Category-4 Hurricane Charley came ashore on the southwest coast of Florida on Friday, August 13, 2004. The USGS, NASA and U.S. Army Corps of Engineers are cooperating in a research project investigating coastal change that occurred during Hurricane Charley.
On August 15, aerial video and still photography were acquired from Venice to Marco Island, Florida. On August 16, coastal topography and bathymetry of the same region were surveyed using NASA's EAARL (Experimental Advanced Airborne Research Lidar), a laser mapping system. These data will be compared to an earlier survey conducted in June 2004 by the U.S. Army Corps of Engineers (USACE) using CHARTS (Compact Hydrographic Airborne Rapid Total Survey). The comparison will detect the magnitude and spatial variability of coastal changes such as beach erosion, overwash deposition, and island breaches. These data will be used to develop and test predictive models of coastal impacts from severe storms. The data will be made available to local, state and federal agencies for purposes of disaster recovery and erosion mitigation.
2004 Breach at North Captiva Island |
North Captiva Island: The right eyewall of Category-4 Hurricane Charley passed over North Captiva Island and severed it into two parts resulting in a breach that was 450 m wide. From the Gulf of Mexico, storm waves and currents flowed across the island driving sand into the back bay leaving clearly visible underwater deposits that extended landward 130 m. Along with the sand, the waves and currents drove trees into the back bay, the vegetation appearing in the post-storm image as black dots. In the southeast United States, most of the inlets cut through the barrier islands were formed in a similar way during hurricanes. [larger version] |
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Previous Breach at North Captiva Island |
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Previous Breach: The pre-Hurricane Charley aerial photo on the left was taken several days following the passage of 2001s Tropical Storm Gabrielle. Note the two relatively small breaches in the central part of the island. On August 13, 2004, Hurricane Charley carved the 450-m-wide breach that is shown in the right photo and in more detail in the first photo pair above. Also, note that the Category-4 winds of Hurricane Charley stripped the leaves from trees and mangroves leaving bare branches. [larger version] |
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