John, The aftershock area is between south of 3 deg N and almost to 14 deg north. I guess I could plug into the distance formula that Petra linked into...but I'm lazy (she can do it?)....there are about 111 km in I deg of latitude, or longitude at the equator. 11 deg of latitude is 1221 km. But, the plate boundary is NNW-SSE, so the rupture would be even longer....maybe 1400 km. The M9.5 Chile quake was only 1000 km. To have a 1400 km (or more?) rupture and only a M9.0, the northern half must have really had small slips...see link in new thread above that the aftershocks were strike-slip and normal in the north.....Chris