Other ID: 81-G-12
Organization(s): USGS, Woods Hole Coastal and Marine Science Center
Principal Investigator(s): Dennis W. O'Leary
Affiliate Investigator(s): Bonnie McGregor - USGS-Miami, FL
Data Type(s): Location-Elevation: Navigation, Seismics: Air Gun / Water Gun, Seismics: Sparker, Seismics: Sub Bottom Profiler, Sonar: Sidescan, Sonar: Single Beam
Scientific Purpose/Goals: Conduct high-resolution mid-range sidescan sonar and single-channel seismic profile surveys of the continental slope around Atlantis to Alvin and Lydonia to Oceanographer Submarine Canyons near lease-sale blocks.
Start Port/Location: Woods Hole, MA
End Port/Location: Woods Hole, MA
Start Date: 1981-07-27
End Date: 1981-08-17
Equipment Used: SeaMARC sidescan sonar system, 3.5 kHz, Air gun, Sparker system, Loran-C, Single channel hydrophone, 12 kHz
Information to be Derived:
Summary of Activity and Data Gathered: The electric motor for the winch caught fire on July 28th after 7 hours of use. Nearly 1,400 m of cable and gear were over the side at the time. Dave Twichell on M/V WHITEFOOT was conducting a survey not far from the GYRE; the WHITEFOOT rendezvoused with GYRE on the night of July 28 to provide us with spare blocks and hawser to facilitate recovery of the cable. We thereupon spent 38 hours hauling in the cable by means of a deck capstan, mooring hawser, and two blocks. The cable was brought in 3 m per pull and hand spooled on the cable drum. On July 31st R/V GYRE returned to Woods Hole to have the electric motor rebuilt. On August 3rd, the survey resumed along the slope in the Atlantis-Alvin Canyons area. About 100 km of image data were collected before a hydraulic pump on the winch failed. On August 5th the gear was brought on board by the marginally operable winch. R/V GYRE returned to Woods Hole on August 6th for emergency pump repair. By August 8th it was clear to us that no repair could be counted on in the foreseeable future. The majority of the Lamont crew returned to shore and USGS personnel came aboard to help conduct a seismic survey. An excellent seismic survey was completed in 4.7 days using airgun, sparker, and 3.5 kHz profiles at 2 km line spacing. In the remaining 3 days of the survey, an excellent sonar survey of the slope between and adjacent to Atlantic and Alvin Canyons was completed. Sidescan sonar data: 375 km; Seismic profile and 3.5 kHz data: 1,230 km.
Staff: Kathryn Scanlon Catanach, John C., Jr. Hampson, Frank W. Jennings, C. Wesley Lombard, Bonnie McGregor, Dennis W. O'Leary, Carol M. Parmenter, Kenneth E. Parolski
Notes: Original Center People field contained: Dennis O'Leary - Co-Ch. Sci., Bonnie McGregor - Co-Ch. Sci., Scott Chalker (Aug. 8-17), Robert Douthart, John Hampson, Frank Jennings (Aug. 3-6), Wes Lombard (Aug. 3-6), Carol Parmenter, Kenneth Parolski, Kathy Scanlon, Susan Williams. Original Submitted By field contained: Bonnie McGregor, Dennis O'Leary.
Oceanographer Canyon, Lydonia Canyon, Atlantis Canyon, Alvin Canyon, Georges Bank area, United States, North America, North Atlantic;