A Quarter Century of Coastal Change on San Salvador Island: 1988-2014
In 1988, Daryl Clark completed a Masters thesis outlining the characteristics of modern beach sediment for 18 beaches on San Salvador Island, Bahamas. This study provides an assessment of 9 of the 18 beaches 25 years after Clark’s study. Samples collected from the lower beachface, upper beachface, backbeach, and dune environments were processed to determine particle size, grain texture, sample sorting, sample skewness, and kurtosis. The results of this study, and a smaller study completed by a College of Charleston student in 2010, were compared to Clark’s results to determine coastal changes on the island during the past quarter century. Clark concluded the major determinant of sediment texture and sorting on the island was platform geomorphology and antecedent topography. He also attributed coastal development to major storm events. Clark conducted his research during a relatively calm period in Bahamian hurricane history. From 1990 to 2013, multiple hurricanes have impacted the Bahamas, including San Salvador Island. Despite these storms, no conclusive results support Clark’s conclusion that storm events are a major determinant of modern subaerial sedimentation. Therefore, antecedent topography and platform geomorphology appear to be the greatest factors in coastal development on San Salvador Island.
San Salvador, Bahamas, carbonate geology, coastal change