USGS Coastal and Marine Geology Program

Coastal & Marine Geology Program

Field Activity Details for field activity 1992-023-FA

Other ID: CH 12-92

Status: Completed

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

Funding Program(s):

Principal Investigator(s): William Dillon, William Schwab

Affiliate Investigator(s):

Information Specialist(s):

Data Type(s): Location-Elevation: Navigation, Seismics: Air Gun / Water Gun, Seismics: Sub Bottom Profiler

Scientific Purpose/Goals: To obtain digital seismic profiles in the area of gas hydrate development on the continental rise off North and South Carolina, and to test and obtain data from the new USGS/Datasonics deep-towed sidescan-sonar system.

Vehicle(s):

Start Date: 1992-09-21

Start Port/Location: Morehead City, NC

End Date: 1992-10-04

End Port/Location: Morehead City, NC

Equipment Used: Air gun, Sidescan sonar, 3.5 kHz, Loran-C, Single channel hydrophone

Information to be Derived:

Summary of Activity and Data Gathered: Two research areas were studied; to the north at the head of the Cape Fear slide and to the south on the crest of Blake Ridge. The seismic profiling system worked perfectly and allowed collection of 163 km of excellent quality seismic data at the Cape Fear slide site and 1204 km at the Blake Ridge site. Unfortunately the outer section of the streamer was damaged during operations (presumably it went into the ship's propellers), but the damaged section was replaced by a spare section. Four sidescan sonar test lowerings were carried out. During the first 3 lowerings, only the port side provided data at operating depth. A leaking connector was identified and repaired. During the last day, the sidescan worked properly and collected 91 km data. Weather conditions prevented lowering of the sidescan for much of the cruise and one day was lost to Tropical Storm Earl.

Staff: Dwight Coleman, William Danforth, Barry Irwin, Thomas O'Brien

Affiliate Staff:
PMG - Larry Kooker
John Gann; Timothy Boynton - Duke/UNC; Mark Parent - Datasonics; Fred Hegg - Datasonics

Notes:

Location:

Cape Fear slide, Blake Ridge, United States, North America, North Atlantic;

Boundaries
North: 33 South: 31.5 West: -76.5 East: -75

Platform(s):

photo of Cape Hatteras
Cape Hatteras

Publications

Anton, C., Dillon, W.P., and Lee, M., 1999, Anomalous, nearly horizontal, seismic reflection at the Blake Ridge--Evidence for a gas trap crosses the base of gas hydrate stability [abs.]: Eos, Transactions, American Geophysical Union, Spring Meeting, v. 80 no. 17-supplement, URL: http://www.agu.org/cgi-bin/SFgate/SFgate?language=English&verbose=0&listenv=table&application=sm99&convert=&converthl=&refinequery=&formintern=&formextern=&transquery=dillon&_lines=&multiple=0&descriptor=%2fdata%2fepubs%2fwais%2findexes%2fsm99%2fsm99|537|3089|T51A-08%20%20Anomalous%2c%20Nearly%20Horizontal%2c%20Seismic%20Reflection%20at%20the%20Blake%20Ridge:%20Evidence%20for%20a%20Gas%20%20Trap%20that%20C%20*%20Anton%2c%20C%20H%20Dillon%2c%20W%20P%20Lee%2c|TEXT|localhost:0|%2fdata%2fepubs%2fwais%2findexes%2fsm99%2fsm99|5522885%205525974%20%2fdata2%2fepubs%2fwais%2fdata%2fsm99%2fsm99.txt.

Taylor, M.H., Dillon, William P., Anton, Christopher H., and Danforth, William, 1999, Seismic-reflection surveys of the Blake Ridge, R/V CAPE HATTERAS 1992 and 1995; data acquisition, navigation and processing: URL: http://pubs.usgs.gov/of/1999/of99-372/.

Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
Air gun --- Air Gun / Water Gun
Sidescan sonar --- Sidescan
1992-023-FA-SO-001 ( Digital tape(s) of AIRGUN L1, AIRGUN L2, AIRGUN L2-3, AIRGUN L3-5, AIRGUN L6-7, AIRGUN L8-12, AIRGUN L13-15, AIRGUN L15-21, AIRGUN L22A, AIRGUN L23B-23, AIRGUN L1-5, AIRGUN L6-15B, AIRGUN L15C-23, NAV GPS+LORAN, SIS7000 SSS L24-25, SIS7000 SSS L26-27, SIS7000 SSS RAW+PROC, )
3.5 kHz --- Sub Bottom Profiler
Loran-C --- Navigation
Nav data ( )
1992-023-FA-LN-002-02 ( Navigation files for each line.)
1992-023-FA-LN-002-01 ( Processed shotpoint navigation file prepared by MMS, New Orleans, LA in segp1 format.)
1992-023-FA-LN-001-01 ( Cape Fear Slide trackmap of seismic lines 1, 2 and 5.)
1992-023-FA-LN-001-02 ( Blake Ridge area trackmap of seismic lines 6-23.)
Single channel hydrophone --- Air Gun / Water Gun
Boomer
Bubble Gun
Sparker
Sub Bottom Profiler
Air gun data 2 ( )
Air gun data ( )
1992-023-FA-SE-002 ( Digital tape(s) of AIRGUN L1, AIRGUN L2, AIRGUN L2-3, AIRGUN L3-5, AIRGUN L6-7, AIRGUN L8-12, AIRGUN L13-15, AIRGUN L15-21, AIRGUN L22A, AIRGUN L23B-23, AIRGUN L1-5, AIRGUN L6-15B, AIRGUN L15C-23, NAV GPS+LORAN, SIS7000 SSS L24-25, SIS7000 SSS L26-27, SIS7000 SSS RAW+PROC, )
1992-023-FA-SE-003 ( Collection of paper record displays of seismic data( AIR) for lines )
1992-023-FA-SE-001 ( microfilm of )
1992-023-FA-SE-002-02 ( Processed SEG-Y Data)
1992-023-FA-SE-002-01 ( CD ROM disk of PROCESSED CDP, NAV, )