Survey reveals extent of Hurricane Ike's underwater damage to Galveston

Terra Daily: Conducting a rapid response research mission after Hurricane Ike, scientists at The University of Texas at Austin surveyed the inlet between Galveston Bay and the Gulf of Mexico, discovering the hurricane significantly reshaped the seafloor and likely carried an enormous amount of sand and sediment out into the Gulf.

The ongoing research could help coastal communities gauge the effectiveness of their sometimes controversial efforts to replenish eroding sand along shorelines while revealing the role storms play in building and eroding barrier islands such as Galveston.

"The big question is whether the sand was entirely removed from the system or if it's still close enough to the shoreline to get back into the system," said John Goff, survey team member and senior research scientist at the university's Jackson School of Geosciences.

…Hurricane Ike's surge last Sept. 13 filled Galveston Bay with 12 feet of water, which subsequently drained back into the ocean as a "back surge." Although considerable amounts of water flowed over the Bolivar Peninsula and other lower-lying portions of the barrier system, most of the surge and back surge likely passed through Bolivar Roads, by far the deepest access between the Gulf and the Bay. The very high rate of flow that must have passed through the inlet had the potential to cause substantial erosion and transport sediment long distances.

Comparing pre- and post-Ike surveys, the scientists determined the hurricane's surge and back surge significantly modified the seabed over broad areas. Ike either erased or substantially degraded large shell-gravel ridges up to 10 feet high….

Galveston shortly after Ike. Shot by Staff Sgt. James L. Harper Jr., U.S. Air Force