The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. The bathymetry data in this data set were collected during 2002 for charting applications as part of NOAA project OPR-B340-RU, survey H11043 aboard the NOAA Ship RUDE. The RUDE, which supports NOAA's east-coast nautical charting mission, is outfitted to acquire single-beam bathymetry with an Odom Echotrac DF-3200 duel frequency echosounder and shallow water multibeam bathymetry with a Reson 8125 system. The Reson multibeam system operates at 455 KHz with a 120 degree across track swath and 240 beams along its swath.

The United States Geological Survey (USGS) is working cooperatively with the National Oceanic and Atmospheric Association (NOAA) to interpret the surficial geology in estuaries along the coast of the northeastern United States. The purpose of our present study is to interpret the distributions of surficial sediments and sedimentary environments in an area of Narragansett Bay using sidescan sonar imagery, high-resolution bathymetry, and sediment data. The mosaic and bathymetry presented herein covers an area of the sea floor in central Narragansett Bay. The mosaic, bathymetry, and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The sidescan sonar mosaics and bathymetry images also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretations of point measurements.

The United States Geological Survey (USGS) is working cooperatively with the National Oceanic and Atmospheric Association (NOAA) to interpret the surficial geology in estuaries along the coast of the northeastern United States. The purpose of our present study is to interpret the distributions of surficial sediments and sedimentary environments in an area of Narragansett Bay using sidescan sonar imagery, high-resolution bathymetry, and sediment data. The mosaic and bathymetry presented herein covers an area of the sea floor in central Narragansett Bay. The mosaic, bathymetry, and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The sidescan sonar mosaics and bathymetry images also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretations of point measurements.

Nearshore areas within Long Island Sound are of great interest to the Connecticut and New York research and management communities because of their ecological, recreational, and commercial importance. However, although advances in multibeam echosounder technology permit the construction of detailed digital terrain models of seafloor topography within deeper waters, limitations inherent with collecting multibeam data make using this technology in shallower waters (<10-m deep) more difficult and expensive. These limitations have often resulted in gaps of no data between multibeam bathymetric datasets and the adjacent shoreline. To address this problem, complete-coverage multibeam bathymetry acquired offshore of New London and Niantic Bay, Connecticut, has been integrated with hydrographic LIDAR acquired along the nearshore. The result is a more continuous seafloor perspective and a much smaller gap between the digital bathymetric data and the shoreline. These datasets are provided as ESRI grid and GeoTIFF formats in order to facilitate access, compatibility, and utility.

Nearshore areas within Long Island Sound are of great interest to the Connecticut and New York research and management communities because of their ecological, recreational, and commercial importance. However, although advances in multibeam echosounder technology permit the construction of detailed digital terrain models of seafloor topography within deeper waters, limitations inherent with collecting multibeam data make using this technology in shallower waters (<10-m deep) more difficult and expensive. These limitations have often resulted in gaps of no data between multibeam bathymetric datasets and the adjacent shoreline. To address this problem, complete-coverage multibeam bathymetry acquired offshore of New London and Niantic Bay, Connecticut, has been integrated with hydrographic LIDAR acquired along the nearshore. The result is a more continuous seafloor perspective and a much smaller gap between the digital bathymetric data and the shoreline. These datasets are provided as ESRI grid and GeoTIFF formats in order to facilitate access, compatibility, and utility.

The U.S. Geological Survey (USGS), in cooperation with the National Oceanic and Atmospheric Administration (NOAA), is producing detailed geologic maps of the coastal sea floor. Bathymetry and sidescan-sonar imagery, originally collected by NOAA for charting purposes, provides a fundamental framework for research and management activities in Long Island Sound, shows the composition and terrain of the seabed, and provides information on sediment transport and benthic habitat. During October 2008 NOAA completed hydrographic survey H11251 offshore of Rocky Point, New York and during November 2009, bottom photographs and surficial sediment data were acquired as part of a ground-truth reconnaissance survey of this area. Interpretive data layers were derived from the multibeam echo-sounder and sidescan-sonar data and the ground-truth data used to verify them. For more information on the ground-truth survey see https://cmgds.marine.usgs.gov/fan_info.php?fan=2009-059-FA

The U.S. Geological Survey (USGS), in cooperation with the National Oceanic and Atmospheric Administration (NOAA), is producing detailed geologic maps of the coastal sea floor. Bathymetry and sidescan-sonar imagery, originally collected by NOAA for charting purposes, provides a fundamental framework for research and management activities in Long Island Sound, shows the composition and terrain of the seabed, and provides information on sediment transport and benthic habitat. During October 2008 NOAA completed hydrographic survey H11251 offshore of Rocky Point, New York and during November 2009, bottom photographs and surficial sediment data were acquired as part of a ground-truth reconnaissance survey of this area. Interpretive data layers were derived from the multibeam echo-sounder and sidescan-sonar data and the ground-truth data used to verify them. For more information on the ground-truth survey see http://quashnet.er.usgs.gov/data/2009/09059/

The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted multibeam bathymetric data within specific areas of special interest. The bathymetric grid in UTM Zone 18 projection presented herein covers roughly 92 square km of the sea floor in the area around Six Mile Reef, eastern Long Island Sound. The original multibeam bathymetric data were collected during 2004 as part of charting applications aboard the NOAA Survey Vessel Thomas Jefferson. A Simrad EM1002 multibeam system mounted on the hull of this vessel was used to acquire data along survey lines from the deeper water (>20 m) parts of the study area. Two 29-foot launches with hull-mounted Reson systems were deployed from the ship and were used to acquire data along survey lines from the shallower areas. Detailed bathymetric data and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The bathymetric data models also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.

The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted mulitbeam bathymetric data within specific areas of special interest. The gridded data presented herein covers a roughly 94 km square area of the sea floor in the area known as the Race at the eastern end of Long Island Sound. The original multibeam bathymetric data were collected during October 2003 as part of charting applications aboard the NOAA Survey Vessel Thomas Jefferson. A Simrad EM1002 multibeam system mounted on the hull of this vessel was used to acquire over 560 km of survey lines from the deeper water (>20 m) parts of the study area. Two 29-foot launches with hull-mounted Reson systems were deployed from the ship and were used to acquire an additional 637 km of survey lines from the shallower areas. The detailed bathymetic data and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The bathymetric data models also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.

The U.S. Geological Survey, in cooperation with the National Oceanic and Atmospheric Administration and the Connecticut Department of Environmental Protection, has produced detailed geologic maps of the sea floor in Long Island Sound, a major East Coast estuary surrounded by the most densely populated region of the United States. These studies have built upon cooperative research with the State of Connecticut that was initiated in 1982. The current phase of this research program is directed toward studies of sea-floor sediment distribution, processes that control sediment distribution, nearshore environmental concerns, and the relation of benthic community structures to the sea-floor geology. Anthropogenic wastes, toxic chemicals, and changes in land-use patterns resulting from residential, commercial, and recreational development have stressed the environment of the Sound, causing degradation and potential loss of benthic habitats (Koppelman and others, 1976; Long Island Sound Study, 1994). Detailed maps of the sea floor are needed to help evaluate the extent of adverse impacts and to help manage resources wisely in the future. Therefore, in a continuing effort to better understand Long Island Sound, we have constructed and interpreted multibeam bathymetric data within specific areas of special interest. The bathymetric grid in UTM Zone 18 projection presented herein covers a roughly 64 km square area of the sea floor in the area near Six Mile Reef, eastern Long Island Sound. The original multibeam bathymetric data were collected during 2004 as part of charting applications aboard the NOAA Survey Vessel Thomas Jefferson. A Simrad EM1002 multibeam system mounted on the hull of this vessel was used to acquire data along survey lines from the deeper water (>20 m) parts of the study area. Two 29-foot launches with hull-mounted Reson systems were deployed from the ship and were used to acquire data along survey lines from the shallower areas. Detailed bathymetric data and their interpretations serve many purposes, including: (1) defining the geological variability of the sea floor, which is one of the primary controls of benthic habitat diversity; (2) improving our understanding of the processes that control the distribution and transport of bottom sediments and the distribution of benthic habitats and associated infaunal community structures; and (3) providing a detailed framework for future research, monitoring, and management activities. The bathymetric data models also serve as base maps for subsequent sedimentological, geochemical, and biological observations, because precise information on environmental setting is important for selection of sampling sites and for accurate interpretation of point measurements.