National Centers for Environmental Information (NCEI)

Navarin Basin-Northern Bering Sea-Alaska
USGS Open File Report 86-207

Data Announcement 86-MGG-25

     Approximately 3,200-km of 24-channel seismic-reflection profile data across the continental margin in the northeastern Bering Sea are available for purchase from the National Geophysical Data Center (NGDC) (now the National Centers for Environmental Information (NCEI)). These profiles were provided to NGDC (now NCEI) for public dissemination by the U.S. Geological Survey, U.S. Department of Interior. This data set has 12 seismic lines (20 sections).

     These profile data were collected during the summer of 1977 by the R/V S.P. LEE using a sound source of five airguns with a volume of 1,326 cu. in. of air compressed to approximately 2,000 psi. The recording system consisted of a 24-channel streamer, 2400 m long with a group interval of 100 m and a GUS (Global Universal Science) model 4200 digital recording instrument. Shots were fired every 50 m. Navigational control for the survey was provided by a Marconi-Integrated navigation system using transit satellites and Doppler sonar augmented by Loran C (Rho- Rho). A 2-msec sampling rate was used in the field. The data were later desampled to 4 msec during the demultiplexing process. Record lengths vary from 6 to 12 sec, depending on water depth and geologic structure, to give 6 to 8 sec of data below the seafloor. Processing was handled at the USGS Pacific Marine Geology Multichannel Processing Center in Menlo Park, California in the sequence: editing-demultiplexing, velocity analysis, CDP stacking, deconvolution-filtering, and plotting on an electrostatic plotter. These seismic data are also available in SEG-Y format as stacked or demultiplexed magnetic tapes. Previous data offered by NGDC (now NCEI) for the Navarin Basin are listed in the Previous Data Announcements for the Navarin Basin section of this announcement.
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"Multichannel Seismic-Reflection Profiles Collected in 1977 in the Northern Bering Sea," Alan K. Cooper, Michael S. Marlow, and Dennis M. Mann, USGS Geological Survey Open File Report 86- 207, U.S. Geological Survey, Dept. of Interior, Menlo Park, CA 94025.

DATA AVAILABLE

Electrostatically Plotted Profiles (deconvolved and filtered after stacking):

         20 Lines (sections) available on plastic sepia, paper sepia and blackline.

Navigation Data:

         1 shot-point navigation map available in plastic sepia, paper sepia and paper blackline.

         1 shot-point navigation tape (9-track, 1600 bpi, ASCII). This is also available on CD-ROM.

Digital Seismic Data:

         16 Stacked Tapes
         532 Demultiplexed Tapes

INQUIRIES ARE INVITED REGARDING THE AVAILABILITY AND PRICES OF
OTHER DATA IN THE ALASKA AREA.