Abstract:
The Coastal and Marine Geology Program of the U.S. Geological Survey, in cooperation with the University of Maine, University of New Hampshire, Boston University, and Bigelow Laboratory for Ocean Sciences, has compiled surficial sediment data on the sea floor from off the northeastern U.S. These data, which are presented herein and contain information on sediment grain size and lithology for ... over 47,000 stations, were compiled as part of the U.S. Geological Survey's National Benthic Habitats and Marine Aggregate Resources and Processes Projects to updateGulf of Maine location image showing color encoded shaded bathymetry and elevation the existent maps on surficial sediment distribution available for this region (Schlee, 1973; Poppe and others, 1989). The National Benthic Habitats Project addresses societal needs by studying the interplay of geologic factors and species behavior that gives rise to biologic habitats in general and to the specific habitats deemed essential to the success of particular species. The principal objective of the Marine Aggregate Resources and Processes Project is to produce a series of new geologic maps and reports for regions such as the Gulf of Maine that will provide scientific insights into the character and geologic development of U.S. continental margins and assess the availability of offshore resources. These maps and assessments are being done on a national scale using usSEABED (Williams and others, 2003), and the sediment data compiled as part of this report will be imported into the usSEABED data-mining software system. Potential uses for these data include: (1) defining the geological variability of the sea floor, 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, benthic habitats, and associated infaunal community structures; (3) locating aggregate resources for beach nourishment and industrial applications; and (4) providing a detailed framework for future research, monitoring, and management activities. Because the present distribution of surficial sediment off the northeastern United States is shaped from the deposits left by the last glaciation and reflects the cumulative effects of sediment erosion, transport, sorting, and deposition by storm and tidal currents during and since the Holocene eustatic rise in sea level, these sediments also represent both a historical record of former conditions and a guide to possible future sedimentary environments.
Most of the sediment data in this report are broken into data layers by their original source project and are provided as single-point vector datasets with sample identifiers, navigation, textural attribute information, and metadata. Unpublished data or data from the gray literature that form parts of earlier compilations, such the National Ocean Survey Hydrographic Database (National Geophysical Data Center, 1987) or the Gulf of Maine Contaminated Sediment Database (ten Brink and others, 2002), remain in datasets attributed to these compilations. All data are intended to be GIS-ready inasmuch as the data should not require any additional cleanup, formatting, or renaming of fields in order to use the data in a Geographic Information System (GIS). This project employs the Environmental Systems Research Institute's (ESRI) ArcView as it's GIS mapping tool and contains several data layers (or themes) that are used to create a geographic planar view of the margin off the northeastern U.S. These vector data form a basemap comprised of polygon and line themes that include a U.S. coastline (1:80,000), bathymetry contours (10-m shelf contours; 100-m upper slope and rise contours), U.S. lakes, U.S. rivers, state boundaries, Exclusive Economic Zone (EEZ) boundary, and provinces of Canada.
