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Explanation - Observations of Impacts Caused by Hurricane Bonnie, August 1998, on the North Carolina Coast

Elevation data plotElevation Data - derived from lidar data obtained in September 1998. Water (dark blue) is to the right and land is to the left. The strip is roughly 700m wide and follows the coastline. The lighter blues indicate higher elevations, with red colors indicating the highest points. Buildings show as red and orange squares (not shown here). Change plotChange - elevation differences between lidar surveys obtained in September 1997 and in September 1998, within one week of Hurricane Bonnie. The change data shows elevation loses (erosion) in yellows and reds, and elevation gains (acreation) in blues and purples. To calculate the change, the elevation of each data point in one survey is differenced from all data that occur within 1 m horizontal in the other survey.
   
Passive data plotPassive Data - a "panchromatic" digital image of the coast that is obtained simultaneously with the laser elevation measurements by the NASA Airborne Topographic Mapper. The passive data are geo-referenced in a mosaic that appears as a black and white 'strip' image of the coast. The post-Bonnie (September 1998) passive data are shown in a strip map roughly 700m wide. Profile comparison plotProfile Comparisons - at selected locations shore-normal transects were defined. Profiles along these transects were determined from lidar surveys obtained in September 1997 and September 1998. Each data point shown represents a laser spot elevation. All spot elevations within 1 meter of the shore-normal transect were used to construct the profiles.