In November 2021, the U.S. Geological Survey collected high-resolution multibeam sonar data in the vicinity of Eel Pond, in Woods Hole, Massachusetts using a dual-head Teledyne Seabat T20-R multibeam echo sounder (MBES). The main objective of this survey was to evaluate new sonar system features prior to their use in future field activities. In addition to bathymetry and relative acoustic backscatter data, normalized acoustic backscatter data were also collected. Unlike relative backscatter data, normalized backscatter data compensate for adjustments made to sonar power, gain, absorption, spreading, and frequency parameters made during acquisition. In order for backscatter intensity levels to remain consistent along survey lines, and from line to line, relative backscatter data require that minimal adjustments are made to these parameters during acquisition, which can degrade the sonar performance for a given survey site. However, the ability to allow the sonar acquisition software to change sonar parameters based on variations in bathymetry and the survey environment during acquisition allows these parameters to be optimized. Having these parameters optimized for this survey allowed the USGS to evaluate this new normalized backscatter capability to ensure the collected backscatter intensity levels were referenced to a factory calibrated level. Eel Pond in Woods Hole, MA was chosen as a test area for its proximity to the USGS Coastal and Marine Science Center. It provides a variety of substrates on which to evaluate the performance of the sonar, and bathymetric/backscatter data of this area may prove useful to other projects and institutions in the area.

In June 2022, the U.S. Geological Survey, in collaboration with the Massachusetts Office of Coastal Zone Management, collected high-resolution geophysical data, in Nantucket Sound to understand the regional geology in the vicinity of Horseshoe Shoal. This effort is part of a long-term collaboration between the USGS and the Commonwealth of Massachusetts to map the State’s waters, support research on the Quaternary evolution of coastal Massachusetts, resolve the influence of sea-level change and sediment supply on coastal evolution, and strengthen efforts to understand the type, distribution, and quality of subtidal marine habitats. 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 Open-File Reports and Data Releases https://www.usgs.gov/centers/whcmsc/science/geologic-mapping-massachusetts-seafloor.

Accurate data and maps of sea floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. To address these concerns the U.S. Geological Survey, in cooperation with the Massachusetts Office of Coastal Zone Management (CZM), comprehensively mapped the Cape Cod Bay sea floor to characterize the surface and shallow subsurface geologic framework. 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, support research on the Quaternary evolution of coastal Massachusetts, the influence of sea-level change and sediment supply on coastal evolution, and efforts to understand the type, distribution, and quality of subtidal marine habitats. This collaboration produces high-resolution geologic maps and Geographic Information System (GIS) 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 Open-File Reports and Data Releases (https://www.usgs.gov/centers/whcmsc/science/geologic-mapping-massachusetts-seafloor). This data release provides the geophysical and geologic sampling data collected in Cape Cod Bay during USGS Field Activities 2019-002-FA and 2019-034-FA in 2019.

In November 2021, the U.S. Geological Survey collected high-resolution multibeam sonar data in the vicinity of Eel Pond, in Woods Hole, Massachusetts using a dual-head Teledyne Seabat T20-R multibeam echo sounder (MBES). The main objective of this survey was to evaluate new sonar system features prior to their use in future field activities. In addition to bathymetry and relative acoustic backscatter data, normalized acoustic backscatter data were also collected. Unlike relative backscatter data, normalized backscatter data compensate for adjustments made to sonar power, gain, absorption, spreading, and frequency parameters made during acquisition. In order for backscatter intensity levels to remain consistent along survey lines, and from line to line, relative backscatter data require that minimal adjustments are made to these parameters during acquisition, which can degrade the sonar performance for a given survey site. However, the ability to allow the sonar acquisition software to change sonar parameters based on variations in bathymetry and the survey environment during acquisition allows these parameters to be optimized. Having these parameters optimized for this survey allowed the USGS to evaluate this new normalized backscatter capability to ensure the collected backscatter intensity levels were referenced to a factory calibrated level. Eel Pond in Woods Hole, MA was chosen as a test area for its proximity to the USGS Coastal and Marine Science Center. It provides a variety of substrates on which to evaluate the performance of the sonar, and bathymetric/backscatter data of this area may prove useful to other projects and institutions in the area.

In November 2021, the U.S. Geological Survey collected high-resolution multibeam sonar data in the vicinity of Eel Pond, in Woods Hole, Massachusetts using a dual-head Teledyne Seabat T20-R multibeam echo sounder (MBES). The main objective of this survey was to evaluate new sonar system features prior to their use in future field activities. In addition to bathymetry and relative acoustic backscatter data, normalized acoustic backscatter data were also collected. Unlike relative backscatter data, normalized backscatter data compensate for adjustments made to sonar power, gain, absorption, spreading, and frequency parameters made during acquisition. In order for backscatter intensity levels to remain consistent along survey lines, and from line to line, relative backscatter data require that minimal adjustments are made to these parameters during acquisition, which can degrade the sonar performance for a given survey site. However, the ability to allow the sonar acquisition software to change sonar parameters based on variations in bathymetry and the survey environment during acquisition allows these parameters to be optimized. Having these parameters optimized for this survey allowed the USGS to evaluate this new normalized backscatter capability to ensure the collected backscatter intensity levels were referenced to a factory calibrated level. Eel Pond in Woods Hole, MA was chosen as a test area for its proximity to the USGS Coastal and Marine Science Center. It provides a variety of substrates on which to evaluate the performance of the sonar, and bathymetric/backscatter data of this area may prove useful to other projects and institutions in the area.

In spring and summer 2017, the U.S. Geological Survey’s Gas Hydrates Project conducted two cruises aboard the research vessel Hugh R. Sharp to explore the geology, chemistry, ecology, physics, and oceanography of sea-floor methane seeps and water column gas plumes on the northern U.S. Atlantic margin between the Baltimore and Keller Canyons. Split-beam and multibeam echo sounders and a chirp subbottom profiler were deployed during the cruises to map water column backscatter, sea-floor bathymetry and backscatter, and subsurface stratigraphy associated with known and undiscovered sea-floor methane seeps. The first cruise, known as the Interagency Mission for Methane Research on Seafloor Seeps and designated as field activity 2017-001-FA, was conducted from May 4 to May 11, 2017, and acquired geophysical data to support remotely operated vehicle exploration of seep sites using the Global Explorer, which is operated by Oceaneering International, Inc. Geophysical operations during cruise 2017-002-FA from August 25 to September 6, 2017, were also focused on mapping water column methane plumes, sea-floor seep sites, and subseafloor strata, but primarily supported conductivity, temperature, and depth instrument deployment, surface-water methane-concentration mapping, and water-sampling operations as part of a collaborative study with the University of Rochester of the effect of methane seepage on ocean water biogeochemistry. The National Oceanic and Atmospheric Administration’s Office of Ocean Exploration and Research partially sponsored cruise 2017-001-FA, and the U.S. Department of Energy partially sponsored both cruises.

The natural resiliency of the New Jersey barrier island system, and the efficacy of management efforts to reduce vulnerability, depends on the ability of the system to recover and maintain equilibrium in response to storms and persistent coastal change. This resiliency is largely dependent on the availability of sand in the beach system. In an effort to better understand the system's sand budget and processes in which this system evolves, high-resolution geophysical mapping of the sea floor in Little Egg Inlet and along the southern end of Long Beach Island near Beach Haven, New Jersey was conducted from May 31 to June 10, 2018, followed by a sea floor sampling survey conducted from October 22 to 23, 2018, as part of a collaborative effort between the U.S. Geological Survey and Stockton University. Multibeam echo sounder bathymetry and backscatter data were collected along 741 kilometers of tracklines (approximately 200 square kilometers) of the coastal sea floor to regionally define its depth and morphology, as well as the type and distribution of sea-floor sediments. Six hundred ninety-two kilometers of seismic-reflection profile data were also collected to define the thickness and structure of sediment deposits in the inlet and offshore. These new data will help inform future management decisions that affect the natural and recreational resources of the area around and offshore of Little Egg Inlet. These mapping surveys provide high-quality data needed to build scientific knowledge of the evolution and behavior of the New Jersey barrier island system.

The natural resiliency of the New Jersey barrier island system, and the efficacy of management efforts to reduce vulnerability, depends on the ability of the system to recover and maintain equilibrium in response to storms and persistent coastal change. This resiliency is largely dependent on the availability of sand in the beach system. In an effort to better understand the system's sand budget and processes in which this system evolves, high-resolution geophysical mapping of the sea floor in Little Egg Inlet and along the southern end of Long Beach Island near Beach Haven, New Jersey was conducted from May 31 to June 10, 2018, followed by a sea floor sampling survey conducted from October 22 to 23, 2018, as part of a collaborative effort between the U.S. Geological Survey and Stockton University. Multibeam echo sounder bathymetry and backscatter data were collected along 741 kilometers of tracklines (approximately 200 square kilometers) of the coastal sea floor to regionally define its depth and morphology, as well as the type and distribution of sea-floor sediments. Six hundred ninety-two kilometers of seismic-reflection profile data were also collected to define the thickness and structure of sediment deposits in the inlet and offshore. These new data will help inform future management decisions that affect the natural and recreational resources of the area around and offshore of Little Egg Inlet. These mapping surveys provide high-quality data needed to build scientific knowledge of the evolution and behavior of the New Jersey barrier island system.

In November 2021, the U.S. Geological Survey collected high-resolution multibeam sonar data in the vicinity of Eel Pond, in Woods Hole, Massachusetts using a dual-head Teledyne Seabat T20-R multibeam echo sounder (MBES). The main objective of this survey was to evaluate new sonar system features prior to their use in future field activities. In addition to bathymetry and relative acoustic backscatter data, normalized acoustic backscatter data were also collected. Unlike relative backscatter data, normalized backscatter data compensate for adjustments made to sonar power, gain, absorption, spreading, and frequency parameters made during acquisition. In order for backscatter intensity levels to remain consistent along survey lines, and from line to line, relative backscatter data require that minimal adjustments are made to these parameters during acquisition, which can degrade the sonar performance for a given survey site. However, the ability to allow the sonar acquisition software to change sonar parameters based on variations in bathymetry and the survey environment during acquisition allows these parameters to be optimized. Having these parameters optimized for this survey allowed the USGS to evaluate this new normalized backscatter capability to ensure the collected backscatter intensity levels were referenced to a factory calibrated level. Eel Pond in Woods Hole, MA was chosen as a test area for its proximity to the USGS Coastal and Marine Science Center. It provides a variety of substrates on which to evaluate the performance of the sonar, and bathymetric/backscatter data of this area may prove useful to other projects and institutions in the area.

Marine geophysical mapping of the Queen Charlotte Fault in the eastern Gulf of Alaska was conducted in 2016 as part of a collaborative effort between the U.S. Geological Survey and the Alaska Department of Fish and Game to understand the morphology and subsurface geology of the entire Queen Charlotte system. The Queen Charlotte fault is the offshore portion of the Queen Charlotte-Fairweather Fault: a major structural feature that extends more than 1,200 kilometers from the Fairweather Range of southern Alaska to northern Vancouver Island, Canada. The data published in this data release were collected along the Queen Charlotte Fault between Cross Sound and Noyes Canyon, offshore southeastern Alaska from May 18 to June 11, 2016. Data were collected aboard the Alaska Department of Fish and Game research vessel Medeia using a Reson SeaBat 7160 multibeam echosounder. This data release contains approximately 453 square kilometers of multibeam bathymetric and backscatter data gridded at 10-meter resolution. Multibeam water column imagery and seismic profile data also collected during this survey are not published in this data release