Brian D. Andrews 20260521 1.0 vector digital data data release DOI:10.5066/P14NWTX8 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/P14NWTX8 https://www.sciencebase.gov/catalog/item/68b08645d4be021f0facf2da Brian D. Andrews Wayne E. Baldwin Seth D. Ackerman Charles R. Worley Eric M. Moore Alex R. Nichols Patrick J. Berube Emily C. Huntley Laura L. Brothers 2026 1.0 data release DOI:10.5066/P14NWTX8 Reston, VA U.S. Geological Survey Suggested citation: Andrews, B.D., Baldwin, W.E., Ackerman, S.D., Worley, C.R., Moore, E.M., Nichols, A.R., Berube, P.J., Huntley, E.C., and Brothers, L.L., 2026, High-resolution geophysical and sampling data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2023-001-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P14NWTX8 https://doi.org/10.5066/P14NWTX8 https://www.sciencebase.gov/catalog/item/68adc403d4be027f635b3f90 In May and June 2023, the U.S. Geological Survey, in collaboration with the Massachusetts Office of Coastal Zone Management, collected high-resolution geophysical and seafloor sampling data, in Nantucket Sound to understand the regional geology in the vicinity of Horseshoe Shoal. Geophysical data collected include swath bathymetry, backscatter, and seismic reflection profile data. Ground-truth data, including sediment samples, underwater video, and bottom photographs were also collected. This effort is part of a long-term collaboration between the USGS and the Commonwealth of Massachusetts to map the State’s waters. In addition to resolving coastal hazards, habitats and resources, these data can be used to better understand the Quaternary history of coastal Massachusetts including the influence of sea-level change and sediment supply on coastal evolution. This collaboration produces high-resolution geologic data that serve the needs of research, management, and the public. Data collected as part of this mapping cooperative continue to be released in a series of USGS Reports and Data Releases https://www.usgs.gov/centers/whcmsc/science/geologic-mapping-massachusetts-seafloor The purpose of this polyline shapefile is to provide a geospatial record of the tracklines recorded by the multibeam sonar and to provide the line names and dates for each file collected. Support for 2023-001-FA was provided to the USGS from the Massachusetts Office of Coastal Zone Management. Approximately 441 linear kilometers of multibeam echosounder data, 400 km of seismic reflection profiling data were collected during 8 survey days along tracklines spaced 87 or 52 meters apart. Part 2 of this survey included ground validation using SEABOSS imagery and sediment samples collected at 59 stations covering both the 2022-001-FA and 2023-001-FA survey areas. Data were collected using the R/V Rafael, owned and operated by the USGS Woods Hole Coastal and Marine Science Center. Additional information on both the 2022 and 2023 field activities are available from https://cmgds.marine.usgs.gov/services/activity.php?fan=2022-001-FA, https://cmgds.marine.usgs.gov/services/activity.php?fan=2023-001-FA 20230601 20230611 Bathymetry data were collected on the following dates: 20230601-20230602 (Julian day 152-153), 20230606-20230611 (Julian day 157-162) Complete None planned -70.481861 -70.324596 41.584365 41.525813 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 Massachusetts Office of Coastal Zone Management CZM MassCZM field activity number 2023-001-FA R/V Rafael shapefile multibeam echosounder multibeam bathymetry backscatter Reson Teledyne T20-P ISO 19115 Topic Category geoscientificInformation imageryBaseMapsEarthCover USGS Thesaurus multibeam sonar navigational data geospatial datasets USGS Metadata Identifier USGS:68b08645d4be021f0facf2da None United States of America Massachusetts Atlantic Ocean Nantucket Sound Horseshoe Shoal Eldridge Shoal Succonnesset Shoal Wreck Shoal None sea floor seafloor none 2023 No access constraints. Please see 'Distribution Information' for details. These data are marked with a Creative Commons CC0 1.0 Universal License. These data are in the public domain and do not have any use constraints. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. U.S. Geological Survey Brian Andrews Geographer mailing and physical

384 Woods Hole Road

Woods Hole Massachusetts 02543-1598 USA 508-548-8700 x2348 508-457-2310 bandrews@usgs.gov https://www.sciencebase.gov/catalog/file/get/68b08645d4be021f0facf2da?name=2023-001-FA_TeledyneSeaBat_T20P_Tracklines_browse.jpg Thumbnail image of multibeam echosounder trackline data collected within Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2023-001-FA. JPEG Brian D. Andrews Wayne E. Baldwin Charles R. Worley Eric M. Moore Alex R. Nichols William W. Danforth David S. Foster Seth D. Ackerman Laura L. Brothers 2023 1.0 data release DOI:10.5066/P9O5G5OT Reston, VA U.S. Geological Survey This previous data release was also published as part of the USGS/CZM cooperative and may be of interest to others because it is directly south of, and overlaps, with the data collected during USGS Field Activity 2023-001-FA. https://doi.org/10.5066/P9O5G5OT https://www.sciencebase.gov/catalog/item/63e3e041d34e9fa19a9bb703 Linear gaps between consecutive polyline features in this shapefile reflect those time periods where data were not recorded This shapefile contains tracklines for all Teledyne Reson SeaBat T20-P files collected during survey 2023-001-FA. Data collected along sonar calibration lines and cross lines were used for data quality control but are not included in the final bathymetry and backscatter mosaics. Navigation data were acquired using the WGS 84 coordinate system with an Applanix POS MV Wavemaster (model 220, V5), which utilizes multiple GNSS satellites and acceleration data from a Motion Reference Unit (MRU) and GNSS azimuthal heading. The POS MV was configured with two AeroAntenna Technologies GNSS antennas located at either end of a 2-m baseline, which was oriented athwartship and mounted atop the after end of the cabin. DGPS positions were obtained from the primary antenna located on the starboard 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 8.8). U.S. Geological Survey Unpublished Material digital data disc 20230601 20230611 ground condition RAW Teledyne T20-P MULTIBEAM ECHOSOUNDER FILES Multibeam echosounder (MBES) bathymetry and backscatter data were collected using integrated, dual-head Teledyne Reson 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 1.215 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 GNSS antennas located at either end of a 2-m baseline, which was oriented athwartship and mounted atop the after end of the 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 AML-3LGR or Minos X CTDSV profilers were used to collect water column sound speed profiles 3 to 7 times each survey day. The Teledyne SeaBat User Interface (version 5.2.0.1) was used to control the sonars, which were operated in intermediate mode at full power (220 dB), with frequency-modulated pulse at 400 kHz. The range of the 1024 across track beams formed by the sonars were adjusted manually depending on water depth and resulted in combined swath widths of 50 to 300 meters or typically 3 to 6 times the water depth. Data were monitored and recorded using the Teledyne SeaBat User Interface (UI) (version 5.2.0.1) and Hypack/Hysweep (v. 2022). The SeaBat User Interface logged the navigation, attitude, bathymetry, time-series backscatter, (using the normalized backscatter datagram), and water column data to s7k format files for each sonar into one, integrated s7k file. The s7k line files were created by the Teledyne UI using the following naming convention: YYYYMMDD_HHMMSS. PROCESSING STEP 1: QIMERA DATA PROCESSING. Multibeam bathymetry processing within Qimera multibeam processing software (version 2.5.0) during the survey consisted of the following workflow: 1) A new Qimera project was created with projection information set to Universal Transverse Mercator (UTM) Zone 19N, WGS 84. The s7k files for each Julian day were imported to the project using the Source/add raw sonar files menu. 2) A Vessel configuration file was created with the linear and angular installation offsets for each T20-P sonar head as well as vendor specified uncertainty values for each of the survey sensors. 3) Sound Velocity profiles for each day were imported and converted to Qimera using the Source/import/Caris svp menu. Each profile was reviewed for incorrect records using the SVP editor. Incorrect records near the surface or within the water column were flagged using the "reject selection" context menu. 4) Predicted Tides from the Woods Hole, MA tidal station (id 8447930) for the month of June, were downloaded and imported using the Source/Add Tide Files menu. Predicted tides were referenced to Mean Lower Low Water (MLLW) at 6-minute intervals. 5) Delayed heave data from the raw POS MV files (.000) were used to update raw sonar lines using the Source/add binary navigation menu function. 6) The Processing Settings Editor was used to establish the following: a) Sound velocity Strategy: nearest in time, Use surface sound speed as first entry in raytrace profile. b) Position, Motion, and Heading Source Priorities: were set position 1, Motion 1, and Motion 1 respectively. c)Vertical Referencing was set to the Woods Hole predicted Tide file. d) Blocking filters were set to Across Track = 0-to-80 meters on each sonar head. Colinearity Fail was also selected. 7)Each raw sonar file was processed using the settings described above. 8) A preliminary, 2-m resolution dynamic surface (2023-001-FA_2m_Draft) was created and reviewed for inconsistencies and anomalies. The swath editor was used to remove spurious points through manual editing and filter application. The contact person for this and all subsequent processing steps below is Brian Andrews. 202306 2023-001-FA_TeledyneT20P_Bathymetry_2m_Draft U.S. Geological Survey Brian Andrews Geographer mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-548-8700 x2348 508-457-2310 bandrews@usgs.gov PROCESSING STEP 2: APPLY POST PROCESSED SBET FILES AND EDIT SOUNDINGS. Post-survey processing within Qimera (version 2.5.0) consisted of the following workflow: 1) Post-processed navigation, vessel attitude, and GNSS height data from POSPac Smoothed Best Estimate of Trajectory (SBET) files, and post-processed RMS attitude error data from POSPac smrmsg files were used to update each Sonar file using the Source/Add Binary Navigation Files function. The SBET files were referenced to the WGS 84 Ellipsoid (meters). 2) Once the sbet and smrmsg files were imported for each raw sonar file, the Processing Settings Editor was used to replace the attitude and tide referencing data using the following settings: a) Position, Motion, and Heading Source Priorities were superseded by "sbet" file. b) Vertical Referencing Method was set to "RTK (Accurate Height)" using the "sbet" file. 202311 PROCESSSING STEP 3: EXPORT TRACKLINE NAVIGTATION AND CONVERT TO SHAPEFILE. Processed navigation for each sonar file was exported from Qimera using the Export/Raw Sonar File/Export Trackline to ASCII menu. A python Jupyter notebook utilized the python modules pandas (version 1.5.2), geopandas (version 0.12.1), pyproj (version 3.4.0), shapely (version 1.8.5.post1), and sqlite3 (version 3.40.0) to process the navigation data for each profile line in the following steps. The separate ascii files were imported to pandas dataframes and sub-sampled to preserve the first and last records and records at ten second intervals in between. Coordinates for the reduced data were transformed from UTM Zone 19N (meters) to WGS84 geographic (decimal degrees), UTC date time objects reformatted to produce columns containing the filename, a combined year-julian day number string, a combined Julian day number UTC time string, survey id, vehicle id, and device id. Geopandas and shapely were used to create a point geometry column from the geographic coordinates. SQL queries was used to load each navigation dataframe into a geospatial SQLite database using the pyspatialite interface. Records were appended to two database tables, the first containing the reduced coordinate navigation, and the second containing trackline features created from the coordinated navigation point geometries. The trackline table was imported into QGIS (v.3.26) from the SQLite database, then exported (Right click on database feature class > Data > Save Features As) to the new Esri point and polyline shapefile ‘2023-001-FA_TeledyneT20P_Tracklines'. Additional processing included adding and calculating the fields described in the Entity and Attribute Section below. 20231203 2023-001-FA_TeledyneT20P_Tracklines.shp Vector string 155 0.000001 0.000001 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.257224 2023-001-FA_TeledyneT20P_Tracklines T20P multibeam echosounder tracklines for survey 2023-001-FA U.S. Geological Survey FID Internal feature number. QGIS Sequential unique whole numbers that are automatically generated. Shape Feature geometry. QGIS Coordinates defining the features. LineName Teledyne filename for the T20-P MBES trackline in the format:YYYYMMDD_HHMMSS, where YYYY is the year, MM is the month, DD is the day, HH is the minute in UTC, MM is the minutes, and SS is the seconds. Teledyne Character set YRJD_str The Year and Julian Day of the start of the line in the format: YYYY-DDD. USGS Character set YRJD_end The Year and Julian Day of the end of the line in the format: YYYY-DDD. USGS Character set JDUTC_str The Julian day and time (UTC) of the start of the line in the format DDD:HH:MM:SS.sss. USGS Character set JDUTC_end The Julian day and time (UTC) of the end of the line in the format DDD:HH:MM:SS.sss. USGS Character set SurveyID Woods Hole Coastal and Marine Science Center (WHCMSC) field activity identifier (e.g. "2023-001-FA" where 2023 is the survey year, 001 is sequential survey number of that year, and FA is Field Activity). U.S. Geological Survey Character set VehicleID Survey vessel name. U.S. Geological Survey Character set DeviceID Sonar device used to collect MBES data. U.S. Geological Survey Character set Length_km The length of the trackline feature in kilometers calculated using UTM 19N, WGS84. USGS 0.109 9.0 kilometers 0.001 U.S. Geological Survey - ScienceBase mailing and physical address

Denver Federal Center

Building 810

Mail Stop 302

Denver CO 80225 1-888-275-8747 sciencebase@usgs.gov Multibeam echosounder navigation data collected in Nantucket Sound, Massachusetts, in the vicinity of Horseshoe Shoal, during USGS Field Activity 2023-001-FA using a dual-head Teledyne T20-P multibeam echosounder: includes the shapefile 2023-001-FA_TeledyneT20P_Tracklines.shp, the browse graphic 2023-001-FA_TeledyneT20P_Tracklines_browse.jpg, and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file (2023-001-FA_TeledyneT20P_Tracklines_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. Shapefile QGIS 3.24.3 Shapefile Shapefile of T20-P MBES tracklines collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center and the associated metadata. Use any zip decompression utility 0.384 https://www.sciencebase.gov/catalog/item/68b08645d4be021f0facf2da https://www.sciencebase.gov/catalog/file/get/68b08645d4be021f0facf2da https://doi.org/10.5066/P9O5G5OT The first link is to the page containing the data, the second link downloads all data available from the page as a zip file, and the third link is to the publication landing page. none To utilize these data, the user must have software capable of uncompressing the zip file and viewing an Esri shapefile. 20260521 U.S. Geological Survey Brian Andrews Geographer mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 508-548-8700 x2348 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