Jenna C. Hill SeanPaul M. La Selle Janet T. Watt Nora M. Nieminski Alicia F. Balster-Gee Peter Dal Ferro Jason S. Padgett Daniel C. Powers Rachel K. Marcuson George R. Snyder 20250326 Comma Separated Value (CSV) tabular data data release DOI:10.5066/P1VQIJ2Q Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/P1VQIJ2Q Jenna C. Hill SeanPaul M. La Selle Janet T. Watt Nora M. Nieminski Alicia F. Balster-Gee Peter Dal Ferro Jason S. Padgett Daniel C. Powers Rachel K. Marcuson George R. Snyder 2025 data release DOI:10.5066/P1VQIJ2Q Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey Suggested Citation: Hill, J.C., La Selle, S.M., Watt, J.W., Nieminski, N.M., Balster-Gee, A.F., Dal Ferro, P., Padgett, J.S., Powers, D.C., Marcuson, R.K., and Snyder, G.R., 2025, Sediment core data from offshore Cascadia during field activity 2022-653-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P1VQIJ2Q. https://doi.org/10.5066/P1VQIJ2Q This dataset includes multi-sensor core logger (MSCL) data of sediment cores collected in Cascadia (offshore northern California, Washington, and Oregon) aboard the M/V Bold Horizon September 2022. As part of a multi-year project focused on characterizing offshore marine geohazards (tsunamis, earthquakes, and landslides), the U.S. Geological Survey (USGS) Coastal and Marine Hazards and Resources Program is conducting research offshore northern California, Oregon, and Washington to gain a better understanding of the geologic hazards of the region, improve risk assessments for local communities and critical infrastructure, and to provide data for future research on regional tectonic, sedimentary, and geomorphic evolution. Sediment cores were collected to enable a detailed investigation of Cascadia's geologic history and ongoing activity. 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=2022-653-FA Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government. 20220918 20250117 Ground conditions at the time data were collected Complete None planned -125.215927 -124.723058 41.711749 41.374695 USGS Metadata Identifier USGS:3f5700be-bb27-4654-8cd9-8ed5af565e0d USGS Thesaurus core analysis ocean processes sediment transport geospatial datasets ISO 19115 Topic Category oceans geoscientificInformation Data Categories for Marine Planning substrate Marine Realms Information Bank (MRIB) keywords sediment None U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC Department of the Interior DOI field activity number 2022-653-FA Geographic Names Information System (GNIS) Pacific Ocean State of California State of Oregon State of Washington Humboldt County Eureka No access constraints USGS-authored or produced data and information from the U.S. Government are in the public domain 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. 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 mscl_preview.jpg Example from core JPC-30 of MSCL data plotted from .csv file. JPG Data were obtained with a Geotek MSCL-S system. Jenna C. Hill SeanPaul M. La Selle Janet T. Watt Nora M. Nieminski Alicia F. Balster-Gee Peter Dal Ferro Jason S. Padgett Daniel C. Powers Rachel K. Marcuson George R. Snyder 2025 Hill, J.C., La Selle, S.M., Watt, J.W., Nieminski, N.M., Balster-Gee, A.F., Dal Ferro, P., Padgett, J.S., Powers, D.C., Marcuson, R.K., and Snyder, G.R., 2025, Sediment core data from offshore Cascadia during field activity 2022-653-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P1VQIJ2Q. https://doi.org/10.5066/P1VQIJ2Q Quality control of attribute accuracy was conducted during field data collection and processing workflows. No formal logical consistency tests were conducted. This dataset is considered complete for the information presented, as described in the abstract. Users are advised to carefully read the rest of the metadata record for additional details. Core depth values are relative to the top of sediment in the uppermost core section. Coring-induced compaction, if any, was not determined. No formal vertical accuracy tests were conducted. Cores were collected aboard MV Bold Horizon using a U.S. Geological Survey (USGS) jumbo piston corer (JPC) on cruise 2022-653-FA. The JPC system consisted of a 2500-lb head weight, 3.43-inch diameter barrel, and polybutyrate liner. The JPC trigger arm was set up to collect a trigger core (TC) associated with each JPC (if successful). JPCs were extruded and sectioned at sea. The cores were then transported back to the USGS Pacific Coastal and Marine Science Center. 2022 Cores were segmented into 150 cm (or shorter) sections and split into "working" and "archive" halves in the USGS Pacific Coastal and Marine Science Center core lab. Sediment surfaces were cleaned and smoothed on the "working" halves of split cores. Multi-sensor core logger (MSCL) data were acquired on a Geotek MSCL-S system (www.geotek.co.uk/products/mscl-s/). Each core was scanned through the system and measured simultaneously for density and magnetic susceptibility. Cores with multiple segments are composited into a single comma delimited text CSV file. Total depth in core, depth in an individual core segment, and core segment numbers are provided in the CSV files. File names correspond to the names of each core. For example, ‘2022_653_FA_JPC03.tif’ corresponds to all sections of jumbo piston core ‘JPC03’. A list of MSCL CSV files is included in this data release in the 2022-653-FA_cores.csv file (Hill and others (2025)). 2022 MSCL CSV files were renamed for consistency with other datasets in this data release (Hill and others (2025)). 2025 Core ID Point Point 793 Local surface 1.0 centimeters Attribute values 2022-653-FA_core_mscl.zip A zip file containing 6 comma delimited text files of multi-sensor core logger data. Producer defined sb_depth_cm Depth in full core of MSCL measurement (value represents the upper edge of a 1 cm interval). Producer Defined 0 792 centimeters 1 sect_num Section number of core Producer Defined 1 6 1 sect_depth_cm Depth in section of MSCL measurement (value represents the upper edge of a 1 cm interval). Producer defined 0.0 153.1 centimeters density Density of sediment in sample interval. Values of ‘-9999’ represent no data, where intervals extend beyond the ends of core sections, or where no data was collected. Producer defined 0.1573 1.9108 g/cc (grams per cubic centimeter) 0.0001 mag_sus Magnetic susceptibility of sediment in sample interval. Values of ‘-9999’ represent no data, where intervals extend beyond the ends of core sections, or where no data was collected. Producer defined -6.5794 361.8663 SI units times 10^-5 0.0001 The first line of each csv file is a header line. U.S. Geological Survey U.S. Geological Survey - CMGDS mailing and physical

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Santa Cruz CA 95060 1-831-427-4747 pcmsc_data@usgs.gov MSCL CSV files are provided in a zip archive (2022-653-FA_cores_mscl.zip) accompanied by CSDGM FGDC-compliant metadata. Please contact the PCMSC Data Coordinator about availability. 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. comma-delimited text Zip file contains MSCL data from cores in CSV format. Zip files may be decompressed with any zip utility (for example, 7zip, WinZip, Archive Utility). 0.189 https://doi.org/10.5066/P1VQIJ2Q Data can be downloaded using the Network_Resource_Name link and scrolling to 2022-653-FA_cores_mscl.zip in the Sampling Data section. None. CSV files can be viewed with any standard table editing software (for example, excel, numbers). 20250326 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