Peter Dartnell Janet T. Watt Jenna C. Hill James E. Conrad 20231130 GeoTIFF data release DOI:10.5066/P9PERGFK Pacific Coastal and Marine Science Center, Santa Cruz, California U.S. Geological Survey https://doi.org/10.5066/P9PERGFK Peter Dartnell Janet T. Watt Jenna C. Hill James E. Conrad 2023 data release DOI:10.5066/P9PERGFK Pacific Coastal and Marine Science Center, Santa Cruz, CA U.S. Geological Survey Suggested Citation: Dartnell, P., Watt, J.T., Hill, J.C., and Conrad, J.E., 2023, Composite multibeam bathymetry surface and data sources of the central Cascadia Margin offshore Oregon: U.S. Geological Survey data release, https://doi.org/10.5066/P9PERGFK. https://doi.org/10.5066/P9PERGFK Data from various sources, including 2018 and 2019 multibeam bathymetry data collected by the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Geological Survey (USGS) were combined to create a composite 30-m resolution multibeam bathymetry surface of central Cascadia Margin offshore Oregon. The data are available as a geoTIFF file. In 2018 and 2019 the NOAA ships Rainier and Fairweather collected multibeam bathymetry data in 4 areas along the central Cascadia Margin offshore Oregon as part of a cooperative project between the U.S. Geological Survey, Pacific Coastal and Marine Science Center and NOAA. These regions were combined with other publicly available multibeam bathymetry data. The surface was generated to assist research projects studying offshore geohazards including mapping faults, submarine landslides, sediment transport pathways, and seafloor seeps. These data are not intended to be used for navigation. Additional information about the USGS field activities from which some of these data were derived is available online at: https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-642-FA https://cmgds.marine.usgs.gov/fan_info.php?fan=2019-636-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. 1998 2021 ground condition at time data were collected. Complete None -126.156 -124.093 46.607 43.408 USGS Metadata Identifier USGS:39d6085b-9d70-4a7d-9523-8eba44bde4ae 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 Geographic Names Information System (GNIS) State of Oregon State of Washington 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 originators of the dataset and in products derived from these data. Portions of the map used data provided by the Ocean Exploration Trust’s Nautilus Exploration Program, Cruises NA072, NA080, NA082, NA088, NA095, NA122, NA128, NA130. The surface was generated to assist research projects studying offshore geohazards including mapping faults, submarine landslides, sediment transport pathways, and seafloor seeps. The bathymetry grid is not intended to be used for navigation. 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 CentralCascadia_composite_bathymetry_UTM10_NAD83_QV.jpg Quick view image of the central Cascadia Margin composite multibeam bathymetry surface JPEG Caris HIPS and SIPS (ver. 11) and ArcMap (ver. 10.3.1) on a Windows 10 computer. The attribute table in the bathymetry source shapefile (CentralCascadia_composite_bathymetry_UTM10_NAD83_data_sources.shp) included in this data release provides mean differences and standard deviations calculated between each dataset and an adjacent, overlapping dataset. In general, there is good agreement in depth values between adjacent datasets. Also, the mean difference between the 30-m composite bathymetry surface and the publicly available Global Multi-Resolution Topography Data Synthesis (https://www.gmrt.org/) bathymetry surface is 2.09m 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 composite multibeam bathymetry surface was generated from a combination of dedicated multibeam surveys, processed bathymetry surfaces received from other institutions, as well as transit data (ancillary data collected while a ship was underway). The bathymetry data were collected over a span of nearly 23 years using a variety of models of multibeam echosounders, GPS systems, position and motion compensation systems, sound velocity profilers, and tide measurements. The attribute table in the bathymetry source shapefile (CentralCascadia_composite_bathymetry_UTM10_NAD83_data_sources.shp) included in this data release provides links to the survey page for each dataset. Some of the datasets provide metadata and reports that describe mapping procedures and data quality including uncertainty measurements and comparisons with other bathymetry data. The horizontal accuracy of bathymetry data in this data release may be lower than stated in the reports due to further processing of the data. The composite multibeam bathymetry surface was generated from a combination of dedicated multibeam surveys, processed bathymetry surfaces received from other institutions, as well as transit data (ancillary data collected while a ship was underway). The bathymetry data were collected over a span of nearly 23 years using a variety of models of multibeam echosounders, GPS systems, position and motion compensation systems, sound velocity profilers, and tide measurements. The attribute table in the bathymetry source shapefile (CentralCascadia_composite_bathymetry_UTM10_NAD83_data_sources.shp) included in this data release provides links to the survey page for each dataset. Some of the datasets provide metadata and reports that describe mapping procedures and data quality including uncertainty measurements and comparisons with other bathymetry data. The vertical accuracy of bathymetry data in this data release may be lower than stated in the reports due to further processing of the data. The Ocean Exploration Trust's, Nautilus Exploration Program collected multibeam echosounder data along the central Cascadia Margin between 2016 and 2022 (OET survey ID's NA072, NA080, NA082, NA088, NA095, NA122, NA128, NA130). The U.S. Geological Survey Pacific Coastal and Marine Science Center requested and received both raw line files and processed grids as well as processed raw line files available from NOAA, National Centers for Environmental Information, https://ngdc.noaa.gov/mgg/bathymetry/multibeam.html). Raw survey line files were imported and processed in Caris HIPS and SIPS software (version 11). The data were gridded into 30-m surfaces and exported as geoTIFF's or ASCIIRaster files and imported into ArcMap. 2022 Publicly available multibeam echosounder data available from NOAA, National Centers for Environmental Information were downloaded from https://ngdc.noaa.gov/mgg/bathymetry/multibeam.html. Survey IDs include TN149, TN173, TN265, KM1812, FK180731, FK180824, FK190612, RR1807, SKQ201607S, MGL2104, MGL1216, AT26-16, AT26-17, TN312. The raw survey and transit line files were imported and processed in Caris HIPS and SIPS software (version 11). The data were gridded into 30-m surfaces and exported as geoTIFF or ASCIIRaster files and imported into ArcMAP. 2022 Processed multibeam bathymetry grids from Monterey Bay Aquarium Research Institute (MBARI) were downloaded as ASCIIRaster files from http://www3.mbari.org/data/mapping/NorCal_Oregon_Margin/oregon_a.htm(OregonMarginB-I.asc). The bathymetry data were imported into ArcMap and projected from geographic coordinates to UTM, zone 10, WGS84 coordinates. The UTM grid was reprojected to UTM, zone 10, NAD83 coordinates and resampled to 30-m resolution. 2021 Accessed processed multibeam bathymetry data collected by the USGS during field activity 2014-607-FA. Cochrane, G.R., Dartnell, P., Hemery, L.G., and Hatcher, G., 2017, Data release for USGS field activity 2014-607-FA, Oregon OCS seafloor mapping: selected lease blocks relevant to renewable energy (ver. 2.0, July 2017), U.S. Geological Survey data release, https://doi.org/10.5066/F7V40S8V 2021 In 2018 and 2019 the NOAA ships Rainier and Fairweather mapped four regions along the central Cascadia Margin (NOAA survey IDs H13119, H13137, H13118, W00474) using Kongsberg EM-710 multibeam echosounders. These bathymetry surfaces are available from NOAA, National Centers for Environmental Information and were downloaded from https://ngdc.noaa.gov/mgg/bathymetry/multibeam.html as BAG files. The BAG files were imported into Caris HIPS and SIPS, version 11 and converted to LAS files. The files were imported into ArcMap, version 10.8.1 and converted to grids. 2022 If needed, the previously described bathymetry grids were projected to a common horizontal datum (NAD83) using the "Project Raster" tool in ArcToolbox. Also, if needed, the grids were downsampled to 30-m spatial resolution using the "Resample" tool in ArcMap using the bilinear resampling technique. The grids were then merged together using the "Mosaic to New Raster" tool in ArcMap using the "first" mosaic operator. Priority was given to recent dedicated surveys, then older dedicated surveys followed by cleaner transit data and then noisier transit data. The merged grid was exported as a geoTIFF file. 2023 Publicly available Global Multi-Resolution Topography Data Synthesis surface was downloaded from https://www.gmrt.org/. The surface was projected to UTM zone 10, NAD83 coordinates and re-sampled to 30-m resolution. This surface was merged with the composite multibeam bathymetry surface with priority given to the multibeam surface to fill small data gaps not covered by the composite multibeam bathymetry surface. The merged grid was exported as a geoTIFF file. 2023 Raster Grid Cell 10743 6062 1 Universal Transverse Mercator 10 0.9996 -123.00000 0.00000 500000.0 0.00 coordinate pair 30.0 30.0 Meters NAD83 GRS80 6378137.00 298.257223563 instantaneous sealevel 0.1 meters Explicit elevation coordinate included with horizontal coordinates value Raster values represent depth in meters. Producer defined The complete 30-m resolution "CentralCascadia_composite_bathymetry_UTM10_NAD83.tif" grid was originally archived as a TIFF image with the following attributes. >Cell size = 30.0 >Number of rows = 10743 >Number of columns = 6062 > >Data type = floating point > >Boundary >Xmin = 258579 >Xmax = 440439 >Ymin = 4807775 >Ymax = 5130065 > >Statistics >Minimum value = -3863.3 >Maximum value = -20.8 >Mean = -1463.3 >Standard deviation = 893.5 > >Coordinate system description >Projection UTM >Zone 10 >Datum NAD83 >Units meter 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 These data are available in GeoTIFF format, including a tif world file (.tfw) and 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. GeoTIFF ArcMap (version 10.3.1) Downloadable zip file contains the TIFF (.tif), and the projection file (.tfw). WinZip 86.1 https://doi.org/10.5066/P9PERGFK Data 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 and viewing a GeoTIFF file. 20231130 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