u.s. DEPARTMENT OF COMMERCEFrederick 8. Dent, Secretary

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

Robert M. White, Administrator

ENVIRONMENTAL RESEARCH LABORATORIES

Wilmot N. Hess, Director

NOAA TECHNICAL REPORT ERL 261-POL 18

RP-l-0C-70 Southeast PacificGeophysical Survey

H.R. STEVENS, Jr.

BOULDER, COLO.February 1973

For sale by the Superintendent of Documents, U. S. Government Printing Office, Washington, D. C. 20402

TABLE OF CONTENTS

ABSTRACT

1. INTRODUCTION

2. CHRONOLOGY

3. OB~IECTIVES

4. NAVIGATION

5. INSTRUMENTATION/EQUIPMENT

5.1 Coring and Heat Flow

5.2 Gravity

5.3 Magnetics

5.4 Seismic Reflection Profiling

5.5 Sounding

6. DATA PROCESSING

7. PRESENTATION OF PROFILE

8. ACKNOWLEDGEMENTS

9. REFERENCES

APPENDIX A Scientific Personnel

APPENDIX B Special Projects

APPENDIX C Coring Stations Summary

APPENDIX D Heat Flow Stations Summary

A~PENDIX E Gravity Base Tie Summary

APPENDIX F Summary of Underway Operations

iii

Page

1

1

1

6

7

7

7

9

9

10

11

11

14

43

43

45

47

53

55

57

59

Page

POL Geophysical Survey Track 2

Leg I Seattle - Tahiti 3

Leg II Tahiti - EPR - Valparaiso 4

Leg III Valparaiso - EPR - Guayaquil 5

East Pacific Rise 10

LIST OF FIGURES

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6 Data Processing Flow Chart - (1970) USC&GSS OCEANOGRAPHER 12

Figure 7 Data Processing Flow Chart - POL

Figure 8 Seattle - Tahiti Location Index

Figure 9 Tahiti - Valparaiso Location Index

Figure 10 Valparaiso - EPR - Guayaquil Location Index

iv

13

15

21

33

RP-l-OC-70 SOUTHEAST PACIFIC GEOPHYSICAL SURVEY

H. R. Stevens, Jr.

This report summarizes work undertaken aboardthe USC&GSS OCEANOGRAPHER during the early part of1970. Bathymetric, magnetic, and gravity data werecollected between Seattle - Tahiti - Valparaiso ­Guayaquil along a trackline that extended over15,000 nautical miles. Coring operations, heatflow measurements, and continuous seismic profilingwere carried out at several locations. Special sci­entific projects related to chart verification, me­teorology, oceanography, and terrestrial geophysicswere also undertaken on eath of the three Legs.

1. INTRODUCTION

During the months of January through March, 1970, the Pacific

Oceanographic Laboratories conducted a geological/geophysical investi­

gation aboard the USC&GSS OCEANOGRAPHER in the southeastern Pacific

Ocean. Visiting investigators from other institutions participated

with Environmental Science Services Administration* (ESSA) personnel in

carrying out the scientific work (see APPENDIX A). The ship's track

is shown in figure 1. The purpose of this report is to summarize the

objectives, methods, and results of cruise RP-l-OC-70.

2. CHRONOLOGY

The cruise was divided into three Legs (see figs. 2, 3, and 4):

I. Seattle to Papeete, Tahiti - 16 January to 26 January.

II. Papeete to Valparaiso, Chile - 31 January to 27 February.

III. Valparaiso to Guayaquil, Ecuador - 10 March to 30 March.

* National Oceanic and Atmospheric Administration was establishedOctober 3, 1970.

"',

160·

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6000

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Figure 1. POL GeophysicaZ Survey Track RP-1-0C-7016 January - 30 March 1970

2

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Figure 2. Leg I Seattle - TahitiTrackline distance (n. mi.) 0-3429.5

3

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3. OBJECTIVES

Leg I. The USC&GSS OCEANOGRAPHER departed Seattle 13 January. A gravity

signature line was run off Cape Flattery, Washington. The collection of

underway geophysical data commenced 17 January at 37.l00 N and l29.96°W.

The principal objectives for this Leg were to obtain gravity, magnetic,

and bathymetric data across the Murray, Molokai, Clarian, Clipperton, and

Marquesas Fracture Zones. A secondary objective was to develope a routine

for shoipboard data processing which would permit a preliminary evaluation

of the data while the cruise was in progress (see section 6 Data Process­

ing).

Leg II. The OCEANOGRAPHER 1eft Papeete, Tahiti on 31 January for the

East Pacific Rise (EPR) working area and Valparaiso. One of the primary

objectives was the acquisition of underway geophysical data along the

overall trackline that included three crossings normal to the general

axial trend of the East Pacific Rise. These traverses were made along the

42°S, 38°S, and 36°S parallels. Boundaries for the area to be investigated

were set at 300 S to 45°S and 105°W to l15°W. Other objectives were to

obtain on-station data from coring and heat flow operations along 36°S

latitude between 106°W and l14°W.

Leg III. The ship left Valparaiso on 10 March for the EPR and Guayaquil.

Basic objectives were continued on this Leg. Underway bathymetric, gravity,

and magnetic data were collected and heat flow operations were conducted

along the 39°S parallel from 102°43'W to l15°96'W and along l3°37 1 S

between 95°3l'W and 93°44'W.

6

In addition to the principal geophysical objectives special projects

were undertaken on all three Legs of OPR-l-OC-70. This work is summarized

in APPENDIX B.

4. NAVIGATION

Most of the trackline was controlled ~ AN/SRN-9 Satellite Navigation

equipment with an average time between fixes of about two hours. Position

control was within 0.2 n mi in most cases.

Where convenient or necessary satellite navigation was supplemented

with other procedures. Celestial navigation was used when the satellite

system was inoperative. For near shore operations, such as the chart

verification project, radar and visual fixes were employed. Positioning

along the Cape Flattery Signature Line, which was run shortly after leaving

Seattle, was obtained by visual bearings and Loran A.

5. INSTRUMENTATION/EQUIPMENT

5.1 Coring and Heat Flow

A Ewing piston corer with a 3.5 m barrel was used in coring operations.

APPENDIX C llsts the location, depth and lengths of core and pilot core

for each successfully occupied coring station.

Several different instruments and procedures were employed in conduct­

ing the heat flow measurements. On Legs II and III a majority of thermal

gradient measurements were made with outrigger type thermistors attached

to the core barrel and a recorder, inside a pressure case, strapped between

the corer's fins.

7

Two types of geothermal gradient recorders were used. A Massachusetts

Institute of Technology (MIT) instrument photographically recorded the

gradient temperatures in analog form to the nearest O.OloC. Data were

obtained from six thermistors, including one thermistor that sensed bottom

water temperatures. This recorder had two disadvantages. Loading and

unloading of film was done in the dark and errors could be introduced when

reading the processed film and digitizing the analog data.

The other gradient recorder used with the piston corer was an ESSA

instrument which employed three thermistors and recorded digitally on

punched plastic tape. Values were read to the nearest O.OloC. Punched

plastic tape had the advantage that it could immediately be taken from the

pressure case, checked, and run through the computer without need of first

digitizing the data.

In addition to the MIT and ESSA gradient recorders, used in conjunction

with the piston corer on Legs II and III, an in situ thermal gradient/con­

ductivity probe was used on several Leg II stations. This instrument,

developed by Clive Lister of the University of Washington, functioned

as an independent unit. While in position on the ocean bottom it measured

both the conductivity of the sediment and the thermal gradient. Gradient

temperatures were measured for 10 minutes. A heating element in the probe

was then activated for 20 minutes to measure the rate of temperature

increase and permit conductivities of the sediment to be determined.

The Lister instrument obtained measurements in the sediment at three

positions along an 8 ft probe of 1/2 in diameter. Data were recorded

digitally on punched plastic tape. The 80 lb weight of the equipment made

8

handling and lowering relatively easy in contrast to that of the piston

corer which required more manpower and heavier equipment.

Thermal conductivities of sediments collected with the piston corer

were determined by the transient measurement method described by Von Herzen

and Maxwell (1959). A needle containing a wire heat"ing element was in­

serted into the core after its recovery from the bottom. Heat was

applied at a known and constant rate. The rise in temperature with time

was monitored and from this the thermal conductivity of the sediment was

determined.

APPENDIX D lists the location, type of equipment used, and the

heat flux value for each successfully occupied station.

5.2 Gravity

The gravity meter aboard the OCEANOGRAPHER was an Askania GSS2, number

22. Gravity data were recorded continuously on an analog trace and also

digitized at 5 min intervals on punched paper tape.

Heavy seas, encountered in the early part of February, introduced

large cross-coupling errors into the data. Because of this and accompany­

ing gyrotable jitter these data were unreliable and eliminated from the

geophysical profile presented in section 7. The quality of other gravity

data acquired throughout the cruise is good. APPENDIX E gives the gravity

base tie summary.

5.3 Magnetic$

A varian V-4937 proton magnetometer was towed at a cable length of

650 ft. Total field magnetic intensities were recorded continuously on

an analog trace and also digitized at 5 min intervals on punched paper

9

tape. The magnetic data were computer processed and are presented in two

formats. These are referred to as the Revised Geophysical Report and the

Geophysical Profile. The quality of the data is considered good.

5.4 Seismic Profiling

Over 1200 n mi of seismic reflection profiling were completed over

the East Pacific Rise and across the Peru-Chile Trench (see fig. 5).

This work was a joint ESSA-University of Washington effort.

+--------+---..,..----+----__-+---+-- --+_- -+:35·

rI-----~~~:::J......C=r_---9000~ --SRP SRP

7000

40·

CARBON 14 STATION XHEAT FLOW STATlON +

CORE STATION 0

CORE &HEAT FLOW STATlON •

1·'±:20::O·------1:T.15:o·----+-----:111!:::O·....----"71r.s:o·----+-+---:1±O:::;·;-+-----~9~~S

Figure 5. East Pacific Rise.

10

The profiler was developed by Clive Lister. It operated at the re­

latively high frequency of 200 Hz and transmitted a single pulse at a

4 sec repetition rate. Bottom penetration of the generated signal was

limited to the upper sediments. Resolution of the record was excellent.

The pulser was mounted on a float and towed 6 ft below the surface

at a cable length of 150 ft. The hydrophone array was towed 500 ft be­

hind the ship at approximately 8 knots.

5.5 Sounding Equipment

Edo transceivers and depth recorders were used to obtain 12 kHz bathy­

metric data. The transceivers were Edo models 248-16 and 248 B. Sound­

ing traces were recorded on Edo model 33A Precision Bottom Recorders

(PBR). Edo wide beam transducers and General Electric narrow beam trans­

ducers were used in conjunction with a PBR. All soundings were recorded

in fathoms.

6. DATA PROCESSING

Data acquired during underway operations were processed aboard ship

and ashore. The Revised Geophysical Report and the Geophysical Profile

are the end products of a series of processing procedures illustrated in

the Data Processing Flow Charts (see figs 6 and 7). The archive retrieval

information and editing system (ARIES) used at POL is described by

Holloway (1971).

11

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7. PRESENTATION OF THE PROFILE

A profile and a print-out are the finalized forms of POL geophysical

data reduction and processing. The profile is a part of this report.

Other RP-l-OC-70 data which may be of special interest can be obtained

by writing to:

National Oceanic and Atmospheric AdministrationEnvironmental Data ServiceChief, Solid Earth &Marine Geophysical

Data Services DivisionBoulder, Colorado 80302

In descending order on each page are the profiles of the Magnetic

Anomaly, Free Air Anomaly, Bathymetry, and Bouguer Anomaly. Appropriate

scales are found along the profile sections. The distance traveled,

course changes, and the ship's positions are shown in conjunction with

the profiles. Latitude and Longitude are indicated at the half-tic marks

and the full-tic marks denote position fixes.

Positions or areas of interest in the trackline charts (figs. 1-5)

may be quickly located with the aid of the four Location Indices (figs.

8-10).

14

Leg I. SEATTLE - TAHITI

FIGURE 8

LOCATION INDEX

(See Figure 2)

Di stance inn mil es Degrees Degrees Pagesalong track Lat. Long. To Lat. Long.

o to 500.2 37.100 N - 129.96°W to 29.18°N - 133.04°W

500.2 to 1000.6 29.18°N - 133.04°W to 21.34°N - 136.09°W

1000.6 to 1499.8 21.34°N - 136.09°W to 13.43°N - 138.77°W

1499.8 to 2000.3 13.43°N - 138.77°W to 5.48°N - 141.32°W

2000.3 to 2499.6

2499.6 to 2999.8 2.32°S - 144.21°W to 10.18°S - 146.98°W

2999.8 to 3433.9 10.18°S - 146.98°W to 17.000 S - 149.39°W

FRACTURE ZONES: (1) Murray, (2) Molokai, (3) Cla~ion, (4)Clipperton and(5) Marquesas.

(1 )133.6 to 321.5 34.99°N - 130.83°W to 32.000 N - 131.94°W

(2)765.4 to 958.3 25.01°N - 134.62°W to 22.000 N - 135.85°W

(3)1273.4 to 1400.4 17.01°N - 137.54°W to 15.000 N - 138.23°W

(4)1904.0 to 2094.8

(5)2861.1 to 3372.8

15

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FIGURE 9

LOCATION INDEX

Leg II. TAHITI - EPR - VALPARAI50 (5ee Figures 3 &5)

Distance in n miles Degrees Degrees Pagesalong track Lat. Long. To Lat. Long.

3471.9 to 3999.1 17.58°5 - 149.66°W to 23.54°5 - 143.15°W

3999.1 to 4499.2 23.54°5 - 143.15°W to 28.88°5 - 136.03°W

4499.2 to 4999.1 28.88°5 - 136.03°W to 34.31°5 - 128.66°W

4999.1 to 5500.2 34.31°5 - 128.66°W to 39.63°5 - 120.62°W

5500.2 to 5999.8 39.63°5 - 120.62°W to 41.94°5 - 111.06°W

5999.8 to 6499.7 41.94°5 - 111 .06°W to 38.40°5 - 102.75°W

6499.7 to 6999.6 38.40°5 - 102.75°W to 38.04°5 - 112.47°W

6999.6 to 7500.3 38.04°5 - 112.47°W to 40.82°5 - 109.83°W

7500.3 to 8000.2 40.82°5 - 109.83°W to 36.04°5 - 107.81°W

8000.2 to 8488.2 36.04°5 - 107.81°W to 36.19°5 - 110.13°W

8488.2 to 8999:3 36.19°5 - 110.13°W to 35.42°5 - 99.89°W

8999.3 to 9499.1 35.42°5 - 99.89°W to 34.59°5 - 89.900 W

9499.1 to 9999.4 34.59°$ - 89.900 W to 33.90°5 - 79.85°W

9999.4 to 10395.4 33.90°$ - 79.85°W to 33.06°$ - 72.01 oW

EA5T PACIFIC RI5E, Phase 1:

5726.4 to 8950.0 42.00°5 - 116.93°W to 35.56°5 - 101.000 W

PERU - CHILE TRENCH:

33.26°5 - 73.99°W to 33.06°5 - 72.Ol oW

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FIGURE 10

LOCATION INDEX

Leg II I. VALPARAISO - EPR - GUAYAQUIL (See Figures 4 &5)

Distance in n miles Degrees Degrees Pagesalong track Lat. Long. To Lat. Long.

10404.5 to 10999.7 33.03°S - 71.88°W to 35.59°S - 83.48°W

10999.7 to 11499.9 35.59°S - 83.48°W to 37.66°S - 93.54°W

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12518.7 to 13000.4 38.98°S - 115.09°W to 31.54°S - 111.42°W

13000.4 to 13500.6 31.54°S - 111 .42°W to 24.19°S - 107.17°W

13500.6 to 14000.6 24.19°S - 107.17°W to 18.17°S - 101.08°W

14000.6 to 14499.9 18.17°S - 101 .08°W to 13.62°S - 94.26°W

14499.9 to 15000.2 13.62°S - 94.26°W to 7.79°S - 88.500 W

15000.2 to 15579.7 7.79°S - 88.500 W to 2.75°S - 80.93°W

EAST PACIFIC RISE, Phase 2:

11809.5 to 12518.7 38.99°S - 99.900 W to 38.99°S - 115.09°W

33

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8. ACKNOWLEDGEMENTS

I thank F.P. Naugler, J.M. Wageman, and D.A. Emilia for helpful sug­

gestions used in the preparation of this report. They, along with R.E.

Burns, read the manuscript and offered constructive criticisms. S.P.

Perry was responsible for producing the geophysical profile. R.R. Uh"lhorn

did the drafting. Laurie Burgess typed the manuscript.

A special acknowledgement is due the officers and crew of the

OCEANOGRAPHER. Their efforts contributed to the success of RP-l-OC-70.

9. REFERENCES

Holloway, Gregory (1971), A Quick Users Guide to ARIES. Archive Re­

trieval Information Editing System, (POL Manual).

Von Herzen, R.P. and A.E. Maxwell (1950), The measurement of thermal

conductivity of deep-sea sediments by a needle probe method. J.

Geophys. Res, Vol. 64, 1557-1563.

43

APPENDIX A SCIENTIFIC PERSONNEL

NAME AFFI LIATION DATE

Robert E. Burns* ESSA - POL 13 January-31 March

Clive R.B. Lister u. of Washington 13 January-5 March

Alexander Ma1ahoff u. of Washington 13 January-30 January

Richard W. Marvin u. of Washington 13 January-30 January

Robert G. Zachariadis u. of Washington 13 January-30 January

Albert Erickson M.LT. 2 March-31 March

Stanley Cisowski M.LT. 2 March-31 March

Beverly Carroll M.LT. 2 March-31 March

Elaine Papworth M.LT. 2 March-31 March

Lawrence Machesky U. of Hawaii 5 March-31 March

*Chief Scientist

45

APPENDIX B SPECIAL PROJECTS

B 1. Bathythermographs

Expendable bathythermograph (XBT) observations were made daily at

OOOOZ, 0600Z, 1200Z, and 1800Z while enroute to Tahiti (Leg I). Surface

bucket temperatures were taken for reference. The seawater temperature

recorder operated continuously. These readings agreed within ~ 0.2°C of

bucket temperatures.

B 2. Chart Verification

Leg I: Matahive Island

Date Position Verified: 25 January 1970

Findings: The position check utilized Satellite Navigation, visual

bearings, and radar distances. The island's position was found to lie as

charted on H.O. Chart 5732.

Leg II: Juan Fernandes Islands: Robinson Crusoe, Santa Clara, and

Alejandro Selkirk Island (Mas Afuera)

Date Position Verified: 25 February 1970

Findings: Positions were checked utilizing Satellite Navigation,

visual bearings, and radar distances. The charted positions of Robinson

Crusoe and Santa Clara Islands on H.O. Chart 1267 differ up to 5 n mi from

the positions shown on the 1969 Chilean Chart No. 509. The positions as

shown on the Chilean chart were substantiated. The position of Alejandro

Selkirk Island appeared to be 2.6 n mi southwest of its charted position

on H.O. 1267.

47

B 3. Deep Sea Camera

The Massachusetts Institute of Technology supplied an EG&G camera and

strobe light for the deep sea photography operations. The camera apparatus

and the Edo pinger were lowered at positions 39.01 0 S - 105.24°W, 39.03°S ­

107.56°W, 38.76°S - 111.36°W, and 39.02°S - 115.08°W on Leg II.

The camera focal length was set between 4 and 20 ft. Depth control

was maintained by using the PBR in conjunction with an oscilloscope. The

camera unit was kept at a distance of approximately 12 ft off the bottom

with the aid of the pinger. Malfunctioning of the camera brought negative

results at two stations.

B 4. Easter Island (Rapa Nui) Gravity Survey

The land gravity survey of Easter Island was not initially one of the

OPR-l-OC-70 projects but resulted from the illness and subsequent medical

evacuation to the Island of the OCEANOGRAPHER'S 3rd Assistant Engineer.

The stop-over at Easter Island offered an opportunity to obtain gravity

data that could be tied into the first order world gravity net. A success­

ful reconnaissance gravity survey was made on the 22nd and 23rd of March

during Leg III portion of the cruise. Readings were taken at 23 stations.

Ship personnel involved in these measurements were Mr. L.F. Machesky,

U. of Hawaii, Lt. F.P. Rossi, and Ensigns J.A. Miller, and A. N. Flior

USESSA of the USC&GSS OCEANOGRAPHER. Their efforts were combined with

those of Mr. Mark Speath, USC&GSS, Rockville, Maryland, Mr. Dan Wa"lker,

U. of Hawaii, and Sr. Bernardo, U. of Chile. These men who volunteered

48

their services, were living on the island at the time and engaged in

completing a new seismic vault. Island transportation was provided by

the Chilean Air Force, Easter Island Detachment.

B 5. Equatorial Surface Current Study

Velocities and directions of equatorial surface currents were measured

between 135°W and 1500 Wlongitude during Leg I of the cruise. The method

of determining ship set and drift used in this study is not complex but it

does require highly accurate navigation. The computed direction and

speed of the surface current is expressed as a vector quantity obtained

after the difference between the indicated course and distance and the

actual course and distance-made-good has been established. Primary control

of the trackline was maintained with AN/SRN-9 Satellite Navigation equip­

ment. Course errors, after averaging, are believed to be within + 1°.

Distance through the water, determined by the underwater log distance

indicator (ULDI), is believed to be accurate to within + 0.1 n mi/hr.

This includes effect of wind on ships speed. After completion of the

smooth plotting, the ship's actual course and distance are probably accu­

rate to within 0.5° and 0.5 n mi/hr.

The results of this surface current study are in general agreement

with the findings of others (summarized by Neumann and Pierson, 1966).

Data acquired along the OCEANOGRAPHER'S trackline indicates that a marked

change in the direction of the South Equatorial Current occurs approxi­

mately 1° south of the equator. The surface currents south of the South

Equatorial Current, at about 60 S latitude, also turn from a south-south­

westerly direction and flow south-southeastward around the western edge

49

of the Marquesas Islands and the Tuamotu Archipelago. The suggestion

has been made that these islands may partially divert the flow of the

South Pacific Gyre with a resulting surface current pattern that is not

a part of the large scale circulation. It is necessary to emphasize,

however, that the data from this surface current study are applicable

only to the region investigated between 135°W and 1500 Win January 1970.

B 6. Meteorology

Surface meteorological observations were taken daily at 0000, 0600,

1200, and 1800 hrs except when in port. The weather program began 17

January and continued for the remainder of the cruise. A recording

barograph operated from 13 January to 30 March.

Forecasts and facsimile weather charts, transmitted from Navy Fleet

Weather Central in Honolulu, aided the ship's meteorology officer in setting

up weather forcasts for shipboard use.

A total of 208 observations were recorded. Of these, 198 were trans­

mitted for relay to weather centers in Washington, D.C. and Honolulu,

Hawaii. Synoptic weather observations and barogram records were checked

and filed for later shipment to the Marine Climatological Branch, U.S.

Weather Bureau.

B 7. Radiocarbon Study

Water samples for a Carbon-14 study were taken at 39°00 1 S and

105°15 1W for Anthony W. Young of the University of Washington Chemistry

Department. Fifteen gallon samples were obtained from the surface and

50

at depths of 50, 100, 200, 300, 500, 750, 1600, 2000 and 2400 meters.

The samples were processed aboard ship to remove the dissolved carbonate

fraction and later sent to the University's Radiocarbon Dating Laboratory

for analyses.

B 8. References

Knauss, J.A. (1963), Equatorial Current Systems, in The Sea, ed. M.N. Hill,

£' 235-252, (Interscience Publishers, New York - London)

Neumann, G. and W.J. Pierson, Jr. (1966), Principles of Physical Oceano­

graphy, (Prentice - Hall, Inc., New Jersey).

51

APPENDIX C CORING STATION SUMMARY

Position Location Depth Core Pilot CoreNumber Lat. Long. (meters) Length(cm) Length(cm)

1059 360 02'5 - 1330 53 1W 3236 187

1089 350 54 1 5 - 1090 51 1W 2850 201

1093 350 59 15 - 1080 28'W 3374 229 52

1096 36 0 04 1 5 - 1070 ll l W 3437 110 45

1097 360 02'5 - 1060 46 1W 3595 130 46

1440 390 01 IS - 1020 01 1W 3994 164 51

1449 390 01 IS - 1020 43 1W 3952 98 37

1465 390 00 1 5 - 1030 32 1W 3889 134 59

1473 390 00'5 - 1040 07 1W 3737 236 51

1503 380 59'S - 1070 30 l W 3509 246 53

1504 380 59 1 5 - 107 0 33'W 3540 203 28

1506 390 04'5 - 1070 34 1W 3548 233

1520 380 58 1 5 - 107 0 54 1W 3510 149 57

1521 390 02'5 - 1080 33'W 3397 219 47

1528 380 56 1 5 - 1090 06'W 3074 214 55

1534 390 01 IS - 1090 44 1W 3170 177 54

1540 390 01 1 5 - 1100 31 1W 2811 184 53

1549 380 58 1 5 - 111 0 21 1W 2754 159 46

1560 390 00'5 - 111 0 51 1W 2924 136 54

53

APPENDIX C (continued)

Position LocationNumber Lat. Long.

Depth(meters)

CoreLength(cm)

Pilot CoreLength(cm)

1567 39° 01'$ - 112° 26 1W 2922 207 52

1575 39° 01'$ - 113° 01 'w 3302 142 42

1582 39° 02 1$ - 113° 43'W 3337 233 57

1590 38° 58 1$ - 114° 38 1W 3431 200 51

1597 39° 01'$ - 115° 05 1W 3530 49 50

1598 39° 02 1 $ - 115° 06 1W 3548 269

1779 13° 37 1$ - 095° 36 1W 3811 121 30

1796 13° 37 1$ - 093° 44 1W 3784 93 54

Note: Cores are archived at the University of Washington in the Depart-

ment of Oceanography's Marine Sediment Library.

54

APPENDIX D HEAT FLOW STATION SUMMARY

Positi on Location Heat FlowNumber Lat. Long. Type of Equipment ~cal/cm sec

1088 35° 52 1S - 110° 09 1W Lister - Probe 4.0

1089 35° 54 1S - 109° 51 'W ESSA - Outrigger 2.7

1090 35° 53'S - 109° 31 'W Lister - Probe 3.2

1091 35° 53'S - 109° 10 l W Lister - Probe 1.4

1092 35° 55 1S - 108° 50 l W Lister - Probe 3.3

1093 35° 59'S - 108° 28 1W ESSA - Outrigger 3. 1

1094 36° 02 1S - 108° 07 1W Lister - Probe 0.5*

1095 36° 02 1S - 107° 41 'W Lister - Probe 2.0

1096 36° 04'S - 107° 11'W ESSA - Outrigger 1.9

1097 36° 02 1S - 106° 45 1W ESSA - Outrigger 3.9

1098 36° OOIS - 105° 59'W Lister - Probe 2.7

1504 38° 59'S - 107° 33 1W MIT - Outrigger 0.79

1521 39° 02'S - 108° 33'W MIT - Outri gger 2.08

1528 38° 56 1S - 109° 06'W MIT - Outrigger 2.32

1534 39° 01 1 S - 109° 44'W MIT - Outri gger 4.32

1540 39° 01 IS - 110° 31 'W MIT - Outrigger 4.05

1549 38° 58 1S _ 111 ° 21 IW MIT- Outri gger 1.50

1560 39° OO'S _ 111 ° 51 1W MIT - Outri gger 2.81

1567 39° 01' S - 112° 26'W MIT - Outri gger 3.71

*Surface sediment colder than bottom water.

55

APPENDIX D (continued)

PositionNumber

LocationLat. Long. Type of Equipment

Heat FlowlJca1/cm sec

1575 39° 01 'S - 113° 01 1W MIT - Outrigger 1.17

1582 39° 02'S _ 113° 43'W MIT - Outri gger 1.48

1590 38° 58 1S - 114° 38 1W MIT - Outri gger 1.62

1597 39° 01 IS - 115° 05'W MIT - Outrigger 2.40

1598 39° 02'S - 115° 06'W MIT - Outrigger 4.10

1796 13° 37'S - 093° 44 1W MIT - Outri gger 1. 91

56

APPENDIX E GRAVITY BASE TIE SUMMARY

Place DateSea-level Grav. Zero Drift

Meter (ga1s) Meter Grav. (mga1s )

PMC 12 Jan. 38.290

Valparaiso 9 Mar.

Guayaquil 31 Mar.

Papeete 26 Jan. 18.300

Papeete 30 Jan. 18.300

Valparaiso 27 Feb. 27.285

PMC 30 Dec. 38.150 980.7428

980.7428

978.7123

978.7130

979.6349

976.8401

976.8257

976.8402

976.8409

976.8436

976.8456

976.8462

-14.4*

14.5

0.7

2.7

2.0

0.6

* This reading appears to be spurious. The second base tie in Papeete.

Tahiti shows negligible drift. No tares had occurred and the gravi­

meter showed no drift. Therefore. the base tie made in Seattle on

30 December 1969 was used instead of the 12 January 1970 base tie.

57

Trackline Soundings

Leg I Seattle to Tahiti

Leg II Tahiti to Valparaiso

Leg III Valparaiso to Guayaquil

Trackline Gravity

Leg I Seattle to Tahiti 3,737.8

Leg II Tahiti to Valparaiso 6,632.0

Leg III Valparaiso to Guayaquil 4,683.3

15,053.1 Lin. Naut. Miles

Trackline Magnetics

Leg I Seattle to Tahiti 3,730.6

Leg II Tahiti to Valparaiso 6,584.1

Leg III Valparaiso to Guayaquil 4,695.3

15,010.0 Lin. Naut. Miles

3,737.8

6,827.2

5,219.0

15,784.0 Lin. Naut. Miles

BT lowerings (Expendable) 36

Bottom sample, cores - more than 1000 m 27

Heat flow - (Needle Probe) 7

(Outri gger) 18

Meteorological observations 208

Oceanographic Stations occupied 34

Photography, underwater - more than 1000 m 2 stations

Radionuclide water samples 9

S9

APPENDIX F (continued)

Sub-bottom profile

Water samples analyzed, salinity

Water temperature observations

60

1200 Lin. Naut. Miles

36

continuous

-tr u. s. GOVERNMENT PRINTING OFFICE: 1972·7B4·213/1146REGION NO.8