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| New Breach on Hatteras Island |
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Hurricane Isabel
Coastal Change from Lidar
Preliminary analyses of NASA EAARL (Experimental Advanced Airborne Research Lidar) data from Hatteras Island show extensive beach changes and dune erosion (see first set of images below), as well as the destruction of infrastructure and buildings, particularly in Hatteras Village, 3 km south of breach (see second set).
The most extensive beach changes were associated with the opening of a new breach (~500 m wide and divided into three separate channels) that completely severed the island south of Cape Hatteras. The main breach, and a smaller one several kilometers to the south (not shown), broke through at minima in both island elevation and island width.
The first two images above show high resolution topography of a portion of Hatteras Island measured with NASA's EAARL before and after Hurricane Isabel. The different colors indicate different elevations, where in general the hotter the color, the higher the elevation (see scale). The third image is an oblique photograph taken by USGS on the same day as the post-storm lidar survey.
On the left are before- and after-Isabel grey-scale images of elevations measured with NASA's EAARL - the lighter the shade, the higher the elevation. On the right are pre- and post-storm oblique photographs of the same area. The laser reflects from buildings as well as from the ground, hence the elevations include those of the tops of man-made structures. Note in the grey-scale elevation surfaces that the dunes were completely destroyed during the storm exposing the motels to attack by Isabel's waves.
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U.S. Department of the Interior |
U.S. Geological Survey
