Field Activity Details for field activity 1975-011-FA

Other ID: ASTR 75-JUN

Status: Completed

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

Funding Program(s):

Principal Investigator(s): Charles J. O'Hara

Affiliate Investigator(s):

Information Specialist(s): Charles J. O'Hara

Data Type(s): Location-Elevation: Navigation, Seismics: Boomer

Scientific Purpose/Goals: The cooperative program is designed to provide detailed geological information and an assessment of mineral resources pertaining to that part of the continental shelf beneath the coastal waters of Massachusetts. In anticipation of the development of offshore natural resources of the Commonwealth, the major focus of the research effort is directed toward the occurrance, nature and distribution of these deposits as well as establishment of baseline data for evaluation of environmental impact of exploitation. The sub-bottom profiling surveys provide the foundation for a planned program of vibracoring and bottom sampling of geological features. Laboratory analysis of the vibracore and bottom samples will evaluate the economic importance of the deposits and, coupled with the seismic data, provide information on the geology and geologic history of the area.

Vehicle(s):

Start Port/Location:

End Port/Location:

Start Date: 1975-06-19

End Date: 1975-06-30

Equipment Used: EG&G 234, Loran-C, Raytheon radar, Visual navigation, Single channel hydrophone

Information to be Derived:

Summary of Activity and Data Gathered: Traverses: 33 (27 in a NW-SE orientation with a line spacing of 1 nm, 6 in a SW-NE orientation with a line spacing of approximately 3 nm); Seismic data: 358 nm (663 km) and penetration of up to 125 meters below the bottom were achieved.

Staff: Susan Barton, Wayne Ferrebee, Patricia Forrestel, Frank W. Jennings, Charles J. O'Hara, Barbara Tausey, Elizabeth Winget

Affiliate Staff:

Notes: All seismic track lines were pre-plotted along LORAN-C navigation lines of position. This approach facilitated control of the survey vessel on the seismic tracks despite the course setting influence of wind and currents. Cape Race, Newfoundland and Dana, Indiana LORAN-C secondary transmitters were utilized as they are the most reliable and provide the best positional accuracy within the area. Navigational fixes were taken at 15 minute intervals and ship's speed over the bottom averaged 4.5 knots. The hydrophone array and catamaran float with mounted transducer were towed about 15 meters astern of the survey vessel. This configuration, coupled with ship's speed, resulted in a sound source/receiver separation of approximately 10 meters. The transducer was triggered every 0.5 second and the sweep rate of the recorder was set at 0.25 second. Only incoming seismic signals within the 200-4000 Hz frequency range were fed to the recorder. Original Center People field contained: Chuck O'Hara - Chief Scientist, Frank Jennings - Electronic Technician, Patricia Forrestal, Wayne Ferrebee, Elizabeth Winget, Susan Purdy, and Barbara Tausey.
Project = Marine Geologic Program, Marine Geologic Program

Location:

Rhode Island Sound, Rhode Island, Westport Harbor, Vineyard Sound, Cuttyhunk Island, Nomans Land, Martha's Vineyard, Massachusetts, United States, North America, North Atlantic;

Platform(s):

Publications

Portals/Viewers

FAN 1975-011-FA has data viewable in the GeoMappApp/Virtual Ocean applications. To view this data in these applications go to http://www.geomapapp.org/ and http://www.virtualocean.org/. See the instructions for locating USGS data in these applications. You can also view the imagery created from the SEGY data at https://cmgds.marine.usgs.gov/images.php?cruise=1975-011-FA.

Documents associated with this activity

Data Acquired