Tsunami propagation of the 2004 Sumatra earthquake and the fractal analysis of the aftershock activity

The 26 December 2004, earthquake of magnitude Mw similar to 9.3 had generated large tsunami waves that traveled large distances lying along the rim of the Indian Ocean, Bay of Bengal and Arabian Sea and as far as the west coast of Americas causing large scale devastation. The seismicity pattern of the fault zone has been modeled by several authors, and it is seen that the fault rupture can be divided into three segments. The aftershock sequences have been analyzed, using the fractal approach, for three segments independently. The first segment of 500 km long is the zone of the fastest rupture and has the largest fractal dimension of about 2.10 implying that the fault rupture is two dimensional. This region has a lower b value indicative of high stress regime. In this paper the fastest rupture zone has been considered for the generation and propagation of the tsunami waves. The tsunami wave propagation has been modeled using the nonlinear form of long wave equations. The governing equations are expressed as the partial differential equations which have been solved numerically using the finite differences and the tsunami wave heights have been computed at two Gauge locations i.e at Chennai and Visakhapatnam. The wave heights at Chennai and Visakhapatnam have been compared with the tidal data observed at two of these locations. Results show that the arrival times and the magnitude of the wave heights are seen to be in agreement.