RAPID: 2018 Hurricane Season: Sedimentological and Morphological Characteristics of Hurricane Michael Induced Storm Deposits in Apalachicola Bay

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An extremely strong Hurricane Michael hit the Florida Panhandle in October 2018 and caused devastating destruction along the coastline. Documenting damage by this record-breaking storm in various coastal environments, such as beaches; dunes; bays; barrier islands; and marshes, in a timely fashion, can inform the coastal community and resource managers about the dangers and frequency of energetic tropical storms. A better scientific understanding of these impacts and raising public awareness and knowledge of such storm impacts plays a crucial role in hazard preparation. This research involves collecting samples and making measurements along an area of the Florida coast subject normally to microtidal ranges. Sediment and macrofaunal samples will be collected via cores and grab sampling along two transects radiating out of Apalachicola Bay in southern Florida and ending in the sea offshore of the barrier islands. Other characterization of subaerial parts of the transects will be carried out to document morphological changes in dunes and changes in elevation of nominally subaerial and shallow subaqueous environments. To document the preservation potential of storm deposits in the stratigraphic record, transects will be sampled twice. Once as soon as possible after the storm and once six months later. Data and findings from this study, in combination with dissemination of the results of the project to the greater coastal community, will help the public and institutions that assess risk associated with coastal areas, understand the impacts of strong storms on a wide variety of coastal environments resulting in better preparation and knowledge of resiliency for this significant natural hazard.This study takes advantage of the rare opportunity to systematically document the sedimentary record produced by Hurricane Michael along the Apalachicola Bay coast. Surface sediment and sediment cores are collected along two transects extending from seaward of the barrier islands to the coastal marshes along the two rivers that discharge into Apalachicola Bay. Sediment cores from the barrier islands, back-barrier, bay, and coastal marsh will be used to establish regional scale characteristics of storm deposits. Two field sampling campaigns will be conducted, with the first one shortly after the storm impact and the second one roughly 6 months later with the goals of investigating the preservation of the storm deposits. Storm deposits by extreme hurricanes in low-energy (i.e., microtidal) environments, e.g., coastal marsh and coastal lakes or sinkholes, have been broadly used to reconstruct paleo-hurricane records, thereby providing valuable insights to how climate and storm strength have changed with time. Furthermore, preservation of, often, very thin storm deposits in the face of processes that tend to erase these records (e.g., bioturbation and erosion) will be examined. Because storm deposits of layers of sediment on top of existing geomorphic features constitutes a major mechanism for coastal marshes to gain elevation, strong storms, like Hurricane Michael, likely play an important role in combating the drowning of marshes and other coastal environments due to sea-level rise.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.