Coastal Change Hazards: Hurricanes and Extreme Storms

Hurricane Dennis

Before and After Photo Comparisons: Santa Rosa Island, FL

On Tuesday July 12, 2005, scientists from the U.S. Geological Survey (USGS) conducted an aerial photographic survey of Santa Rosa Island, Florida that was impacted by Hurricane Dennis. The photographs have been compared to pre-Dennis photographs taken by USGS to illustrate extreme coastal change.

For each photo triplet below, the upper photo was taken on July 17, 2001, the middle photo was taken on September 17, 2004, one day after the landfall of Hurricane Ivan, and the lower photo was taken on July 12, 2005, two days after the landfall of Hurricane Dennis.

See additional photographs of coastal bluff erosion in Seagrove Beach, FL.

Map showing locations of pre-and post-storm photo sets. Scroll down or click on the red text above to view the photo sets. Blue line represents path of Hurricane Dennis.

Overwash, Pensacola Beach, FL: Overwash during both Hurricane Ivan and Hurricane Dennis extends landward of the Gulf-front road, but only Ivan overwash deposits reach the next road landward. (Note: Some of the houses present after Ivan but missing after Dennis were likely condemned and demolished sometime between the two storms.) [larger version]

Building Damage and Overwash, Navarre Beach, FL: Overwash deposits resulting from both Hurricane Ivan and Hurricane Dennis cover the main road with sand and extend landward into the back bay. Note the bottom right arrow showing where one half of a house is missing following Dennis. [larger version]

Overwash, Navarre Beach, FL: On this part of Navarre Beach, overwash deposits from Hurricane Dennis extend farther landward than overwash deposits from Hurricane Ivan. Both storms cover the two coast-parallel roads with overwash deposits. [larger version]

Overwash and Walkover Damage, Navarre Beach, FL: Overwash during Hurricane Ivan covers the parking lot and road with sand. Overwash from Hurricane Dennis again covers the parking lot with sand, but does not extend as far inland here as did the overwash during Ivan. A section of the pier is missing following landfall of Dennis. [larger version]

Road Overwash, East Santa Rosa Island, FL: Hurricane Dennis overwash deposits extend farther landward than Hurricane Ivan deposits. (Compare the landward extent of sand in each photograph to the arrow position.) [larger version]