28 March 2005, Mw 8.5, Northern Sumatra

An earthquake occuring off the coast of Sumatra, Indonesia with an epicenter at 2.1°N and 97° E, was the largest earthquake recorded in 2005. It occured on 28 March, 2005, 3 months after the massive 26 December 2004 earthquake, and was measured with a Moment Magnitude (Mw) of 8.7 (HRV) (Figure 1). The earth- quake occured 187 km distance from the 26 December 2004 Earthquake in an area to the south, which had previously ruptured in 1861. (Figure 2). Because the rupture area was much smaller, 300 km as compared to 1200 km for the 26 December earthquake, and the epicenter was situated between the main island of Sumatra and smaller outlying islands, this earthquake did not generate a destructive basin wide tsunami.