<;>ot adjustment :~~i:;~·--~· ill-bY means of a control
.. ·~nob.~ Tt,is; varies., t~ pc)sit:lon on the chart o( ~~smitter sign~ I. but"'~li~ws~a sharp f.ixed reference r · Y .~. ,. · . -:. . ~ .. ~· . ~ · · -·. 'f·il'···
., .; ~ . ~~~~~~~~~~. re~aJ~ :~'t the ·.chart ~ero calibration }jilt ,. .
' ;~ ·· ; • ·Soti1'16 ._Spet!d (;O.,Pensation;t: __ A control is provid~qfth compen$ilte for wat~ temperatur.e and salinity con-
~· , "t · ~ ~ent. ;Ad»-.4't~ -~()f:the control periTiits the rec~f.!tlg accuracy' to be · calibrated to a "check-bar" reading.
. ,, ;,_,, ~ c~p~[a~1o_~;~~!'!'~ihat in.dl~tes the degree of co~nsa]ion. is per~n~ritly~(eeorded on the char~.
'N)t''llilarj_(i2 .:A ~t~qftt :panel switch is pro~ided to insCf'i.be a solid, vertital ·'nJfe;eJ'\ce line on the ehart. This line is
used ' as ~bf.~~¥ ::~~rk:er or ti(tle reference. A rec~tacl.e is ifl.¢.1~ed t~ permit connection' of an external
fix-mark switch. available as an accessory . ' '·. ' . . ' : ~' ~ -~.
·Standby ·~l~: this switch eliminates warm-up d4~·during surv'y o.,J;atiQ~·s.
·-~........... .--..-·
:----__ ,/
~
200T5HAD Transducer 7245A Narrow-Beam Transducer
(Note 1) All of the above basic depth ranges may be multiplied by two by means of the range doubling switch.
(Note 21 The system will operate within specifications between 11 .5 and 14.8V DC input. On order. the equipment can be
furnished with a built-in power converter. The converter will permit operation on 115/230V AC, 50 to 60Hz, in
addition to 12V DC.
RAYTHEON MARINE COMPANY
I
I
I
I
I
I
I
I
I
I
I
676 ISLAND POND ROAD • MANCHESTER. N.H. 03103 • 603·668·1600 I
Raytheon Factory Sales & Service Facilities. Seattie, Wilmington (Los Angeles!; Houston ; New Orleans: Tampa ; Norlolk ; Brooklyn : Manchester • IN EUROPE
Raytheon Service Co .. 6·8, Siliangade. 2300 Copenhagen S. Denmark , Telephone AM 3311 • OT~ER WORLD AREAS : Raytheon Company, lnternattonal
Sales & Service. Lexington. Massachusetts, U.S .A., Telephone 617·862·6600.
-,_c:;;_ca.A PRINTED IN U.S.A.
I
... !!/.,JC~ ~-r<•.:JJ ®,3T3MO•;TA.~
ATAO T~:'-l;:.JOfl'~
n Et;;s..G 211!"'' . " 3q~ ~~-"'::: ao~-oat ,ezr .(l(j~ c.t '-;J;. ~<::-·~ . , •.
t~-,.9~.-, a .. ~ v .. ~~ ~.c . ~\Jt ~a,·:.-~; t a .. ,:t ~ l
s11mit't ·~-.v ··., .... ·' : ..... ~ f'•f.<':
I'· ,-t(lti'. ; \::", t."IO ' ~I
~.~-:· 1'ni·· c ,..
rf1'~JS~; .-,,.tr"~,t.J~ tc· · ~::.. ,;.",.*'~· -
. r '
r,
~· . ' tJ,
• ~ ... r\ ~:J.J .
·"'~!P' .~·~ P"'i'Jt···!..· ..
0 0 • • ··sot .... of 1l
~··)i. ~.rn9o.~r 255
~,,: ,' ·e,gl[leer ing . survey . ·reCOrde r
\'
n ~~EGC..G ENVIRONMENTAL EQUIPMENT DIVISION
''
1,:
•. 1 ...
151 Bear Hill Road
Waltham, Mass. 02154
(617) 890-3710
TWX: (710) 324-7648 TELEX: 92-3429
CABLE: EGGINTER
Specifications
Recorder
Record Width
Record Length
Record Type··--
Record Density
Paper Take-up
Sweep ~peeds
Scale Lines
Print Programmer
Record Annotation
Hydrophone Input
Impede nee
Signal Threshold
Frequency
Variable Fil t~r
Gain
Time Variaple Gain
Phase Discriminator
Auxiliary OutJ.~.t
Trigger Pulse
Trigger Rat.e
Event Marker
22cm {?:5 inches) ~f't>-:i _ -~
·· 3'1 m/roiT {JOO feet/roll) t-? :· ,·<-; .
-Dry Paper,' NDK or Alumi~h.ed':'Mvlar~~ ·-
Variable, 20 to 80 lines/em (so' t~ 2oo-lines/inch)
with push bu'tton rapid advance···~,: -
Cons~artt '.tensi-on -reversiJ?fu' .·' _ ~-
Selectable; -~0, 100, 200, ~00 milli~onds
Variable; 601-b ,_soo-~illis~to~tls ' ·_. . _,
Variable intensity; 10 milliseconds/division, alter·
nating solid and d'ashed lines
Adjustable, in !4 sweep steps and 3 sweep steps to
give a delay of printing from 0 t~ 3Q sweeps
Automatic annotation of Automatic G'ate Position
every 4 minutes
5000 ohms
5 millivolts to 5 ':volts adjustable
50 Hz to 20 kHz with high pass filter
Low cut-off 50 Hz to 2 kHz
0 to 60db (-20 to Odb ~ontinuous and 20,
40, 60db selectable steps)
Initial Gain; -60db to .Odb
Slbpe; Maximum 60db in 50 milliseconds selectable
bypass in or out '
Plus, minus and ± phase
+10 volts, 100 microseconds long, into 10K ohms
Every 3,6,9,12,15,18,21,24,27 or 30 sweeps
Local or remote push bottom
Tape Recording Capability
Output
Input
Synchronized
Power Requirements
Voltage
Frequency
Physical Characteristics
Dimension
Weight
Protective Case
Processed Signal; 5 volts
Sweep Control; 500Hz continuous plus
1 pulse/trigger
Signal Level; 5 microvolts to 5 volts
Automatic phasing, sweep speed offset until external
and internal trigger pulses are synchronized
105 to 130, or 210 to 260 VAC
50 or 60Hz ± 5%
40cm. X 5Qcm X 3Qcm ( 16" X 20" X 11.5")
20Kg (45 pounds)
Fiberglass Instrument Case
11/74 2M CH
Printed in U.S.A.
-
J
J
J
J
J
J
J
J
J
J
J ,
cl
-.
OCEAN SURVEYS, INC.
,.,. ·,. TL''=llf . ' ·•(' ., -~
. ·\..!f1 SHEFFrEr.D STREET"'·. . . .• -, ...
OLD SA YBROOI(, CONNECTICUT 06475
····-·r-•• _ .... ~----~· --·~-"'* -~
'·
·'
SEISMIC PROFILING BOOMER
The 100-1000 joule Boomer is a moderate
:penetration, high resolution Sound Source
transducer utilized for widely varied
.. seismic profiling applications. The
electromechanical sound transducer is
mounted on a catamaran and is designed to
operate with the capacitance Energy
Sources, Seismic Recorder and matching
Hydrophone streamer.
Vl.l ·.•<!•.;· · t
The unique electromechanical assembly consists of an insulated metal plate and rubber
diaphragm adjacent to a-flat1-wound electrical coil. A short duration, high power
electrical plil se --discharges :;from the separate Energy Sources into the coil and the
resultant magnetfc ·fiE!':ld explosively repels 'the metal plate. The plate motion in the
water generates a single broad band acoustic pressure pulse.
! ~ ~ ' • l -'
The elimination:-; of .th'e , st,ro·ng .. ~¢:~.vitatiori · o;P· ringfhg pulse associated with Sparkers -
combined with 'the broad band fre·quency spect.rum, (1) permits the bottom echo to appear
as a fine line;.;.(2) provides _.a clear ,,ic r,oss-sectional record of the sub-bottom
interfaces; and {3) penetrates most types.. of marine materials, including hard-packed
sand, up to 75 meters. The Boomer operat~~~ · .
equally well in ·salt 'wa'ter. or ·tr~~ water. ii .. i; ,il iij,.iie!iti~iiliji~jj8i~ilitiiJi'!itijj.
' .. • ,. . . t j
Applications for the Boomer · include ~5::1:::::=$~:1::!~:=:=~~~=:::*==~ reconnaissance geological survey, mi neraln J:
exploration. foundation -studies for
offshore platforms, harbor d~ve'lop.nent and
cable/pipeline crossing surveys ~~,·.
SPECIFICATIONS
Pulse Character
Energy Level: @ 300 watt-seconds
Duration:
Source Level :
0.2 milliseconds
107 db ref. 1 microbar
at 1 meter
Spectrum: 400 Hz to 8 kHz
Repetition Rate: 2 pulses/second
' ' .
Dimensions: 84 em {w) to 59 em {H) x
158 em {L) {33" X 23" X
62")
Weight:
Cable Length:
Towing Speed:
90 kg {200 lbs)
25 meters {80 ft)
2 to 8 knots
....
I' ,:; :
·; ·~ ..
. .. ;
Chart Paper:
Paper Width:
Paper Feed Rates:
Sweep Scales:
Sweep Speed Accuracy:
Sweep Speed Stability:
Scale Lines:
Scale Line Time Breaks:
Speed of Sound Calibration:
Program Length:
Recorder Input Impedance:
Recorder Input Sensitivity:
Recorder Frequency Response:
Keying Pulse Lengths:
Internal Self-Check:
Transmit Power Output:
Output Impedance:
Transceiver Operating Frequency:
Transmit Overload Protection:
Receiver Sensitivity:
Receiver Band Width:
Input Power:
Power:
Recorder Size:
Transceiver Size:
Weight:
RECORDER SPECIFICATIONS
Recorders are compatible with catechol, sepia and silver
paper. (Special blade required for silver paper.)
Model 4000 -19"
.010 11
, .005", .003" or .002 11 per sweep.
Model 4000 -20,40,200,400,1000 and 2000 Fathoms; or
optional metric version -75,150,300,750,1500 and 3000
Meters -or optiona1 time version -1/16, 1/8, 1/4, 1/2, 1
and 2 seconds.
50 ppm
10 ppm
20 scale line divisions
Precision 30 second and 5 minute breaks; 30 second breaks
18 seconds in duration; 5 minute breaks 30 seconds in
duration. Accurate to within 1/10 second. Resetable to
within one second.
800 fathoms/second
Variable from 2 to 8 sweeps
500 ohms
150 mV for full dark marking
Flat from DC to 50 kHz
Variable 0.1%, 1.2%, 0.5%, or 1% or sweep time
The crystal oscillator output may be fed to the printing
electrodes to form a bar pattern on the chart. A stable
pattern indicates precisely correct sweep speed.
800 watts peak power
Variable 100 to 300 ohms with 8 position tap switch
12kHz normally provided. Any frequency from 3.5 kHz to 27
kHz is available on special order.
Automatic collapse of ping; flashing overload indicator.
10 uV for full dark marking
Variable, matched to pulse length
90-140 VAC, 45-70 Hz. Stepdown transformer for 220 VAC
operation available as standard accessory.
70 watts
7-1/2" high, 15-1/2" wide, 9" deep
5-1/4" high, 17" wide, 9" deep
70 lbs.