GSA Connects 2021 in Portland, Oregon

Paper No. 103-3
Presentation Time: 2:05 PM


MORALES, Ilexxis, Florida Gulf Coast University, FL and MULLER, Joanne, Dept. of Marine and Earth Sciences, Environmental Geology Program, Florida Gulf Coast University, 10501 FGCU Blvd S, Fort Myers, FL 33965

A crucial tool in predicting future hurricane impacts is the National Hurricane Center’s storm database HURDAT, currently dating back to 1851. Instrumental records show fewer major hurricanes (category 3-5) making landfall on the east coast of Florida compared to the west coast. To further extend the record and better understand this discrepancy between Florida’s east and west coast tropical cyclone return periods, sediment cores were taken in select back-barrier lagoons along the Florida east coast to determine the frequency of hurricane landfalls through geologic time and were compared with existing paleotempestologic records from Florida’s Gulf coast. Sediment coring in areas of low energy behind a narrow barrier can provide information on frequency and intensity of storms dating well back into the Holocene. Preliminary data 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 features, such as the position of the semi-permanent Bermuda High in the western Atlantic, El Nino Southern Oscillation, and sea surface temperatures . The shift in the Bermuda High has a significant impact on the direction of Atlantic basin hurricanes. With a more southerly positioned high, we can expect more frequent storms in the Gulf of Mexico, and a northerly positioned high we tend to see more hurricanes like 2012 Hurricane Sandy. Sea surface temperatures have likely had a significant effect on hurricane intensity and frequency over time. Studies have shown heavy tropical storm activity between 1,400-1,700 Years BP correlating with the Medieval Warm Period, our data also shows these similar patterns. With increasing sea surface temperatures due to anthropogenic climate change, a deeper understanding of hurricanes’ landfall, intensity and how it is impacted by climate is necessary for a greater understanding of future storm activity. As coastal populations increase, it is essential to be prepared for more destructive and severe tropical systems to come.