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Summary Information for Field Activity 1987-029-FA

Area of Operations: Senegal, Gambia, Guinea-Bissau, Guinea, Sierra Leone, Africa, North Atlantic

Dates: July 22, 1987 to August 20, 1987

Chief scientist: Barry Irwin

Objectives: Collect gravity, magnetics and bathymetric data around Senegal, Gambia, Guinea-Bissau, Guinea, and Sierra Leone to a 3 nm grid with internal consistency +/-3 mgals.

Type of Activity:

Information to be derived:

Summary: Departed Dakar at 1920 on 22 Jul. 1987. The ship proceeded south to survops area. After completing the two remaining lines in Senegal, all runable lines in the waters off The Gambia, Guinea-Bissau, Guinea and Sierra Leone were completed. Most of the onshore lines run north of Sierra Leone were shortened due to shoals on the eastern ends. Gravimeter S-26 lost its 200 Hz power supply on 2 Aug. 87. The unit was swapped with the unit in meter S-41, which was then shut down. S-26 remained online for the remainder of the cruise and showed no evidence of data tears. Arrived in Freetown, Sierra Leone at 1230 on 20 Aug. 1987.

Contact: Barry Irwin (

InfoBank: uses the identifier S-5-87-AF. Visit this site for more information.

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Platform Info:

Publications resulting from these data

Folger, David W., McCullough, James R., Irwin, Barry J., Driscoll, George R., and Polloni, Christopher F.,1990, Map showing free-air gravity anomalies off the western coast of Africa; Senegal (south of 15 degrees north latitude) to Sierra Leone: U.S. Geological Survey Miscellaneous Field Studies Map MF-2098-D, scale 1:1,500,000. (Available as a PDF version)

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