As a Japanese word, tsunami, can be seen in English dictionaries, the disaster has tortured Japan for many times. Of course this is not a particular phenomenon only in Japan. But it’s easily supposed that the tsunami risk is much higher as an island country facing the Pacific ocean.

Tsunami is a natural disaster mostly caused by the earthquakes afterward on the ocean floors. Tidal waves are brought about by the slides of the bottom soils resulting from quake jolts. Even though it's a small one shaking the ocean floors, it sometimes causes a big tsunami. It's seemingly because a little shaking makes successive slides of the faults on the bottom of the sea. Therefore, small waves amplify big tsunami.

There have been four quake-related major disasters involving over 10,000 deaths in the past. Among them, three were caused by tsunami. They occurred in 1498(41,000 deaths), in 1707(20,000 deaths), and then in 1896(26,360 dead). In terms of the number of causalities, it’s the most destructive disaster. In the past decade, the tsunami that happened in Hokkaido in 1993 was one of the biggest. The tidal waves assaulted on a small island in the southwest of Hokkaido, bringing about as high waves as ten meters. The first tidal wave came up to the island five minutes after an earthquake. And then twelve minutes after the first one, the second tsunami destroyed or washed away almost two-third of houses built on the coast of the island.

Tsunami comes up to the land by not only the earthquakes nearby coasts, but also the earthquakes that occurred in remote places. In the case of 1960, for example, a big tsunami rushed for Japan from off the coast of Chile where a sea earthquake happened. The foreign-made tidal waves came up to Japan, taking 22 hours. It killed more than one hundred Japanese living along the Pacific Ocean. As you can easily find how fast the waves came if you calculate it with the time and distance, amazingly the speed crossing the immense Pacific Ocean was nearly like a jet plane. Here is a question that what was going on with ships or tankers floating on the sea during the tsunami was swimming at that time. I don’t know, however, we should not make light of even earthquake overseas from the lesson although the risk is very small.

In Japan, the information system on tsunami is much advanced because of the experiences. No matter how small earthquakes are, there are warnings mainly through TV saying ” No worries about tsunami in this quake(if there is no risk of it) ”. Even though you don’t understand Japanese, you can see the warnings if you carefully watch the TV. But, If you live near coasts and feel some shakings, I’m not sure which is quicker, the coming of tsunami or the screen appearance of the warning.