Numerical modelling of the 2004 Indonesian tsunami: methodology and results
Florent Lyard(1) , Olivia Fachan(1) , and Yves Menard(1)
14 avenue Edouard Belin,
The Indonesian tsunami has been triggered by the vertical deformation of the ocean bottom due to the earthquake. The modelling of the tsunami wave generation, propagation and dissipation is a challenging task as the dynamic of the tsunami wave is highly complex, and the realistic numerical modelling of such phenomenon would require huge computer power. Nevertheless, it can be seen, at least at the first order, as a gravity wave problem by many aspects, especially for the wave propagation, and thus be partially treated using a barotropic model with the adequate grid resolution. Such an approach has been carried out at LEGOS, using mog2D model and thus the finite element variable resolution capabilities. Sensitivity on the initial conditions, hence the realistic knowledge of the ocean bottom deformation in terms of location, amplitude and timing, was found to be determinant for the simulation accuracy when comparing to existing observations like altimetry and arrival time along the Indian oceans coastlines. Methodology and results of the simulations are discussed, as well as the need for further improvements.