Calculated seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_clc.txt)

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Frequently-anticipated questions:

What does this data set describe?

Title:
Calculated seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_clc.txt)
Abstract:
This data layer (PAC_CLC.txt) is one of five point coverages of known sediment samples, inspections, and probes from the usSEABED data collection for the U.S Pacific continental margin integrated using the software system dbSEABED. This data layer represents the calculated (CLC) output of the dbSEABED mining software. Data in this file extend variables determined through the data extraction (EXT) and data parsing (PRS) processes of dbSEABED, calculated using empirical relations or known functions. The CLC data is the most derivative and least accurate of the usSEABED data files and should be used with caution; however, many users may appreciate that it extends the coverage of map areas with attributes, especially physical properties attributes. Please refer to the dbSEABED page (<https://pubs.usgs.gov/ds/2006/182/dbseabed.html>), and the Frequently Asked Questions (<https://pubs.usgs.gov/ds/2006/182/faq.html>) pages for more information on the calculation process. This file contains the same data fields as the extracted (PAC_EXT) and parsed (PAC_PRS) data files, and the three files may be combined.
  1. How should this data set be cited?

    Reid, Jane A. , Reid, Jamey M. , Jenkins, Chris J. , Zimmermann, Mark, Williams, S. Jeffress , and Field, Michael E. , 2006, Calculated seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_clc.txt):.

    Online Links:

    This is part of the following larger work.

    Reid, Jane A. , Reid, Jamey M. , Jenkins, Chris J. , Zimmermann, Mark, Williams, S. Jeffress , and Field, Michael E. , 2006, usSEABED: Pacific Coast Offshore Surficial-Sediment Data Release: Data Series 182, U.S. Geological Survey, Coastal and Marine Geology Program, Pacific Science Center, Santa Cruz, CA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -129.28899
    East_Bounding_Coordinate: -117.00678
    North_Bounding_Coordinate: 48.99833
    South_Bounding_Coordinate: 30.57000

  3. What does it look like?

    <https://pubs.usgs.gov/ds/2006/182/data/pac_clc.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 (25320)

    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 0.00001. Longitudes are given to the nearest 0.00001. 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?

    Entity_and_Attribute_Overview:
    Values of -99 for any field (-999 for longitude) are indications that there was no data available.
    Entity_and_Attribute_Detail_Citation: See dbSEABED page in Larger_Work_Citation
    Point
    Sample location (Source: Source reports)

    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: Defined by original source)

    Location information in decimal degrees

    Longitude
    Longitude coordinate of sample location (Source: Defined by original source)

    Location information in decimal degrees

    WaterDepth
    Water depth of sample (Source: Defined by original source)

    Water depth of sample in meters

    SampleTop
    Measured subbottom depth information for each point sample or subsample (top) (Source: Defined by original source)

    Subsample location information in meters

    SampleBase
    Measured subbottom depth information for each point sample or subsample (bottom) (Source: Defined by original source)

    Subsample location information in meters

    DataSetKey
    Data set key (relational link) (Source: dbSEABED MNEv program)

    Unique sequential numeric key to PAC_SRC file

    SiteKey
    Site key (relational link) (Source: dbSEABED MNEv program)

    Unique sequential numeric key to information about the same site in other usSEABED data files

    SampleKey
    Sample key (relational link) (Source: dbSEABED MNEv program)

    Unique sequential numeric key to information about the same sample or subsample in other usSEABED data files

    DataType
    Type of data that were used to derive values held in characterization (Source: dbSEABED MNEv program)

    ValueDefinition
    ACUAcoustic properties
    AGEAge of sample
    BIOBiota
    CMPSediment composition
    COLColor of sample
    GTCGeotechnical properties
    GRZGranulometric analyses
    LTHLithologic descriptions
    SFTSea floor type descriptions
    TXRTextural analyses and statistics

    Gravel
    Gravel grain-size fraction (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    Sand
    Sand grainsize fraction (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    Mud
    Mud grainsize fraction (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    Clay
    Clay grainsize fraction (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    Grainsize
    Phi characteristic grainsize (moment mean or median) see Larger_Work_Citation (Source: dbSEABED MNEv program and thesaurus)

    Range of values
    Minimum:-12
    Maximum:12
    Units:Phi
    Resolution:0.1

    Sorting
    Phi grainsize dispersion; Moment measure standard deviation sorting only (Source: dbSEABED MNEv program and thesaurus)

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

    SeabedCls
    Seabed class; (Facies) with the maximum fuzzy membership value > 30%; see pac_fac.txt file (Source: dbSEABED program MNEv and thesaurus)

    ValueDefinition
    [blank]No data

    ClsMShp
    Class membership; fuzzy membership (%) of above Class (Facies) (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    FolkCode
    Grainsize classification (Source: Folk, Andrews, and Lewis, 1970)

    ValueDefinition
    [blank]No data

    ShepardCode
    Shepard code; grain size classification (Source: Shepard, 1954)

    ValueDefinition
    [blank]No data

    RockMshp
    Rock membership; fuzzy membership (%) reflecting percent exposure of rock (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    WeedMshp
    Weed membership; fuzzy membership reflecting abundance of seaweed and seagrass (Source: dbSEABED processing software MNEv and thesaurus)

    ValueDefinition
    [blank]No data

    Carbonate
    Carbonate, including finest to coarsest sampled fractions (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

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

    ValueDefinition
    [blank]No data

    OrgCarbon
    Organic carbon in the sample (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    LgShearStr
    Undrained compressive shear strength, Log10 of KiloPascals (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    -99No data

    Porosity
    Void volume (Source: dbSEABED MNEv program and thesaurus)

    Range of values
    Minimum:0
    Maximum:Unknown
    Units:Percent
    Resolution:1

    PWaveVel
    Compressional wave velocity (Source: dbSEABED MNEv program and thesaurus)

    Range of values
    Minimum:1464
    Maximum:1784
    Units:Meters per second
    Resolution:1.0

    Roughness
    A coded output representing the V:H of the roughness element with greatest aspect ratio (Source: dbSEABED MNEv program and thesaurus)

    ValueDefinition
    [blank]No data

    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 (Source: dbSEABED MNEv program and thesaurus)

    Range of values
    Minimum:-1.33
    Maximum:1.7
    Units:Log (10) Tau in KPa
    Resolution:0.1

    SamplePhase
    Sample Phase; records whether the results are for the whole, bulk sediment or just to some special part (Source: Original source)

    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.

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 contributors of the data and the following interns for their assistance in data entry, coding, and testing, and (or) assistance with source metadata: K. Halimeda Kilbourne, Carolynn Box, Tara Kneeshaw, Jennifer Mendonca, April Villagomez, Monica Iglecia, and Adam Jackson.

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

    Jane A. Reid
    U.S. Geological Survey
    Geologist
    USGS Pacific Science Center
    Santa Cruz, CA 95060-5792
    USA

    831-427-4727 (voice)
    jareid@usgs.gov

    Contact_Instructions: email preferred

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?

    Varies with source (source 1 of 1)
    Various, Unknown, See Data Sources page (<https://pubs.usgs.gov/ds/2006/182/pac_sources.html> and links therein, or the relationally linked file <https://pubs.usgs.gov/ds/2006/182/data/pac_src.txt> (PAC_SRC.txt), and links therein, within the data publication (see <https://pubs.usgs.gov/ds/2006/182/>) for the specific sources and associated metadata.: Various publishers/originators, Various publication places.

    Other_Citation_Details:
    Over 300 sources, both published and unpublished, are used as the sources of information for usSEABED. Metadata for each source is given through the Data Sources page (<https://pubs.usgs.gov/ds/2006/182/pac_sources.html>) and relationally linked to the data through the file <https://pubs.usgs.gov/ds/2006/182/data/pac_src.txt> (PAC_SRC.txt). Sources include the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), Minerals Management Service (MMS), National Oceanic and Atmospheric Administration (NOAA), the University of Washington, Seattle, Oregon State University, Corvallis, Universities of California, Berkeley, Los Angeles, and San Diego, University of Southern California, San Jose and Humboldt State Universities, Naval Postgraduate School, Virginia Institute of Marine Science (VIMS) and other educational institutions, the Maryland and New Jersey State Geological Surveys (MGS, NJGS), U.S. Navy, Southern California Coastal Water Research Project (SCCWRP), other local and regional consortia and authorities, NOAA's National Geophysical Data Center (NGDC), the Smithsonian Institution, and others.
    Type_of_Source_Media: Hard copy and digital
    Source_Contribution:
    Point locations, descriptions, and various analytical data (textural, granulometric, geochemical, geophysical, acoustic) on sediments, rock exposure, and benthos. Contributions vary with source.

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

    Date: 22-Dec-2005 (process 1 of 1)
    Source data may be digitized as necessary (typed or scanned in), with a visual inspection of digitized data to the source report and corrections as necessary, and are tested for completeness in Microsoft Excel as appropriate. Other digital data may be decoded using source-specific programs, downloaded via the web, or sent directly to the USGS or University of Colorado via email. Data are formatted into the dbSEABED Data Entry template (db9_DataEntry.xls, version 05/27/05) by hand, and tested using the dbSEABED relational database program (RDBi, version 01/05/2005) for correctness of formatting. For consistency, simple unit changes may be done. Data are compiled into source data resource files (DRF) and were processed through the dbSEABED data mining program (MNEv, version 12/18/2005) program, using the dbSEABED thesaurus (db9_dict.rtf, version 10/29/2005) and component set up file for U.S. waters (SET_ABUN.txt, version 07/20/2005). Data are iteratively reprocessed and corrected until noted errors are fixed, as recorded by the _RBDS.2fx and _MNE.DGN files. Data are exercised in a GIS for location tests and useability.

    Person who carried out this activity:

    U.S. Geological Survey
    c/o Jane A. Reid
    Geologist
    USGS Pacific Science Center
    Santa Cruz, CA 95060-5792
    USA

    831.427.4727 (voice)
    jareid@usgs.gov

    Contact_Instructions: Email preferred
    Data sources produced in this process:
    • PAC_CLC.txt

  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, and the accuracy of the mining software, dbSEABED, and the assumptions made by the empirical relationships noted between variables.

  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 the usSEABED data collection 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 absences) of 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)

    U.S. Geological Survey
    c/o Jane A. Reid
    Geologist
    400 Natural Bridges Drive
    Santa Cruz, CA 95060-5792
    USA

    831.427.4727 (voice)
    jareid@usgs.gov

    Contact_Instructions: Email preferred
  2. What's the catalog number I need to order this data set?

    USGS Data Series 182 (data are downloadable through the web)

  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?

    None; these data are provided as comma-delimited text files useable in most softwares. Additionally, 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 <http://www.esri.com>.

Who wrote the metadata?

Dates:
Last modified: 2006
Metadata author:
Jane A. Reid
U.S. Geological Survey
Geologist
400 Natural Bridges Drive
Santa Cruz, CA 95060-5792

831-427-4727 (voice)
jareid@usgs.gov

Contact_Instructions: email preferred
Metadata standard:
CSDGM Version 2 (FGDC-STD-001-1998)

Generated by mp version 2.8.17 on Thu May 18 16:51:17 2006