Short-Term Inundation Forecasting for Tsunamis

Abstract

Since 1997, PMEL has been involved in the R&D effort to provide tsunami-forecasting capabilities for the Pacific Disaster Center (PDC) in Hawaii. As a part of this effort, modeling tools for the short-term forecasting and assessing the risk of tsunami inundation have been developed. The Short-term Inundation Forecasting for Tsunamis (SIFT) will involve gathering information from several observation system - seismic network, Deep-ocean Assessment and Reporting of Tsunamis (DART) and coastal tide-gages-, "sifting" through the information that will be used for tsunami modeling and, finally, provide inundation forecast for selected communities based on simulation results. The modeling part of the SIFT project will employ a two-step procedure. The first step will estimate the offshore wave heights using a database of the pre-computed tsunami propagation runs. This phase will utilize linearity of the tsunami propagation to construct a solution that matches observations for a particular event. This offshore forecasting methodology has been implemented for the PDC [1] to predict tsunami amplitudes in deep ocean for tsunamis originated in Alaska. The second step of the tsunami forecasting procedure will include model estimates of tsunami inundation for specified coastal sites. The inundation modeling will use the offshore estimates from the first step as input to obtain amplitude and current velocity estimates of tsunami inundation for selected sites.