Landslide Tsunami Generation Models: Validation and Case Studies

There has been a proliferation of landslide tsunami generation and propagation models in recent time, spurred largely by the 1998 Papua New Guinea event. However, few of these models or techniques have been carefully validated. Moreover, few of these models have proven capable of integrating the best available geological data and interpretations into convincing case studies. The Tsunami Open and Progressive Initial Conditions System (TOPICS) rapidly provides approximate landslide tsunami sources for tsunami propagation models. We present 3D laboratory experiments and 3D Boundary Element Method simulations that validate the tsunami sources given by TOPICS. Geowave is a combination of TOPICS with the fully nonlinear and dispersive Boussinesq model FUNWAVE, which has been the subject of extensive testing and validation over the course of the last decade. Geowave is currently a tsunami community model made available to all tsunami researchers on the web site www.tsunamicommunity.org. We validate Geowave with case studies of the 1946 Unimak, Alaska, the 1994 Skagway, Alaska, and the 1998 Papua New Guinea events. The benefits of Boussinesq wave propagation over traditional shallow water wave models is very apparent for these relatively steep and nonlinear waves. For the first time, a tsunami community model appear sufficiently powerful to reproduce all observations and records with the first numerical simulation. This can only be accomplished by first assembling geological data and interpretations into a reasonable tsunami source.