Reprocessed 3D seismic-reflection data and neural-network fault cube, offshore of Point Sal, central California, from 2012-08-12 to 2012-10-05 (USGS field activity P-04-11-CC)

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Frequently anticipated questions:

What does this data set describe?

Title:
Reprocessed 3D seismic-reflection data and neural-network fault cube, offshore of Point Sal, central California, from 2012-08-12 to 2012-10-05 (USGS field activity P-04-11-CC)
Abstract:
This dataset includes reprocessed boomer 3D seismic data collected by the Fugro Consultants Inc. in 2012, offshore Point Sal, central California.
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=P0411CC 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?
    Kluesner, Jared W., Brothers, Daniel S., and Sliter, Ray W., 2017, Reprocessed 3D seismic-reflection data and neural-network fault cube, offshore of Point Sal, central California, from 2012-08-12 to 2012-10-05 (USGS field activity P-04-11-CC): data release DOI:10.5066/F7HD7TKM, 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: -120.79588
    East_Bounding_Coordinate: -120.74060
    North_Bounding_Coordinate: 34.95434
    South_Bounding_Coordinate: 34.85861
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 22-Aug-2012
    Ending_Date: 05-Oct-2012
    Currentness_Reference:
    ground condition at the time the data were collected
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: 3D boomer seismic-reflection data in SEG-Y format
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      Indirect_Spatial_Reference:
      Horizontal X and Y locations for the seismic profile locations are provided in shapefiles and are stored in the SEG-Y data trace headers in the standard header locations.
    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 D_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: Local surface
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    Navigation and Seismic Shots with Time Stamp in standard SEG-Y file format
    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)
    • Jared W. Kluesner
    • Daniel S. Brothers
    • Ray W. Sliter
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    PCMSC Science Data Coordinator
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    2885 Mission Street
    Santa Cruz, CA

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

Why was the data set created?

This data release includes boomer 3D seismic data collected in 2012 offshore Point Sal, central California as part of PG&E’s Central California Seismic Imaging Project (Pacific Gas and Electric Company [PG&E],2014). The U.S. Geological Survey conducted advanced post-processing and neural-network fault calculations on the data for improved fault detection (Kluesner and Brothers, 2016). Following generation of the cleaned, 3D, volume- and neural-network fault cube, each volume was exported using the OpendTect software package. Both the cleaned 3D volume and fault volume are in SEG-Y format and are provided here.

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: 2012 (process 1 of 4)
    Seismic data were acquired using a triple-plate boomer source operated at 1.75 kJ and the P-Cable streamer system. The 3D data show a frequency range of approximately 100-700 Hz, with a dominant frequency of 200-225 Hz (PG&E, 2014). The P-Cable system consisted of 14, 8-channel digital streamers with 6.25 m hydrophone group spacing (Nishenko and others, 2012; Ebuna and others, 2013). Data were sampled at 0.25 ms with a record length of 0.75 s two-way travel-time. Seismic processing steps conducted by Fugro Consultants included quality control, tidal corrections, velocity analysis, NMO correction, stacking, surface related multiple elimination, deconvolution, crossline statics, and pre-stack migration (Fugro Consultants Inc., 2012; PG&E, 2014). However, upon public release and inspection by the USGS, significant high-frequency noise was observed, limiting the interpretation of imaged fault structures (Kluesner and Brothers, 2016).
    Date: 2016 (process 2 of 4)
    The publically released 3D seismic data were downloaded and analyzed by the USGS and a post-stack data-conditioning workflow was designed to reduce noise, short-period multiples, and enhance the overall quality. The workflow followed the methods described in Kluesner and Brothers, 2016. Data were imported into the OpendTect software package, and a dip-steering volume was calculated using a 1x1x1 (inline, crossline, sample interval) calculation window. Following dip-steering calculation a median filter was applied with a 1x1x1 step-out, resulting in a smoothed 3D volume of dip and azimuth information for all seismic events. The dip-steered median filter was then applied to the data with a 1x1 (inline, crossline) stepout, with no time window. Filtered results were then subtracted from the original data to produce a volume with significant noise suppression. Both random and apparent acquisition noise were suppressed, while enhancing laterally continuous events. Following filtering and noise suppression, a post-stack 3D predictive deconvolution filter was designed in order to suppress apparent ringing within the data. Throughout the 3D volume, the seafloor reflection suffers from a long wavelength, masking geology below. The filter effectively suppressed the ringing/short-period multiples and also sharpened reflections at depth. For enhanced fault detection, a neural-network multi-attribute workflow was designed that used 32 different seismic attributes. The 32 attributes, which consisted of calculations such as similarity, curvature, and noise, were used as input nodes in the neural-network. The hidden layer of the neural-network consisted of 16 nodes, and user picks of faults and non-faults were used to supervise the network training. Training was stopped when the normalized root-mean-square (RMS) error reached a minimum value (< 0.5), along with misclassification percentage of picks. Post training, a 3D volume was generated (fault cube) that contains fault probability measurements scaled between 0 (non-fault) and 1 (fault). This information was then projected onto vertical and horizontal seismic slices to help identify and interpret probable faults imaged within the dataset.
    Date: 19-Oct-2020 (process 3 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
    Date: 31-Aug-2021 (process 4 of 4)
    Data were moved to a new repository, and metadata was edited to reflect the new location. Other edits were performed as needed to bring the metadata up to PCMSC standards, including a slight rewording of the title. 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?
    Ebuna, D.R., Mitchell, T.R., Hogan, P.J., Nishenko, S., and Greene, H.G., 2013, The California Seafloor Mapping Program - Providing science and geospatial data for California's State Waters: 26th Symposium on the Application of Geophysics to Engineering and Environmental Problems p. 311-320, Curran Associates, Inc., Red Hook, NY.

    Online Links:

    Inc., Fugro Consultants, 2012, Software validation of Uniseis and 3D data qualification of 2010–2011 high-resolution marine survey data, Offshore Diablo Canyon Power Plant, Central Coastal California Seismic ImagingProject: Report No. PGEQ-PR-03 (Rev0), FSI Project No. 2011-4493 p. 1-67, Fugro Consultants Inc., Oakland, CA.

    Online Links:

    Kluesner, Jared W., and Brothers, Daniel J., 2016, Seismic attribute detection of faults and fluid pathways within an active strike-slip shear zone: New Insights from high-resolution 3D P-Cable seismic data along the Hosgri Fault, offshore California: AAPG/SEG Interpretation volume 4, issue 1, Society of Exploration Geophysicists, Tulsa, OK.

    Online Links:

    Nishenko, S., Hogan, P., and Kvitek, R., 2012, Seafloor mapping for earthquake, tsunami hazard assessments: Sea Technology v. 53, p. 15-20, Sea Technology, Arlington, VA.

    Online Links:

    Pacific Gas and Electric Company (PG&E), 2014, Offshore low-energy seismic reflection studies in Estero Bay, San Luis Obispo Bay, and Point Sal Areas: PG&E Technical Report GEO.DCPP.TR.14.02, Fugro Consultants Inc., Oakland, CA.

    Online Links:

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 Differential Global Positioning System (DGPS) navigation receiver.
  3. How accurate are the heights or depths?
    Depths shown in the seismic data volumes are in milliseconds (round trip travel time) and are referenced to sea level. Vertical resolution is approximately 1 millisecond and vertical accuracy is approximately plus or minus 4 milliseconds depending on sea state.
  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?
    Seismic data were acquired using a triple-plate boomer source operated at 1.75 kJ and the P-Cable streamer system. Quality control was conducted during the collection 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 as the originator(s) of the dataset and in products derived from these data. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. This information is not intended for navigational purposes.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - CMGDS
    2885 Mission Street
    Santa Cruz, CA
    USA

    1-831-427-4747 (voice)
  2. What's the catalog number I need to order this data set? P-04-11-CC_ps.mcs3d.boomer.zip This zip file contains reprocessed seismic-reflection 3D volume (SEG-Y) and navigation (shapefile) data collected during field activity P-04-11-CC.
  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 the reprocessed seismic data in format SEG-Y (version SEG-Y rev 1) Size: 11854
      Network links: https://doi.org/10.5066/F7HD7TKM
    • Cost to order the data: None

Who wrote the metadata?

Dates:
Last modified: 10-Sep-2021
Metadata author:
PCMSC Science Data Coordinator
U.S. Geological Survey, Pacific Coastal and Marine Science Center
2885 Mission St.
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_F7HD7TKM/P-04-11-CC_ps.mcs3d.boomer_metadata.faq.html>
Generated by mp version 2.9.50 on Thu Oct 21 09:29:12 2021