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/68c9bd24d4be0274ff4afd9b 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 Water column speed of sound data were acquired periodically throughout the survey and used during collection and post-processing of Reson T-20P bathymetry data. Sound speed profile data are included in this publication as CARIS SVP format text files, PNG image plots of the profiles, and an ESRI point shapefile of the profile locations. 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 area. 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 -70.464167 -70.328056 41.582778 41.526389 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 sound velocity profile SVP SSP sound speed profile AML-3 LGR AML Minos-X CTDSV T20-P ISO 19115 Topic Category geoscientificInformation location elevation USGS Thesaurus sound velocity profiles ocean sciences navigational data marine geophysics marine geology USGS Metadata Identifier USGS:68c9bd24d4be0274ff4afd9b None United States of America Massachusetts Atlantic Ocean Nantucket Sound Horseshoe Shoal Eldridge Shoal Succonnesset Shoal Wreck Shoal None water column 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/68c9bd24d4be0274ff4afd9b?name=2023-001-FA_SVP_data_browse.jpg Thumbnail image of SVP locations collected within Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2023-001-FA. JPEG Fofonoff, N. Millard, R. 1983 UNESCO Tech. Pap. Mar. Sci. 44 https://www.researchgate.net/publication/33549403_Algorithms_for_Computation_of_Fundamental_Properties_of_Seawater 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 Sound velocity profiles were acquired with an AML-3 LGR or AML Minos-X CTDSV sensor. A total of 27 sound velocity profiles were collected during cruise 2023-001-FA and are included in this dataset. When using the AML-3 LGR unit, navigation data were acquired by the Differential Global Positioning System (DGPS) inside the unit and directly inserted into the raw AML file header. When using the AML Minos-X, navigation data were recorded using an Applanix POS MV Wavemaster (model 220, V5) Global Navigation Satellite Systems (GNSS) and logged continuously in HYPACK (version 22.1.4.0). HYPACK targets were created at each cast location, coordinates were copied, and inserted manually into the AML SeaCast software (version 4.40) during download and export of each profile. 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 after end of the cabin. POS MV DGPS positions were obtained from the primary antenna (port end of the 2-m baseline configuration). DGPS positions are horizontally accurate to 0.5 - 2 meters. However, offsets between the deployment location and the primary antenna were not accounted for, so the sound velocity profile positions are considered to be accurate to within 2-5 m. AML-3 LGR or Minos-X profile depths are calculated by either AML SeaCast (version 4.4) or Sailfish (version 4.4) software, respectively; both softwares convert pressure sensor readings to depth using the standard formulas described in Fofonoff, N.P. and Millard, R.C., Jr., 1988, Algorithms for computation of fundamental properties of seawater, UNESCO Technical Papers in Marine Science, No. 44. The depths are estimated to be accurate to within 1 meter. U.S. Geological Survey Unpublished Material digital data disc 20230601 20230611 ground condition RAW SOUND VELOCITY PROFILE DATA Twenty-seven sound velocity profiles were collected during the survey to correct refraction artifacts in the multibeam bathymetric data that can occur due to changes in the speed of sound throughout the water column. PROCESSING STEP 1: COLLECT SOUND VELOCITY PROFILES. Sound velocity profiles were collected 1-7 times per survey day using AML-3 LGR or Minos-X CTDSV sensors. Cast timing was determined depending on water column properties and the quality of real-time multibeam bathymetric data acquisition. The profiler sensor was hand-deployed from the after deck of R/V Rafael while the vessel was not making way. Once back on deck, data from the sensor were downloaded using either AML SeaCast (version 4.4; for AML-3 LGR) or Sailfish (version 4.4; for AML Minos-X) software, then files containing the full cast information were saved to the raw AML format (.csv) and downcast portions were saved to the CARIS SVP (.svp) format. 202306 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: SOUND VELOCITY PROFILE PROCESSING AND EXPORT FROM QIMERA. Sound Velocity profiles for each day were imported and converted to Qimera (version 2.5.0) format using the Source/import/Caris svp menu. Each profile was reviewed for positional accuracy and erroneous depth/sound velocity values using the SVP editor. Incorrect records near the surface or within the water column were flagged using the "reject selection" context menu. Edited SVP data were exported from Qimera using the Export/svp/export to CARIS SVP option, resulting in one svp text file that included all 27 svp casts. 20231001 2023-001-FA_SVP_QimeraExport.svp 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 PROCESSSING STEP 3: CREATE SVP PROFILE TEXT FILES, PNG IMAGES, AND POINT NAVIGATION FEATURE CLASS. A python Jupyter notebook was used to read the single svp file exported from Qimera, split it by profile, and write out a CARIS SVP format file for each profile. A second python Jupyter notebook utilized the python modules pandas (version 1.5.2), geopandas (version 0.12.1), shapely (version 1.8.5.post1), matplotlib (version 3.6.2), and sqlite3 (version 3.40.0) to read the individual svp files and create a PNG plot for each, containing speed of sound (meter/second) on the x-axis and depth (meters) on the y-axis. Position, Date, Time, and Profile ID were extracted from the SVP header line and written into the image as a title line for reference. The image files were named based on the date and time each sound velocity cast was collected. The latitude and longitude position, Cast ID, and Date/UTC time information for each cast, along with fields containing the Survey ID, Device ID, and Vehicle ID were appended as rows by profile to a Pandas dataframe during processing. After all profiles were processed, geopandas and shapely were used to create a point geometry column from the geographic station coordinates and the composite dataframe was imported to a geospatial SQLite database table using the pyspatialite interface. Finally, the svp location SQLite database table was imported to QGIS (version 3.26) as a point feature layer and exported (Right click on database feature class > Data > Save Features As) to the ESRI point shapefile 2023-001-FA_SVP_data.shp. 2023 SVP profile PNG images, SVP text files, and point shapefile Wayne E. Baldwin U.S. Geological Survey Geologist mailing and physical address

384 Woods Hole Rd.

Woods Hole MA 02543-1598 (508) 548-8700 x2226 (508) 457-2310 wbaldwin@usgs.gov vector point 27 0.000001 0.000001 Decimal degrees D_WGS_1984 WGS_1984 6378137.000000 298.257224 2023-001-FA_SVP_data.shp Sound velocity profile locations collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2023-001-FA (27 point features). U.S. Geological Survey Lon Decimal degree longitude value in GCS WGS 84. U.S. Geological Survey -70.464167 -70.328056 degrees .000001 Lat Decimal degree latitude value in GCS WGS 84. U.S. Geological Survey 41.526389 41.582778 degrees .000001 SVP Name of sound velocity profile used to distinguish between casts. Profile names are in the format: 2023-001-FA_SV2023-06-12_13-54-10 "FAN_SVyyyy-mm-dd_hh-mm-ss", where 'FAN' indicate the WHCMSC field activity number, 'SV' indicates sound velocity cast, 'yyyy' indicates the year, 'mm' indicates the month, 'dd' indicates the day, and 'hh-mm-ss' indicates the UTC time of the cast. U.S. Geological Survey Character set SVPImage Name of sound velocity profile image used to distinguish between casts. Profile names are in the format: 2023-001-FA_SV2023-06-12_13-54-10 "FAN_SVyyyy-mm-dd_hh-mm-ss", where 'FAN' indicate the WHCMSC field activity number, 'SV' indicates sound velocity cast, 'yyyy' indicates the year, 'mm' indicates the month, 'dd' indicates the day, and 'hh-mm-ss' indicates the UTC time of the cast. U.S. Geological Survey Character set Date Year-Month-Day when the sound velocity cast was collected. U.S. Geological Survey Character set JD_UTC Julian day and UTC time when the sound velocity cast was collected in the format: JD:HH:MM:SS; Julian day is the integer number (although recorded here in text string format) representing the interval of time in days since January 1 of the year of collection. U.S. Geological Survey Character set SurveyID WHCMSC field activity identifier (e.g. "2023-001-FA" where 2023 is the survey year, 001 is 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 Device used to collect sound speed profile data. U.S. Geological Survey Character set 2023-001-FA_SVP_Images Portable network graphic images of sound velocity profile data for survey 2023-001-FA (27 PNG files) U.S. Geological Survey 2023-001-FA_SVP_Text Sound velocity profile data in CARIS SVP ASCII format for survey 2023-001-FA (27 SVP files) U.S. Geological Survey The PNG images can be hyperlinked to their shapefile point locations in ArcGIS using the field called SVPImage. The graphs show depth on the y-axis and speed of sound on the x-axis. The format of the CARIS SVP files is as follows: Header line 1:[SVP_VERSION_2] - the standard CARIS SVP header line; Header line 2:filename; Header line 3:Section YYYY-JJJ HH:MM:SS DD:MM:SS -DD:MM:SS where YYYY is the year, JJJ is the Julian day, HH:MM:SS is the UTC time, DD:MM:SS is the latitude (in degrees, minutes, seconds) and -DD:MM:SS is the longitude (in degrees, minutes, seconds). The header is followed by column data of depth (meters) and speed of sound (meters per second). UTC times in the file svp file names contain seconds values times in the svp header lines all contain seconds values of zero. U.S. Geological Survey 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 Sound velocity profile data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2023-001-FA using AML-3 LGR or AML Minos-X CTDSV sensors: includes the shapefile 2023-001-FA_SVP_data.shp, 27 PNG images representing all sound speed profiles graphically 2023-001-FA_SVP_Images.zip), 27 svp ASCII files that represent all sound speed profile data (2023-001-FA_SVPText.zip), a browse graphic 2023-001-FA_SVP_data_browse.jpg) and a Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file (2023-001-FA_SVP_data_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 sound velocity profile data cast locations collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center during USGS Field Activity 2023-001-FA and the associated metadata. To utilize these data, the user must have software capable of viewing shapefiles. 0.1 https://www.sciencebase.gov/catalog/item/63eba5fcd34efa0476af1fa5 https://www.sciencebase.gov/catalog/file/get/63eba5fcd34efa0476af1fa5 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. PNG Matplotlib 3.6.2 Portable Network Graphic (PNG) The zip file contains images of sound speed profile data collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center in Nantucket Sound Massachusetts during USGS Field Activity 2023-001-FA and the associated metadata. Use any zip decompression utility (e.g. 7zip, Keka, WinZip) 2 https://www.sciencebase.gov/catalog/item/63eba5fcd34efa0476af1fa5 https://www.sciencebase.gov/catalog/file/get/63eba5fcd34efa0476af1fa5 https://doi.org/10.5066/P14NWTX8 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. SVP 2.0 CARIS ASCII sound velocity profile format (SVP) The zip file contains CARIS SVP text files of sound speed profile data collected by the U.S. Geological Survey - Woods Hole Coastal and Marine Science Center in Nantucket Sound Massachusetts during USGS Field Activity 2023-001-FA and the associated metadata. Use any zip decompression utility (e.g. 7zip, Keka, WinZip) 0.03 https://www.sciencebase.gov/catalog/item/63eba5fcd34efa0476af1fa5 https://www.sciencebase.gov/catalog/file/get/63eba5fcd34efa0476af1fa5 https://doi.org/10.5066/P14NWTX8 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 This publication contains data available in shapefile, SVP and PNG formats. The user must have software capable of reading shapefile format to use these data. The SVP files can be read with a text editor. PNG files can be viewed with any PNG image viewing software. The zip files must be uncompressed in order to view the images. 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