Shokin Y.   Beisel S.   Rychkov A.D.   Khakimzyanov G.S.   Chubarov L.  

The study of tsunami runup on the east coast of Japan by numerical simulation

Reporter: Chubarov L.

The report presents the results of the assessment of tsunami runup on the east coast of Japan, according to the five historical events. These estimates are based on the results of numerical modeling of all stages of the evolution of tsunami waves: from its generation in the areas of tsunamigenic earthquakes to the runup on the shore. Models of earthquakes are based on the dislocation model of Podiapolsky-Gusiakov-Okada. The processes of waves propagation over the ocean and runup on the shore are modeled within the framework of the shallow water equations. Particular attention is paid to the methods of definition of the flooding zone boundaries, which were calculated using different approaches. Among them, along with a direct two-dimensional modeling, an integrated approach was used in which the results of the two-dimensional modeling of wave propagation at control gauges located at a given depth, are used as boundary conditions for the one-dimensional simulations of runup along pre-selected cross-sections. The different ways of defining the boundary conditions at the moving line's edge are also considered – from the use of special analytical relations to techniques of through computation, without isolating the shoreline. In the calculations, the numerical algorithms were used that are based on the finite-difference approach, as well as algorithms of large-particle method. Some of the calculations were carried out using adaptive curvilinear grids. The results are compared with the known data of field observations, their dependence is defined on the accuracy of the used bathymetry and topography, on the friction magnitude, and on the methods of the boundary conditions definition.

This study was supported by the Program of Integration Research, Siberian Branch of RAS (grants 37B and 117A), the Russian Foundation for Basic Research (grant 12-05-00894) and by the Grant Council of the President of Russian Federation for state support of leading scientific schools of RF (project NSh-6293.2012.9).