Japan is located in the Pacific Ring of Fire, an area known for tectonic activity. In the next five years, however, earthquakes will be even more frequent and severe. This is due to aftershock and aftershock of aftershock. Basically, the Pacific Plate and the Phillipine Sea Plate have slid under the landward plate that includes Japan, experts tell Daily Yomiuri. Prof. Koshun Yamaoka of Nagoya University says magnitude-7 quakes are likely to occur once or twice in the next month. "After that, they can be expected to happen once in two months. The occurrence of such huge earthquakes will gradually decrease to once in a half year. But the possibility remains that a magnitude-8 earthquake could happen at any time." This warning has been echoed by Japan's Metrological Agency. Since the March 11 earthquake there have been at least 430 perciptible earthquakes in Japan. http://www.businessinsider.com/japan-aftershock-2011-4
Yes the ring of fire is always active at some point of its vast perimeter. Rumor has it LA is in for a big quake pretty soon.
The Earth/land in the high risk Earthquake zone had to crack or move some day. 100,000+ years is more than enough support provided by the Japan land. In has been proven by Science that massive land mass break and move away. If I am correct millions or billions of years ago there was only one world land (Asia, Africa, America etc). Later they broke away into many continents. Earth land changes and many lands disappear. Earlier where there was land, now there is sea and where there was sea now there is land. Japan knows that their land is high-risk Earthquake zone. Why did Japan establish one of the biggest countries in high risk earthquake zone? Are they trying to defeat/conquer Mother Nature? My final warning to good Japanese people. Abandon/leave Japan.
Obviously, Japanese have lived on the land for several thousand years. But this is a very bad earthquake period they have to cope with.
I was waiting watching the weather channel waiting for my local forecast, and some quake experts were pointing out that CA is 40 years overdue for a big one. They were using statistics and probability from historical "big ones" CA quakes from the past to base their projection. I hope this doesn't happen anytime soon as it would be the final straw for the financially weak California...