The main objective is to provide an estimate of wave arrival time, wave height and inundation area immediately after a tsunami event
Tsunami forecast models are run in real time while a tsunami is propagating in the open ocean; consequently they are designed to perform under very stringent time limitations.
Given the time constraints of this type of study, the process of computing the three stages namely, wave generation, propagation and inundation has been expedited by generating a database of pre-computed scenarios. The pre-computed database contains information about tsunami propagation in the open ocean from a multitude of potential sources. When a tsunami event occurs, an initial source is selected from the pre-computed database. In the initial stages of the tsunami, this selection is based only on the available seismic information for the earthquake event. As the wave propagates across the ocean and successively reaches the DART (The Deep-ocean Assessment and Reporting of Tsunamis) systems these report the recorded sea level information back to the TWCs which, in turn, process the information and produce a new and more refined estimate of the tsunami source. The result is an increasingly accurate forecast of the tsunami that can be used to issue, watches, warnings or evacuations.
When an event similar to one of the pre-computed scenarios occurs, the available propagation information is used to compute the last stage of the study, wave inundation.
Inundation studies can be conducted taking a probabilistic approach in which multiple tsunami scenarios are considered, and an assessment of the vulnerability of the coast to tsunami hazard is evaluated, or they may focus on the effect of a particular ‘worst case scenario” and assess the impact of such a particularly high impact event on the areas under investigation.
The results of a tsunami inundation study should include information about the maximum wave height and maximum current speed as a function of location, maximum inundation line, as well as time series of wave height at different locations indicating wave arrival time. This information can be used by emergency managers and urban planners primarily to establish evacuation routes and location of vital infrastructure.