At what speed was the Indian Ocean Tsunami traveling at before landfall?

Answer 1

As the first poster says, the phase-speed of the wave traveling through deep water is on the order of hundreds of miles per hour, but the actual forward motion of the water when it hits shore is much much less. This reference has a good description of how the phase speed varies as a function of water depth.

http://www.tsunami.org/summary.html

The video from Banda Aceh showed a wave front that a man could have easily outsprinted were it not for all the people screaming in terror blocking the way, and if he could have sprinted for about a mile. There are some really nice videos here of the tsunami, no, nice isn't the right word. They're not nice. I'm not sure what they are.

http://www.asiantsunamivideos.com/

(The Aceh Indonesia video about halfway down shot by the wedding photographer is the one I was talking about above.)

Answer 2

Several hundred miles per hour. Look at the arrival times at various locations and measure the distances.