Project SIFT (Short-term Inundation Forecasting for Tsunamis)

PMEL's Project SIFT conducts research and development to provide the Pacific Dis- aster Center (PDC) and NOAA's Tsunami Warning Centers with forecast guidance tools during an actual tsumami event. The Method Of Splitting Tsunami (MOST) model is being used to create a forecast database of pre-computed generation/propagation and inundation scenarios, which will be combined with real-time data to optimize the final, site-specific forecast. The current effort concentrates on forecasting the inundation of Hilo and Kahului, Hawaii by tsunamis generated by earthquakes in the Alaska Aleutian Seismic Zone. The initial real-time data stream to be assimilated consists of seismic information and tsunami measurements acquired by Deep-ocean Assessment and Reporting of Tsunamis (DART) systems. First, offshore wave parameters will be estimated by ex- ploiting the linearity of tsunami generation/propagation scenarios to construct a composite solution that best matches the available seismic and DART data (Titov and Gonzalez, 1999). These offshore estimates are then combined with the site-specific inundation scenarios to construct an inundation forecast for that particular location. An overview of the implementation and testing of this method- ology for the Hawaii sites will be presented. Future plans include the assimilation of coastal tide gage data and an extension of coverage to West Coast, Alaska, Hawaii, and other Pacific island communities at risk. 1. The Need for SIFT Emergency managers and other officials are in urgent need of operational tools that will provide short-term inundation forecasting for tsunamis (SIFT) as guidance for rapid, critical decisions in which lives and property are at stake. These decision-makers must issue warnings, direct vessels to put to sea, order the evacuation of coastal communities, send search-and-rescue teams into the disaster area, and sound an "all clear" that officially declares to citizens and vessel operators that it is safe to return to homes, businesses, coastal ports, and harbors. Because such decisions must be made throughout the life of the emergency, forecasts must be constantly updated to assess the current hazard and provide continual guidance during the entire duration of the event.