Wow, the original 'checkmark' is filling in an a new tail is growing inline with the old one. That means there is a prominent weakness parallel to the main graben. These things always have multiple walls.
Probably means the thrust portion could not grow much past the injection point, which is a good thing. The lower tail is penetrating the footwall, and I can't see it going that far. The strike-slip earthquakes are normally split at the thrust fault so I can't see it ripping all the way with an M6. However, we are well set now for an M5. We really need fault plane solutions here!
Like I said facetiously earlier, another injection point along the thrust line could really give us something!! :)