Records of prehistoric hurricanes on the South Carolina coast based on micropaleontological and sedimentological evidence, with comparison to other Atlantic Coast records
Singleton Swash on the South Carolina coast provides an extended record of storm events for this coast. We used experience gained by looking at storm traces detected as layers of offshore foraminifera intercalated with marsh sediments from a known storm in the area ( Hugo, which occurred in 1989) to detect storm horizons from the sediments that have been accumulating in Singleton Swash since 5700 yr B.P. We suggest here that the most intense storm activity occurred in the 0–1000 yr B.P. interval (six storms); only three occurred in the 1000–2000 yr B.P. interval and two in the 2000–3000 yr B.P. time interval (calibrated radiocarbon years). There was one giant storm in the pre–5000 yr B.P. interval; a sea-level oscillation in the 3500–5000 yr B.P. interval appears to have destroyed most records during that period. Previous work suggests that the position of the Bermuda (or Azores) High influences the direction of general storm paths for major North Atlantic hurricanes: a position of the Bermuda High farther to the south tends to force storms into the Gulf of Mexico, whereas a northern position allows them to track up the Atlantic Coast. Results here combined with results of other workers on the Gulf Coast suggest a more southern position for the Bermuda High, causing more storms on the Gulf Coast in the interval of 1000–3400 yr B.P. Conversely, a more northern position during the past 1000 yr is suggested to have contributed to higher frequencies of storms on the Atlantic Coast in that period. To test this hypothesis, modern records of the movement of the North Atlantic Oscillation (NAO, which controls the position of the Bermuda High) have been compared with historical records of hurricane tracks over the twentieth century. There does appear to be a strong correlation between the position of the NAO and the track the storms have pursued in modern times.