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 sidescan sonar mosaics (complete-coverage acoustic images of the sea floor) within specific areas of special interest. The mosaic presented herein covers almost 300 km square area of the sea floor in west-central Long Island Sound off Milford, Connecticut.
The mosaics and their interpretations (represented in part by this data layer) 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 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.
Paskevich, Valerie, 2005, H11044_OUTLINE - Outline of the sidescan sonar mosaic completed during NOAA survey H11044: Open-File Report 2005-1018, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.This is part of the following larger work.
McMullen, K.Y., Poppe, L.J., Paskevich, V.F., Doran, E.F., Moser, M.S., Christman, E.B., and Beaver, A.L., 2005, Surficial Geology of the Sea Floor in West-Central Long Island Sound as shown by Sidescan Sonar Imagery: Open-File Report 2005-1018, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.
This is a Vector data set. It contains the following vector data types (SDTS terminology):
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.
The horizontal datum used is D_WGS_1984.
The ellipsoid used is WGS84.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257224.
Sequential unique whole numbers that are automatically generated.
Coordinates defining the features.
(508) 548-8700 x2314 (voice)
(508) 457-2281 (FAX)
This GIS overlay is a component of the Milford / West-Central Survey, Long Island Sound, ArcGIS database and represents an interpretation of the sidescan sonar mosaic for the study area. The interpretation can be used as an overlay for the mosaic image and shows the distribution of surficial sediments in the study area such as gravel, sand, silty sand, etc. This layer can be used in conjunction with layers: h11044sedenv.shp, h11044int.shp, and images h11044_e_geo.tif and h11044_geo_wgs84.tif
U.S. Geological Survey, and National Oceanic and Atmospheric Administration, 2005, h11044_geo.tif: Open-File Report 2005-1018, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.
Person who carried out this activity:
(508) 548-8700 x2281 (voice)
(508) 457-2310 (FAX)
Data sources produced in this process:
McMullen, K.Y., Poppe, L.J., DiGiacomo-Cohen, M.L., Moser, M.S., and Christman, E.B., 2005, Surficial Geology of the Sea Floor in West-Central Long Island Sound as shown by Sidescan Sonar Imagery: Northeastern Geology and Environmental Sciences v. 27, no. 1, p. 60-70, Allen Press, Lawrence, Kansas.
Poppe, Larry, Paskevich, Valerie, LTJG Marc S. Moser, NOAA, DiGiacomo-Cohen, Mary, and CDR Emily Christman, NOAA, 200409, Sidescan Sonar Imagery and Surficial Geologic Interpretation of the Sea Floor off Branford, Connecticut: Open-File Report 2004-1003, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.
Poppe, Larry, Paskevich, Valerie, Lewis, Ralph S. , and DiGiacomo-Cohen, Mary L. , 20020930, Geological Framework Data from Long Island Sound, 1981-1990: A Digital Data Release: Open-File Report 02-002, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Public domain data are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration, and Long Island Sound Resource Center as the originators of this dataset.
Although this data set has been used by the U.S. Geological Survey (USGS), no warranty, expressed or implied, is made by the USGS as to the accuracy of the data and/or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials.
|Data format:||The SHP file contains the geospatial data. The SHX file contains the index of the geospatial data. The DBF file contains the attribute data in dBASE format. The PRJ file contains the coordinate system information (optional). The AVL file contains the legend information (optional). The SBN and SBX files contain the spatial index of the geospatial data (optional). The XML file contains the metadata describing the data set <data set name>.shp.xml. An ASCII version of the metadata file. A browse graphic showing the data layer coverage and extent (optional). in format SHP (version 3.3) ESRI shapefile Size: 0.101|
|Media you can order:||
These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS® or ArcView® 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of the importing data. A free data viewer, arcexplorer, capable of displaying the data is available from ESRI at www.esri.com.
508-548-8700 x2314 (voice)
(508) 457-2310 (FAX)