Reconstructing Tropical Cyclone Frequency Using Mud Layers in Speleothems

April 11th, 2011

Our ability to understand multi-decadal to centennial-scale trends in tropical cyclone activity is limited by the short duration of, and limitations in, historical records. In order to extend these records for tropical Western Australia, we have analyzed mud layers in stalagmite KNI-51-11 from the Kimberley region of north-central Australia that appear to be formed by cyclone-induced flooding.  KNI-51-11 grew over the last 250 years and contains 39 mud layers. High uranium and low detrital Th abundances in this aragonite stalagmite allow extremely precise dating (±1 year over the past century) via U/Th mass spectrometry.  Linear interpolation between 13 U/Th dates was used to establish an age model for the mud layers.  When these mud layers are compared to historical storm records since 1906, the KNI-51-11 mud layers correlate 78% of the time with tropical cyclones that passed within 200 km of the cave.

Nicholas Campbell, ’11
West Liberty, IA
Majors: Environmental Studies, Geology

Sponsor: Rhawn Denniston

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