Clues from Past Hurricanes Help Assess Future Storm Risks

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December 1, 2004

Reconstructing the history and intensity of hurricanes is useful when assessing
future risks of these extreme events in coastal regions. Previous studies of
North Atlantic hurricane activity have identified many of the environmental
factors that presently influence tropical cyclone activity. However, study data
is restricted to a relatively short 100-150 year historic record, making it
difficult to identify and study variability on timescales greater then a few
decades. Sediment cores from lagoons and salt ponds contain overwash deposits
that document previous flooding events over thousands of years and provide
insights into wave and current conditions at the time of each event. Results
from a study on Vieques, Puerto Rico, show how catastrophic flooding events,
most likely intense hurricanes, have been preserved in a natural lagoon system
for thousands of years. Hurricane activity on Vieques shows a strong correlation
with proxy records of El Nino/Southern Oscillation (ENSO) variability,
suggesting that ENSO may have been a dominant control on tropical cyclone
activity in the Caribbean over the past 3,500 years. WHOI scientists are also
looking for similar records on other Caribbean islands severely damaged by 2004
hurricanes.
H41C-0304 Sedimentary Archives of Extreme Flooding Events in
the Northeastern Caribbean