Sediment thickness from seismic reflection data collected offshore of Arcata, California

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Frequently anticipated questions:


What does this data set describe?

Title:
Sediment thickness from seismic reflection data collected offshore of Arcata, California
Abstract:
This 100-m-resolution sediment thickness data raster for the Offshore of Arcata, California, map area is part of USGS Data Series 781 (Golden and Cochrane, 2019). Seismic data were collected by the USGS in 2009 using a mini-sparker seismic systems installed on the Humboldt State University R/V Coral Sea. The data were processed by the USGS into segy format files. The data are available as a georeferenced TIFF image.
Supplemental_Information:
Additional information about the USGS field activity from which some of these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=C109NC
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.
  1. How might this data set be cited?
    Cochrane, Guy R., 20240325, Sediment thickness from seismic reflection data collected offshore of Arcata, California: data release DOI:10.5066/P9J1K4QX, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Cochrane, Guy R., 2024, Bathymetry, backscatter intensity, seismic reflection, and benthic habitat offshore of Arcata, California: data release DOI:10.5066/P9J1K4QX, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

    Other_Citation_Details:
    Suggested Citation: Cochrane, G.R., 2024, Bathymetry, backscatter intensity, seismic reflection, and benthic habitat offshore of Arcata, California: U.S. Geological Survey data release, https://doi.org/10.5066/P9J1K4QX.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -124.257998
    East_Bounding_Coordinate: -124.126736
    North_Bounding_Coordinate: 41.00036
    South_Bounding_Coordinate: 40.842639
  3. What does it look like?
    SedimentThickness_OffshoreArcata.jpg (JPG)
    Preview image of post transgressive sediment thickness offshore of Arcata
  4. Does the data set describe conditions during a particular time period?
    Calendar_Date: 2009
    Currentness_Reference:
    ground condition at time data were collected.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: GeoTIFF
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 178 x 109 x 1, type Grid Cell
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 10
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -123.00000
      Latitude_of_Projection_Origin: 0.00000
      False_Easting: 500000.0
      False_Northing: 0.00
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 10.0
      Ordinates (y-coordinates) are specified to the nearest 10.0
      Planar coordinates are specified in Meters
      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_844.
      The semi-major axis of the ellipsoid used is 6378137.00.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    value
    Depth as a digital value (Source: Producer defined)
    Entity_and_Attribute_Overview:
    The complete 100-m resolution Offshore of Arcata sediment thickness raster has a minimum value of 2.89 meters and a maximum value of 17.00 meters.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Guy R. Cochrane
  2. Who also contributed to the data set?
    Data acquisition was a joint effort between the U.S. Geological Survey, California State University Monterey Bay, and Humboldt State University. The authors acknowledge the crew of Humboldt State University’s R/V Coral Sea and all those involved in in survey planning and execution. Funding was provided by the California Ocean Protection Council Cochrane, G.R., 2024, Bathymetry, backscatter intensity, seismic reflection, and benthic habitat offshore of Arcata, California, California: U.S. Geological Survey data release, https://doi.org/10.5066/P9J1K4QX
  3. To whom should users address questions about the data?
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Attn: PCMSC Science Data Coordinator
    2885 Mission Street
    Santa Cruz, CA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

The surveys were conducted to map geology and benthic habitat as part of the USGS California Seafloor Mapping Program (CSMP), a collaboration with California State University Monterey Bay (CSUMB) and the National Oceanic and Atmospheric Administration (NOAA). Partial funding was provided by the California Ocean Protection Council. These data are intended to provide regional geospatial information in California State waters for offshore resource and ecosystem management. These data are also intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to help identify geomorphologic features and surficial lithology. These data are not intended to be used for navigation.

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: 2024 (process 1 of 2)
    Water bottom (seabed) and depth to an interpreted base of the Last Glacial Maximum (LGM) horizons were digitized from seismic-reflection data using Kingdom Suite software. The difference between the two horizons was calculated. The difference horizon was exported from Kingdom Suite for every shot point as XY coordinates (UTM Zone 10) and two-way travel time (TWT). The thickness was determined by applying a sound velocity of 1,600 m/sec velocity, resulting in sediment thickness values in meters.
    Date: 2024 (process 2 of 2)
    XY locations and sediment thickness values Z were imported to ArcGIS format as points and interpolated to a surface using the Trend tool.
  3. What similar or related data should the user be aware of?
    Golden, Nadine, and Cochrane, Guy R., 2019, California State Waters Map Series Data Catalog: Data Series DS 781, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Golden, N.E. and Cochrane, G.R., compiler, 2019, California State Waters Map Series Data Catalog, https://doi.org/10.3133/ds781.

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

  1. How well have the observations been checked?
    Not applicable for raster data.
  2. How accurate are the geographic locations?
    The sparker position may vary as much as 20 m from the navigation reference on the vessel.
  3. How accurate are the heights or depths?
    Estimated to be approximately 1 m, along the track lines where data is well constrained, but may be much greater in areas between tracklines where interpolation occurred, or data processing swell correction was inaccurate.
  4. Where are the gaps in the data? What is missing?
    Dataset is considered complete for the area mapped with MBES data.
  5. How consistent are the relationships among the observations, including topology?
    No formal logical accuracy tests were conducted.

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 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 - CMGDS
    2885 Mission Street
    Santa Cruz, CA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov
  2. What's the catalog number I need to order this data set? These data are available in GeoTIFF format (SedimentThickness_OffshoreArcata.tif), along with a tif world file (.tfw) and CSDGM FGDC-compliant metadata.
  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?
    • Availability in digital form:
      Data format: Downloadable zip file contains the GeoTIFF (.tif), a projection file (.tfw), and FGDC compliant metadata. in format GeoTIFF (version ArcMap (version 10.8.2)) Size: 0.48
      Network links: https://doi.org/10.5066/P9J1K4QX
      https://doi.org/10.3133/ds781
    • Cost to order the data: None

  5. What hardware or software do I need in order to use the data set?
    The downloadable data file has been compressed with the Windows 10 "zip" command and can be unzipped using Windows File Explorer or with Winzip (or other tools). To utilize these data, the user must have software capable importing and viewing a GeoTIFF file.

Who wrote the metadata?

Dates:
Last modified: 25-Mar-2024
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA

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

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Generated by mp version 2.9.51 on Fri Mar 29 12:17:37 2024