The NEIC page now shows a map (see link). There have been a few aftershocks posted now...they range from latitude 2.7 N to about 1 N. For a 8.7, I would expect the full rupture zone to be larger...although this is 200 km. This covers part of the area of the 1861 rupture. It will be interesting whether this one broke the full (estimated) extent of 1861. If the added stress from Dec 26 quake could make the 1861 area fail, then the one today might be able to make the next piece fail.....I think it is pretty basic/accepted that the timing of the next Great earthquake on the next part of the subduction zone had been advanced (that part has been weakened). But, no-one knows when this next part would fail...could be today, next year, in 30 years, in 100 years...although I'm not betting on 100 years.
Chris

• USGS NEIC map