While we in the other parts of the world worry and pray for the safety of family and friends living in Japan, the Japanese are have actually accepted earthquakes as part of their day to day event.
Japan sits in what is called the Pacific Ring of Fire along with other countries like the Philippines, Indonesia, Russia, United States, Chile, Mexico, and New Zealand. The Ring of Fire is that area in the world where 90% of the world's largest earthquakes and 80% of the world's biggest volcanic eruptions occur. It is where 75% of the world's active volcanoes can be found (10% of which are in Japan).
Japan's location happens to be in the area where there is much crustial instability. As many as 1,500 earthquakes are recorded yearly where magnitude 4-6 on the Richter scale a normal occurence. Minor tremors occur daily in various parts of the country. Major earthquakes happen infrequently. The Great Kanto Earthquake in 1923, where 130,000 perished, the Great Hanshin Earthquake in 1995, which claimed 6,434 lives, and the one which rocked the country yesterday measuring 8.9 on the Richter scale occured in the 20th century.
Underwater earthquakes also exposes Japan to tsunamis or tidal waves. One hundred ninety five events has been recorded over the last 1,313 years until 1997 which happens to be the most in the world---no wonder the Japanese coined the word "tsunami" roughly transalted into English as "harbor wave".
Earthquakes and tsunamis are basically a Japanese event. You'll know who is not Japanese when such event happen---they are the ones who are running around in panic. My apologies, just making light the situation worrying about friends and relatives in Japan. Praying for their safety.