Collaborative Research: Holocene Tropical Cyclone Variability in the Western North Atlantic

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Damage from hurricanes has increased markedly over the last century, largely the result of increased coastal population, urbanization and wealth. The recent impacts of hurricanes Katrina, Irene, and Sandy highlight the vulnerability of the United States to tropical cyclones. Unfortunately, the short instrumental record of hurricane occurrence (~160 years) in the western North Atlantic significantly hampers efforts to understand the driving mechanisms responsible for modulating hurricane activity. Additionally, the relative rarity of hurricane landfalls at any particular region further limits the extraction of meaningful patterns from an already limited data set. This collaborative project, conducted by researchers at the Woods Hole Oceanographic Institution and Texas A&M University at Galveston, is aimed at extending the record of hurricane activity back thousands of years with sedimentary evidence of hurricane passage preserved in coastal sink holes and blue holes. During an intense hurricane strike, storm surge and waves mobilize and transport coarse sediment such as sand and gravel. Some of this coarse sediment is preserved as a layer in the finer grained sediments normally deposited in sink holes and blue holes. These coarse grained layers can be used to reconstruct prehistoric storm events over the thousands of years, throughout the time sink holes and blue holes have been collecting sediments. This current work is focused on developing these long-term records of past tropical cyclone activity from sites in the Bahamas and Jamaica. These records will complement existing records from the panhandle of Florida and the Northeastern US and will help elucidate spatial and temporal patterns in tropical cyclone activity and allow for the examination of the climatic drivers of this variability.Broader impacts of the work include a more comprehensive understanding of the array of climate factors that influence hurricane activity over the past several millennia. This improved insight into natural variability is essential to inform modeling efforts and assess future risks from these storms. The project will also provide a platform for training the next generation of geoscientists through practical, hands-on interdisciplinary research experiences at the undergraduate and graduate level.