Case Studies and Tsunami Community Model for Underwater Landslide Tsunamis

University Of Rhode Island, Kingston RI

Investigators

Abstract

Underwater landslides have generated several local tsunamis reaching at least 30 meters in elevation this century -- most recently on Flores Island, Indonesia in 1992. In addition, these events typically occur close to shore and offer very little time for warning, and can be devastating to nearby coastal development. Underwater landslides often pose the greatest local tsunami hazard. Tsunamis generated by underwater landslides are governed by at least six fundamental parameters, which are functions of landslide geometry and kinematics. In addition, nonlinear interactions may occur between waves, shoreline, and landslide. Consequently, predicting landslide tsunami amplitudes requires sophisticated numerical methods. The PIs have developed an accurate and efficient model of inviscid, irrotational, fluid dynamics during tsunami generation, based on a Boundary Element Method (BEM). A three-dimensional (3D) version, the ''Tsunami Open and Progressive Initial Conditions System'' (TOPICS) is an analytical tool that provides estimates of tsunami features and initial conditions. The source code is distributed freely to academic, nonprofit, and government researchers, in order to facilitate tsunami hazard assessment within the tsunami community (see: www.tsunamicommunity.org). This action is to support research to refine the effects of landslide shape, motion, and deformation, on tsunami generation, describing three-dimensional effects during tsunami generation, coupling tsunami generation and propagation models, validating these numerical methods with experiments and actual case studies, and producing more accurate versions of TOPICS for the tsunami community. The fundamental goal is to predict accurate tsunami source features.