I've only seen the seismicity maps, but it looks like a northward propagating rupture, which then focused strong shaking to the north, triggering more events beyond the end of the rupture into India.

The 1960 Chilean earthquake broke about 1000km of the South American coast, so this might have broken a fair fraction of that distance. The 1960 quake was an M9.5, however, so this wasn't nearly as big.