The recent Japanese Sendai earthquake was massive at 9.0 which means it is approximately 10 times as strong as an 8.0. Earthquakes of this magnitude are rare, the Sendai being one of the strongest recorded. This tsunami apparently had some extremely tall wave heights; I’ve read some reports of 112’, a local event due to the ocean’s bottom topography. Though I’ve not been able to determine the ‘thickness’ of the wave, I have read reports that it was moving around 600 mph which would be a period of 200 seconds. So it would have been a very thick wave, probably greater than 1 kilomater! I offer the following small collection of videos for your education; the power of the tsunami over the ground is largely due to the crest’s thickness.
Wave's Height Over Houses Seen From Ground Level
Flowing Far InlandBefore and After Photos Tom Bergh MIKCo Ocean School Peaks Island, ME