PAC_EXT - Extracted seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_ext.txt)

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

Frequently anticipated questions:


What does this data set describe?

Title:
PAC_EXT - Extracted seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_ext.txt)
Abstract:
This data layer (PAC_EXT.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 extracted (EXT) output of the dbSEABED mining software and contains data items which were extracted from the data resources files and generally represent lab-based analytical data. The EXT data are usually considered the most rigorous data available, although some data may represent a subsample of the sediment (that is, large shells or stones may have been excluded from the analysis). This file contains the same data fields as the parsed (PAC_PRS) and calculated (PAC_CLC) data files, and the three files may be combined.
  1. How might this data set be cited?
    Reid, Jane A., Reid, Jamey M., Jenkins, Chris J., Zimmermann, Mark, Williams, S. Jeffress, and Field, Michael E., 2006, PAC_EXT - Extracted seabed data for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_ext.txt): Data Series 182, U.S. Geological Survey, Coastal and Marine Geology Program, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    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 Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -128.66600
    East_Bounding_Coordinate: -117.10170
    North_Bounding_Coordinate: 48.99883
    South_Bounding_Coordinate: 30.57000
  3. What does it look like?
    https://pubs.usgs.gov/ds/2006/182/data/pac_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: comma-delimited text and 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 (16486)
    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?
    pac_ext
    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.
    LATITUDE
    Latitude coordinate of sample location (Source: USGS) Location information in decimal degrees
    LONGITUDE
    Longitude coordinate of sample location (Source: USGS) Location information in decimal degrees
    WATERDEPTH
    Water depth of sample (Source: USGS) Water depth of sample in meters
    SAMPLETOP
    Measured subbottom depth information for each point sample or subsample (top) (Source: USGS) Subsample location information in meters
    SAMPLEBASE
    Measured subbottom depth information for each point sample or subsample (bottom) (Source: USGS) Subsample location information in meters
    SITENAME
    Survey or laboratory code for site (non-unique) (Source: USGS) Character string
    DATASETKEY
    Data set key (relational link) (Source: USGS) Unique sequential numeric key to 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
    SAMPLER
    Equipment used to collect samples (Source: USGS) Character string containing name of device used to acquire sample
    DATATYPES
    Type of data that were used to derive values held in characterization (Source: USGS)
    ValueDefinition
    ACUAcoustic Properties
    CMPSediment Composition
    COLColor
    GTCGeotechnical Properties
    GRZGrain Size
    TXRTexture
    TXGTexture (Graphic)
    LTHLithology
    GRAVEL
    Gravel grainsize fraction (Source: Defined by original source)
    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:1
    SAND
    Sand grainsize fraction (Source: Defined by original source)
    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:1
    MUD
    Mud grainsize fraction (Source: Defined by original source)
    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:1
    CLAY
    Clay grainsize fraction (Source: Defined by original source)
    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:1
    GRAINSIZE
    Phi characteristic grainsize (moment mean or median) see Larger_Work_Citation (Source: USGS)
    Range of values
    Minimum:-12
    Maximum:12
    Units:Phi
    Resolution:0.1
    SORTING
    Phi grainsize dispersion; Moment measure standard deviation sorting only (Source: USGS)
    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: USGS) Alpha characters
    CLSMSHP
    Class membership; fuzzy membership (%) of above Class (Facies) (Source: USGS)
    Range of values
    Minimum:30
    Maximum:100
    Units:Fuzzy membership
    Resolution:1
    FOLKCODE
    Grainsize classification (Source: Folk, Andrews, and Lewis, 1970)
    ValueDefinition
    (g)MSlightly gravelly mud
    (g)mSSlightly gravelly muddy sand
    (g)sMSlightly gravelly sandy mud
    (g)SSlightly gravelly sand
    GGravel
    gMGravelly mud
    gmSGravelly muddy sand
    gSGravelly sand
    MMud
    mGMuddy gravel
    mSMuddy sand
    msGMuddy sandy gravel
    SSand
    sGSandy gravel
    sMSandy mud
    HHard ground
    SHEPARDCOD
    modified Shepard code; grain size classification (Source: USGS)
    ValueDefinition
    CLAYEY SILTSediment that is mostly silt with clay as the next most common component
    SANDY SILTSediment that is mostly silt with sand as the next most common component
    SAND SILT CLAYSediment with significant sand, silt, and clay
    SILTY CLAYSediment that is mostly clay with silt as the next most common component
    SANDSediment with greater than 80 percent in the 62 micron to 2 mm fraction
    SILTY SANDSediment that is mostly sand with silt (greater than 20 percent) as the next most common component
    SEDIMENTRelative primary textural class
    CLAYEY SANDRelative primary textural class
    CLAYRelative primary textural class
    SANDY CLAYRelative primary textural class
    SILTRelative primary textural class
    GRAVELLY SEDIMENTSediment with greater than 10 percent gravel, but less than 50 percent
    GRAVELSediment with nominal diameter coarser than 2mm
    SEDIMENTRelative primary textural class
    ROCKMSHP
    Rock membership; fuzzy membership (%) reflecting percent exposure of rock (Source: dbSEABED processing software)
    ValueDefinition
    -99No data
    WEEDMSHP
    Weed membership; fuzzy membership reflecting abundance of seaweed and seagrass (Source: dbSEABED processing software MNEv and thesaurus)
    ValueDefinition
    -99No data
    CARBONATE
    Carbonate, including finest to coarsest sampled fractions (Source: USGS)
    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:1
    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 (Source: USGS)
    Range of values
    Minimum:0
    Maximum:100
    Units:Percent
    Resolution:0.1
    LGSHEARSTR
    Undrained compressive shear strength, Log10 of KiloPascals (Source: Defined by original source)
    ValueDefinition
    -99No data
    ROUGHNESS
    A coded output representing the V:H of the roughness element with greatest aspect ratio (Source: dbSEABED processing software MNEv and thesaurus) Values expressed as (rounded) integer log2 of V and H in cm
    POROSITY
    Void volume (Source: USGS)
    Range of values
    Minimum:0
    Maximum:Unknown
    Units:kPa
    Resolution:1
    PWAVEVEL
    Compressional wave velocity (Source: dbSEABED processing software MNEv and thesaurus)
    ValueDefinition
    -99No 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: USGS)
    ValueDefinition
    -99No data
    SAMPLEPHAS
    Sample Phase; records whether the results are for the whole, bulk sediment or just to some special part (Source: dbSEABED processing software) Character string 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.
    Entity_and_Attribute_Overview:
    Values of -99 for any field are indications that there was no data available.
    Entity_and_Attribute_Detail_Citation: See dbSEABED page in Larger_Work_Citation

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Jane A. Reid
    • Jamey M. Reid
    • Chris J. Jenkins
    • Mark Zimmermann
    • S. Jeffress Williams
    • Michael E. Field
  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
    Pacific Coastal and Marine Science Center
    Santa Cruz, CA
    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/index.html) 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 4)
    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
    Attn: Jane A. Reid
    Geologist
    USGS Pacific Coastal and Marine Science Center
    Santa Cruz, CA
    USA

    831.427.4727 (voice)
    jareid@usgs.gov
    Contact_Instructions: Email preferred
    Data sources produced in this process:
    • PAC_EXT.txt
    Date: 26-Apr-2018 (process 2 of 4)
    Keywords added to metadata support discovery in the USGS Coastal and Marine Geology Data Catalog. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Alan O. Allwardt
    Contractor -- Information Specialist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7551 (voice)
    831-427-4748 (FAX)
    aallwardt@usgs.gov
    Date: 04-Dec-2019 (process 3 of 4)
    Edits were made to bring the metadata up to current PCMSC standards including adding a doi# link, correcting typos, refining keywords, and using current access and distribution liability statements. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version. Person who carried out this activity:
    Susan A Cochran
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    2885 Mission St.
    Santa Cruz, CA
    United States

    831-460-7545 (voice)
    scochran@usgs.gov
    Date: 19-Oct-2020 (process 4 of 4)
    Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 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?

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 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:
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigation purposes.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    Attn: Jane A. Reid
    Geologist
    2885 Mission Street
    Santa Cruz, CA
    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? Downloadable Data: USGS Data Series 182 (downloadable through the web).
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty..
  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 https://www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 19-Oct-2020
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA
US

831-427-4747 (voice)
pcmsc_data@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/SeriesReports/DS_DDS/DS_182/pac_ext.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:17:35 2021