Regional Coastal Studies
Coastal erosion is a serious national problem that poses a significant threat to human lives and property and the environment. Developed areas are threatened with billions of dollars in property damage as a result of storm impacts and long-term erosion. A priority of the USGS Coastal Marine and Geology Program is to provide relevant information on the geologic and oceanographic processes controlling coastal erosion to decision makers at the local, State, and Federal agencies that are responsible for coastal zone management.
The USGS is working closely with MMS throughout the South Carolina Coastal Erosion project. Severe erosion is occurring along much of the rapidly developing South Carolina coast. The USGS, in cooperation with the NOAA Sea Grant Program, the State of South Carolina, and several university partners, is conducting research to examine the causes of coastal erosion.
The 680 km2 region off northern South Carolina was mapped in approximately
four weeks to collect baseline information for the project.
During Phase I of the project centered off Charleston, the inner shelf and lower shoreface of Long Bay were surveyed using state-of-the-art geophysical tools and extensive sediment sampling.
In FY 2003, these mapping results will be merged with geologic mapping of the onshore areas of the coastal system and analyzed along with coastal change data, shoreline monitoring data, and physical oceanographic data to form a conceptual model of sediment flux in the coastal zone.
Phase II, which focuses on the Grand Strand-Santee Delta and the Hilton Head areas, of the regional erosion investigation addresses:
- The role that the inner-shelf geologic framework plays in the evolution of this coastal region;
- The regional-scale distribution of aggregate resource needed for planned beach nourishment projects; and
- The baseline geologic characterization required for understanding biologic habitats.
This comprehensive characterization of the sedimentary system also supports assessment of regional sand resource potential of interest to the State and Federal (USACE and MMS) cooperators responsible for mitigating erosion as well as utilizing and protecting seabed resources.
Example of USGS investigation of the offshore sand resources. Shown here is an area south of Long Island, where USGS is studying the processes responsible for erosion and are determining the availability of sand resources for beach nourishment. Results are showing a solid link between offshore geology and shoreline erosion. Apparently, the underlying regional geology is the principal control on long-term patterns of beach erosion.
