Calculations of tsunamis from submarine landslides

Abstract

Great underwater landslides like Storegga off the Norwegian coast leave massive deposits on the seafloor and probably produce enormous tsunamis. We have performed a numerical study of such landslides using the multi-material compressible hydrocode Sage in order to understand the relationship between the rheology of the slide material, the configuration of the resulting deposits on the seafloor, and the tsunami that is produced. Instabilities in the fluid-fluid mixing between slide material and seawater produce vortices and swirls with sizes that depend on the rheology of the slide material. These dynamical features of the flow may be preserved as ridges when the sliding material finally stops. Thus studying the configuration of the morphology of prehistoric slide relics on the abyssal plain may help us understand the circumstances under which the slide was initiated. © Springer Science + Business Media B.V. 2010.