File:TsunamiSimFig98.png

A snapshot from a simulation of the Indian Ocean tsunami that occurred on 26th December 2004 resulting from a magnitude 9.3 earthquake off the west coast of Sumatra. The non-circular wave-fronts are clearly visible, which indicates curved rays.

The simulation was performed in Matlab using a 2D, 3rd Order WENO scheme, and covers approximately the area on the globe between points:

• Lat\[27^o\] N - Lon\[72^o\] E (UTM: X = 2989976.0, Y = 202273.4) Region 43R,

• Lat\[5^o\] S - Lon\[104^o\] E (UTM: X = 9447251.0, Y = 389140.1) Region 48M.

The spatial domain (approx. 3500x3500 km) was divided into 500x500 rectangular cells. The model was based upon the linearized shallow water equations with land topographic and sea bathymetric data obtained from the NDGC website. Wave speeds were calculated for each cell based on the celerity relationship \(\sqrt{gh}\). Coriolis effects were included.

The earthquake was due to a 1200km long subduction rupture zone at around 5100m depth in the deepest part of the Java Trench. The subduction consisted of four segments, of lengths 220km, 410km, 300km and 350km respectively. The segments were modelled using physical data as reported by Watts, et al, 2005.

References

Watts, P., M. Ioualalen, S. Grilli, F. Shi and J. T. Kirby, (2005). Numerical Simulation of the December 26, 2004 Indian Ocean Tsunami using a High-order Broussineq Model. Ocean Waves Measurement and Analysis, Fifth International Symposium WAVES 2005, 3-7, July, 2005. Madrid, Spain.