Ray W. Sliter James E. Conrad Holly F. Ryan Peter J. Triezenberg 2017 minisparker seismic-reflection data in SEG-Y format data release DOI:10.5066/F7SF2TCV Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey, Coastal and Marine Geology Program https://doi.org/10.5066/F7SF2TCV This dataset includes raw and processed, high-resolution seismic-reflection data collected in 2011 to collect information on active offshore faults. The survey area is offshore southern California between Long Beach and San Diego. The data were collected aboard the U.S. Geological Survey R/V Parke Snavely. The seismic-reflection data were acquired using a SIG 2mille minisparker system. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location and equipment type. The U.S. Geological Survey (USGS) collected high-resolution seismic-reflection in June 2011, between Long Beach and San Diego, southern California. The survey was designed to image faults and folds associated with movement on the numerous faults offshore southern California, including the Newport-Inglewood, Palos Verdes, Coronado Bank, San Pedro Basin, San Diego Trough, and several other unnamed fault zones. This data can be used to update the USGS Quaternary fault database and in shaking hazard models developed by the Working Group for California Earthquake probabilities. This work was funded by the USGS Coastal and Marine Catastrophic Hazards Project. Data were collected aboard the USGS R/V Parke Snavely. Approximately 331 km of single-channel seismic-reflection data were acquired, mainly using a SIG 2mille minisparker. About 204 km of data were collected simultaneously using an EdgeTech Chirp 512 [DOI:10.5066/F7X63K3K]. Subbottom acoustic penetration spanned tens to several hundreds of meters, variable by location. This dataset also includes navigation files of the surveyed transects. The images of bedrock, sediment deposits and tectonic structure provide geologic information that is essential to hazard assessment, regional sediment management and coastal and marine spatial planning at Federal, State and local levels, as well as to future research on the geomorphic, sedimentary, tectonic and climatic record of Southern California. 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=S0711SC . Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 20110608 20110622 ground condition at the time the data were collected Complete As needed -118.45020 -117.33957 33.54561 32.92887 USGS Metadata Identifier USGS:d5a43913-1bc3-44f6-8135-c7910d6765af Global Change Master Directory (GCMD) Bathymetry Continental Margins ISO 19115 Topic Category geoscientificInformation oceans USGS Thesaurus sub-bottom profiling Marine Realms Information Bank (MRIB) keywords seismic reflection profiling Data Categories for Marine Planning Bathymetry and Elevation None minisparker U.S. Geological Survey USGS Coastal and Marine Geology Program CMG CMGP Pacific Coastal and Marine Science Center PCMSC Geographic Names Information System (GNIS) Pacific Ocean State of California San Diego County Los Angeles County Long Beach San Diego None. 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. PCMSC Science Data Coordinator U.S. Geological Survey, Pacific Coastal and Marine Science Center mailing and physical

2885 Mission Street

Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov SEG-Y Rev 1 Identified as best available version. Subbottom data were collected during USGS cruise S-07-11-SC using a SIG 2mille minisparker system consisting of a hydrophone streamer, high-voltage power supply and discharge sparker tips. Quality control was conducted during the collection process. 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. Position data were provided by a Differential Global Positioning System (DGPS) navigation receiver. The SIG 2mille hydrophone streamer and sparker electrodes were deployed 20m behind the DGPS receiver. Layback is estimated to be 20 ± 5m. No layback correction from the DGPS receiver position was applied to navigation data. Depths shown in the seismic data files are in milliseconds (round trip travel time) and are referenced to sea level. Vertical resolution is approximately 1 millisecond and vertical accuracy is approximately ±4 milliseconds depending on sea state. Seismic-reflection data were collected using a minisparker system that creates an acoustic signal by discharging a 500-Joule, high-voltage electrical pulse between electrodes and a ground that generates a frequency spectrum roughly between 200 and 1,600 Hz. At boat speeds of 4 to 4.5 nm/hour, seismic traces were collected roughly every 1 to 2 meters. The data were recorded on a 15-m-long hydrophone streamer in standard SEG-Y 32-bit floating-point format with Triton Subbottom Logger (SBL) software that merges seismic-reflection data with differential GPS navigation data. 2011 Seismic-reflection SEG-Y files were corrected for swell effects using Sioseis software (see: http://sioseis.ucsd.edu/procs.html): 1) SEG-Y header cdp numbers were defined using the "header" Sioseis processes, and a band pass filter was applied; 2) Water-bottom time/shot-point pairs where created and added to the headers to guide the automated swell correction; 3) A swell filter was applied to the data; and 4) A 120- to 800-Hz bandpass filter, direct-arrival mute and agc were applied, and the results were exported as a processed SEG-Y file. 2011 Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 20201019 U.S. Geological Survey VeeAnn A. Cross Marine Geologist Mailing and Physical

384 Woods Hole Road

Woods Hole MA 02543-1598 508-548-8700 x2251 508-457-2310 vatnipp@usgs.gov 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. 20210831 U.S. Geological Survey Susan A Cochran Geologist Mailing and Physical

2885 Mission Street

Santa Cruz CA 95060 831-460-7545 scochran@usgs.gov Horizontal X and Y locations for the seismic profile locations are provided in ASCII position files and are stored in the SEG-Y data trace headers in the standard header locations. 0.00001 0.00001 Decimal degrees D_WGS_84 WGS_84 6378137.0 298.257223563 Local surface 0.1 meters Attribute values Navigation and Seismic Shots with Time Stamp in standard SEG-Y file format Society of Exploration Geophysicists (SEG) Technical Standards, available for download at http://seg.org/Publications/SEG-Technical-Standards U.S. Geological Survey - CMGDS mailing and physical address

2885 Mission Street

Santa Cruz CA 95060 USA 1-831-427-4747 S-07-11-SC.scs.sparker.zip – this zip file contains raw and swell-corrected high-resolution seismic-reflection (SEG-Y) and navigation (ASCII) data collected during PCMSC field activity S-07-11-SC. The data are divided up and presented by navigation line, as reflected in the individual file name(s). 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. SEG-Y SEG-Y rev 1 Zip file contains the raw and swell-corrected seismic data per navigation line Winzip, 7-zip, or Winrar are free software that will open .zip files 10685 https://doi.org/10.5066/F7SF2TCV None 20210913 PCMSC Science Data Coordinator U.S. Geological Survey, Pacific Coastal and Marine Science Center mailing and physical

2885 Mission St.

Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998