Update: Amazing video here: http://www.youtube.com/watch?v=j3fUqdGXLbM

The strongest earthquake ever recorded in Japan struck at 0546 GMT Friday. It was 3:46 PM on a Friday afternoon and a massive tsunami struck minutes later. The damage you can see on TV (The BBC coverage is exc. as usual) but here is a little science behind why it happened.

Seismogram in Alaska records massive shake. It literally range the Earth like a bell. Click image for larger size.

Japan sits on top of three of the Earths Tectonic plates. Mount Fuji is were they meet. The large Pacific Plate is subducting under the Filipino and Eurasian plates. The image below has been annotated by me and is from a geology text book I have.

Where the quake hit in relation to the tectonic plates around Japan.

There is an excellent site at Penn State University, that explains how these large plates cause earthquakes and Tsunamis. Click the image below to learn more.

Click image to learn more.

Check out the other blogs on the AGU Blogosphere for more of the science behind this disaster. Geologist Callan Bentley on Mountain Beltway will certainly have info early Friday. Dave Petley in the UK already has info up on The Landslide Blog.