Tsunami's and giant tsunami's in the geological history

Prof.dr. J. Smit, Sedimentology and Marine Geology, Vrije Universiteit, Amsterdam

The recent Indian Ocean tsunami reminded us that tsunamis are a geological force to be reckoned with. In the geological record, several witnesses of larger tsunamis are known, but their sedimentology and mode of deposition are poorly understood.

The tsunami in the Indian Ocean has been well documented, and provides insight into the mechanisms of tsunami wave propagation, with which we can better understand ancient tsunami deposits. Some spectacular examples of fossil tsunami deposits are reviewed, most of them triggered by major meteorite impacts like Chicxulub, Manson. Earth quake triggered tsunami deposits rarely survive the erosive action of normal storm-wave erosion.. The Netherlands has witnessed at least one major tsunami: the Storegga slide induced tsunami that left traces of flooding in ancient coastal lagoons behind the beach barrier.