Raw computed tomography (CT) images of sediment cores collected in 2009 offshore from Palos Verdes, California

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Frequently anticipated questions:

What does this data set describe?

Title:
Raw computed tomography (CT) images of sediment cores collected in 2009 offshore from Palos Verdes, California
Abstract:
This part of the data release includes raw computed tomography (CT) images of sediment cores collected in 2009 offshore of Palos Verdes, California. It is one of seven files included in this U.S. Geological Survey data release that include data from a set of sediment cores acquired from the continental slope, offshore Los Angeles and the Palos Verdes Peninsula, adjacent to the Palos Verdes Fault. Gravity cores were collected by the USGS in 2009 (cruise ID S-I2-09-SC; http://cmgds.marine.usgs.gov/fan_info.php?fan=SI209SC), and vibracores were collected with the Monterey Bay Aquarium Research Institute's remotely operated vehicle (ROV) Doc Ricketts in 2010 (cruise ID W-1-10-SC; http://cmgds.marine.usgs.gov/fan_info.php?fan=W110SC). One spreadsheet (PalosVerdesCores_Info.xlsx) contains core name, location, and length. One spreadsheet (PalosVerdesCores_MSCLdata.xlsx) contains Multi-Sensor Core Logger P-wave velocity, gamma-ray density, and magnetic susceptibility whole-core logs. One zipped folder of .bmp files (PalosVerdesCores_Photos.zip) contains continuous core photographs of the archive half of each core. One spreadsheet (PalosVerdesCores_GrainSize.xlsx) contains laser particle grain size sample information and analytical results. One spreadsheet (PalosVerdesCores_Radiocarbon.xlsx) contains radiocarbon sample information, results, and calibrated ages. One zipped folder of DICOM files (PalosVerdesCores_CT.zip) contains raw computed tomography (CT) image files. One .pdf file (PalosVerdesCores_Figures.pdf) contains combined displays of data for each core, including graphic diagram descriptive logs. This particular metadata file describes the information contained in the file PalosVerdesCores_CT.zip. All cores are archived by the U.S. Geological Survey Pacific Coastal and Marine Science Center.
  1. How might this data set be cited?
    Maier, Katherine L., Paull, Charles K., McGann, Mary, and Conrad, James E., 20160325, Raw computed tomography (CT) images of sediment cores collected in 2009 offshore from Palos Verdes, California: data release DOI:10.5066/F7G44NB6, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Maier, Katherine L., Paull, Charles K., McGann, Mary, and Conrad, James E., 2016, Sediment core data from offshore Palos Verdes, California: data release DOI:10.5066/F7G44NB6, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -118.15795898325
    East_Bounding_Coordinate: -117.99316406138
    North_Bounding_Coordinate: 33.593666691854
    South_Bounding_Coordinate: 33.355402040003
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2009
    Ending_Date: 2010
    Currentness_Reference:
    ground condition at the time the cores were collected
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: .zip (zipped file of DICOM files)
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      Indirect_Spatial_Reference: none
      This is a Point data set.
    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 0.001. Longitudes are given to the nearest 0.001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is WGS 84.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: water depth (depth below sea level)
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters below sea level
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    CT scan DICOM files are presented for four sediment cores. The zip file "PalosVerdesCores_CT.zip" contains five zipped files, each containing DICOM files for a single scanned D-tube. These files are named by core ID and section number (for example, DR125VC-89_Section1.zip; see PalosVerdesCores_Info.xlsx, this data release, for more information on cores IDs). Sections 1 for three cores were scanned together in a single D-tube are contained in the file "PV2-G1_DR136VC-134_DR135VC-131_Sections1.zip" (named from the top to bottom of the image). DR125 VC-89 Section 2 was not scanned because it is mostly the empty core catcher (see PalosVerdesCores_Figures.pdf and PalosVerdesCores_Photos.zip, this data release, for more information). All quantitative data in these files is in Hounsfield units.
    Entity_and_Attribute_Detail_Citation:
    Sediment core computed tomography (CT) scans are available in file PalosVerdesCores_CT.zip at: https://doi.org/10.5066/F7G44NB6

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Katherine L. Maier
    • Charles K. Paull
    • Mary McGann
    • James E. Conrad
  2. Who also contributed to the data set?
    U.S. Geological Survey Pacific Coastal and Marine Science Center and Monterey Bay Aquarium Research Institute
  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
    US

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

Why was the data set created?

The sediment cores and subsequent core data were collected to investigate the Palos Verdes Fault and continental slope sedimentation.

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: 2015 (process 1 of 3)
    The USGS recovered gravity cores with the R/V Robert Gordon Sproul in 2009 from six sites flanking the Palos Verdes Fault on the continental slope northwest of San Gabriel Canyon (see cruise ID S-I2-09-SC (http://cmgds.marine.usgs.gov/fan_info.php?fan=SI209SC) for additional information), and in 2010, the Monterey Bay Aquarium Research Institute (MBARI) collected vibracores along transects in the same area using their remotely operated vehicle (ROV) Doc Ricketts aboard the R/V Western Flyer (see cruise ID W-1-10-SC (http://cmgds.marine.usgs.gov/fan_info.php?fan=W110SC) for additional information). Five of these cores were scanned with x-ray commuted tomography (CT) using a GE LightSpeed Ultra instrument at a Stanford University Petroleum Research Institute (SUPRI-A) Enhanced Oil Recovery and Unconventional Resources laboratory facility of Anthony Kovscek in Stanford, California. Split core tubes (i.e., D-tubes) containing about 150 cm of core material were scanned in either 1.25 mm (DR136 VC-134; DR135 VC-131; PV2-G1 section 1) or 2.50 mm (DR125 VC-89, PV2-G1) axial slices at 120 kV and 200 mA. Laboratory assistance was provided by Elliot Kim and Jason Addison.
    Date: 02-Oct-2025 (process 2 of 3)
    Data and metadata files were moved to a different location on ScienceBase, resulting in a change of ID number in the Online_Linkage and Network_Resources URLs of the metadata. In addition, edits were made as needed to bring the metadata up to current PCMSC standards including standardizing doi# links, correcting typos, adding disclaimers, and refining keywords. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. No data were changed. 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 3 of 3)
    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?
    Brothers, D.S., Conrad, J.E., Maier, K.L., Paull, C.K., McGann, M., and Caress, D.W., 2015, The Palos Verdes Fault offshore southern California: Late Pleistocene to Present tectonic geomorphology, seascape evolution and slip-rate estimate based on AUV and ROV surveys.

    Online Links:

    Maier, K.L., Brothers, D.S., Paull, C.K., McGann, M., Caress, D.W., and Conrad, J.E., 2016, Records of continental slope sediment flow morphodynamic responses to gradient and active faulting from integrated AUV and ROV data, offshore Palos Verdes, southern California Borderland.

    Online Links:

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

  1. How well have the observations been checked?
    No formal attribute accuracy tests were conducted
  2. How accurate are the geographic locations?
    No formal positional accuracy tests were conducted
  3. How accurate are the heights or depths?
    No formal positional accuracy tests were conducted
  4. Where are the gaps in the data? What is missing?
    Data set 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?
    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 and Monterey Bay Aquarium Research Institute 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 - ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    USA

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set?
  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?

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/DataReleases/ScienceBase/DR_F7G44NB6/PalosVerdesCores_CT_Metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:17:11 2021