Mapping of the Major Morphologic Features and Seafloor Sediments of the New Hampshire Continental Shelf Using the Coastal and Marine Ecologic Classification Standard (CMECS)

TitleMapping of the Major Morphologic Features and Seafloor Sediments of the New Hampshire Continental Shelf Using the Coastal and Marine Ecologic Classification Standard (CMECS)
Publication TypeConference Abstract
Year2017
AuthorsWard, LG, McAvoy, ZS, Nagel, E
Conference Name2017 GeoHab Conference
Conference LocationDartmouth, Nova Scotia, Canada
Conference DatesMay 1-5

The New Hampshire continental shelf is extremely heterogeneous and includes extensive bedrock outcrops, sand and gravel deposits, and muddy basins. Many of the depositional features are glacial in origin and have been significantly modified by marine processes as sea level fluctuated since the end of the last major glaciation. Glacial deposits (e.g., drumlins) on the shelf have been eroded, leaving very coarse lag deposits, while supplying sand to develop wave-formed features (shoals). Many of these features have positive relief standing above the seafloor, lending evidence of their formation by waves and shallow water currents. Some of these deposits may represent significant sand and gravel deposits and have the potential for future use for beach nourishment and other efforts to build coastal resiliency.

Relatively recent high resolution multibeam echosounder (MBES) bathymetric and backscatter surveys have revealed features of the New Hampshire shelf and vicinity seafloor in exceptional detail that has not been previously described. Synthesis of the MBES bathymetry and backscatter (along with bathymetric derivatives), coupled with an extensive archived database consisting of subbottom seismics, bottom sediment grain size data, and vibracores, were used to develop new surficial geology maps based on CMECS (partially supported by the Bureau of Ocean Energy Management). The new surficial geology maps of the New Hampshire shelf produced in ArcGIS represent a major improvement over previous mapping efforts and provide ground truth for testing automated classification approaches. Presently, the CMECS maps are being refined and the classification of the geoforms expanded for paraglacial environments. In addition, automated characterization and segmentation approaches using QPS Fledermaus Geocoder Toolbox Angle Range Analysis (ARA) and ESRI ArcGIS Spatial Analyst Tools are being evaluated.

URLhttp://docs.wixstatic.com/ugd/eaa54f_0194ec66feec4dad8f97b84951606910.pdf