Near-annually resolved records of northern Bahamian hurricane activity during the Common Era: Emerging patterns and implications

Abstract:

The northern Bahamas have experienced more frequent intense-hurricane impacts than almost anywhere else in the Atlantic since 1850 CE. In 2019, category 5 (Saffir-Simpson scale) Hurricane Dorian demonstrated the destructive potential of these events across the northern Bahamas. Problematically, it is difficult to ascertain if these high activity levels remained constant through time due to the short observational record (<170 yrs). To extend this record, we present the results of four near-annual resolution stratigraphic records of paleohurricane activity from blue holes on Abaco Island (Thatchpoint Blue Hole: ~700 years), Grand Bahama (Turtle Pond: ~1100 years; Lane’s Delight: ~1800 years), and Cay Sal Bank (Hines Hole: ~750 years). Thatchpoint Blue Hole records at least 13 proximal hurricanes per century from 1500 to 1670 CE, which is substantially higher than recorded events from 1850 CE to present. The reconstructions from Grand Bahama suggest a coherent active period from 1300 to 1650 CE, along with earlier active periods from 1100 to 1200 CE during the Medieval Climate Anomaly and from 400 to 600 CE. These active periods were separated by a lull in activity from 600 to 1100 CE. Compiled reconstructions from the US Eastern Seaboard reveal frequent regional hurricanes during the two most active periods in the northern Bahamas, suggesting that these regions are impacted by similar storm populations. However, hurricane activity in the US Gulf Coast, central Bahamas, and southern Caribbean was diminished during these active periods, indicating that spatial heterogeneity in hurricane activity since 1850 CE likely persisted in some capacity throughout the last millennium. Spatiotemporal variability in paleohurricane activity reflects the combined influence of climatic and stochastic variability, and climatic modulation of hurricanes during the last 2000 years likely manifests regionally. However, additional high-resolution hurricane reconstructions coupled with downscaled models will help delineate the spatial extent of these regions through time.