USGS Coastal and Marine Geology Program

Coastal & Marine Geology Program

Field Activity Details for field activity 1984-009-FA

Other ID: J-163 (Leg IV)

Status: Completed

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

Funding Program(s):

Location: Middle Grounds area, Block Canyon, Atlantis Canyon, Veatch Canyon, mid-Atlantic Bight, North America, North Atlantic;

Principal Investigator(s): David Twichell

Affiliate Investigator(s): Dr. Robert S. Jones (HBF); Dr. Churchill B. Grimes (Rutgers)

Information Specialist(s):

Data Type(s): Environmental Data: CTD, Imagery: Photo, Imagery: Video, Location-Elevation: Navigation, Sampling: Biology, Sampling: Geology, Seismics: Sub Bottom Profiler

Scientific Purpose/Goals: 1) Test our hypothesis that rough bottom topography in the Mid-Atlantic Bight resulted from bioerosion by the tilefish community, and 2) further develop the use of sidescan sonar and sub-bottom profiling as a tool for assessing critical habitat for fishery resources.


Start Date: 1984-07-28

Start Port/Location:

End Date: 1984-08-04

End Port/Location:

Equipment Used: Video camera - deep sea, Camera- deep sea, Grab sampler, Loran-C, Seismic reflection, Sidescan sonar, Mooring tripod, CTD, 3.5 kHz, Geomechanique streamer

Information to be Derived:

Summary of Activity and Data Gathered: Optimal weather conditions allowed us to conduct a variety of submersible, sidescan sonar and sub-bottom profiling operations in the Middle Ground area between Block and Atlantis submarine canyons. Overall, we successfully completed 13 submersible dives and made numerous transects for sidescan sonar. Sidescan Sonar: 129.64 km; Sub-bottom profiling: 290.39; Sediment samples: 26; video and photos.

Staff: David Twichell

Affiliate Staff:
Dr. Robert S. Jones - co-Ch. Sci. (HBF); Dr. Churchill B. Grimes - co-Ch. Sci. (Rutgers); Dr. Kenneth W. Able - scientist (Rutgers); Dr. Edward P. Laine - scientist (URI); Mr. Gregory C. Kennedy - engineer (HBF); Mr. Simon Sainsbury - engineer (HBF)

Notes: Original Center People field contained: Dave Twichell - scientist.

Location Map:


photo of Johnson
photo of Johnson Sea-link
Johnson Sea-link


Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
Video camera - deep sea --- Video
Camera- deep sea --- Photo
Grab sampler --- Biology
Loran-C --- Navigation
1984-009-FA-LN-001 ( Paper printouts of navigation with 15 minute or random fix intervals: includes time, lat., long., speed and course over ground.)
1984-009-FA-LN-001-01 ( Track maps of geophysical survey areas and submersible dives, plotted from ship navigation with MapGen software, in Lat./Long.: UTM projection, 1:25,000 scale, 2 maps for each of 5 areas.)
1984-009-FA-LN-002 ( Paper charts from bridge plotter of sidescan sonar and 3.5 kHz survey lines and submersible dives; Loran-C coordinates.)
Seismic reflection ---
Sidescan sonar --- Sidescan
1984-009-FA-SO-001 ( Paper sidescan sonar profiles in folders; images not slant-range or ground-range corrected.)
Mooring tripod --- Ground Truthing
1984-009-FA-OM-001 ( Digital tape(s) of CTD STATION DATA, )
3.5 kHz --- Sub Bottom Profiler
1984-009-FA-SE-001 ( Paper 3.5 kHz seismic profiles in folders: collected via EPC recorder.)
Geomechanique streamer --- Temperature