LOBE.SHP - Extent of a depositional lobe on the Mississippi Fan

Metadata also available as - [Outline] - [Parseable text]

Frequently-anticipated questions:


What does this data set describe?

Title: LOBE.SHP - Extent of a depositional lobe on the Mississippi Fan
Abstract:
Since 1982 the U.S. Geological Survey (USGS) has collected a large amount of surficial and shallow subsurface geologic information in the deep parts of the Gulf of Mexico. These data include digital sidescan sonar imagery, digital seismic-reflection data, and descriptions and analyses of piston and gravity cores. The data were collected during several different projects that addressed surficial and shallow subsurface geologic processes. Some of these data sets have already been published, but the growing interest in the occurrence and distribution of gas hydrates in the Gulf of Mexico warrants integrating these existing data and associated interpretations into a GIS to provide regional background information for ongoing and future gas hydrate research.
  1. How should this data set be cited?

    Twichell, David, 20000404, LOBE.SHP - Extent of a depositional lobe on the Mississippi Fan: Open-File Report 2005-1071, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole 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, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details: 1 DVD-ROM

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -86.423326
    East_Bounding_Coordinate: -85.015959
    North_Bounding_Coordinate: 26.836068
    South_Bounding_Coordinate: 26.117291

  3. What does it look like?

    <http://pubs.usgs.gov/of/2005/1071/data/sidescan/interpretation/seamarc/lobe-thumb.gif> (GIF)
    Thumbnail image showing the extent and content of the data layer.
    <http://pubs.usgs.gov/of/2005/1071/data/sidescan/interpretation/seamarc/lobe.gif> (GIF)
    Overview image showing the extent and content of the data layer.

  4. Does the data set describe conditions during a particular time period?

    Calendar_Date: 02-Feb-1982
    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):

      • G-polygon (1)

    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 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.

  7. How does the data set describe geographic features?

    lobe
    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
    an ArcInfo internal control parameter automatically created during processing (Source: Software Generated)

    Range of values
    Minimum:0
    Maximum:0
    Units:integer count
    Resolution:1


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@usgs.gov


Why was the data set created?

This GIS data layer contains an interpretive layer outlining the extent of the youngest depositional lobe on the Mississippi Fan that was mapped using the GLORIA sidescan sonar imagery


How was the data set created?

  1. From what previous works were the data drawn?

    LOBE shapefile and enhanced GLORIA sidescan sonar image (source 1 of 1)
    Twichell, David, 2001, LOBE - shapefile containing interpretation of the extent of the depositional lobe of the Mississippi Fan: Open-File Report 00-352, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Paskevich, V., Twichell, D., and Schwab, W., 2001, SeaMARC1A sidescan mosaic, cores and depositional interpretation of the Mississippi Fan: ArcView GIS Data Release: Open-File Report 00-352, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details: 1 CD-ROM
    Type_of_Source_Media: CD-ROM
    Source_Contribution:
    The GOIRIA sidescan sonar mosaic was used as the source from which to identify the depositional lobe in the Mississippi Fan on which the SeaMARC 1A sidescan sonar survey was conducted.

  2. How were the data generated, processed, and modified?

    Date: 28-Feb-2000 (process 1 of 3)
    The GLORIA sidescan sonar mosaic was registered and displayed in ArcView. The interpretaiton of the extent of the depositional lobe was then interactively drawn over the mosaic to create the ArcView GIS layer.

    Person who carried out this activity:

    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@usgs.gov

    Data sources used in this process:
    • gloria.tif

    Data sources produced in this process:

    • lobe.shp
    • lobe.dbf
    • lobe.shx

    Date: 2005 (process 2 of 3)
    The projection of the shapefile was originally Geographic-NAD27, and it was changed to Geographic-WGS84 using the Project utility in ArcToolBox.

    Person who carried out this activity:

    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@usgs.gov

    Data sources used in this process:
    • lobe.shp

    Data sources produced in this process:

    • lobe_project.shp

    Date: 2005 (process 3 of 3)
    Dataset copied and renamed.

    Person who carried out this activity:

    David Twichell
    U.S. Geological Survey
    Oceanographer
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2266 (voice)
    (508) 457-2310 (FAX)
    dtwichell@usgs.gov

    Data sources used in this process:
    • lobe_project.shp

    Data sources produced in this process:

    • lobe.shp

  3. What similar or related data should the user be aware of?

    Paskevich, V., Twichell, D., and Schwab, W., 2001, SeaMARC 1A sidescan sonar mosaic, cores and depositional interpretation of the Mississippi Fan: ArcView GIS data release: Open-File Report 00-352, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    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?

  5. How consistent are the relationships among the observations, including topology?

    No additional checks for topological consistency were performed on this data set.


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 Road
    Woods Hole, MA 02543-1598
    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?

  5. What hardware or software do I need in order to use the data set?

    The 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 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: 13-Dec-2005
Metadata author:
U.S. Geological Survey
c/o Valerie Paskevich
Information Specialist / GIS Coordinator
384 Woods Hole Road
Woods Hole, MA 02543-1598
USA

(508) 548-8700 x 2281 (voice)
(508) 457-2310 (FAX)
vpaskevich@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


Generated by mp version 2.8.6 on Tue Dec 13 13:35:25 2005