Denniston lectures on stalagmite research for analyzing hurricane activity

Rhawn Denniston, Associate Professor of Geology will give a lecture on Oct 20th entitled “Reconstructing 5,000 Years of Hurricane Activity across the Northern Australia Coast using Stalagmites.” Our ability to recognize trends in hurricane activity is complicated by short and often incomplete historical records. As a means of extending the time frame of these records, geologists have developed the discipline of paleotempestology, which uses sediments from lakes, rubble deposits on coastlines, and chemical signatures in tree rings to reconstruct severe storm activity over the past several thousand years. Stalagmites from caves in tropical Western Australia may serve as a new paleotempestology archive. Mud layers trapped within these stalagmites can be dated with extremely high precision (±1 year) and mud is mobilized and deposited on stalagmite tops during years when hurricanes pass through the area. Because stalagmites grew throughout the past 5,000 years, mud layers within these samples may allow us to extend the record of hurricane activity far beyond the reach of historical documents, thereby allowing an examination of decade-, century- and millenium-long trends.