15-s half duration
Posted by John Vidale on October 12, 2005 at 17:13:01:

Is listed as part of the Harvard CMT solution. That gives roughly 30s seconds for most of the energy to be radiated, about right, maybe a little on the short side, for an M7.6 earthquake. I don't know where they are getting the 11-minute duration, maybe they are counting some of the early aftershocks.