Figure 4
From: Historically unprecedented Northern Gulf of Mexico hurricane activity from 650 to 1250 CE
Sand contents from 1850 CE to present in Shotgun Pond (a) and Basin Bayou (b) are plotted alongside historical hurricanes with modeled storm tides (SLOSH-modeled surge plus tide) that reached the overwash and inundation regimes at each site. Percent sand values identified as “events” are marked with an asterisk. The gray shading represents the age uncertainty for each time series. Dashed lines connect event deposits to the historical hurricane interpreted to result in the deposition of each sand bed, although as noted in the Supplementary Information, individual sand beds could reflect storm deposition caused by multiple storms, and age model uncertainties prevent confident attribution of events to only one hurricane in many cases. (a) SLOSH modeled overwash regime (≥ 1.1 masl) storm tides at Shotgun Pond occurred during Category 1 storms in 1929, 1941, and 1966 (Alma), the Category 2 storms in 1856, 1886, and 1985 (Kate), Category 3 storms in 1877, 1894, 1896, 1926, 1975 (Eloise), 1985 (Elena), and 2005 (Dennis), and the Category 5 storm in 2018 CE (Michael). ADCIRC results41 indicate the storm tide for the Category 2 storm in 1852 CE surpassed the inundation regime threshold (≥ 5 masl). (b) SLOSH derived overwash regime (≥ 1.1 masl) storm tides at Basin Bayou occurred during the Category 1 hurricane in 1860, the Category 2 hurricane in 1936, and Category 3 hurricanes in 1917, 1926, 1985 (Elena), 1995 (Opal), and 2004 CE (Ivan). The modeled storm tides for the Category 3 hurricane in 1882 and the Category 2 hurricane in 1916 CE exceeded the inundation regime elevation at Basin Bayou (≥ 1.8 masl). (c) Comparison of the Bacon model (shaded) and 210Pb constant rate of supply model (not shaded) determinations of the age of the base of the event deposit at 21 cm (~ 1930 CE in panel b). Both age models overlap with the 1916 CE inundation regime hurricane (Supplementary Information).
