For a small indication of what the people in Japan have been enduring, take a gander at this chart of global seismic activity from the U.S. Geological Service. You can find the 9.0 quake that rocked the nation on March 11 at 05:46.
Fear and Trembling
The latest from america
call it brave, call it saintly, call it love
I could never make a meal of skate again
remembering you, brave wingless thing.
Discerning through troubled times
With his new encyclical, Pope Francis added his voice to this chorus of encouragement inviting people not to lose heart.
And from the list on the linked page there seems to be a constant movement of the plates in the area of the original quake and a couple dozen or more of 6.0 quakes which were the size of the Christchurch quake since the 9.0 quake off the coast of Honshu. My guess is that we will learn a lot more about the effects of earthquakes and the potential damage depending upon the distance from the epi-center.
http://www.abc.net.au/news/events/japan-quake-2011/beforeafter.htm