Excitation Process of the 2004 Indian Ocean Tsunami Determined from Seismic Fault Rupture
Hiroyuki Matsumoto*, Hitoshi Mikada**, and Masanori Suzuki**
*Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka 237-0061, Japan
**Department of Civil and Earth Resources Engineering, Kyoto University, Kyoto-Daigaku-Katsura, Saikyo-ku, Kyoto 615-8540, Japan
We simulated the tsunami that had took place after the 2004 Sumatra-Andaman earthquake for two fault models – one from teleseismic body wave inversion and the other from tsunami data. After including the dynamic behavior of the seafloor by fault rupture propagation in the tsunami excitation process in detail, we found the difference in tsunami wave heights from the two fault models, in particular due to the difference in slip distribution. We then estimated the effects of the dynamic behavior due to fault rupture propagation, changing the initial conditions of tsunami simulation. Although the effects of dynamic contribution due to seismic fault rupture on tsunami propagating across the Indian Ocean were found to be negligible, the effect of seismic fault rupture propagation contributes to the arrival time of the tsunami because of the huge size of the seismic fault plane. A fault model based on seismic data, however, still cannot explain the tsunami captured by the satellite.