Multi-proxy Characterization of Storm Deposits on Sanibel Island, Florida: A Modern Analog for Paleotempestology

Document Type

Article

Publication Date

2022

Keywords

Hurricane, Storm surge, Overwash, Barrier island, Tempestite

Digital Object Identifier (DOI)

https://doi.org/10.1016/j.geomorph.2022.108148

Abstract

Hurricanes have serious impacts on human lives and infrastructure, especially as a result of flooding caused by storm surge and precipitation. To better prepare coastal populations for future hurricanes due to an increasingly warming world, a better understanding of hurricane storm surge is key. Southwest Florida is particularly vulnerable to hurricane storm surge where most of the coastline is within 2.5 m of sea level and population is on the rise (2.5% between 2019 and 2020 in Lee County). This study presents a geologic record of intense hurricane strikes from Sanibel Island dating back to approximately ca. 1920. Based on sedimentary proxies such as grain size, organics, moisture content, and calcium carbonate, three tempestites were identified in cores from the Sanibel Island Marsh. Radiometric dating constrained Tempestite 1 as Hurricane Donna (1960) and Tempestites 2 and 3 as the 1926 Great Miami Hurricane and the Tampa Bay hurricane of 1921. Of the eight intense hurricanes (category 3–5) taking place between ~1920–2016, only three hurricanes were recorded in the geologic record. Tempestites 1, 2, and 3 were deposited by intense, large radius storms with significant storm surge, which would indicate that at least three storms made significant impact on the Southwest Florida region between ~1920–1960. Since 1960 no storms have breached the Sanibel Island barrier. It is important for the public to recognize that even though this region has not experienced significant storm surge in the last ~60 years, several hurricanes occurring between 1920 and 1960 produced storms surges greater than ~10 ft. that were able to breach a major barrier island (Sanibel Island). Human-induced climate change is predicted to increase storminess and sea level rise in Southwest Florida with concomitant risk for future storm surge.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Geomorphology, v. 402, art. 108148

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