A portion of the USGS-SC Sea Grant Consortium coastal erosion program, this study presents a comparison of historical shorelines, LIDAR and coastal geomorphology to the geologic framework of the lower Coastal Plain and inner Continental Shelf of South Carolina.

Shoreline change trends of historical data of Anders et al. (1990) and recent aerial photographs were analyzed using a geographic information system (GIS) and scripts based on those currently being used in the USGS National Shoreline Change Program. Coastal geomorphology data were extracted from digital USGS topography, Horry County, and NOAA LIDAR surveys for the immediate coastal region. USGS-generated bathymetry was merged with these data for South Carolina to produce a seamless hypsographic surface for the study region. Sidescan sonar surveys over the past eight years in South Carolina provide additional shoreface data for the Charleston and Grand Strand (Myrtle Beach) areas of South Carolina.

In regions outside those typically associated with hot spots of erosion critical trends in coastal change point to other, non-hydrodynamic influences on the coastal system. These influences may include truncation of modern dune ridges, of low-elevation Pleistocene terraces and beach faces, of highly varied stratigraphic units, and of indurated near-surface strata. Various instances of their direct influence on long-term average shoreline change trends at the scale of a few hundred meters along the coast can be identified. Continued studies combining high-resolution subaerial and submarine subsurface stratigraphic data with high-resolution shoreline and shoreface change models will further help communities mitigate future and imminent coastal issues.