Objectives:

A region of beach that demonstrates long-term, heightened erosion does not necessarily behave in the same manner over a season or in response to a storm. Several sections of beach near Kitty Hawk, NC, for example, exhibit very different responses when compared through time. There is mounting evidence that these regions of high erosion and subsequent accretion may be controlled by underlying geology but the mechanism(s) that link geology and shoreline behavior remain speculative. Establishing a clear link between the locations of older consolidated sedimentary rocks, which crop out on the shallow shoreface, with beach erosion, and a better understanding of the processes responsible for this connection are critical to accurate, long-term predictions of shoreline evolution.

This task, currently in the planning stage, will fill the need for maps of both bathymetry and bottom characteristics extending offshore from the dry beach on the ocean side of the barrier islands out to depths of 10 m to fill the gap between detailed USGS lidar-based terrestrial surveys and USGS geophysical surveys offshore of the 8 m isobath. To obtain data in this difficult-to-access portion of the coastal zone, survey vehicles such as the LARC will be used. The major objectives of this task are to:

1) Map the bathymetry and shallow geologic framework of the nearshore zone, from the beach to the 8 m isobath;

2) Determine if a spatial correlation exists between underlying geologic characteristics of the shallow shoreface;

3) Determine if the morphodynamics of the shallow shoreface differ between long-term and short-term hotspots (active erosional or depositional areas) and adjacent, more stable shorelines.

Related Sites:

USACOE Field Research Facility

Field studies at the US Army Waterways Experiment Station