Extreme tsunami runup simulation at Babi Island due to 1992 Flores tsunami and Okushiri due to 1993 Hokkido tsunami

Abstract

This study is based on a series of three dimensional numerical modeling experiments to understand the tsunamirun-up and inundation process at the circular shape Babi Island in the Indonesia caused by 1992 Flores earthquaketsunami and at Monai valley in Okushiri Island, west part of East (Japan) Sea caused by the 1993 Hokkaido Nansei-Oki earthquake. The wave field in the coastal area is modeled within the framework of fully nonlinear dispersiveReynolds-averaged Navier&#8211 Stokes (RANS) equations solved using the FLOW3D code. Boundary conditions forthis model were extracted from computed wave characteristics obtained from the 2D tsunami propagation modelbased on the shallow water equations. This model has shown it effectivity to explain extreme runup characteristicsduring the 2004 Indian Ocean tsunami and 2011 Japan tsunami (Kim et al, 2013). In case of the 1992 Flores Islandtsunami the results of numerical simulation run-up results are compared with field measured run-up heights. Ithas good agreement with measurement and computational run-up heights. The particle velocity distribution is alsocomputed. In the case of 1993 Okushiri tsunami the numerical simulation reproduces extreme run-up at the Monaivalley (31.7 m). Monai valley in Okushiri Island, west part of East (Japan) Sea caused by the 1993 Hokkaido Nansei-Oki earthquake. The wave field in the coastal area is modeled within the framework of fully nonlinear dispersiveReynolds-averaged Navier&#8211 Stokes (RANS) equations solved using the FLOW3D code. Boundary conditions forthis model were extracted from computed wave characteristics obtained from the 2D tsunami propagation modelbased on the shallow water equations. This model has shown it effectivity to explain extreme runup characteristicsduring the 2004 Indian Ocean tsunami and 2011 Japan tsunami (Kim et al, 2013). In case of the 1992 Flores Islandtsunami the results of numerical simulation run-up results are compared with field measured run-up heights. Ithas good agreement with measurement and computational run-up heights. The particle velocity distribution is alsocomputed. In the case of 1993 Okushiri tsunami the numerical simulation reproduces extreme run-up at the Monaivalley (31.7 m).