INVESTIGATIONS INTO SOUTH CAROLINA AND GEORGIA’S OUTER CONTINENTAL SHELF (OCS) RESOURCES: IDENTIFICATION AND MAPPING OF PALEOLANDSCAPES AND MODEL CREATION FOR LOCATION OF SAND RESOURCES

Following the impact of Hurricane Sandy on the U.S. Atlantic coastline in 2012 and subsequent interest in working to improve coastal resiliency to storms, the Bureau of Ocean Energy Management (BOEM), in cooperation with state partners, instituted several regional offshore resource studies for the near outer continental shelf (OCS) in SC and GA. New and previously-collected data are being used to identify paleolandscapes, sediment resources for beach renourishment projects, and wind farm placement feasibility. The new data collected for BOEM include ~900 km of high-resolution chirp subbottom profiler (SBP) data, ~1700 trackline km of magnetic data, ~7900 km² of sidescan sonar data, and ~430 km² of multibeam bathymetry data, ground-truthed with 26 cores. These new data are combined with previously-collected SBP (~1000-km) and sidescan (~150km²) data in SC waters. These data have been processed and interpreted at Universtiy of Charleston using Chesapeake Technology SonarWiz7 and QPS Qimera and Fledermaus, and have been combined with previously collected SBP (~1000 km) and sidescan (~150 km²) data in SC waters.

Areas of focus for Atlantic Sand Assessment Program (ASAP) data collection along the SC coast are located within the 3 to 8 nautical mile (nm) OCS offshore of Little River, Cape Romain, Folly Beach, and Hilton Head Island. Three additional coverage blocks located approximately 11 nm east of Little River were also included. Additional areas in GA include the 3 to 8 nm OCS offshore of Wassaw, Ossabaw, Jekyll, St. Simons, and Cumberland Islands. Ravinement and pre-Holocene surfaces were mapped along with numerous other surfaces. Hardbottom areas were mapped in several of the survey areas to the north. Numerous subsurface paleochannels/valleys were identified and are possibly related to transgressive channeling, Pleistocene low-level stand river channeling, as well as braided stream formation during glacial maxima. Further research will be conducted once the surveys are compiled and merged with previous data sets to build a more complete understanding of the paleolandscapes, shelf development, and sand resources in the South Carolina and Georgia OCS.