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Dataset Overview | National Centers for Environmental Information (NCEI)

MGL1109 Chirp - US Extended Continental Shelf Project: Gulf of Alaska 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 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.
  • 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].
  • NCEI Metadata ID: gov.noaa.ngdc.mgg.seismic:MGL1109_SubbottomProfiler
gov.noaa.ngdc.mgg.seismic:MGL1109_SubbottomProfiler
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Search Data
  • Trackline Geophysical Data Viewer (search)
    An interactive map of tracklines providing access to marine geophysical survey data (bathymetry, gravity, magnetics, seismics), and aeromagnetic surveys in the archive.
Order Data
Distribution Formats
  • Raw Knudsen SEG-Y Datagram
Ordering Instructions Contact NCEI for other distribution options and instructions.
Distributor NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Dataset Point of Contact NOAA National Centers for Environmental Information
ncei.info@noaa.gov
Dataset Point of Contact Jennifer Jencks
NOAA National Centers for Environmental Information
303 497-6419
Jennifer.Jencks@noaa.gov
Time Period
Spatial Reference System urn:ogc:def:crs:EPSG::4326urn:ogc:def:crs:EPSG::5831
Spatial Bounding Box Coordinates
West: -153.01673
East: -138.18889
South: 53.18759
North: 57.78363
Spatial Coverage Map
General Documentation
Associated Resources
  • MGL1109
Publication Dates
  • creation: 2011-06-07
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 and velocity structure, stratigraphic architecture, and basement structure of the North Pacific seafloor in support of requirements for continental shelf maritime zone definition in the Gulf of Alaska. The program was focused on the geologic structures and dynamic processes that control the distribution of sediment, including the manner in which the processes of the slope meet the deep sea floor, and the places where sediment is thickest due to the coincidence of basement depressions and abundant sediment supply. The survey explored portions of the Surveyor and Baranof sedimentary systems, the Aja Fracture Zone and the Kodiak Bowie seamount corridor.
Dataset Citation
  • 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].
Cited Authors
  • Dr. Ginger Barth
    United States Geological Survey
Publishers
  • NOAA National Centers for Environmental Information
Theme keywords ProcessedMethod Keywords
  • Seismic:Reflection
ProcessedDataClass Keywords
  • Other
Global Change Master Directory (GCMD) Service Keywords
  • DATA ANALYSIS AND VISUALIZATION > GEOGRAPHIC INFORMATION SYSTEMS > WEB-BASED GEOGRAPHIC INFORMATION SYSTEMS
  • DATA MANAGEMENT/DATA HANDLING > DATA SEARCH AND RETRIEVAL
  • DATA ANALYSIS AND VISUALIZATION > VISUALIZATION/IMAGE PROCESSING
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
  • UNH/CCOM-JHC > Center for Coastal and Ocean Mapping - Joint Hydrographic Center, University of New Hampshire
Place keywords
  • [1137] Gulf of Alaska
  • [1139] Aja Fracture Zone
  • [1141] Surveyor Fan
  • [1140] Kodiak Bowie Seamount Corridor
  • [1138] Baranof Fan
Keywords DataType Keywords
  • Seismic:Active:Subbottom
Keywords SeismicDataProvenance Keywords
  • DigitalSeg:DigitallyAcquired
Use Constraints
  • 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.
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.
  • openRelease Date: 2011
Other Constraints 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].
Fees
  • In most cases, electronic downloads of the data are free. However, fees may apply for custom orders, data certifications, copies of analog materials, and data distribution on physical media.
Lineage information for: dataset
Lineage Statement 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.
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)
Instrument
  • Knudsen 2620
  • Kongsberg EM122
Platform
  • Marcus G. Langseth
Last Modified: 2020-05-07
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