Storm Signatures in Coastal Ponds and Marshes Over the Late Holocene

Katherine Castagno, Ph.D., 2019
Jeffrey Donnelly, Advisor

Tropical cyclones pose a growing threat to coastal populations, especially as both populations and infrastructure are increasingly concentrated along the eastern coast of the United States. This thesis seeks to characterize the impacts of storms on coastal ponds and marshes, using a variety of methods to quantify the spatiotemporal signatures of tropical cyclone events in these systems.  Trends in grain-size distribution and sediment coarse fraction are used to broaden our understanding of deposition and sediment sources during tropical cyclone events. The complexity of how storms interact with these systems requires a process-based, whole-site analysis to adequately develop a storm record.  Given the many nuances to storm deposition in these systems, the potential utility and caveats to inversely modeling storm intensity from deposit grain-size characteristics is discussed. Finally, the question of whether hurricanes can produce widespread erosion of marsh platforms is addressed through field and modeling techniques. Patterns of deposition and erosion during major storms remain complex, emphasizing the importance of contextualizing storm signatures within a broader view of the study area.  This provides an opportunity to strengthen both paleo-reconstructions of storm activity and our ability to make informed decisions for coastal management in response to potential future changes in storminess.