Paleotempestology

rdf:langString Paleotempestology

rdf:langString Paleotempestology is the study of past tropical cyclone activity by means of geological proxies as well as historical documentary records. The term was coined by American meteorologist Kerry Emanuel. The usual approach in paleotempestology is the identification of deposits left by storms. Most commonly, these are overwash deposits in waterbodies close to the coast; other means are oxygen isotope ratio variations caused by tropical cyclone rainfall in trees or speleothems (cave deposits), and identifying beach ridges kicked up by storm waves. The occurrence rate of tropical cyclones can then be inferred from these deposits and sometimes also their intensity – typically the stronger events are the most easily recognizable ones –, by comparing them to deposits left by historical events. Paleotempestological research has shown that in the Coast of the Gulf of Mexico and in Australia, the occurrence rate of intense tropical cyclones is about once every few centuries, and there are long-term variations in occurrence which are caused, for example, by shifts in their paths. Common problems in paleotempestology are confounding factors such as tsunami-generated deposits, and the fact that only some parts of the world have been investigated.