Paper No. 13-4
Presentation Time: 9:20 AM
STORM IMPACTS ON COASTAL AND INNER SHELF STRATIGRAPHY, PALEOENVIRONMENTAL RECONSTRUCTION, AND SAND RESOURCES: NORTHERN ONSLOW BAY, NORTH CAROLINA, USA
Over several days in mid-September, 2018, Hurricane Florence impacted the coastal region of Onslow Bay, North Carolina, and the eye passed approximately 50 km south of Bear Island and Bogue Banks. Winds of 50 to 90 mph, with gusts exceeding 100 mph, and wave heights of 8 m were experienced along this coast for several days. A storm surge of 2 to 3 m occurred in central and northern Onslow Bay and was sustained over several tidal cycles causing substantial erosion to the coastal islands and inlets, and impacting sediments and the morphology of the seafloor across the continental shelf. Our research group has pre-storm data on the sediments, microfossils, and the morphology of Bear Island and subtidal environments, including the inner shelf region. This project is revisiting and sampling those areas to understand the impacts of this storm on the various environments. Specifically, the investigation is assessing the impact of the storm on: 1) erosion and sedimentation throughout the region; 2) changes to the sand resources (location, volume, etc.); 3) changes to the types of microfossils and sediments in the various environments and; 4) the potential for retaining and identifying this storm signal in the stratigraphic record. Understanding inner shelf and coastal processes, and the response to high energy storm events like Hurricane Florence is important for accurately calculating sand volumes for beach nourishment, understanding where the sand goes following such an event, and forecasting coastal erosion rates in response to sea-level rise and storm impacts. Characterizing erosion and deposition on the inner shelf and shoreface in response to this event will advance the understanding of the resiliency of sand resources, which are vital for beach nourishment in this region. Identification of changes to sediments and microfossils will aid in the interpretation of stratigraphy (with wide-ranging applications) and the identification of similar deposits and associated storm events in the stratigraphic record.