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    • MGL1109 Chirp - US Extended Continental Shelf Project: Gulf of Alaska CHIRP High-Resolution Seismic Profile Data

    Metadata Updated: October 18, 2024

    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 200 meters and assumed sound velocity of 1500 m/s remained constant through the cruise. The resulting data records were 267 msec long, with a sample interval 0.16667 msec (6 kHz). The ping rate varied over the course of the cruise. For most of the first two weeks, the ping rate was approximately 5 seconds. On or about June 23, the ping rate was increased to approximately 2 seconds.

    Access & Use Information

    License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Date May 7, 2020
    Metadata Created Date October 18, 2024
    Metadata Updated Date October 18, 2024
    Reference Date(s) June 7, 2011 (publication)
    Frequency Of Update

    Metadata Source

    Harvested from NGDC MGG Seismic

    Other Data Resources

    Additional Metadata

    Resource Type Series
    Metadata Date May 7, 2020
    Metadata Created Date October 18, 2024
    Metadata Updated Date October 18, 2024
    Reference Date(s) June 7, 2011 (publication)
    Responsible Party NOAA National Centers for Environmental Information (Point of Contact)
    Contact Email
    Guid gov.noaa.ngdc.mgg.seismic:MGL1109_SubbottomProfiler
    Access Constraints Distribution liability: NOAA and NCEI make no warranty, expressed or implied, regarding these data, nor does the fact of distribution constitute such a warranty. NOAA and NCEI cannot assume liability for any damages caused by any errors or omissions in these data. If appropriate, NCEI can only certify that the data it distributes are an authentic copy of the records that were accepted for inclusion in the NCEI archives., Use liability: NOAA and NCEI cannot provide any warranty as to the accuracy, reliability, or completeness of furnished data. Users assume responsibility to determine the usability of these data. The user is responsible for the results of any application of this data for other than its intended purpose., Cite as: Dr. Ginger Barth. 2011: MGL1109 Chirp - US Extended Continental Shelf Project: Gulf of Alaska CHIRP High-Resolution Seismic Profile Data. NOAA National Centers for Environmental Information. Accessed [date]., open, Release Date: 2011
    Bbox East Long -138.18889
    Bbox North Lat 57.78363
    Bbox South Lat 53.18759
    Bbox West Long -153.01673
    Coupled Resource
    Frequency Of Update
    Harvest Object Id 6e93c97c-a87b-4b42-8fea-8d15ddb5f8ed
    Harvest Source Id b61d2448-d8a9-4f41-b41e-db67b3e70446
    Harvest Source Title NGDC MGG Seismic
    Licence These data not to be used for navigation. Although these data are of high quality and useful for planning and modeling purposes, they are not suitable for navigation. For official navigation products, please refer to the U.S. nautical charts available from the NOAA Office of Coast Survey: http://www.nauticalcharts.noaa.gov.
    Lineage Data Quality: The Knudsen operated continuously through the entire cruise, with only minor (on the order of minutes) data gaps. For the first two weeks of the cruise the Knudsen operated at a ping rate of approximately 5 seconds. For the final 4 or 5 days, the ping rate was reduced to approximately 2 seconds. The higher ping repetition rate improved the lateral resolution on the sub-bottom images.
    Metadata Language
    Metadata Type geospatial
    Old Spatial {"type": "Polygon", "coordinates": [[[-153.01673, 53.18759], [-138.18889, 53.18759], [-138.18889, 57.78363], [-153.01673, 57.78363], [-153.01673, 53.18759]]]}
    Progress
    Spatial Data Service Type ArcGIS Map Service
    Spatial Reference System urn:ogc:def:crs:EPSG::4326
    Spatial Harvester True

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