Japan is well prepared for earthquakes and small tsunamis. They routinely get hit with them a few times a year.
Just two days before the 9.0 they were hit with a 7.2 on March 9th with minimal damage. There was no media attention given to it, nor is there rarely ever (that is until now, after the biggest quake in recorded Japanese history hit).
It gives you an idea just how big that March 11th quake was though. Each point measures an amplitude 10 times larger, so an 8.0 is 10 times more destructive than a 7.0 and a 9.0 would be 10 times more destructive than a 8.0.
It also goes to show you can NEVER be prepared for when mother nature deals a blow like that. Japan is way more prepared than any other country for earthquakes and tsunamis, yet they were left in ruins after the March 11th quake.
