Sumatra earthquake
The earthquake was the result of thrust faulting at the Sunda Trench. A rupture length of approximately (and an unusually low rupture velocity of per second) resulted in a duration of about 185 seconds (just over three minutes) for the event. The shock was centered from the trench, and about from the south coast of the island. A comparison was made with the earlier 2002 Sumatra earthquake, a M7.5 submarine earthquake of a similar size that also occurred along the Sunda Arc and at a shallow depth, but one that did not result in a tsunami.