Our current understanding of trends in tropical cyclone activity in the Indo-Pacific is restricted by a limited historical record. Mud layers deposited in stalagmites during flooding events in cave KNI-51 from tropical Western Australia appear to be a proxy for tropical cyclone activity in the region. Aragonite stalagmites were precisely dated using U/Th mass spectrometry techniques, and these high resolution dates were used to construct age models that can, in turn, be used to calculate the age of each mud layer. Stalagmite KNI-51-G is 63 cm tall and cylindrically shaped, and preserves evidence of increased flooding frequency from 1310-1460 AD and decreasing flooding frequency from 1460-1640 AD. These data compare well with similar analyses of two other stalagmites collected from KNI-51. West Pacific Warm Pool sea surface temperatures, which exert a first-order control on tropical cyclone activity, track flood layer frequency from 1000-1637 AD suggesting that tropical cyclone-induced flooding increased during periods of warmer sea surface temperatures from 1100-1250 AD.
Daniel Cleary, ’13
Sponsor: Rhawn Denniston