Tsunamis
The coasts of Japan, Chile and Hawaii are more often than others beset by tsunamis, a kind of waves (nami) that have wreaked havoc in Japanese harbors (tsu) for as long as can be remembered, crushing ships by the thousands. A 100 m high tsunami wave with a few following waves killed 15,000 people in and around Shimabara Bay in southern Japan in 1792. It was caused by a landslide, but a more common cause is an earthquake in the ocean floor, like on the summer evening in 1896 when the Meji Tsunami killed more than 26,000 people and destroyed 9300 houses and 6900 boats on the eastern coast of Honshu. Japan established the world’s first tsunami warning system in 1941, and today there are six centers that can issue local tsunami warnings—faster than anyone else in the world.
It is common knowledge in Japan that a tsunami rarely is just a single wave, but rather a series of less than ten waves. Nine out of ten tsunamis reach the shore with the wave trough before the first wave crest. If the sea suddenly recedes from the beach, one must leave immediately and head for higher ground, preferably a point 50 m above sea level. It is also well known to the Japanese that the third wave may well be the highest, that the time between the waves is 10–30 minutes—and that the waves together form the tsunami.
The Chilean coast can be struck by tsunamis caused by local seaquakes, but also by tsunamis from the other side of the Pacific, originating outside Alaska, the Aleutian Islands, the Kuril Islands, Kamchatka, Japan, the Philippines, Indonesia, and the Hawaiian Islands. Chile has a good tsunami warning system, part of the coordinated system for the Pacific Ocean that has its center in Honolulu. Like Japanese children, Chilean children are taught what a tsunami is and what they should do if they see the signs. Every child in the world should know this!
The Hawaiian Islands are often struck by tsunamis caused by seaquakes and submarine mass movements outside its own coasts, but it is also vulnerable to tsunamis generated anywhere along the volcano-dense coasts of the Pacific, known as the ”Ring of Fire”. The Hawaiian language even has two words for tsunami, one for the incoming wave and another for the phase when the water returns to the sea. The world’s only tsunami museum can be found in Hilo, which has been struck by tsunamis several times, most recently in 1946, 1957 and 1960. All tourists that want to learn something important should visit this valuable and well-kept museum.
Unfortunately noone around the Indian Ocean has understood the importance of creating a tsunami museum to preserve and make use of the knowledge that will be available for only a short time after the 2004 tsunami disaster in the Indian Ocean. Governments across the world should also realize that school education about natural hazards is essential in a time when more and more people are travelling further abroad. This cannot be left to the individual traveller.
The tsunami warning system in the Pacific Ocean is fast and reliable—especially in Japan—and tourists must always take warnings seriously. If ships in port have time to head to deeper water, they should, but always follow the instructions given on the radio. If you want information about tsunami risk on a specific coast, consult us. Our TRITON database has information on all known tsunamis, and we have extensive experience of educating rescue staff.