National Geophysical Data Center
MULTICHANNEL SEISMIC-REFLECTION PROFILES
Eastern Gulf of Alaska
USGS Open File Report 84-6*
Data Announcement 84-MGG-17
Approximately 2,492 km of 24-channel seismic-reflection
profiles are now available for the Eastern Gulf of Alaska. The
profiles were collected by the U.S. Geological Survey (USGS) on
the USGS Research Vessel S.P. LEE during the summer of 1977 (USGS
Open File Report 84-6).* A sound source of five airguns was used
with a volume of 1,326 cu. in. of air compressed to approximately
1,950 psi. The recording system consisted of a 24-group
streamer, 2,400 m long and a GUS (Global Universal Science) model
4200 recording instrument. Shots were fired every 50 m with a
group interval of 100 m. A 2-msec sampling rate was used in the
field. The data were later desampled to 4 msec during the
demultiplexing process. Navigational control for the survey was
obtained with a Marconi integrated satellite-Doppler sonar
navigation system.
The seismic-reflection record lengths vary from 6 to 10 sec,
depending on water depth, to obtain a 5-to 6-sec penetration
below the seafloor. The data have been processed in a sequence
of editing, demultiplexing, velocity analysis, stacking, and
deconvolution filtering; and graphically displayed on an
electrostatic plotter. The USGS, Department of Interior, has
provided these data to the National Geophysical Data Center
(NGDC) for public dissemination.
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* "Multichannel Seismic-Reflection Profiles Collected in 1977 in
the Eastern Gulf of Alaska," Dennis M. Mann and Terry R. Bruns,
U.S. Geological Survey, Menlo Park, CA USGS Open Report 84-6.
DATA AVAILABILITY
Electrostatically plotted profiles which have been
deconvolved and filtered after stacking:
34 lines available in plastic sepia, paper sepia, and
blackline.
1 navigation tape, 9-track, 1600 bpi, ASCII. This is
also available on CD-ROM.
1 trackline map available in plastic sepia, paper
sepia, and blackline.
Please contact NGDC for prices.
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