DID CLIMATE CHANGE CAUSE EXTREME EROSION DURING HURRICANE IRENE? EXPECTATIONS MOVING FORWARD

Flooding associated with the passage of Hurricane Irene generated extreme runoff and unprecedented observed sediment loads in the Connecticut River. Sedimentary archives in both the headwaters and floodplain of the Connecticut River show that deposition from Irene flooding was chemically distinct from previous event layers. The Irene event layer displays anomalous enrichment in clays that make up glacial till, reflecting an increase in upland erosion relative to previous events. Analysis of long-term historical daily precipitation data shows that high antecedent precipitation explains in large part the severity of erosion during Irene. Trends in precipitation data as well as regional climate model projections suggest that the conditions that caused such extreme runoff and erosion are likely to become more frequent in the coming century.