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Mapping the Gulf of Maine with side-scan sonar: A new bottom-type classification for complex seafloors

January 1, 1998

The bedrock-framed seafloor in the northwestern Gulf of Maine is characterized by extreme changes in bathymetric relief and covered with a wide variety of surficial materials. Traditional methods of mapping cannot accurately represent the great heterogeneity of such a glaciated region. A new mapping scheme for complex seafloors, based primarily on the interpretation of side-scan sonar imagery, utilizes four easily recognized units: rock, gravel, sand and mud. In many places, however, the seafloor exhibits a complicated mixture or extremely 'patchy' distribution of the four basic units, which are too small to map individually. Twelve composite units, each a two-component mixture of the basic units, were established to represent this patchiness at a small scale (1:100,000). Using a geographic information system, these and all other available data (seismic profiles, grab samples, submersible dives and cores) were referenced to a common geographic base, superimposed on bathymetric contours and then integrated into surficial geologic maps of the regional inner continental shelf. This digital representation of the seafloor comprises a multidimensional, interactive model complete with explicit attributes (depth, bottom type) that allow for detailed analysis of marine environments.

Citation Information

Publication Year 1998
Title Mapping the Gulf of Maine with side-scan sonar: A new bottom-type classification for complex seafloors
Authors W. A. Barnhardt, J. T. Kelley, S.M. Dickson, D. F. Belknap
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Coastal Research
Index ID 70020702
Record Source USGS Publications Warehouse