This is a very active tectonic zone, and earthquakes are common.
The aftershock zone will most likely extend for the length of the rift. We are looking at a couple hundred km of length. This is a 'clearing earthquake' and is probably the maximum size for the area. When they get around to measuring, the rift will have widened.
The problem for rescue right now is that we have Siberian air pouring down on the place. It is mountainous with probably 10 foot snow.
ps. two earthquakes - one side dropping, and then the other.
pps. aftershocks show the size of the fault