Rapid forecast of tsunami wave heights from a database of pre-computed simulations, and application during the 2011 Tohoku tsunami in French Polynesia

We present a method for the rapid estimation of tsunami wave heights, either in the deep Pacific Basin, or at specific shore locations. It uses a database of 260 pre-computed scenarios of generic sources distributed along the Pacific trenches, and can provide an estimate of wave heights within minutes of the location of the earthquake and the estimation of its moment. The method is tested against a set of DART data, and of 51 maregraph records in Tahiti and the Marquesas Islands. It was used in real time to successfully predict tsunami amplitudes in Polynesia during the 2011 Tohoku alert.