Near-field tsunami inundation forecast method assimilating ocean bottom pressure data: A synthetic test for the 2011 Tohoku-oki tsunami

Abstract

An approach for forecasting near-field tsunami inundation was developed by combining two methods. The first method computes tsunami by assimilating pressure data observed at numerous ocean bottom sensors without tsunami source information, and the second method forecasts near-field tsunami inundation by selecting a site-specific scenario from a precomputed tsunami inundation database. In order to evaluate the validity of this combined method, we performed a synthetic forecast test for the 2011 Tohoku-oki tsunami along the Pacific coast in Japan. A tsunami computation test performed using the assimilation of synthetic pressure data reveals that the method reproduced well the tsunami field for the 2011 Tohoku-oki tsunami. A synthetic near-field tsunami inundation forecast at four sites, Kamaishi, Rikuzentakata, Minamisanriku, and the Sendai Plain for the 2011 Tohoku-oki tsunami also worked. The results indicate that an accurate tsunami inundation forecast method by this combined approach using pressure data from numerous ocean bottom sensors is now available.