Kilbourne, K. Halimeda, Ryan P. Moyer, Terrence M. Quinn, and Andrea G. Grottoli. 2011. Testing coral-based tropical cyclone reconstructions: An example from puerto rico. Palaeogeography Palaeoclimatology Palaeoecology 307 (1-4) (JUL 1): 90-7.
Complimenting modern records of tropical cyclone activity with longer historical and paleoclimatological
records would increase our understanding of natural tropical cyclone variability on decadal to centennial time
scales. Tropical cyclones produce large amounts of precipitation with significantly lower δ18O values than
normal precipitation, and hence may be geochemically identifiable as negative δ18O anomalies in marine
carbonate δ18O records. This study investigates the usefulness of coral skeletal δ18O as a means of
reconstructing past tropical cyclone events. Isotopic modeling of rainfall mixing with seawater shows that
detecting an isotopic signal from a tropical cyclone in a coral requires a salinity of ~33 psu at the time of coral
growth, but this threshold is dependent on the isotopic composition of both fresh and saline end-members. A
comparison between coral δ18O and historical records of tropical cyclone activity, river discharge, and
precipitation from multiple sites in Puerto Rico shows that tropical cyclones are not distinguishable in the
coral record from normal rainfall using this approach at these sites.