The St. Petersburg Coastal and Marine Science Center’s Estuarine and MaRsh Geology (EMRG) group published a new USGS geonarrative on the extensive research that has taken place in Grand Bay, Mississippi and Alabama over the past nine years.
New USGS Geonarrative: A Century of Change in Grand Bay, Mississippi and Alabama
Over the past few centuries, Grand Bay, located along the northern Gulf of Mexico, has been impacted by the avulsion of the Escawapa River, large storm events, and the erosion of Grand Batture Island. To assess the past and future environmental impact of these changes, SPCMSC researchers have spent the last nine years assessing the effects of storms, sea-level rise, and restoration activities in Grand Bay. To address those goals, current and past long-term change and short-term variability studies have focused on digitizing historical maps of the area, calculating historical and modern shoreline change rates, generating bathymetric maps based on historical maps and modern data, and collecting surficial and downcore sediment samples. Surficial and downcore sediment samples are used to calculate seasonal and long-term (centurial) sediment accumulation rates, generate regional distribution maps, and assess sediment source through the use of multiple proxies including sediment characteristics, and foraminiferal and diatom biofacies. Accurate historical and modern maps and sedimentation rates can be fed into a variety of different numerical models to evaluate model efficacy and the impact of future coastal erosion hazards or environmental change, and inform managers on the predicted impacts of various restoration efforts.