Speed of the Tsunami

The Honshu earthquake traveled about 350 mi/hr across the Pacific ocean to reach Brookings, OR.

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Earthquake time/lat/long: 

3/10/11 9:46 pm PST

38.322°N   142.369°E

Brookings, OR tsunami arrival (appx):
3/11/11 11:00 am PST
42°3′27″N   124°17′11″W

Then it's some spherical trigonometry (or you can use this handy site) to find the surface distance traveled was about 4,633 miles in 13 hrs 14 minutes.