9:30 AM - 9:45 AM
[HDS09-03] Numerical simulations for the 2006 and 2007 Kuril tsunamis
Keywords:tsunami
Numerical simulations for the 2006 and 2007 Kuril tsunamis
Keiji Akai and Toshitaka Baba
Tokushima Univ.
During the tsunami caused by the 2006 Kuril earthquake, the maximum amplitude arrived at the Japan coast after lifting the tsunami warning. Accurate predictions for far-field tsunamis lasting a long time are vital in lifting the tsunami warning. The 2006 Kuril earthquake was followed by an outer-rise earthquake (the 2007 Kuril earthquake) two months later. The 2007 Kuril earthquake also caused a significant tsunami. In this study, we calculated the tsunamis of the 2006 and 2007 Kuril earthquakes and compared observations by DART systems.
Fault models to calculate for the 2006 and 2007 tsunamis were based on Fujii and Satake (2008)'s models estimated by inversion analysis. For the 2006 earthquake, we used three fault models: the two models of them consisting of eight sub-faults and the other consisting of ten sub-faults. For the 2007 earthquake, we used two fault models consisting of six sub-faults. We calculated crustal displacement at the seafloor using the fault models and an analytical solution in the half-space homo-elastic medium. We applied the horizontal movement effect and the Kajiura filter to the seafloor displacement to estimate the initial sea surface displacement. The tsunami governing equations were the linear and nonlinear long-wave equations with the effects of dispersion, elastic loading, and seawater density stratification. The grid interval of the bathymetric data is 5 minutes re-sampled by GEBCO. The computed tsunami waveforms were compared at DART stations.
The numerical simulations predicted the arrival times, the amplitudes of the first waves, and the later phases with high accuracy for the 2006 tsunami. However, for the 2007 tsunami, the prediction was not as accurate as of the simulation for the 2006 tsunami. We will continue the investigations by such as changing fault models and using long calculation time.
Keiji Akai and Toshitaka Baba
Tokushima Univ.
During the tsunami caused by the 2006 Kuril earthquake, the maximum amplitude arrived at the Japan coast after lifting the tsunami warning. Accurate predictions for far-field tsunamis lasting a long time are vital in lifting the tsunami warning. The 2006 Kuril earthquake was followed by an outer-rise earthquake (the 2007 Kuril earthquake) two months later. The 2007 Kuril earthquake also caused a significant tsunami. In this study, we calculated the tsunamis of the 2006 and 2007 Kuril earthquakes and compared observations by DART systems.
Fault models to calculate for the 2006 and 2007 tsunamis were based on Fujii and Satake (2008)'s models estimated by inversion analysis. For the 2006 earthquake, we used three fault models: the two models of them consisting of eight sub-faults and the other consisting of ten sub-faults. For the 2007 earthquake, we used two fault models consisting of six sub-faults. We calculated crustal displacement at the seafloor using the fault models and an analytical solution in the half-space homo-elastic medium. We applied the horizontal movement effect and the Kajiura filter to the seafloor displacement to estimate the initial sea surface displacement. The tsunami governing equations were the linear and nonlinear long-wave equations with the effects of dispersion, elastic loading, and seawater density stratification. The grid interval of the bathymetric data is 5 minutes re-sampled by GEBCO. The computed tsunami waveforms were compared at DART stations.
The numerical simulations predicted the arrival times, the amplitudes of the first waves, and the later phases with high accuracy for the 2006 tsunami. However, for the 2007 tsunami, the prediction was not as accurate as of the simulation for the 2006 tsunami. We will continue the investigations by such as changing fault models and using long calculation time.