Multichannel seismic-reflection and navigation data collected offshore central California, during field activity 2019-651-FA

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Frequently anticipated questions:

What does this data set describe?

Title:
Multichannel seismic-reflection and navigation data collected offshore central California, during field activity 2019-651-FA
Abstract:
Multichannel seismic-reflection data and associated navigation files were collected offshore central California in the vicinity of Morro Bay. These data were collected aboard the M/V Bold Horizon in October 2019 for use in regional hazard assessments relating to the Hosgri Fault.
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=2019-651-FA
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?
    Snyder, George R., Balster-Gee, Alicia F., Kluesner, Jared W., Johnson, Samuel Y., Medri, Elisa, Simms, Alex, Nishenko, Stu, Greene, H. Gary, and Conrad, James E., 20221213, Multichannel seismic-reflection and navigation data collected offshore central California, during field activity 2019-651-FA: data release DOI:10.5066/P9A0U8J7, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Snyder, George R., Balster-Gee, Alicia F., Kluesner, Jared W., Johnson, Samuel Y., Medri, Elisa, Simms, Alex, Nishenko, Stu, Greene, H. Gary, and Conrad, James E., 2022, Geophysical and core sample data collected offshore central California, during field activity 2019-651-FA: data release DOI:10.5066/P9A0U8J7, 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: -121.075135
    East_Bounding_Coordinate: -121.068258
    North_Bounding_Coordinate: 35.492908
    South_Bounding_Coordinate: 35.474742
  3. What does it look like?
    2019-651-FA_mcs_02A.jpg (JPG)
    Example plot of processed multichannel seismic data.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 18-Oct-2019
    Ending_Date: 24-Oct-2019
    Currentness_Reference:
    Ground conditions at time data were collected
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form:
    Multichannel seismic-reflection data in SEG-Y format and navigation polylines in shapefile format.
  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 (1)
    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 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal Degrees. The horizontal datum used is WGS 1984.
      The ellipsoid used is WGS 84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257224.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Local surface
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    2019-651-FA_mcs_nav.shp
    multichannel seismic navigation in polyline format (Source: U.S. Geological Survey)
    FID
    Internal feature number (Source: Esri) Sequential unique integers automatically generated
    Shape
    Feature Geometry (Source: Esri) Feature shape automatically generated
    Length
    Calculated length of the line in meters (Source: U.S. Geological Survey)
    Range of values
    Minimum:2220.51
    Maximum:2220.51
    Units:meters
    Resolution:0.01
    FA_num
    USGS Pacific Coastal and Marine Science Center (PCMSC) field activity identifier (Source: U.S. Geological Survey) Unique field activity ID generated by the USGS
    Line_num
    Name of trackline associated with seismic data. (Source: U.S. Geological Survey) Unique line number assigned in the field
    Entity_and_Attribute_Overview:
    Zip archive of seismic shots with time stamp in standard SEG-Y format. Data for individual seismic lines follow file name format of 2019-651-FA_seismic_mcs_LINE#.segy.
    Entity_and_Attribute_Detail_Citation:
    Society of Exploration Geophysicists (SEG) Technical Standards, available for download at http://seg.org/Publications/SEG-Technical-Standards].

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • George R. Snyder
    • Alicia F. Balster-Gee
    • Jared W. Kluesner
    • Samuel Y. Johnson
    • Elisa Medri
    • Alex Simms
    • Stu Nishenko
    • H. Gary Greene
    • James E. Conrad
  2. Who also contributed to the data set?
    USGS PCMSC Marine Facility personnel Rachel Marcuson assisted with multichannel seismic data acquisition.
  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?

Identification of fault-related submarine hazards is a primary mission of the USGS Coastal and Marine Hazards and Resources Program. The Hosgri Fault is a submarine fault system that likely poses the greatest submarine earthquake threat in the central California region. To gain a better understanding of this fault system, the USGS collected sparker multichannel seismic, CHIRP seismic, and sediment cores to enable a detailed investigation of its geologic history and ongoing activity. These data are intended to further our understanding of geologic hazards near the Hosgri Fault, improve risk assessments for local communities and critical infrastructure, and to provide data for future research on regional tectonic, sedimentary, and geomorphic evolution of coastal California. This work was funded through a Cooperative Research and Development Agreement (CRADA) between the USGS and Pacific Gas and Electric Corporation.

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: 24-Oct-2019 (process 1 of 3)
    Field seismic data collection: Seismic data were collected onboard the M/V Bold Horizon using a SIG ELP790 sparker source powered at 700 joules and recorded by a Geometrics GeoEel hydrophone streamer with 24-40 channels depending on conditions. Field data were collected in a SEG-D format. Navigation data were collected simultaneously with a Hemisphere V110 GPS with shot coordinates saved into the SEG-D external headers.
    Date: 26-Aug-2022 (process 2 of 3)
    The following processing flow was carried out in Shearwater Reveal (v. 5.1) to process field data through a post-stack time migration and output to SEG-Y files: (1) Field-collected SEG-D files were imported to Shearwater Reveal and navigation was converted to WGS 1984 coordinate system; (2) Common midpoint (CMP) coordinates were defined using survey geometry setup; (3) Traces were corrected for normal moveout using semblance plots and interactive velocity picking; (4) Source signatures were removed from stacked traces using a spiking deconvolution to increase vertical resolution; (5) A stoltz-time migration was applied to each seismic line; (6) Shearwater reveal internal seismic files were output to processed SEG-Y format files and ArcGIS compatible shapefiles.
    Date: 04-Jan-2023 (process 3 of 3)
    Corrected author/Originator spelling in Citation and Larger Work Citation sections of metadata (Media to Medri). No data were changed. (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?
    Quality control of attribute accuracy was conducted during field data collection and processing workflows.
  2. How accurate are the geographic locations?
    A Hemisphere V110 GPS system was used for obtaining navigation data during the cruise with a stated accuracy of 0.6 meters (95 percent confidence).
  3. How accurate are the heights or depths?
    Two-way travel time in milliseconds referenced to sea level is provided in the SEG-Y files. Referencing two-way travel time to sea level is accomplished via an RBR Solo-D depth logger mounted beneath the hydrophone array with a stated accuracy of approximately 1 cm. If this depth information is recorded, it is populated in the receiver group elevation header in the SEG-Y files (bytes 41-44).
  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?
    All SEG-Y and navigation data were derived from the same instruments and processing workflows. Paired navigation and SEG-Y files have corresponding filenames and/or corresponding names indicated in shapefile attribute fields.

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 - CMGDS
    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? Seismic data are available in SEG-Y format (2019-651-FA_seismic_mcs.zip) with navigation provided in a shapefile format (2019-651-FA_mcs_nav.zip) and accompanied by 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: Zip file contains processed seismic data per single navigation line. Data for individual seismic lines follow file name format of 2019-651-FA_seismic_mcs_LINE#.segy. in format SEG-Y (version SEG-Y rev 1) Size: 16
      Network links: https://doi.org/10.5066/P9A0U8J7
      Data format: Zip file contains polyline shapefiles of seismic navigation. in format shapefile (version ArcGIS Pro (version 2.9.1)) Size: 0.009
      Network links: https://doi.org/10.5066/P9A0U8J7
    • Cost to order the data: None.

  5. What hardware or software do I need in order to use the data set?
    Viewing SEG-Y data requires specialized software. A list of common SEG-Y processing and visualization software is available at http://www.oilfieldwiki.com/wiki/List_of_free_geophysics_software. Shapefile navigation data can be viewed using any Geographic Information System (GIS) software (for example, ArcGIS, QGIS).

Who wrote the metadata?

Dates:
Last modified: 04-Jan-2023
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_P9A0U8J7/2019-651-FA_seismic_mcs_metadata.faq.html>
Generated by mp version 2.9.51 on Wed Jan 4 11:32:24 2023