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USGS Coastal and Marine Geology Program

Field Activity Details for field activity 1987-040-FA

Other ID: STRL S7-87-AFR

Status: Completed

Organization(s): USGS, Woods Hole Coastal and Marine Science Center

Funding Program(s):

Principal Investigator(s): George R. Driscoll

Affiliate Investigator(s):

Information Specialist(s): George R. Driscoll

Data Type(s): Electro-Magnetic: Gravity, Sonar: Single Beam, Electro-Magnetic: Magnetics, Location-Elevation: Navigation

Scientific Purpose/Goals: Collect gravity, magnetics and bathymetric data off the west coast of Africa on a 5 nmi grid with an internal consistency of +/- 3 milligals.


Start Port/Location: Abidjan, Cote d'Ivoire

End Port/Location: Douala, Cameroon

Start Date: 1987-09-24

End Date: 1987-10-20

Equipment Used: GPS (wh), 12 kHz, LaCoste-Romberg gravimeter G-179, Geometrics G-856 magnetometer, Gyro compass, GE 810 Correlation sonar

Information to be Derived:

Summary of Activity and Data Gathered: Departed Abidjan, Ivory Coast on 24 Sep. On 25 Sep., resurveyed 2 Ghana lines due to high cross checks. On 26 Sep., surveyed 1 Togo line and 1 Benin line and started Nigeria survey. On 5 Oct., completed Nigeria and began Cameroon survey. On 8 Oct., completed Cameroon survey and began Gabon survey. 18 Oct., transit to Douala. 20 Oct., arrived Douala, Cameroon for crew change and provisions. The 810 Sonar/MK 29 Gyro system worked flawlessly as did gravimeters and all gravity processing equipment and software. Many lines had to be cut short on the eastern end due to shoals, or shifted due to restricted oil platform areas.

Staff: Nancy K. Soderberg, Catherine Delorey, George R. Driscoll

Affiliate Staff:
Robert Bowles - consultant; Larry Awosika - Nigerian Institute of Oceanography & Marine Research; Lt. A.G. Inusa - Nigerian Navy Hydrography Office; Tomah Jabez Nhabay - Geological Survey
Sierra Leone

Project = Defense Mapping Agency Gravity, Defense Mapping Agency Gravity


Ghana, Togo, Benin, Nigeria, Cameroon, Gabon, Equatorial Guinea, Africa, North Atlantic, South Atlantic;

North: 7 South: 3 West: 1 East: 8


photo of Starella


Folger, D.W., McCullough, James R., Irwin, Barry J., Driscoll, George R., Delorey, Catherine M., and Polloni, Christopher F., 1990, Map showing free-air gravity anomalies off the western coast of Africa; Nigeria to Gabon: U.S. Geological Survey Miscellaneous Field Studies Map MF-2098-F, scale 1:1,500,000.


Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
LaCoste-Romberg gravimeter G-179 --- Gravity
12 kHz --- Single Beam
1987-040-FA-SE-001 ( Collection of paper record displays of seismic data (12 kHz) for lines )
Geometrics G-856 magnetometer --- Magnetics
GE 810 Correlation sonar --- Navigation
Gyro compass --- Navigation
GPS (wh) --- Navigation

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