This shows the magnitude 7.3 Japan quake — and how its energy rumbled right under Mt. Hood on December 7, 2012.
The quake generated just a small tsunami of 1-3 feet. Much smaller than the monster waves created by the 9.0 mega quake in March 2011.
And while cruising twitter for more info on the quake, I can across this tweet. I suggest clicking the link & reading the blogpost. Very, very interesting about Japan, quakes and an early warning system.
Countdown to disaster: predicting earthquakes in the age of Twitter http://t.co/NdQTD2Qh #earthquake