Here's some doom for you:

[link to www3.nhk.or.jp]

Apparently since this would be 32 times the strength of a magnitude 9, the shaking could continue for up to an hour and tsunamis would continue for days. Japan would most likely be underwater and there would be no way to save the melted fuel pool at reactor 4 and other reactor's elsewhere which would be at threat. This would be the end of the world...