Potential of Cave Sediments as a Proxy for Tropical Cyclone and Storm Activity

Abstract

Abstract Cave sediments show promise as a proxy for the reconstruction of paleo-storm activity. Here, we present a study of allochthonous sediments from two different caves located in west-central Florida that exhibit high variability in sediment layer thickness and are characterized by mostly alternating organic matter/sand couplets. Both sediment records are well constrained chronologically by 210Pb for Vandal Cave in Citrus County and by 14C for Jennings Cave in Marion County, with ∼50 and 2,700 years of deposition, respectively. Consequently, the Vandal Cave sediments were used to determine whether historic tropical storms produced changes in stratigraphy. The three thickest layers in Vandal Cave correspond with high-precipitation events between 325 and 500 mm. There are similar sedimentary layers found in Jennings Cave, but the upper sediments representing 50 years of deposition are unfortunately highly compacted due to human traffic in the cave. Episodes of intense deposition were noted, specifically from 1,560 to 1,580 years B.P., when 15 cm of sediment was deposited in eight sand layers, indicating a recurrence interval of ∼2.5 years for major storms. Results from this study suggest cave sediments in certain geographic settings may serve as accurate proxies for storm activity.