The most prominent morphologic features along the shoreline of the Carolinas are its four capes. From north to south, Cape Hatteras, Cape Lookout, Cape Fear, and Cape Romain segment the coastline into the northern outer banks, Raliegh Bay, Onslo Bay, and Long Bay regions. Continental shelf areas seaward of the capes are characterized by large, highly dynamic shoal complexes, which influence coastal circulation patterns and represent navigational hazards. These shoals contain a significant percentage of the total volume of sediment in the overall coastal system (including the barrier islands, subaerial capes, shoreface, and cape-associated shoals). The shoals are generally thought to be the major sink in the coastal sediment transport system. Understanding the formation of these capes and their effects on regional sediment transport is significant for management of our coastal waters.
Geophysical surveys will be conducted across Diamond Shoals offshore of Cape Hatteras in order to investigate the geologic framework of this sedimentary system and assess the extent to which the shoals may be composed of modern, mobile sediment.
The surveys will utilize the standard suite of USGS - Woods Hole Science Center Seafloor Mapping Group tools (swath bathymetry, sidescan sonar, chirp and boomer/gun seismic reflection) to map seafloor morphology and sub-surface stratigraphy. The data should allow us to define the areal and vertical extent of "modern" sediment, identify any structural controls on sediment thickness and distribution, and provide detailed bathymetry and sediment characteristics needed for the sub-regional and regional coastal process modling.
Arcuate shape of the South East Coast of the US showing Cape Hatteras, Cape Lookout, Cape Fear, and Cape Romain with their associated shoals.