26 Paleoclimatology/Paleoceanography (Posters)

Sunday, 4 November 2012
9:00 AM - 6:30 PM
Hall B

TRACKING HURRICANE LANDFALLS IN SOUTHWEST FLORIDA USING GEOLOGIC PROXIES IN LAGOONAL SEDIMENT CORES

Paper number: 26-27
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

Scientific literature has proposed that the recent rise in sea surface temperatures driven by anthropogenic climate change has lead to more frequent and intense tropical hurricanes. However, due to the limited availability of instrumental and observational hurricane data this hypothesis has been challenged. Currently, the use of Paleotempestology in identifying geologic remnants of past storms is being used to assess storm frequency and strength over much longer periods of time. Specifically, storm overwash deposits, that are preserved in coastal lagoon and back barrier bay sediments, provide the opportunity to study the connections between past climate change and hurricanes over thousands of years.

The goal of this study was to develop the first continuous hurricane record for the Southwest Florida region that extends back well beyond the historic observational record. Data from this study was collected from the inner lagoonal margin on the backside of a barrier island in Naples, Florida. Individual cores were analyzed using several paleo-proxies including percent calcium carbonate, percent organic and inorganic content, and grain size distribution. Relative ages of the storm overwash events were obtained through 14C and 210Pb dating. In total, at least nine storm layers have been identified in the cores, which appear as shell layers, presumably brought to the lagoon via storm overwash. The storm layers provide evidence of active versus inactive periods of past storm events in Southwest Florida. Here we also attempt to identify the most recent storm layers as known hurricane events.

This work will contribute to our understanding of past hurricane landfalls in Southwest Florida, and more broadly hurricane dynamics in the Atlantic Ocean and Gulf of Mexico in the distant past.