GSA Connects 2021 in Portland, Oregon

Paper No. 103-4
Presentation Time: 2:20 PM


ELLIOTT, Emily1, BREGY, Josh C.2, TUCKER, Clay S.3, LEHRMANN, Asmara4, MINZONI, Rebecca Totten4, WALLACE, Davin5 and THERRELL, Matthew D.3, (1)Department of Geography; Department of Geological Sciences, University of Alabama, Tuscaloosa, AL 35487, (2)Department of Geography; Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, IN 47405, (3)Department of Geography, University of Alabama, Tuscaloosa, AL 35487, (4)Department of Geological Sciences, University of Alabama, Tuscaloosa, AL 35487, (5)Division of Marine Science, The University of Southern Mississippi, 1020 Balch Blvd, Stennis Space Center, MS 39529

In the last five years, coasts along the northern Gulf of Mexico (nGoM) have experienced some of the most damaging tropical cyclones in the modern record, prompting concern that the frequency of these extreme events is increasing. While unprecedented in the instrumental period, our understanding of the frequency of intense tropical cyclones (TC) prior to the last century is limited, leaving coastal communities along the nGoM vulnerable. To better understand and predict TC activity, we must contextualize recent extreme events within a long-term (millennial), high-resolution record of TC activity.

Tree-ring records at sub-annual resolution (continuing up to ~1,400 years long in the nGoM) capture year-to-year variability of TC activity, while sedimentological records capture TC activity at decadal to centennial resolution over multiple millennia. By calibrating dendrochronological and sedimentological TC records into a comprehensive multi-proxy database of TC activity for the nGoM throughout the late Holocene, we contextualize the TC events that have occurred in the 21st century while also better understanding the drivers of these events. Utilizing sedimentological, dendro- and geo-chronological records of TC activity in the nGoM, we compare newly established sediment archives of surge and flood events within Bon Secour and Mobile Bays, to regionally established records of TC precipitation and floods from tree rings. Comparisons of dendrochronological and sedimentological TC records suggest correlation, indicating the potential to use calibrated multi-proxy records to clarify the spatial and temporal variability of TC occurrence in the region over the late Holocene before the instrumental record. As shown in our calibration, frequency of events, differences in storm characteristics and intensity, and regional impacts elucidate the need for pre-instrumental records to contextualize TC events of the 21st century. These preliminary results indicate the potential to expand these multi-proxy methods to develop a complete and calibrated paleotempest record from archives throughout the nGoM that will not only calibrate TC frequency and intensity over the last millennium but will also be used to inform improved management and policy around coastal resiliency in the nGoM.