Seth D. Ackerman 20231114 1.0 raster digital data data release DOI:10.5066/P9GO90TI Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts U.S. Geological Survey, Coastal and Marine Hazards and Resources Program https://doi.org/10.5066/P9GO90TI https://cmgds.marine.usgs.gov/data-releases/datarelease/10.5066-P9GO90TI/ Seth D. Ackerman David S. Foster Charles R. Worley Alexander R. Nichols 2023 1.0 data release DOI:10.5066/P9GO90TI Reston, VA U.S. Geological Survey Suggested citation: Ackerman, S.D., Foster, D.S., Worley, C.R., and Nichols, A.R., 2023, High-resolution geophysical and geological data collected from outer Cape Cod, Massachusetts during USGS Field Activity 2021-004-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P9GO90TI. https://doi.org/10.5066/P9GO90TI https://cmgds.marine.usgs.gov/data-releases/datarelease/10.5066-P9GO90TI/ The U.S. Geological Survey (USGS) Woods Hole Coastal and Marine Science Center (WHCMSC) completed a bathymetric and shallow seismic-reflection survey during the period of June 9, 2021 to June 24, 2021 in water depths from 2 m to 30 m for a portion of the outer Cape Cod nearshore environment between Marconi and Nauset Beaches. The products from this survey will help to support white shark research on their shallow-water behavior in the dynamic nearshore environment at Cape Cod National Seashore (CACO). CACO visitors’ safety is threatened by interactions between the public and white sharks. This project provides CACO with baseline data and information on nearshore white shark habitat, specifically in the nearshore shoreface, bathymetric trough, and longshore bar. This data release provides the geophysical data collected from outer Cape Cod during USGS Field Activities 2021-002-FA in 2021. This dataset provides a high-resolution digital elevation model (DEM) of the seabed created from bathymetric sonar data collected by the U.S. Geological Survey during survey 2021-004-FA from outer Cape Cod, Massachusetts. The final dataset is referenced to the North American Vertical Datum of 1988 (NAVD 88). In conjunction with other geophysical and sample data, this bathymetry dataset will be used to investigate the morphology and geologic framework of the sea floor and coastal environment of Massachusetts. Support for 2021-004-FA was provided to the USGS from the National Park Service, Cape Cod National Seashore. Additional information on the field activities associated with this project are available at https://cmgds.marine.usgs.gov/fan_info.php?fan=2021-004-FA 20210609 20210624 ground condition Complete None planned -69.98022 -69.90958 41.94444 41.78144 USGS Metadata Identifier USGS:3439141a-1597-42c4-a26c-3c15678688e9 None U.S. Geological Survey USGS Woods Hole Coastal and Marine Science Center WHCMSC Coastal and Marine Hazards and Resources Program CMHRP Department of the Interior DOI Cape Cod National Seashore CACO National Park Service NPS Massachusetts Office of Coastal Zone Management CZM MassCZM field activity number 2021-004-FA RV Rafael GeoTIFF multibeam echo sounder multibeam bathymetry Reson Teledyne SeaBat T20P bathymetry Marine Geology ISO 19115 Topic Category oceans geoscientificInformation imageryBaseMapsEarthCover elevation USGS Thesaurus multibeam sonar sea-floor acoustic reflectivity bathymetry marine geophysics marine geology geospatial datasets None United States of America Atlantic Ocean Atlantic Margin Cape Cod Massachusetts Orleans Eastham Wellfleet Marconi Beach Nauset Beach None sea floor seafloor none 2021 none Public domain data from the U.S. Government are freely distributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset. These data are not to be used for navigation. Seth Ackerman U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 USA 508-548-8700 x2315 508-457-2310 sackerman@usgs.gov https://cmgds.marine.usgs.gov/data-releases/media/2022/10.5066-P9GO90TI/4e4c2a14e2ee4eb3a7694072bc144ba0/2021-004-FA_T20P_Bathymetry_2m_NAVD88_browse.jpg Thumbnail image of 2-m multibeam echo sounder bathymetry data collected from outer Cape Cod, Massachusetts. JPEG This grid represents processed dual-head Teledyne SeaBat T20-P multibeam echo sounder (MBES) bathymetry data gridded at 2-m resolution. Quality control and data processing were conducted to remove spurious points and reduce sound speed artifacts (refraction) using Computer Aided Resource Information System (CARIS) Hydrographic Information Processing System (HIPS; version 11.3). Despite this processing, small areas of vessel motion and refraction artifacts remain in the data. Small "no data" gaps exist throughout the dataset. These are the result of editing the artifacts and, in some areas, eliminating low quality soundings. In addition, gaps exist in shallow areas where underwater obstructions created hazards for the safe navigation of the survey vessel. While navigation and attitude data in the bathymetry data and coincident backscatter data (see larger work citation https://doi.org/10.5066/P9GO90TI) are identical the extents of the processed bathymetry grid and backscatter mosaic differs slightly due to differences in processing. Cross lines, collected to check tide corrections in bathymetry data and to provide dip angle seismic profile data, were incorporated into the final bathymetry dataset. Data were collected on the following dates: 20210609 and 20210615-20210624 (Julian day 160 and 166-175); several lines of bathymetry data was collected on 20210609 (Julian day 160) while the survey team was out testing the seismic system before the formal start of the survey. Data collected during some turns and along lines that extend beyond the area of a continuous bathymetry data were excluded. Navigation data were acquired using the WGS 84 coordinate system with an Applanix POS MV Wavemaster (model 220, V5), which blends Global Navigation Satellite Systems (GNSS) data, acceleration data from a Motion Reference Unit (MRU) and GPS azimuthal heading. The POS MV was configured with two AeroAntenna Technologies GPS antennas located at either end of a 2-m baseline, which was oriented athwartship and mounted atop the aft end of cabin. DGPS positions were obtained from the primary antenna located on the forward end of the baseline, and the positional offsets between the antenna and the navigational reference point (the POS MV IMU) were accounted for in the Applanix POSView (version 11.00) acquisition software. DGPS positions are horizontally accurate to 0.5 - 2 meters, but accuracy can increase to less than 10 cm after post-processing with Applanix POSPac (version 8.7). Vertical accuracy of the raw data based on system specifications may be approximately 1 percent of water depth (ranging from 0.02 to 0.3 meters based on the water depth range of approximately 2 to 30 meters within the survey area). The Applanix Wavemaster POS MV Attitude and Positioning system, used to correct for vessel roll, pitch, heave, and yaw, has a theoretical vertical accuracy of a few mm. Post-Processed Kinematic (PPK) GPS height corrections (from Applanix POSPac smoothed best estimate of trajectory (SBET) files) were used to reference soundings to the World Geodetic System 1984 (WGS 84) ellipsoid and remove water depth fluctuations in sea level during the survey. Forty-five sound speed profiles acquired with an AML Oceanographic MINOS X sound velocity profiler (SVP) were used during processing to minimize acoustic refraction artifacts in the bathymetry data. Changes in vessel draft due to water and fuel usage were not considered. Additionally, uncertainty associated with the vertical transformation of the bathymetric grid from WGS 84 (ITRF 2000) to the North American Vertical Datum of 1988 (NAVD 88) using VDatum transformation tool (NOAA) is approximately 7.62 cm as calculated by the VDatum tool (v. 4.1.2). U.S. Geological Survey Unpublished Material digital data disc 20210609 20210624 ground condition Teledyne SeaBat T20P multibeam echo sounder raw bathymetry and backscatter Multibeam echosounder (MBES) bathymetry and backscatter data were collected using dual-head Teledyne SeaBat T20-P sonars. The pair of mills cross transmit and receive arrays were mounted side-by-side within a bracket that oriented them at opposing 30-degree angles (relative to horizontal). The bracket was pole-mounted on the starboard side of the R/V Rafael so that the sonar arrays were oriented athwart ships (primary and secondary arrays facing outward and down to port and starboard, respectively) and located approximately 1.235 m below the waterline when deployed. Vessel navigation and attitude data were acquired using an Applanix POS MV Wavemaster (model 220, V5) configured with two AeroAntenna Technologies GPS antennas located at either end of a 2-m baseline, which was oriented athwartship and mounted atop the aft end of cabin, and the wetpod MRU mounted atop the sonar bracket just aft of the pole. An AML Micro X SV mounted on the sonar bracket monitored sound speed near the sonars during acquisition, and an AML Minos X SVPT was used to collect water column sound speed profiles 1 to 3 times each survey day. The Teledyne SeaBat User Interface (version 5.0.0.18) was used to control the sonars, which were operated in intermediate mode at full power (220 dB), with frequency-modulated pulses centered at 400 kHz. The range of across track beams (2048 for JD 160, 1024 for the rest of the survey) formed by the sonars were adjusted manually depending on water depth, and resulted in combined swath widths of 50 to 250 meters or typically 3 to 6 times the water depth. Data were monitored and recorded using the Teledyne SeaBat User Interface (UI) (version 5.0.0.18) and Hypack Hysweep (version 2021, 21.1.3.0). The SeaBat User Interface logged the navigation, attitude, bathymetry, and time-series backscatter data to s7k format files for each sonar. The s7k line files were created by the Teledyne SeaBat UI using the following naming convention: M/S_YYYYMMDD_HHMMSS. The line files were appended with an "M" and "S" prefix to denote the port (or main/primary) "M" and "S" starboard (or secondary) sonar heads, respectively. Hypack Hysweep 2021 also was used to log the navigation, attitude, and bathymetry data for both sonars to a single HSX format file. Hypack Hysweep filenames have the format 'LLL_HHMM', where LLL indicates the three digit planned line number and HHMM is the UTC time. The Hypack Hysweep HSX data were used to produce the final processed bathymetry grid and the trackline shapefile. PROCESSING STEP 1: CARIS HIPS DATA PROCESSING. Multibeam bathymetry processing within CARIS HIPS (version 11.3) post-survey consisted of the following flow: 1) A vessel configuration file was created in CARIS for the HSX sonar files (RVRafael_DualT20P_2048.hvf for JD160 data, RVRafael_DualT20P.hvf for the rest of the survey) which includes, linear and angular installation offsets for each T20-P unit as well as vendor specified uncertainty values for each of the survey sensors. 2) A CARIS HIPS project (version 11.3) was created with projection information set to Universal Transverse Mercator (UTM) Zone 19N, WGS84 using the vessel configuration file from step 1.1. 3) Each HSX file was imported to the new CARIS project using the Import/Conversion Wizard. 4) Delayed heave data from raw POS MV files (.000) were used to update HIPS survey lines using the import auxiliary data function. 5) Post-processed navigation, vessel attitude, and GPS height data from POSPac SBET files, and post-processed RMS attitude error data from POSPac smrmsg files were used to update HIPS survey lines using the import auxiliary data function. 6) Navigation source was set to Applanix SBET, and navigation was reviewed and edited as needed using the Navigation Editor tool. 7) Georeference Bathymetry was done to apply the sound velocity corrections from the final SVP files containing all the sound velocity profiles collected for each survey day, specifying the nearest in time method, 'delayed' heave source, and use surface sound speed. SVP files for each survey day were created as part of the sound velocity profile processing workflow, see SVP dataset in the larger work citation. 8) 2-m resolution Swath Angle Weighted (SWATH) surfaces were created by sub-area to incorporate all the files as they were processed, and the SWATH surfaces were reviewed for inconsistencies and anomalies. 9) The swath and subset editors were used to remove spurious points through manual editing and filter application, and the refraction editor was used to adjust sound speed values in areas where sound velocity data did not adequately correct depth profiles, which were obviously influenced by local anomalies in speed of sound through the water column. The steps described above were performed by Seth Ackerman between June and December 2021. The contact person for this and all subsequent processing steps below is Seth Ackerman. 202111 Seth Ackerman U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 USA 508-548-8700 x2315 508-457-2310 sackerman@usgs.gov PROCESSING STEP 2: CREATE FINAL BATHYMETRY SURFACE. A final 2-m bathymetry SWATH surface for the entire survey area was created in CARIS 11.3. Small "no data" holidays were filled twice using the "Fill Raster Holiday" tool and a 3x3 matrix size filter using data from a minimum of 4 neighboring cells. 202309 PROCESSSING STEP 3: EXPORT AND TRANSFORM TO NAVD88. The final CARIS HIPS SWATH surface was exported as a 2-m per pixel ASCII file referenced to UTM Zone 19N, WGS84 and ellipsoidal heights. The National Oceanic and Atmospheric Administration's Vertical Datum Transformation tool (VDatum v.4.1.2) was used to transform surfaces to the North American Vertical Datum of 1988 (NAVD 88). The process required transformation of the horizontal and vertical reference frames from UTM Zone 19N, WGS84 (using ITRF2008) and ellipsoidal heights to UTM Zone 19N, North American Datum of 1983 (NAD 83) and NAVD 88 orthometric heights (all in meters) using the default geoid model. The resulting ASCII raster was opened in Global Mapper (version 24.0) and converted into a 32-bit floating point GeoTIFF 2021-004-FA_T20P_Bathymetry2m_NAVD88.tif) using Export, Export Elevation Grid Format, GeoTIFF. 202309 Raster Grid Cell 9020 2833 1 Universal Transverse Mercator 19N 0.9996 -69 0 500000 0 row and column 2.0 2.0 meters GCS_North_American_1983_2011 GRS_1980 6378137.000000 298.257222101 North American Vertical Datum of 1988 0.1 meters Explicit depth coordinate included with horizontal coordinates Elevation values in 32-bit GeoTIFF format. Data values represent depths referenced to the North American Vertical Datum of 1988 (NAVD 88). U.S. Geological Survey U.S. Geological Survey Coastal and Marine Hazards and Resources Program Geologist mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 USA 508-548-8700 x2315 508-457-2310 whsc_data_contact@usgs.gov Multibeam echo sounder 2-m bathymetry data collected from outer Cape Cod, Massachusetts during USGS Field Activity 2021-004-FA, using a dual-head Teledyne SeaBat T20-P multibeam echo sounder: includes the GeoTIFF raster 2021-004-FA_T20P_Bathymetry_2m_NAVD88.tif, world file 2021-004-FA_T20P_Bathymetry_2m_NAVD88.tfw, the browse graphic 2021-004-FA_T20P_Bathymetry_2m_NAVD88_browse.jpg, and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata files (2021-004-FA_T20P_Bathymetry_2m_NAVD88_meta.xml). 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 for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. GeoTIFF Global Mapper version 24.0 32-bit GeoTIFF file GeoTIFF image file derived from MBES bathymetry data collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center during survey 2021-004-FA and the associated metadata. Use any zip decompression utility 12 https://cmgds.marine.usgs.gov/data-releases/media/2022/10.5066-P9GO90TI/c40a678b9d3f4e58bbedd762cf7b965c/2021-004-FA_T20P_Bathymetry_2m_NAVD88.zip https://cmgds.marine.usgs.gov/data-releases/datarelease/10.5066-P9GO90TI/ https://doi.org/10.5066/P9GO90TI The data can be downloaded using the Network Resource Name links. The first link is a direct link to download the zipped file of data. The second and third links are to a landing page for the entire data release where the data, metadata, and browse graphic can be downloaded. none To utilize these data, the user must have software capable of viewing GeoTIFF files. 20231114 Seth Ackerman U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 USA 508-548-8700 x2315 508-457-2310 whsc_data_contact@usgs.gov The metadata contact email address is a generic address in the event the person is no longer with the USGS. FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time