GMX_EXT: usSEABED EXTracted data for the entire U.S. Gulf of Mexico and Caribbean (Puerto Rico and U.S. Virgin Islands)

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Frequently-anticipated questions:


What does this data set describe?

Title:
GMX_EXT: usSEABED EXTracted data for the entire U.S. Gulf of Mexico and Caribbean (Puerto Rico and U.S. Virgin Islands)
Abstract:
This data layer is a point coverage of known sediment samplings, inspections and probings from the usSEABED data collection and integrated using the software system dbSEABED. This data layer represents the extracted (EXT) output of the dbSEABED mining software. It contains data items which were simply extracted from the data resources through data mining. The EXT data is usually based on instrumental analyses (probe or laboratory) but may apply to just a subsample of the sediment (eg. no large shells).
  1. How should this data set be cited?

    U.S. Geological Survey, and Colorado, University of , 2006, GMX_EXT: usSEABED EXTracted data for the entire U.S. Gulf of Mexico and Caribbean (Puerto Rico and U.S. Virgin Islands):.

    Online Links:

    This is part of the following larger work.

    Buczkowski, B.J., Reid, J.A., Jenkins, C.J., Reid, J.M., Williams, S.J., and Flocks, J.G., 2006, usSEABED: Gulf of Mexico and Caribbean (Puerto Rico and U.S. Virgin Islands) Offshore Surficial Sediment Data Release: Data Series 146, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -97.731850
    East_Bounding_Coordinate: -63.800000
    North_Bounding_Coordinate: 30.808300
    South_Bounding_Coordinate: 16.666670

  3. What does it look like?

    <https://pubs.usgs.gov/ds/2006/146/data/gmx_ext.jpg> (JPEG)
    Image map showing extent of data layer coverage

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

    Calendar_Date: 2006
    Currentness_Reference: publication date

  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):

      • Entity point (51290)

    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 North American Datum of 1927.
      The ellipsoid used is Clarke 1866.
      The semi-major axis of the ellipsoid used is 6378206.400000.
      The flattening of the ellipsoid used is 1/294.978698.

  7. How does the data set describe geographic features?

    gmx_ext

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    LATITUDE
    Latitude coordinate of sample location (Source: source data)

    Range of values
    Units:decimal degrees

    LONGITUDE
    Longitude coordinate of sample location (Source: source data)

    Range of values
    Units:decimal degrees

    WATERDEPTH
    measured water depth for site (usually uncorrected) (Source: source data)

    Range of values
    Units:meters

    SAMPLETOP
    measured subbottom depth information for each point sample

    Range of values
    Units:meters

    SAMPLEBASE
    measured subbottom depth information for each point sample

    Range of values
    Units:meters

    SITENAME
    Survey or laboratory code for site (non-unique)

    DATASETKEY
    Unique sequential numeric key to SRC file (Source: dbSEABED processing software)

    SITEKEY
    Unique sequential numeric key to SRC file (Source: dbSEABED processing software)

    SAMPLEKEY
    Unique sequential numeric key to SRC file (Source: dbSEABED processing software)

    SAMPLER
    Equipment used to collect samples (Source: Original data source)

    DATATYPES
    Type of data that were used to derive values held in characterization

    ValueDefinition
    ACUAcoustic Properties
    CMPSediment Composition
    COLColor
    GTCGeotechnical Properties
    GRZGrain Size
    TXRTexture
    TXGTexture (Graphic)
    LTHLithology

    GRAVEL
    Gravel grainsize fraction (Source: Original data source)

    Range of values
    Minimum:0
    Maximum:100
    Units:percent
    Resolution:1

    SAND
    Sand grainsize fraction (Source: Original data source)

    Range of values
    Minimum:0
    Maximum:100
    Units:percent
    Resolution:1

    MUD
    Mud grainsize fraction (Source: Original data source)

    Range of values
    Minimum:0
    Maximum:100
    Units:percent
    Resolution:1

    CLAY
    Clay grainsize fraction (Source: Original data source)

    Range of values
    Minimum:0
    Maximum:100
    Units:percent
    Resolution:1

    GRAINSIZE
    Phi characteristic grainsize

    Range of values
    Minimum:-7.3
    Maximum:12
    Units:phi
    Resolution:0.1

    SORTING
    Phi grainsize dispersion; standard deviation sorting only

    Range of values
    Minimum:0
    Maximum:6
    Units:phi
    Resolution:0.1

    LGCRSHST
    Log Critical Shear Stress, Log10 of Tau in kPa, being the Shear Stress required to initiate easily observable erosion and transport, whether by traction or suspension

    Range of values
    Units:kPa

    SEABEDCLS
    Seabed class; (Facies) with the maximum Fuzzy Membership value > 30% (Source: dbSEABED processing software)

    CLSMSHP
    Class membership; fuzzy membership (%) of above Class (Facies) (Source: dbSEABED processing software)

    ROCKMSHP
    Rock membership; fuzzy membership (%) reflecting percent exposure of rock (Source: dbSEABED processing software)

    ValueDefinition
    -99no data

    WEEDMSHP
    Weed membership; fuzzy membership (%) reflecting percent abundance of seaweed and seagrass (Source: dbSEABED processing software)

    ValueDefinition
    -99no data

    CARBONATE
    Carbonate, including finest to coarsest sampled fractions

    MUNSLCODE
    Munsell color code (Source: GSA Rock-Color Chart, 1991)

    non-unique code based on HVC (Hue, Value, Chroma)

    ORGCARBON
    organic carbon in the sample

    Range of values
    Minimum:0
    Maximum:100
    Units:percent

    LGSHEARSTR
    Undrained compressive shear strength, Log10 of KiloPascals (Source: dbSEABED processing software)

    ValueDefinition
    -99no data

    POROSITY
    Void volume (Source: dbSEABED processing software)

    Range of values
    Units:percent

    PWAVEVEL
    Compressional wave velocity (Source: dbSEABED processing software)

    Range of values
    Units:meters/second

    ROUGHNESS
    A coded output representing the V:H of the roughness element with greatest aspect ratio (Source: dbSEABED processing software)

    Range of values
    Units:values expressed as (rounded) integer log2 of V and H in cm

    SAMPLEPHAS
    Sample Phase; records whether the results are for the whole, bulk sediment or just to some special part (Source: dbSEABED processing software)

    Range of values
    Units:Output as a word-based description that may involve numerics. This field will need to be selected against when GIS mappings of the bulk sedient characters are being mapped. Only blank entries should be included in such a mapping.

    FOLKCODE_F

    Entity_and_Attribute_Overview:
    Values of -99 for any field are indications that there was no data available.


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?

    We thank the following interns for their assistance in data entry, coding, and data testing: Viness Ubert, Emma Mitchell, Emily Denham ,Shea Quinn and Ariadne Prior-Grosch.

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

    Brian Buczkowski
    U.S. Geological Survey
    Core Curator and Data Management Specialist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    (508) 548-8700 x2361 (voice)
    (508) 457-2310 (FAX)
    bbuczkowski@usgs.gov


Why was the data set created?

To build a digital mapping of the character of the seabed on regional, national and global scales. These data are intended for science researchers, students, policy makers, and the general public. The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.


How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    Type_of_Source_Media: various hard copy documents and digital files
    Source_Scale_Denominator:
    See separate listing within this publication for specific sources and associated metadata
    Source_Contribution:
    point locations, descriptions and analytical data on many different types of sediment and rock materials and benthos

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

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


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

  1. How well have the observations been checked?

    Accuracy of each attribute is dependent on the accuracy of the lineage data.

  2. How accurate are the geographic locations?

    Locational accuracy is dependent on the accuracy of the navigational technique from the individual data sources and may vary widely (e.g., from 0.005km (differential GPS) in more recent surveys to greater than 2 km based on radar, Loran, or dead reckoning in older surveys.) Users of the data should use their own criteria for assessing the accuracy of the locations.

  3. How accurate are the heights or depths?

    Locational accuracy is dependent on the accuracy of the navigational technique from the individual data sources. Users of the data should use their own criteria for assessing the accuracy of the locations.

  4. Where are the gaps in the data? What is missing?

    Additional useable data may exist in this area; the authors appreciate any information and leads.

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

    Data in usSEABED are based on the observations and analyses of others, filtered through a unifying and mining software. Each source report varies in type of information/data recorded and format. Only those observations that are recorded can be filtered and mined; only presence (not absence) or information can be noted.


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)

    Brian Buczkowski
    U.S. Geological Survey
    Core Curator and Data Management Specialist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700x2361 (voice)
    (508) 457-2310 (FAX)
    bbuczkowski@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. Trade, firm, or product names and other references to non-USGS products and services are provided for information only and do not constitute endorsement or warranty, express or implied, by the USGS, USDOI, or U.S. Government, as to their suitability, content, usefulness, functioning, completeness, or accuracy.

  4. How can I download or order the data?

  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 importing the 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: 09-Feb-2006
Metadata author:
Brian Buczkowski
U.S. Geological Survey
Core Curator and Data Management Specialist
384 Woods Hole Rd.
Woods Hole, MA 02543-1598

(508) 548-8700x2361 (voice)
(508) 457-2310 (FAX)
bbuczkowski@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 Thu Feb 09 14:33:25 2006