Peter Dartnell Daniel S. Brothers Peter J. Haeussler Gerry A. Hatcher Robert M. Wyland 20250412 GSF data release DOI:10.5066/P1ED3GXB Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey Suggested Citation: Dartnell, P., Brothers, D.S., Haeussler, P.J., Hatcher, G.A., Wyland, R., 2025, Multibeam line files from Cross Sound, Alaska collected during USGS field activity 2015-629-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P1ED3GXB. https://doi.org/10.5066/P1ED3GXB Processed Reson 7111 multibeam line files from a May 2015 survey offshore Cross Sound, southeast Alaska. Data were collected and processed by the U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center (PCMSC) with fieldwork activity number 2015-629-FA. Data are provided as generic sensor format (GSF) line files. In 2015 the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) in cooperation with the Alaska Department of Fish and Game (ADFG) collected bathymetry and acoustic backscatter data offshore Cross Sound in southeast Alaska using an Reson 7111 multibeam echosounder mounded to the ADFG R/V Solstice. The survey was conducted to map the offshore expression of the Queen Charlotte fault system that runs for approximately 500 kilometers off the coast of southeast Alaska and British Columbia. This was the first in a series of surveys to map the entire offshore component of the fault. The fault system has generated numerous powerful earthquakes in the magnitude 7 and 8 range. This mapping will help understand the fault's slip rate, earthquake recurrence intervals, and paleoseismic history. These data are intended for science researchers, students, policy makers, and the general public. These data can be used with multibeam processing software. Geographic information systems (GIS) ready multibeam bathymetry and acoustic backscatter grids are available in the associated data release (https://doi.org/10.5066/F7JH3KG6). These data are not intended to be used for navigation. Additional information about the field activities from which these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2015-629-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 dataset in nonproprietary form, as well as in a number of multibeam echosounder processing software, this metadata file may include some multibeam echosounder processing software-specific terminology. 20150505 20150521 ground condition at time data were collected. Complete None planned -137.202 -136.217 58.426 57.808 USGS Metadata Identifier USGS:4ad43d19-0026-4ab9-889e-a64e52676703 Global Change Master Directory (GCMD) Bathymetry Seafloor Topography ISO 19115 Topic Category geoscientificInformation USGS Thesaurus bathymetry bathymetry measurement sea-floor characteristics geospatial datasets marine geophysics multibeam sonar Data Categories for Marine Planning Bathymetry and Elevation Marine Realms Information Bank (MRIB) Keywords seabed field observation none U.S. Geological Survey USGS Coastal and Marine Hazards and Resources Program CMHRP Pacific Coastal and Marine Science Center PCMSC generic sensor format Geographic Names Information System (GNIS) State of Alaska Cross Sound None Queen Charlotte Fault Yakobi Sea Valley No access 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 and the Alaska Department of Fish and Game as the originators 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

2885 Mission Street

Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov 2015-629-FA_GSF_Files_QV.jpg Preview image of 2015 Cross Sound GSF tracklines JPEG Caris HIPS and SIPS (ver. 9) on a Windows 10 computer. Peter Dartnell Daniel S. Brothers Peter J. Haeussler 2022 Dartnell, P., Brothers, D.S., and Haeussler, P.J., 2022, Multibeam bathymetry and acoustic-backscatter data collected in 2015 near Cross Sound, southeast Alaska, during field activity 2015-629-FA: U.S. Geological Survey data release, https://doi.org/10.5066/F7JH3KG6. https://doi.org/10.5066/F7JH3KG6 No formal attribute accuracy tests were conducted. No formal logical accuracy tests were conducted. 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. The Coda Octopus F180 position and motion compensation system has a horizontal positional accuracy of about 0.4 m with Differential Global Positioning Systems (DGPS) corrections and roll and pitch accuracies of about 0.025 degrees (https://www.oceanscan.net/gallery/Data_Sheets/CODA_F180_PRECISION_ALTITUDE__POSITIONING_SYSTEMS.pdf). Accuracies of final products may be lower due to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations. The Coda Octopus F180 position and motion compensation system has heave accuracy between 3.5cm - 5cm (https://www.oceanscan.net/gallery/Data_Sheets/CODA_F180_PRECISION_ALTITUDE__POSITIONING_SYSTEMS.pdf). Accuracies of final products may be lower due to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations. National Oceanic and Atmospheric Administration 2015 online National Oceanic and Atmospheric Administration https://tidesandcurrents.noaa.gov/stationhome.html?id=9452634 online database 20150501 20150530 ground condition at time data were collected verified tides Tide station data In May 2015 the USGS, PCMSC mapped offshore Cross Sound in southeast Alaska over the northern section of the Queen Charlotte-Fairweather fault. A Reson 7111 multibeam echosounder was pole-mounted to the Alaska Department of Fish and Game R/V Solstice. The survey line files were imported into Caris HIPS and SIPS software (version 9) for bathymetric processing. Water column sound velocity data that were collected throughout the survey were applied to the bathymetry data and verified tides from the Elfin Cove tide station (9452634) were applied in post-processing. The data were cleaned of obvious bad soundings. GSF line files were exported from Caris HIPS and SIPS software. The data release support file section has sound velocity profiles as a single file (2015-629-FA_ALL_SVP.svp) with geographic locations, times, and sound velocities relative to depth in Caris HIPS and SIPS format. The support file section has the survey vessel file in Caris HIPS and SIPS format (ADFG_Solstice.hvf) that includes the vessel lever arm offsets and multibeam calibration corrections. The support file section has a verified tide table used in post-processing that includes data, time, and verified tide in Caris HIPS and SIPS format. The GSF files should have all this information applied but the files are included in the data release for completion. verified tides 2024 point String 504 0.000001 0.000001 Decimal degrees WGS84 WGS84 6378137.000000 298.257224 Mean lower low water 0.01 meters Explicit depth coordinate included with horizontal coordinates These data are organized into separate zip files based on the date of collection (Julian day). Within each Julian day folder, there are Generic Senso Format (GSF) files labeled in the format "year_month_day_line_number_shipname". Additionally, these data are supplemented by files used for bathymetric processing. The data release support file section has sound velocity profiles as a single file (2015-629-FA_ALL_SVP.svp) with geographic locations, times, and sound velocities relative to depth in Caris HIPS and SIPS format. The support file section has the survey vessel file in Caris HIPS and SIPS format (ADFG_Solstice.hvf) that includes the vessel lever arm offsets and multibeam calibration corrections. The support file section has a verified tide table used in post-processing that includes data, time, and verified tide in Caris HIPS and SIPS format. The GSF files should have all this information applied but the files are included in the data release for completion. files were exported from Teledyne Geospatial Caris HIPS and SIPS software (version 9) and have entity and attributes as published at https://www.ldeo.columbia.edu/res/pi/MB-System/mbweb/tmp/formatdoc/gsf_spec.pdf. U.S. Geological Survey - CMGDS Mailing and Physical

2885 Mission Street

Santa Cruz CA 95060 831-427-4747 pcmsc_data@usgs.gov These data are available in Generic Sensor Format (.gsf) along with 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. GSF Caris HIPS and SIPS (version 9) Downloadable zip files contains survey day directories which contain the survey line files collected during that day. WinZip 2154 https://doi.org/10.5066/P1ED3GXB Data and metadata can be downloaded using the Network_Resource_Name link and scrolling down to the sonar data section. None. The downloadable data file has been compressed with the "zip" command and can be unzipped with Winzip (or other tool) on Windows systems. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing GSF files. The support files can be viewed with any text reader. 20250412 U.S. Geological Survey, Pacific Coastal and Marine Science Center PCMSC Science Data Coordinator mailing and physical

2885 Mission Street

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