North Carolina Coastal Change
The objective of this task is to improve the capabilities of coastal change models to predict large-scale shoreline change on open-ocean sandy coasts, with specific application to the Northern Outer Banks of North Carolina. Numerical models will be tested and developed using high-resolution observations of geological framework and shoreline change in North Carolina, with the objective of first simulating past changes (hindcasting) and then developing a forecasting capability.
The coastal change observations collected under the North Carolina Regional Coastal Erosion Study provide unprecedented resolution, revealing patterns of shoreline change along 130 km of coast at an interannual (several year) time scale. Geologic framework observations reveal bathymetric features and near-surface sediment distribution patterns that appear to be tied to the observed shoreline variability. Along one 5-km section of coast, a strong pattern of interannual erosion and accretion appears to be associated with a set of shore-oblique bars on the shoreface (in 4 -15 m water depths). This location will be evaluated using several modeling systems.
The influence of nearshore geology is quite apparent at Kitty Hawk, North Carolina, where zones of enhanced erosion have impacted coastal development. A) Perspective view of Kitty Hawk, North Carolina, showing a system of shore-oblique bars in the nearshore bathymetry (blue tones) of the surf zone and inner continental shelf. Zones of significantly enhanced erosion are indicated by red bands along the shoreline. The white arrow indicates the location of the buildings and roadway shown in the inset photograph. 2 B) seismic profile A (A-A , location indicated in part A) illustrating a relict paleo-fluvial channel traversing this section of coast. The heterogeneous shallow geologic framework likely influences the location of shore-oblique bars. Feedback between the geology and physical processes (waves and currents) may lead to the enhanced erosion at this location.