T178 Lake Systems Through Space and Time (Posters)

Tuesday, 6 November 2012
9:00 AM - 6:00 PM
Hall B

RECONCILING DEPOSITIONAL RECORDS OF STORM INFLUENCE ON COASTAL PONDS ACROSS SAN SALVADOR ISLAND, BAHAMAS

Paper number: T178-1
Program: Technical Sessions
Time: 9:00 AM – 6:00 PM

Authors

Abstract

The Bahamian island of San Salvador, an isolated Carbonate platform, faces the Atlantic and is subjected to frequent hurricane activity. Prior research focusing on the Salt Pond Salina provides insight into storm impacts along the island’s eastern shores. Our study aims to reconstruct patterns of storm deposition in other coastal settings to address whether or not ponds elsewhere on the island contain comparable records of sedimentation or whether they require reconciliation.

Pushcores collected from hypersaline coastal ponds situated along the eastern and southern portions of the island provide insight into ambient and storm-induced deposition, largely distinguished by high constituencies of carbonate sand in storm layers. Despite similar appearances, ponds from different parts of San Salvador contain highly variable storm signatures. A core from the island’s southern extent contains a single prominent carbonate sand layer that is sharply separated from under- and overlying organic deposits, which reflect ambient pond accretion. Interpreted as beach overwash, the internally homogenous unit was likely emplaced by one storm event. Cores from the island’s eastern-southeastern ponds are sandier overall, some containing multiple storm layers; however, they lack the pronounced distinction between ambient and storm-induced sedimentation.

Our data suggest factors including shoreline orientation, vegetation, and nearshore morphology leave a significant imprint on storm-sedimentation patterns. Additional research is required to further assess these linkages and to elucidate a more complete historical record of storm events impacting the island of San Salvador. A remaining challenge is reconciling existing storm records across the island by establishing an accurate chronology.