Summary for Field Activity Number 1976-020-FA

Alternate Leg ID: FAY 017

Area of Operations: outer continental shelf, inner Blake Plateau, Florida, Georgia, South Carolina, North Carolina, United States, North America, North Atlantic

Dates: June 20, 1976 to June 29, 1976

Objectives: Geophysical reconnaissance of southeast Georgia Embayment.

Type of Activity: Seismic profiling
magnetics
gravity

Information to be derived: Morphology

Summary: FAY sailed from Ft. Lauderdale at noon on June 20, 1976. All systems began operation on June 21, 1976 at 0800 and continued until June 29, 1976 at 0800. One tie line was run along the shelf from Daytona Beach to Cape Fear, then 8 cross-shelf lines were obtained between Cape Fear and Charleston, spaced about 30 km apart. These lines were about 160 km long, extending from shallow water (10 m) to 600 m on the inner Blake Plateau. Average operating speed was about 6.5 kts. Due to a 4-day delay, the survey of a possibly active fault on the outer edge of the Blake Plateau was postponed until fall. The relatively high operating speed and generally excellent weather allowed us to make up some lost time. The sparker system produced excellent high-resolution records and the airgun system was adjusted for a relatively high-frequency bandpass (32 - 205 Hz) to improve resolution. No apparent loss of penetration could be noted with this high bandpass. The addition of the 160 cu. in. airgun to the 3 small guns did not appear to change gun signature but did increase power, so the 4 guns were run together for the remainder of the cruise. The FAY was an exceptionally well run, well maintained ship under Captain Olander and Chief Engineer Weeks, and we received excellent cooperation throughout the cruise from all the officers and crew members. Seismic profiles: 2000 km; Magnetics: 2000 km; Gravity: 2600 km.

USGS Project Number: RA-EA

Contact: Bill Dillon (bdillon@usgs.gov)