Summary for Field Activity Number 1975-022-FA

Alternate Leg ID: FAY 003

Area of Operations: Georges Bank, Nantucket Shoals, Massachusetts, United States, North America, North Atlantic

Dates: October 02, 1975 to October 17, 1975

Objectives: The main purposes of the cruise were to (1) investigate the shallow structure of the area (as a key to spot potential geologic hazards), (2) to conduct a study of the deeper crustal structure through measurement of gravity and magnetics and through seismic reflection profiles, and (3) to collect shallow seismic reflection profiles over areas where vibracores were taken on the first cruise of the FAY.

Type of Activity: Seismic profiling

Information to be derived: Bathymetric maps

Summary: The cruise completed a survey with a 20 km line spacing (N-S) over the bank with 3 tie lines along the central northern and southern parts of the bank. Lines were extended into the deep ocean (1800 m) to assure coverage over the continental slope. 3.5 kHz: 3486 km (1882 nm); Minisparker: 3187 km (1721 nm); Airgun: 3608 km (1948 nm); Gravity: 3897+ km (2104 nm); Magnetics (gradiometer): 3700 km (1998 nm).

USGS Project Number: EA-RA

Contact: John Schlee (jschlee@usgs.gov)