MGL111 Chirp - US Extended Continental Shelf Project: Bering Sea CHIRP high-resolution Seismic Profile data.

The Knudsen 2620 acquired sub-bottom profiles continuously
throughout the cruise. The Knudsen was operated in 3.5 kHz Chirp mode, emitting a 1.5
kHz to 5 kHz (3 kHz bandwidth centered on 3.5 kHz) pulse from transducers mounted in
the pod beneath the hull. A record window of 100 or 200 meters and assumed sound
velocity of 1500 m/s remained constant through the cruise, except for areas where
topographic variation dictated a >200meter record window. The resulting data
records were 131 or 261 msec long, with a sample interval 0.038 msec. The ping rate
varied over the course of the cruise, generally between 4 and 6
Cite this dataset when used as a source.
  • gov.usgs.mgl1111chirp_field
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Distribution Formats
  • Raw Knudsen SEG-Y Datagram
    • File Compression: None (transfer size in MB)
Distributor User Services
DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Dataset author Dr. Ginger Barth
United States Geological Survey
Dataset Principal Investigator Dr. Ginger Barth
United States Geological Survey
Time Period 2011-08-08 to 2011-09-02
Spatial Reference System urn:ogc:def:crs:EPSG::4326urn:ogc:def:crs:EPSG::5831
Spatial Bounding Box Coordinates
N: 58.82082
S: 53.89308
E: -166.47889
W: 174.12081
Spatial Coverage Map
Documentation links not available.
Publication Dates
  • creation: 2011-08-08
Dataset Progress Status Status not available
Data Update Frequency Data update frequency not available
Purpose The purpose of this field program was to determine sediment thickness, sedimentary architecture and velocity structure, and basement structure in support of requirements for continental shelf maritime zone definition in the Bering Sea. The program was focused on the velocity structure of the sedimentary fill in the central Aleutian basin, and the structures and processes that control variability in that velocity profile, including the influence of basement structure and the distribution of natural gas and hydrate charged sediments. The survey primarily explored the region of the central ??donut hole?? of international waters in the deep Aleutian basin, and included some coverage southward into the US EEZ approaching Bowers ridge. Project website:
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
Theme keywords ProcessedMethod Keywords
  • Seismic:Reflection
ProcessedDataClass Keywords
  • Other
Global Change Master Directory (GCMD) Service Keywords
Data Center keywords Global Change Master Directory (GCMD) Data Center Keywords
  • DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce
  • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
Place keywords
  • [1495] Bowers Ridge
  • [1494] Shirshov Ridge
  • [1493] Aleutian Basin
Keywords DataType Keywords
  • Seismic:Active:Subbottom
Keywords SeismicDataProvenance Keywords
  • DigitalSeg:DigitallyAcquired
Use Constraints No constraint information available
Access Constraints
  • open
Fees Fee information not available.
Lineage information for: dataset
Lineage Statement Data Quality: The Knudsen operated continuously through the entire cruise except for OBS deployment and recovery stations when pinger systems were secured. Several data gaps occurred (on MCS lines 2,7 and 9) when the system stopped recording .segy format ?? this missing data is recorded in the kea- keb format files.
Lineage information for: repository
Processing Steps
  • 2015-04-22T00:00:00 - NOAA created the National Centers for Environmental Information (NCEI) by merging NOAA's National Climatic Data Center (NCDC), National Geophysical Data Center (NGDC), and National Oceanographic Data Center (NODC), including the National Coastal Data Development Center (NCDDC), per the Consolidated and Further Continuing Appropriations Act, 2015, Public Law 113-235. NCEI launched publicly on April 22, 2015.
Acquisition Information (collection)
  • Knudsen 2620
  • Kongsberg EM122
  • Marcus G. Langseth
Last Modified: 2017-12-21
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