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 20221213 Multichannel seismic-reflection data in SEG-Y format and navigation polylines in shapefile format. data release DOI:10.5066/P9A0U8J7 Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/P9A0U8J7 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 2022 data release DOI:10.5066/P9A0U8J7 Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey https://doi.org/10.5066/P9A0U8J7 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. 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. 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. 20191018 20191024 Ground conditions at time data were collected In work As needed -121.075135 -121.068258 35.492908 35.474742 USGS Metadata Identifier USGS:d5380fed-f652-4c39-b206-5fb44051fb12 ISO 19115 Topic Category oceans geoscientificInformation location Data Categories for Marine Planning substrate USGS Thesaurus marine geophysics sub-bottom profiling geospatial datasets Marine Realms Information Bank (MRIB) keywords data processing seismic reflection profiling Global Positioning System (GPS) observations None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC seismic reflection Geographic Names Information System (GNIS) Pacific Ocean State of California San Luis Obispo County Cayucos Cambria Estero Bay 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. This information is not intended for navigation purposes. U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

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Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov 2019-651-FA_mcs_02A.jpg Example plot of processed multichannel seismic data. JPG USGS PCMSC Marine Facility personnel Rachel Marcuson assisted with multichannel seismic data acquisition. Field seismic data were collected with Geometrics CNT-1 seismic acquisition software (v. 5.64) and processed using Shearwater Reveal (v. 5.1) on a CentOS Linux 7 operating system. Seismic navigation was processed using ArcGIS Pro (v. 2.9.1) on a Windows 10 operating system. Quality control of attribute accuracy was conducted during field data collection and processing workflows. 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. 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. 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). 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). 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. 20191024 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. 20220826 Corrected author/Originator spelling in Citation and Larger Work Citation sections of metadata (Media to Medri). No data were changed. (scochran@usgs.gov) 20230104 Point Point 1 0.000001 0.000001 Decimal Degrees WGS 1984 WGS 84 6378137.0 298.257224 Local surface 0.1 meters Attribute values 2019-651-FA_mcs_nav.shp multichannel seismic navigation in polyline format U.S. Geological Survey FID Internal feature number Esri Sequential unique integers automatically generated Shape Feature Geometry Esri Feature shape automatically generated Length Calculated length of the line in meters U.S. Geological Survey 2220.51 2220.51 meters 0.01 FA_num USGS Pacific Coastal and Marine Science Center (PCMSC) field activity identifier U.S. Geological Survey Unique field activity ID generated by the USGS Line_num Name of trackline associated with seismic data. U.S. Geological Survey Unique line number assigned in the field 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. 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

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Santa Cruz CA 95060 1-831-427-4747 pcmsc_data@usgs.gov 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. 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 processed seismic data per single navigation line. Data for individual seismic lines follow file name format of 2019-651-FA_seismic_mcs_LINE#.segy. Zip files may be decompressed with any zip utility (for example, 7zip, WinZip, Archive Utility). 16 https://doi.org/10.5066/P9A0U8J7 Data can be downloaded using the Network_Resource_Name link and scrolling to the Seismic Data section. shapefile ArcGIS Pro (version 2.9.1) Zip file contains polyline shapefiles of seismic navigation. Zip files may be decompressed with any zip utility (for example, 7zip, WinZip, Archive Utility). 0.009 https://doi.org/10.5066/P9A0U8J7 Data can be downloaded using the Network_Resource_Name link and scrolling to the Seismic Data section. None. 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). 20230104 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

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