Thursday, 18 January 2007: 2:00 PM
A Multi-Millennial Record of Intense Hurricanes in New England
214B (Henry B. Gonzalez Convention Center)
New England is susceptible to destructive tropical cyclones. However, only a few intense hurricanes have visited the region since European settlement. The rarity of these events along with the brevity of the observational record make it difficult to quantify the risk posed to the region by infrequent but costly hurricane disasters. We use geologic archives of storms as a means of extending the instrumental and historical records of intense hurricanes back several millennia. Such records provide a more wide-angled view of coastal risk by enabling millennial-scale estimates for the frequency of extreme storm surge events at different locations along the coast. Furthermore, the distribution of paleohurricanes through time may reveal millennial-scale variability in tropical cyclone behavior. Understanding the causes of this variability in New England and elsewhere could help clarify the relationship between hurricanes and climate.
Buzzards Bay in southeastern Massachusetts is particularly vulnerable to coastal flooding during landfalling hurricanes. The Bay's north-south orientation can focus storm surges when hurricanes make landfall to the west of Cape Cod. Ponds around the perimeter of the bay preserve evidence of these enhanced surge events as detectible sedimentary layers. During a storm surge event, sand and marine materials are washed into and deposited in these normally quiet freshwater ponds creating records of intense storm events. Sediment cores retrieved from several of these ponds establish a chronology of historic and pre-colonial hurricanes in the region dating back at least 2500 years.