In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

These data were collected under a cooperative agreement between the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center (WHCMSC). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of seafloor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. The project is focused on the inshore waters of coastal Massachusetts, primarily in water depths of 2-30 meters. Data collected for the mapping cooperative have been released in a series of USGS Open-File Reports (https://woodshole.er.usgs.gov/project-pages/coastal_mass/). The data collected in this study area are located in both Buzzards Bay and Vineyard Sound and are primarily in the shallow water areas around the eastern Elizabeth Islands and Martha's Vineyard, Massachusetts. The data include high resolution bathymetry, acoustic-backscatter intensity, sound velocity in water, seismic-reflection profiles, and navigation data. These data were collected during several cruises between 2007 and 2011 onboard the R/V Rafael using the following equipment: an SEA Ltd SwathPlus interferometric sonar (234 kHz), Klein 3000 dual frequency sidescan sonar, a boomer source and Geometrics 8-channel GeoEel streamer, a Knudsen 3200 subbottom profiling system, and 4 GPS antennae. More information about the cruises conducted as part of the project: Geologic Mapping of the Seafloor Offshore of Massachusetts can be found on the Woods Hole Coastal and Marine Science Center Field Activity webpages: https://cmgds.marine.usgs.gov/fan_info.php?fan=2011-013-FA, https://cmgds.marine.usgs.gov/fan_info.php?fan=2009-068-FA, https://cmgds.marine.usgs.gov/fan_info.php?fan=2007-039-FA, https://cmgds.marine.usgs.gov/fan_info.php?fan=2010-100-FA, and https://cmgds.marine.usgs.gov/fan_info.php?fan=2010-047-FA.

The Hudson Shelf Valley is the submerged seaward extension of the ancestral Hudson River drainage system and is the largest physiographic feature on the Middle Atlantic continental shelf. The valley begins offshore of New York and New Jersey at about 30-meter (m) water depth, runs southerly and then southeasterly across the Continental Shelf, and terminates on the outer shelf at about 85-m water depth landward of the head of the Hudson Canyon. Portions of the 150-kilometer-long valley were surveyed in 1996, 1998, and 2000 using a Simrad EM1000 multibeam echosounder mounted on the Canadian Coast Guard ship Frederick G. Creed. The purpose of the multibeam echosounder surveys was to map the bathymetry and backscatter intensity of the sea floor of the valley, providing a framework for geologic, oceanographic, and geochemical studies. The data from the three surveys are combined to produce grids of bathymetry and backscatter intensity at 12-m resolution that cover the entire valley and the head of the Hudson Canyon. The mapping was done by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers with support from the Canadian Hydrographic Service and the University of New Brunswick.

The Hudson Shelf Valley is the submerged seaward extension of the ancestral Hudson River drainage system and is the largest physiographic feature on the Middle Atlantic continental shelf. The valley begins offshore of New York and New Jersey at about 30-meter (m) water depth, runs southerly and then southeasterly across the Continental Shelf, and terminates on the outer shelf at about 85-m water depth landward of the head of the Hudson Canyon. Portions of the 150-kilometer-long valley were surveyed in 1996, 1998, and 2000 using a Simrad EM1000 multibeam echosounder mounted on the Canadian Coast Guard ship Frederick G. Creed. The purpose of the multibeam echosounder surveys was to map the bathymetry and backscatter intensity of the sea floor of the valley, providing a framework for geologic, oceanographic, and geochemical studies. The data from the three surveys are combined to produce grids of bathymetry and backscatter intensity at 12-m resolution that cover the entire valley and the head of the Hudson Canyon. The mapping was done by the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers with support from the Canadian Hydrographic Service and the University of New Brunswick.

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

In 2006 and 2007, the U.S. Geological Survey, in partnership with Louisiana Department of Natural Resources and the University of New Orleans, conducted geologic mapping to characterize the sea floor and shallow subsurface stratigraphy offshore of the Chandeleur Islands in Eastern Louisiana. The mapping was carried out during two cruises on the R/V Acadiana. Data were acquired with the following equipment: an SEA Ltd SwathPlus interferometric sonar (234 kHz), Klein 3000 dual frequency sidescan sonar, and an Edgetech 512i chirp subbottom profiling system. The long-term goal of this mapping effort is to produce high-quality geologic maps and geophysical interpretations that can be utilized to investigate the impact of Hurricane Katrina in 2005 and to identify sand resources within the region.

These data were collected in a collaboration between the Woods Hole Oceanographic Institution and the U.S. Geological Survey (USGS). The primary objective of this program was to collect baseline bathymetry for Muskeget Channel, Massachusetts, and identify areas of morphologic change within and around the channel. Repeat surveys in select areas were collected one month apart to monitor change. These data were collected to support an assessment of the effect on sediment transport that a tidal instream energy conversion facility would have within Muskeget Channel. Accurate data and maps of sea-floor topography are important first steps in monitoring bedform migration, fish habitat, marine resources, and environmental changes due to natural or human impacts. The data include high-resolution bathymetry, acoustic-backscatter intensity, sound velocity in water, and navigation data. These data were collected during two surveys between October 2010 and November 2011 onboard the research vessel (RV) Rafael using an SEA Ltd. SwathPlus interferometric sonar (234 kilohertz). More information about the cruise can be found on the Woods Hole Coastal and Marine Science Center field activity Web page at https://cmgds.marine.usgs.gov/fan_info.php?fan=2010-072-FA.

In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.

The United States Geological Survey Saint Petersburg Coastal and Marine Science Center (USGS SPCMSC), in cooperation with the United States Army Corps of Engineers (USACE) conducted bathymetric surveys of the nearshore waters surrounding Ship and Horn Islands, Gulf Islands National Seashore, Mississippi (GUIS). Camille Cut separates Ship Island into East Ship Island and West Ship Island. The objective of this study was to establish base-level elevation conditions around West Ship Island, East Ship Island, Horn Island and their associated active littoral system prior to restoration activities. These activities include the closure of Camille Cut and the placement of sediment in the littoral zone of West Ship Island. This survey will be used to verify sediment migration patterns by monitoring elevation change over time. The dataset produced by this survey will also be compared with historic bathymetric datasets to help further understand island elevation over time. This data release provides 667-line kilometers (km) of processed Single-Beam Bathymetry (SBB) data and 773-line km of processed Interferometric Bathymetry (IFB) collected by the USGS SPCMSC in July 2016 (field activity number [FAN] 2016-347-FA). The IFB data were acquired aboard the Research Vessel (RV) Sallenger (subFAN, 16BIM04), and the SBB data were acquired aboard the RV Jabba Jaw (subFAN, 16BIM05) and the RV Mako (subFAN, 16BIM06). The IFB and SBB point data are provided in three datums: 1) the International Terrestrial Reference Frame of 2000 (ITRF00), ellipsoid height (-49.70 meters [m] to -28.87 m); 2) the North American Datum of 1983 (NAD83) CORS96 realization and the North American Vertical Datum 1988 (NAVD88) with respect to the GEOID12B model (-0.07 m to -20.69 m); and 3) NAD83 (CORS96) and Mean Lower Low Water (MLLW) (-0.04 m to -20.60 m). This metadata record describes the comprehensive, 50-meter (m) Digital Elevation Model (DEM) created from the IFB and SBB point data and provided in NAD83 NAVD88 GEOID12B. For additional information regarding data collection and processing, please refer to the field logs and formal Federal Geographic Data Committee (FGDC) metadata for the individual XYZ point data files and survey trackline shapefiles also included within this data release (https://doi.org/10.5066/F7B8571Q).