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 (Poppe and Polloni, 1998; fig. 1). The mosaic presented herein covers a xx.x km2 of the sea floor in north-central Long Island Sound off Branford, Connecticut.
The mosaics 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 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.
Poppe, Larry, 2003, H11043_OUTLINE: Outline of the sidescan sonar mosaic completed during NOAA survey H11043: U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.Online Links:
Poppe, L.J., Paskevich, V.F., Moser, M.S., DiGiacomo-Cohen, M.L., and Christman, E.B., 2004, 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.Online Links:
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 WGS_1984.
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.
Larry Poppe, U.S. Geological Survey, for creating the mosaic outline.
U.S. Geological Survey
c/o Larry Poppe
Geologist
U.S. Geological Survey
Woods Hole, MA 02543-1598
USA
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov
This GIS overlay is a component of the Branford Survey (H11043), Long Island Sound, ArcView GIS database and contains the outline of the sidescan sonar mosaic for the study area.
Person who carried out this activity:
Larry PoppeData sources used in this process:
U.S. Geological Survey
Geologist
U.S. Geological Survey
Woods Hole, MA 02543-1598
USA
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov
Data sources produced in this process:
The entire sidescan sonar mosaic area is covered by this outline.
No additional checks for topological consistency were performed on this data.
Are there legal restrictions on access or use of the data?
- Access_Constraints: None
- Use_Constraints:
- Public domain data are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the originator of this dataset.
Larry Poppe
U.S. Geological Survey
Geologist
U.S. Geological Survey
Woods Hole, MA 02543-1598
USA
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov
Downloadable Data: h11043_outline
Although this data set has been used by the U.S. Geological Survey (USGS) and National Oceanic and Atmospheric Administration (NOAA), no warranty, expressed or implied, is made by the USGS or NOAA 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 or NOAA in the use of these data or related materials.
Data format: | outline.shp, outline.shx, and outline.dbf, outline.prj, metadata.txt and browse graphic (h11043_outline.gif) in format ArcView shapefile (version 3.2) ESRI poygon shapefile Size: 0.121 |
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The data are available in the ESRI shapefile format. The user must have Environmental Systems Research Institute's (ESRI) ArcView 3.0 or greater or ArcGIS software to read and process the data file. In lieu of Arcview, the user may utilize another GIS application package capable of importing the data. A free GIS data viewer, ArcExplorer, is available from the ESRI website at www.esri.com/software/arcexplorer/download4.htmlAccess to the data and information contained on this CD-ROM was developed using the HyperText Markup Language (HTML) utilized by the World Wide Web (WWW) project. Development of the CD-ROM documentation and user interface in HTML allows a user to access the information by using a variety of WWW information browsers to facilitate browsing and locating information and data. To access the information contained on this disk with a WWW client browser, open the file 'index.htm' at the top level directory of this CD-ROM with your selected browser.
This CD-ROM should be readable by a variety of operating systems including Windows 95/98/NT, Macintosh and UNIX.
U.S. Geological Survey
c/o Larry Poppe
Geologist
USGS
Woods Hole, MA 02543
USA
(508) 548-8700 x2314 (voice)
(508) 457-2310 (FAX)
lpoppe@usgs.gov