Evidence of past intense tropical cyclones from backbarrier salt pond sediments: A case study from Isla de Culebrita, Puerto Rico, USA

Tropical cyclones pose a significant threat to lives and resources in heavily-populated regions and can extensivelymodify coastal landforms. In appropriate depositional environments a sedimentological record of past tropical cyclones can be preserved. Given the relative rarity of landfalling tropical cyclones and the shortness of the instrumental record, little is known about past patterns of hurricane activity. The development of long-term records of tropical cyclone activity will make it possible to examine how past climate change may have influenced the frequency, intensity, and locations (origin, tracks) of hurricanes. Previous work has shown that intense hurricane strikes produce a distinctive sedimentary signature that can be used to reconstruct long-term records of these events. Numerous coastal salt ponds and lagoons in eastern Puerto Rico and the U.S. Virgin Islands are well situated to receive allocthonous sediments during intense tropical cyclone landfalls. Coastal salt ponds, normally low-energy environments, are dominated by fine-grained organic sediments, with the exception of episodic deposition of coarser-grained mineral sediments from the beach and nearshore during extreme storms. Sediment obtained from a series of cores taken from Big Culebrita Salt Pond on the Isla de Culebrita, Puerto Rico reveal a record of flooding-induced sedimentation within mangrove and salt-pond sediments dating back more than 2000 years. Reconstructing the history of storm-surge deposition from backbarrier salt-pond sediments may allow for the reconstruction of a millennial-scale record of tropical cyclones for the northeastern Caribbean and other regions.