EFFECTS OF HURRICANE IVAN ON ESTUARINE SEDIMENTATION IN WEEKS BAY, ALABAMA

Major Hurricane Ivan (category 3) made landfall near Gulf Shores, Alabama in the early morning of September 16, 2004. After causing millions of dollars worth of damage along the Alabama and Florida coastlines, the eye of the storm passed over Weeks Bay, a small estuary (c. 7 km²) located on the eastern shore of Mobile Bay. Weeks Bay is conveniently located close to Mobile, Alabama and has proven to be a useful training ground for undergraduate geology majors interested in modern depositional processes and sedimentology research. Approximately three months after Hurricane Ivan’s landfall, we initiated a study to map bottom sediment distribution across Weeks Bay. These data will be compared to previous bottom sediment maps done in 1998 (6 months after category 1 Hurricane Danny made landfall at Weeks Bay), 1999 (four months after category 3 Hurricane Georges made landfall in nearby southern Mississippi), and 2000, a relatively quiet year when no major storms or floods impacted the study area. Hurricane Ivan was the strongest tropical system since Hurricane Fredrick in 1979 to directly affect Weeks Bay and it likely induced significant changes in sediment distribution, particularly in shallow shoreline environments and adjacent to river mouths\inlets. Hurricanes Danny and Georges both transported well-sorted sand well into Weeks Bay, albeit from different directions. Preliminary interpretation of grain size data collected during this study period suggests that similar sediment transport and re-suspension also occurred during Hurricane Ivan.