Collaborative Research: Morphodynamic simulations of coastal storms and overwash to characterize back-barrier lake stratigraphies

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Hurricanes constitute major hazards to coastal communities of the eastern United States, generating strong winds and waves, coastal flooding, and erosion. These storms often induce overwash, a process where water and sediments flow over coastal barriers, erode the beach, and deposit sediments atop and behind the barrier. Geoscientists often use deposits of overwash in coastal ponds to infer when hurricanes occurred in the past, prior to written and satellite records of hurricanes. These sedimentary records of past hurricane activity are useful for constraining the probability of a hurricane making landfall on a stretch of coastline, or for understanding changes in hurricane frequency in response to past changes in climate, and are commonly integrated into hazard assessments. However, these sedimentary records are limited to reconstructing the frequency of past storms, while inferences into the magnitude or track of these events remain preliminary. In this project, the investigators will harness recent advances in computer simulations of coastal sediment transport to develop a new approach for reconstructing storm strength and track from overwash deposits. This project will integrate field-based observations of overwash from sediment cores with state-of-the-art simulations of observed and simulated hurricanes to: (i) evaluate the influences of storm properties on overwash deposition in back-barrier settings, (ii) diagnose the sensitivity of depositional patterns to geomorphic change, and (iii) relate storm strength and track to the properties of overwash deposits. This work will deliver quantitative reconstructions of hurricane magnitude for southern New England — a heavily-populated region that is vulnerable to tropical cyclones — extending the historical record of hurricane activity in this region back centuries to provide insight into strengths and tracks of prehistoric hurricanes that made landfall in this region. The investigators anticipate that the integrative and scalable approach developed here will be applicable to other coastlines in the United States and abroad that are vulnerable to tropical and extratropical cyclones, and will facilitate the critical challenge of predicting and mitigating against coastal erosion and flooding.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.