About 20% of earthquakes of magnitude 6 or larger recorded in the world occurred in Japan, where there are about 2,000 active faults and 110 active volcanoes. Since ancient times, one of the essential roles of a country is to protect its people from natural disasters, such as the flooding of large rivers. It is also extremely important these days to protect the people of Japan from disasters. We should learn as much as possible from the tragic experience of the Great East Japan Earthquake in order to be prepared for any catastrophic disaster that may occur in the near future.