Core logger data from vibracores collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18

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Frequently anticipated questions:

What does this data set describe?

Title:
Core logger data from vibracores collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18
Abstract:
This section of the data release contains core logger tabular data of 34 vibracores that were collected aboard the R/V Bold Horizon in 2019 on U.S. Geological Survey Field Activity 2019-649-FA offshore San Francisco, California. The cores were analyzed for gamma ray density and magnetic susceptibility. The logging was performed at 1-cm intervals from the top of each core section. In addition to the core logger data, the locations of the cores are available as either a comma-delimited file or a shapefile.
Supplemental_Information:
Additional information about the field activity from which these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-649-FA
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  1. How might this data set be cited?
    Lorenson, Thomas D., Sliter, Ray W., Conrad, James E., Papesh, Antoinette G., and Warrick, Jonathan A., 2021, Core logger data from vibracores collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18: data release DOI:10.5066/P9LBG9H5, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Sliter, Ray W., Conrad, James E., Lorenson, Thomas D., Papesh, Antoinette G., Balster-Gee, Alicia F., Watt, Janet T., and Warrick, Jonathan A., 2021, Geophysical and core sample data collected offshore San Francisco, California, during field activity 2019-649-FA from 2019-10-11 to 2019-10-18: data release DOI:10.5066/P9LBG9H5, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -122.87083
    East_Bounding_Coordinate: -122.39324
    North_Bounding_Coordinate: 38.01347
    South_Bounding_Coordinate: 37.49665
  3. What does it look like?
    2019-649-FA_tracks_and_cores.png (PNG)
    Map showing locations of vibracore sites (purple dots) and tracklines (blue) along which chirp seismic data were collected.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 11-Oct-2019
    Ending_Date: 18-Oct-2019
    Currentness_Reference:
    ground condition at time data were collected
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: comma-delimited text
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Point data set. It contains the following vector data types (SDTS terminology):
      • Point (36)
    2. What coordinate system is used to represent geographic features?
      The map projection used is WGS 1984 UTM Zone 11N.
      Projection parameters:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -117.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.0001
      Ordinates (y-coordinates) are specified to the nearest 0.0001
      Planar coordinates are specified in Meter
      The horizontal datum used is D WGS 1984.
      The ellipsoid used is WGS 1984.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    Attribute table
    Table containing attribute information associated with the dataset (Source: Producer defined)
    Depth cm
    section depth in centimeters (Source: producer defined)
    Range of values
    Minimum:1
    Maximum:151
    Units:centimeters
    Den1 g/cc
    gamma ray density, calculated (Source: producer defined)
    Range of values
    Minimum:-0.1598
    Maximum:10.53
    Units:grams per centimeter
    MS1 SI x 10^-5
    uncorrected magnetic susceptibility in 10exp-5 SI dimensionless units (Source: producer defined)
    Range of values
    Minimum:20.815
    Maximum:609.97
    Units:dimensionless
    Entity_and_Attribute_Overview: The first line of the csv file is a header line.
    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)
    • Thomas D. Lorenson
    • Ray W. Sliter
    • James E. Conrad
    • Antoinette G. Papesh
    • Jonathan A. Warrick
  2. Who also contributed to the data set?
  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?

Core logger data were used to assess sand and gravel resources in Federal and State waters for potential use in future beach nourishment projects along stretches of the coast where critical erosion hotspots have been identified. This cruise was funded through partnerships with the Bureau of Ocean Energy Management (BOEM) and the State of California Ocean Protection Council (OPC).

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: 18-Oct-2019 (process 1 of 3)
    34 cores were collected on cruise 2019-649-FA with a Rossfelder P-5 vibracorer.
    Date: 04-Nov-2019 (process 2 of 3)
    36 core logger data files were created for 34 vibracores (cores SF12 and SF18 are in two sections). The core logging was done with a Geotek Multi-Sensor Core Logger running Geotek MSCL software. The logger was equipped for gamma ray density measurements and magnetic susceptibility. The logging was performed at 1-cm intervals from the top of each core section. A 137Cs gamma ray source and gamma detector are mounted on the GeoTek MSCL for measuring bulk density and based on gamma attenuation through core samples. Gamma density was measured on whole cores in a polycarbonate liner at 1 cm intervals. The measurement was calibrated using an aluminum calibration piece mounted inside a water-filled polycarbonate core section. Anomalous values for gamma density were not excluded from the data. A 120 mm diameter Bartington MS2C loop was used to collect magnetic susceptibility data on whole cores. The sensor is electronically calibrated with a supplied stable iron standard. Magnetic susceptibility measurements were collected every 1 cm with 5 second dwell times. The data are shown as uncorrected magnetic susceptibility in 10exp-5 SI dimensionless units. Gamma ray density measurements below 0.1 grams per cubic centimeter or missing data values were the result of poor contact with the core sample or air voids at the logging location.
    Date: 13-Oct-2021 (process 3 of 3)
    Performed minor edits to the metadata to correct typos. No data were changed Person who carried out this activity:
    U.S. Geological Survey
    Attn: Susan A. Cochran
    Geologist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7545 (voice)
    scochran@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?
    Identified as best available version
  2. How accurate are the geographic locations?
    Position data were provided by a Hemisphere V100 Global Positioning System using L1, C/A code and carrier phase smoothing with a stated accuracy of 60 centimeters.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    Core logger data were collected in the lab from vibracores collected during USGS cruise 2019-649-FA using a Geotek Multi-Sensor Core Logger. The logging was performed at regular intervals. Quality control was conducted during the logging process.

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 (USGS, the Bureau of Ocean Energy Management (BOEM), and the California Geological Survey (CGS) as the originator(s) of the dataset and in products derived from these data.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey Pacific Coastal and Marine Science Center
    2885 Mission Street
    Santa Cruz, CA

    1-831-427-4747 (voice)
    pcmsc_data@usgs.gov
  2. What's the catalog number I need to order this data set? 2019-649-FA_core_logs.zip contains core log data for vibracores collected during PCMSC field activity 2019-649-FA. Supplemental files include 2019-649-FA_core_locations.csv and 2019-649-FA_core_locations_shapefile.zip.
  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: 2019-649-FA_ core_logs.zip contains core logger tabular data per vibracore section. in format comma-delimited text Size: 31.5
      Network links: https://doi.org/10.5066/P9LBG9H5
      Data format: 2019-649-FA_core_locations_shapefile.zip is a shapefile of vibracore locations in format shapefile Size: 0.003
      Network links: https://doi.org/10.5066/P9LBG9H5
      Data format: 2019-649-FA_core_locations.csv is a text file containing vibracore locations in format comma-delimited text Size: 0.000935
      Network links: https://doi.org/10.5066/P9LBG9H5
    • Cost to order the data: None.

  5. What hardware or software do I need in order to use the data set?
    These data can be viewed with any graphics viewing software.

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2021
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)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/CMGDS_DR_tool/DR_P9LBG9H5/2019-649-FA_core_log_metadata.faq.html>
Generated by mp version 2.9.50 on Thu Oct 14 14:47:20 2021