Tracklines of Multichannel Seismics Survey Collected During USGS Cruise M1-98-GM (GOM98LINE.SHP)

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Frequently anticipated questions:

What does this data set describe?

Title:
Tracklines of Multichannel Seismics Survey Collected During USGS Cruise M1-98-GM (GOM98LINE.SHP)
Abstract:
Shapefile showing tracklines of Multichannel Seismics Survey Collected During USGS Cruise M1-98-GM. This cruise was to the Mississippi Canyon region of the Gulf of Mexico, and data were collected along 555 km of tracklines.
During June 1998 and April 1999, the U.S. Geological Survey (USGS) conducted two research cruises in the northern Gulf of Mexico to acquire high-resolution seismic reflection data across the upper and middle continental slope as part of an investigation of the seismic character, distribution, and potential effects of naturally-occurring marine gas hydrates and related free gas within the gas hydrate stability zone. Over 1600 km of two-dimensional multichannel seismic reflection profiles were acquired during these two cruises. The specific objectives of this investigation are (a) to produce high-resolution images of the gas hydrate stability zone; (b) to study the distribution and character of potential seafloor failures and their relationship to known and inferred gas hydrate deposits; (c) to look at systematic variations in subsurface structure in gas hydrate and non-hydrate areas; and (d) to estimate, if possible, the amounts of hydrates present within the gas hydrate stability zone. The multichannel profiles provide high-quality images with approximately 5 meters of vertical resolution and up to 2 km of penetration. This report gives an overview of the acquisition and data processing of the multichannel seismic reflection profiles and provides references and links to reports with more detailed information. Geologic interpretations of these seismic profiles regarding gas hydrate occurrence and distribution within the study areas of this investigation are given in Hart and others (2002).
  1. How might this data set be cited?
    Hart, Patrick E., Cooper, Alan K., and Twichell, David, 2005, Tracklines of Multichannel Seismics Survey Collected During USGS Cruise M1-98-GM (GOM98LINE.SHP): Open-File Report 2005-1071, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Twichell, D.C., Cross, V.A., Paskevich, V.F., Hutchinson, D.R., Winters, W.J., and Hart, P.E., 2005, GIS of selected geophysical and core data in the northern Gulf of Mexico continental slope collected by the U.S. Geological Survey: Open-File Report 2005-1071, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details: 1 DVD-ROM
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -89.941090
    East_Bounding_Coordinate: -88.997710
    North_Bounding_Coordinate: 28.657360
    South_Bounding_Coordinate: 28.026890
  3. What does it look like?
    https://pubs.usgs.gov/of/2005/1071/data/seismic/1998/nav/gom98_line-thumb.gif (GIF)
    Thumbnail image showing the extent and coverage of the data layer.
    https://pubs.usgs.gov/of/2005/1071/data/seismic/1998/nav/gom98_line.gif (GIF)
    Image showing the extent and coverage of the data layer.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 01-Jun-1998
    Ending_Date: 30-Jun-1998
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • String (41)
    2. What coordinate system is used to represent geographic features?
      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.
  7. How does the data set describe geographic features?
    gom98line
    Shapefile Attribute Table (Source: ESRI)
    FID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: ESRI) Coordinates defining the features.
    ID
    sequential numbers (Source: user defined)
    Range of values
    Minimum:1
    Maximum:41
    Units:integer
    Resolution:1
    LINENUM
    Number associated with each seismic survey line (Source: USGS) Character string representing the survey line
    IMAGE
    Path to and name of image of seismic profile associated with each survey line. (Source: USGS) Character stringin containing the relative path and name of image of seismic profile that is linked to this track line.
    LENGTH
    length of trackline in meters (Source: Software Computed)
    Range of values
    Minimum:3282.795
    Maximum:55944.282
    Units:meters
    Resolution:.001

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Hart, Patrick E.
    • Cooper, Alan K.
    • Twichell, David
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Hart, Patrick
    U.S. Geological Survey
    Geophysicist
    345 Middlefield Road, MS 999
    Menlo Park, CA
    USA

    650-329-5160 (voice)
    650-329-5190 (FAX)
    hart@usgs.gov

Why was the data set created?

This GIS overlay is a component of the U.S. Geological Survey, Woods Hole Field Center's, Gulf of Mexico GIS database. The Gulf of Mexico GIS database is intended to organize and display USGS held data and provide on-line (WWW) access to the data and/or metadata.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: unknown (process 1 of 6)
    The navigation text file gm98nav.txt was imported form USGS Open-File Report 02-368. This ASCII file was imported to Microsoft Excel and then exported as a comma delimited text file. ArcView 3.3 was uses to add the comma delimited text to the project as a table, and the table then was saved as a shapefile. Person who carried out this activity:
    VeeAnn Cross
    U.S. Geological Survey
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
    Data sources used in this process: Data sources produced in this process:
    • gom98shtallg.shp
    Date: unknown (process 2 of 6)
    The point shapefile (gom99shtallg.shp) was converted to a line file using an Avenue script "navpnts2line.ave" written by VeeAnn Cross. Person who carried out this activity:
    VeeAnn Cross
    U.S. Geological Survey
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA
    USA

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov
    Data sources used in this process:
    • gom99shtallg.shp
    Data sources produced in this process:
    • gom99lmcs.shp
    Date: 07-Mar-2017 (process 3 of 6)
    Edits to the metadata were made to fix any errors that MP v 2.9.36 flagged. This is necessary to enable the metadata to be successfully harvested for various data catalogs. In some cases, this meant adding text "Information unavailable" or "Information unavailable from original metadata" for those required fields that were left blank. Other minor edits were probably performed (title, publisher, publication place, etc.). Attempted to modify http to https where appropriate. The link to the larger work citation had to be fixed. Updated the online links to the cross-references. The metadata date (but not the metadata creator) was edited to reflect the date of these changes. The metadata available from a harvester may supersede metadata bundled within a download file. Compare the metadata dates to determine which metadata file is most recent. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 20-Jul-2018 (process 4 of 6)
    USGS Thesaurus keywords added to the keyword section. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 18-Nov-2019 (process 5 of 6)
    Crossref DOI link was added as the first link in the metadata. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
    Date: 08-Sep-2020 (process 6 of 6)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Hart, P.E., Cooper, A.K., Twichell, D.C., Lee, M., and Agena, W., 2002, High-resolution multichannel seismic-reflection data acquired in the northern Gulf of Mexico, 1998-99: Open-File Report 02-368, U.S. Geological Survey, Reston, VA.

    Online Links:

    Cooper, Alan, Hart, Patrick, and Pecher, Ingo, 1998, Cruise Report for a Seismic Investigation of Gas Hydrates in the Mississippi Canyon Region, Northern Gulf of Mexico - Cruise M1-98-GM: Open-File Report 98-506, U.S. Geological Survey, Reston, VA.

    Online Links:

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Information unavailable from original metadata.
  5. How consistent are the relationships among the observations, including topology?
    No additional checks for topological consistency were performed on this data set. No duplicate features are present.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.
  1. Who distributes the data set? (Distributor 1 of 1)
    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@usgs.gov
  2. What's the catalog number I need to order this data set? Downloadable Data
  3. What legal disclaimers am I supposed to read?
    Although this data set has been used by the U.S. Geological Survey (USGS), no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?
    • Availability in digital form:
      Data format: The SHP file contains the geospatial data. The SHX file contains the index of the geospatial data. The DBF file contains the attribute data in dBase format. The PRJ file contains the coordinate system information (optional). The AVL file contains the legend information (optional). The SBN and SBX files contain the spatial index of the geospatial data (optional). The XML file contains the metadata describing the data set <data set name>.shp.xml. An ASCII version of the metadata file. A browse graphic showing the data layer coverage and extent (optional). in format SHP (version 3.3) ESRI Shapefile Format Size: 0.060
      Network links: https://pubs.usgs.gov/of/2005/1071/data/seismic/1998/nav/gom98line.zip
      Media you can order: DVD-ROM (Density 4.75 Gbytes) (format UDF)
    • Cost to order the data: None

  5. What hardware or software do I need in order to use the data set?
    These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS® or ArcView® 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of the importing data. A free data viewer, arcexplorer, capable of displaying the data is available from ESRI at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 11-Nov-2021
Metadata author:
David C. Twichell
U.S. Geological Survey
Oceanographer
384 Woods Hole Road
Woods Hole, MA
USA

(508) 548-8700 x2266 (voice)
(508) 457-2310 (FAX)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the metadata contact is no longer with the USGS
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/open_file_report/ofr2005-1071/gom98linemeta.faq.html>
Generated by mp version 2.9.50 on Mon Nov 15 14:24:34 2021