What tectonic plates were involved?
The zone where the earthquake of December 26, 2004 occurred lies on the seismic boundary of three large plates of the earth’s crust: the Indian and Australian plates have been colliding with the Eurasian plate for millions of years. The northward movement of the Indian plate as it collides with the Eurasian plate is responble for the rise of the Himalayan Mountains. In addition, there is some relative motion between the Australian plate and the Indian plate in this area since the Australian plate is inferred to be rotating counterclockwise. In the region of the earthquake, the part of the Eurasian plate involved is called the Burma sub-plate. A map from the U.S. Geological survey that shows the area of the earthquake is available at http://walrus.wr.usgs.gov/tsunami/sumatraEQ/tectonic.html .
