See link: this is somewhat oblique thrust. It is at 1.7 deg S, which is probably near the south edge of the unbroken part, and at the northern edge of the broken part from a couple weeks ago (the 7.9 and 8.4). There was a little larger aftershock about a week or so ago in this area. Good place to keep an eye on for the area from there to the equator.
Chris

• M6.4 Sumatra