National Geophysical Data Center
MULTICHANNEL COMMON DEPTH POINT (CDP) DATA
Florida to New Jersey - Atlantic OCS
Data Announcement 83-MGG-17
Multichannel Common Depth Point (CDP) data for 17 lines
totaling approximately 1,241-line-km are now available from the
National Geophysical Data Center (NGDC). The data were collected
in June and July 1979 on the Atlantic Outer Continental Shelf
from Florida to New Jersey by the Seismic Division of Whitehall
Corporation under Contract No. 14-08-0001-16330 to the U.S.
Geological Survey (USGS) Conservation Division, now the Minerals
Management Service, U.S. Department of the Interior.
A 21-airgun tuned-array marine acoustic source with a total
gross volume of 2,183 cu. in. was used in this survey. The tuned
system consisted of three sub-arrays having volumes of 182 cu.
in. was used in this survey. The tuned system consisted of three
sub-arrays having volumes of 182 cu. in., 708 cu. in., and 1293
cu. in. The 21 guns were towed astern in two parallel strings 65
ft apart. The gun group on each string was 75 ft overall with
the nearest gun 80 ft form the ship's stern. The CDP data,
available as hard copy in either sepia or blackline, consist of
25 sections of both true relative records and scaled sections,
giving a total of 69 individual records. The average line length
is 75 km. In addition, two survey reports, 25 velocity profiles,
single-trace seismic profiles and fathometer records are
contained on one reel of 35-mm microfilm.
Navigational positions were achieved by an integrated
Satellite-Doppler-Sonar Magnavox MX-200 system. Basic position
reference was obtained from the U.S. Navy Navigation Satellite
System, with fixes available every 60 to 90 min. Loran-C was
integrated with the SatNav positions. Nineteen post-plot maps
are scaled on UTM grids of 1:96,000 or 1:500,000. "Tic" marks at
every 80,000 ft are annotated along with latitude/longitude tics
at every 30 min of arc. Fifteen maps show shot-point locations
for lines D M V G F. Four maps indicate locations of the CH
lines. Labeling of the points on the maps is at 50-shot (2,500
A digital magnetic tape containing latitude, longitude,
time, and date for every plotted point is also available. The
magnetic tape contains every 10th point on each line at an
interval of 500 m. Magnetic tape specifications are in modified
U.K. Offshore Operators Association (UKOOA) format, IBM
compatible, 9-track, 1600 EBCDIC-character coding, odd parity,
record length 80 bytes followed by an inter-record gap. The tape
is divided into two parts: a 4-record header and a multi-record
shot-point data section. Format specifications are provided.
The following data is availabe in plastic sepia, paper sepia, and
25 sections Common Depth Point Seismic Profiles
15 Shot-Point Maps (scale: 1:96,000)
4 Shot-Point Maps (scale: 1:500,000)
The following data is available in 35-mm microfilm:
1 Reel (No. 2046) microfilm. Contains survey reports, trace
1 Navigation magnetic tape/cdrom and documentation.
Please contact NGDC for prices.