Forecast System for Offshore Water Surface Elevation With Inundation Map Integrated for Tsunami Early Warning

Abstract

In this study, a forecast system for tsunami early warning in Taiwan is constructed by integrating the source model that generates the initial tsunami elevation based on earthquake fault parameters, the propagation model that calculates the offshore sea surface quickly by precomputed reciprocal Green's functions, and the nearshore module that interpolates the inundated distance to the shoreline based on precomputed inundation simulations. This system is integrated and executed by a Matlab graphic utility interface (GUI). In this interface system, the rupture parameters such as epicenter location, focal depth, and fault angles are used to compute the initial tsunami wave elevation. These rupture parameters can be retrieved from the website of the U.S. Geological Survey or the F-net Broadband Seismograph Network of Japan for the most updated earthquake parameters. For the highly nonlinear coastal inundation, a bell-shaped wave is used to generate the inundation map, which is then transformed into a Google Earth format and demonstrated via this geographic information system. This system has been applied in both 2010 Chilean Tsunami and 2011 Great Eastern Japan Tsunami. In both cases, the result has order-of-magnitude accuracy; thus, this system provides a quick first estimation for an early warning of a tsunami when a submarine earthquake occurs.