 The 2004 M9.15 Sumatra–Andaman, the 2005 M8.7 Nias–Simeulue, and the 2007 M8.4 Mentawai earthquakes produced the largest release of elastic strain energy since the 1957/1964 series of shocks on the Aleutian/Alaska Trench.The southeastern (Java) portion of the Sunda Trench extends from the Sunda Strait in the west to Bali Basin in the east.The convergence of relatively old oceanic crust is occurring at a rate of per year in the west portion and per year in the east, and the dip of the Benioff Zone (the angle of the zone of seismicity that defines the down-going slab at a convergent boundary) is around 50° and extends to a depth of approximately .