Epicenters are in fact single point sources. That's where the rupture BEGAN...the fault slippage, however, propagated northwards from that point over 700 miles.
Thanks for the clarification..my mistake..among many..hehehe..was in conceptualizing the epicenter as the source of the tsunami..when in fact it is the entire length of the fault...But since you're obviosuly knowledgeable, I'm going to impose and ask another question..
I heard a scientist say today that when they measured a 9.0 quake..he knew it was a 1000 km fault slippage...HOw/why is the severity of the quake related so rprecisely to the length of the fault..