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Full-Text Articles in Geomorphology

Surficial Geology Of The Continental Shelf Off New Hampshire: Morphologic Features And Surficial Sediment, Larry G. Ward, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani, Rachel C. Morrison Jan 2021

Surficial Geology Of The Continental Shelf Off New Hampshire: Morphologic Features And Surficial Sediment, Larry G. Ward, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani, Rachel C. Morrison

Center for Coastal and Ocean Mapping

The continental shelf off New Hampshire (NH) in the Western Gulf of Maine (WGOM) is extremely complex and includes extensive bedrock outcrops, marine-modified glacial deposits, marine-formed shoals, seafloor plains, and associated features that are composed of a range of sediment types from mud to gravel. Furthermore, the physiography and composition of the seafloor frequently changes dramatically over relatively short distances (tens of meters). The complexity of the WGOM seafloor results from the interplay of glaciations, sea-level fluctuations, and marine processes (waves and currents). High-resolution multibeam echosounder (MBES) bathymetry and backscatter surveys, along with ground truth consisting of archived seismic reflection …


New Hampshire Continental Shelf Geophysical Database: 2002-2005 Jeffreys Ledge Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Raymond E. Grizzle, Rachel C. Morrison Jan 2021

New Hampshire Continental Shelf Geophysical Database: 2002-2005 Jeffreys Ledge Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Raymond E. Grizzle, Rachel C. Morrison

Data Catalog

Jeffreys Ledge is a major physiographic feature in the western Gulf of Maine (WGOM) located ~50 km off the coast of New Hampshire, although coming within ~10 km of shore by Cape Ann, Massachusetts. Jeffreys Ledge rises up as much as ~150 m from the seafloor of the adjacent basins (i.e., Scantum Basin or Wilkinson Basin) to depths less than 50 m on the ridge surface. The ridge extends over 100 km along its north-northeast to south-southwest axes while generally only being 5 to 10 km in width (~20 km maximum). Jeffreys Ledge and the surrounding region, like many features …


New Hampshire Continental Shelf Geophysical Database: 2012-2013 Newbex Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Zachary S. Mcavoy, Rachel C. Morrison Jan 2021

New Hampshire Continental Shelf Geophysical Database: 2012-2013 Newbex Field Campaign – Seafloor Photographs And Sediment Data, Larry G. Ward, Zachary S. Mcavoy, Rachel C. Morrison

Data Catalog

An approximately 4.5 km transect running from lower Portsmouth Harbor seaward onto the inner continental shelf was established to serve as the field site for the Newcastle Backscatter Experiment (NEWBEX). Acoustic backscatter measurements were made along the transect to examine relationships between backscatter and seafloor properties. This transect takes advantage of the diversity and heterogeneity of bottom types in lower Portsmouth Harbor and approach. In support of NEWBEX, a field campaign was undertaken to describe the sedimentologic characteristics of the seafloor along the transect. A total of five cruises were carried out approximately seasonally on November 26, 2012 and June …


New Hampshire Atlantic Beaches: 2017 Field Campaign Database - Field And Sample Photographs And Sediment Data, Larry Ward, Nathan W. Corcoran, Zachary S. Mcavoy, Rachel C. Morrison Jan 2021

New Hampshire Atlantic Beaches: 2017 Field Campaign Database - Field And Sample Photographs And Sediment Data, Larry Ward, Nathan W. Corcoran, Zachary S. Mcavoy, Rachel C. Morrison

Center for Coastal and Ocean Mapping

Sediment data, sediment photographs, and field photographs from a major field campaign conducted on the New Hampshire Atlantic beaches in 2017 are presented here. Research was carried out with the purpose of better understanding how sediment grain size of NH beaches varies under accretional and erosional conditions. Seven major beaches along the NH coast (Wallis Sands, Foss Beach, Jenness Beach, North Hampton Beach, North Beach, Hampton Beach, and Seabrook Beach) representing the range of morphologic and sedimentologic types found on the NH coast were sampled along multiple transects and multiple locations on each transect. This work provides baseline data to …