COASTAL PROCESSES AND MORPHOLOGICAL CHANGE ON SHACKLEFORD BANKS, CAPE LOOKOUT NATIONAL SEASHORE

Interrelationships between the components of the beach-dune-nearshore system of coastal regions are still poorly understood, yet they are important scientifically as well as from a coastal zone/resource management perspective. Cape Lookout National Seashore, NC is probably the least-developed shoreline on the Atlantic Coast and, together with the rest of the Outer Banks, is also the pre-eminent example of a clastic barrier island system in the world. Therefore, it is a great place to study coastal morphology and behavior. Shackleford Banks is ideal for detailed research, as it offers a wide range of morphologies for comparison over a fairly short length (~15km) – from a wide western half with tall dunes to a narrow eastern half dominated by overwash.

Fieldwork for a 3-year study of the coastal geology of Shackleford Banks, including 2 years of detailed monthly high-precision RTK-GPS surveys, was completed in August 2004. This talk will provide a summary of the methodology used, the data collected, the analyses completed, and the results obtained. The GPS surveys included the measurement of 6-11 alongshore lines along the entire length of the island, as well as 3 profile lines and a series of cross-shore tie-in lines at 6 locations chosen for their distinct and representative morphologies. Foredune areas were surveyed on a quarterly basis. Data from USGS/NOAA LIDAR surveys in 1997, 1998, 1999, and 2000 and older aerial photos and maps were also analyzed. Three electromagnetic current meters were deployed for 4-6 weeks semi-annually, and gathered information about waves and tides. Data from bathymetric surveys, including CHIRP, sidescan, and bathymetry were also collected. In addition, 2 large-scale sediment studies were completed, cores were taken in the shoreface, and radiocarbon ages for 5 samples from peat outcrops exposed intermittently at low tide were determined. Much of this data is incorporated into ArcGIS maps and projects, and allows temporal and spatial comparisons to be made. For example, the impact of storm events such as Hurricane Isabel, and the ‘recovery’ of the beach after the storm, was examined.

All of the findings of the study are being shared with the National Park Service, and it is hoped that the methods used may be adopted by the Park and others continuing studies on Shackleford and elsewhere.