PALEOTEMPESTOLOGY OF THE EAST COAST OF FLORIDA

Hurricanes are the costliest natural disaster that impact the U.S.A. In 2017 approximately ~268 billion dollars of damages from Irma, Maria and Harvey was incurred (NOAA 2018). An important aspect in predicting future hurricane impacts, and therefore costs, is the National Hurricane Center’s storm database called HURDAT. Currently the database for the east coast of Florida dates back to only 1851. In addition, the east coast of Florida has a lower recorded landfall of intense hurricanes (category 3-5) compared to that of the west coast. To further extend the record back through time, and in order to better understand this discrepancy in Florida return periods, sediment cores were taken at select back-barrier lagoons along the Florida east coast to determine the frequency of hurricane landfalls going back through geologic time. Sediment coring in areas of low energy behind a narrow barrier can give us information to extend data back thousands of years. Our results indicate that intense hurricanes have made landfall, showing a “tempest” storm layer consisted of sand deposition and shell hash. Preliminary data also indicate that fewer intense storms have impacted the east coast of Florida than the west coast of Florida. These differing return periods are likely due to large scale climate feature, such as the position of the Bermuda High. In addition, sea surface temperatures have likely had a significant effect on hurricane intensity and frequency over time. With humans now contributed to this issue a deeper understanding of hurricanes landfall, intensity and damage costs are needed.