Presentation on theme: "Collapsed five-story building, Romar Beach, AL: The lower two floors of the five- story building in the center of these photos have collapsed and the third."— Presentation transcript:
Collapsed five-story building, Romar Beach, AL: The lower two floors of the five- story building in the center of these photos have collapsed and the third floor has fallen to ground level. Erosion in front of the buildings undermined pools and walkways, and perhaps the buildings themselves (although the failure mode must await analysis by structural engineers.) Note the sandy overwash deposits that were driven landward between the buildings by storm waves and currents.
Collapsed front of multistory building, Orange Beach, AL: This five-story building was perched on top of a dune that was eroded during Hurricane Ivan. The Gulf-front portion of the building collapsed. Compare the pilings in the pre and post-photos of the house adjacent to the multi-story structure to determine the scale of vertical erosion of the dune. In the post- storm photo, the lower, unpainted portions of the pilings were below sand level prior to Hurricane Ivan.
Destroyed houses on top of a dune, Orange Beach, AL: These houses were on built top of a dune that was severely eroded during Ivan. Note the walkways in the pre-storm photo that once served as pathways down to the beach.
Breach through barrier island, Pine Beach, AL: The island was severed by a breach that may have developed as the back bay drained excess water following the peak of the storm surge, although the breach could have been initiated by waves and surge from the Gulf side. More analyses are required to determine the forcing processes.
Villa Sabine, FL: This area of two-story townhouses west of Pensacola Beach was clearly overwashed by the storm surge generated by Hurricane Ivan. The overwash sediments reached the back bay on the left-hand side of the photo and likely would have reached it in the center of the photo, if they had not been blocked by the townhouses. Notice how the Gulf-front beach is relatively clear of debris, which has been deposited on the spit of land behind Little Sabine Bay.