USGS Coastal and Marine Geology Program

Coastal & Marine Geology Program

Field Activity Details for field activity 1984-006-FA

Other ID: 84-1

Status: Completed

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

Funding Program(s):

Location: Enewetak Atoll, Enewetok, Marshall Islands, Trust Territory of the Pacific Islands (TTPI), North Pacific;

Principal Investigator(s): David W. Folger

Affiliate Investigator(s): R.C. Hollar - Party Chief, Meridian Ocean Systems

Information Specialist(s):

Data Type(s): Imagery: Photo, Location-Elevation: Navigation, Seismics: Boomer, Sonar: Sidescan, Sonar: Single Beam

Scientific Purpose/Goals: Geologic investigations of two nuclear craters.


Start Date: 1984-06-10

Start Port/Location: Kwajelein, Trust Territory of the Pacific Islands

End Date: 1984-07-08

End Port/Location: Kwajelein, Trust Territory of the Pacific Islands

Equipment Used: Raytheon DE-719 precision echo sounder, Huntec profiling system (500-2500 Hz), Klein 531 sidescan, 35 mm camera, Motorola Falcon IV Microwave relay Mini-Ranger

Information to be Derived:

Summary of Activity and Data Gathered: In Enewetak Lagoon 12 June - 5 July; on survey 19 June - 4 July following navigation set up and area reconnaissance. This operation was the first of several phases of investigation of two nuclear test craters, OAK and KOA, in the northern part of Enewetak Atoll. Data were acquired in parallel-line grids having nominal line spacings of 26 km (85 ft) for bathymetry, and 76 m (250 ft) for sidescan sonar and sub-bottom (Huntec boomer) profiles. Tie-line data were also acquired. Additional bathymetric data were acquired by small boat. The ship was operated only during daylight hours because hazards from shallow water and proximity to the reef required maximum visibility. A mosaic of the sidescan sonar images was constructed from the field data during the operation. A tide gauge was deployed in each of the craters for bathymetric corrections, although only the KOA gauge appears to have operated successfully. Bathymetry data: 350 km; Sidescan sonar data: 210 km; Sub-bottom profiler (Huntec) data: 115 km.

Staff: Dann Blackwood, David W. Folger, Gregory Miller, Kenneth E. Parolski, James M. Robb

Affiliate Staff:
Meridian Ocean Systems
Inc. (MOS): R.C. Hollar - Party Chief
A. Pearce
S.L. Thoresen
M. Milburn; Defense Nuclear Agency (DNA): E.L. Tremba - observer
B.L. Ristvet - observer; Defense Mapping Agency (DMA): H.V. Woodworth - navigational specialist

Notes: Original Center People field contained: Dave Folger (Ch. Sci./geologist); James Robb (curator/geologist); Greg Miller (technician); Kenneth Parolski (technician); Dann Blackwood (photographer).
Project = Pacific Enewetak Atoll Crater Exploration (PEACE), Pacific Enewetak Atoll Crater Exploration (PEACE)

Location Map:


photo of Egabrag II
Egabrag II


Data Acquired

Survey EquipmentSurvey InfoData Type(s)Data Collected
Raytheon DE-719 precision echo sounder --- Single Beam
Huntec profiling system (500-2500 Hz) --- Boomer
1984-006-FA-SE-004 ( analog tape of seismic data)
1984-006-FA-SE-002 ( microfilm of )
1984-006-FA-SE-001 ( Collection of paper record displays of seismic data( SBP) for lines )
1984-006-FA-SE-003 ( analog tape of seismic data)
Klein 531 sidescan --- Sidescan
1984-006-FA-SO-002 ( analog tape of seismic data)
1984-006-FA-SO-001 ( microfilm of )
35 mm camera --- Photo
Motorola Falcon IV Microwave relay Mini-Ranger --- Navigation