Tsunami is a Japanese word used to designate a tidal wave, which literally means "wave in the port" or "in the bay" ( tsu = port or bay, nami = waves). Despite having Japanese origin, this word has gained popularity and is already used all over the world.
A tsunami is a wave of a long period of time, which travels with great speed through the ocean. When it reaches the coast, it possesses great destructive power, such is its force that it can devastate relatively large buildings, and even inland. It is among the largest natural disasters faced by countries with coasts.
Tsunamis have traditionally been associated with earthquakes, but they can also be produced by volcanic eruptions, meteorites, or any alteration that occurs on the ground due to underwater landslides, landslides, etc. Most of the tsunami phenomena are due to earthquakes, accompanied by various characteristics such as a magnitude greater than 6 and the depth of the hypocenter reduced (up to 40 km).
In deep waters, more than 200 m, a tsunami is barely noticeable on the sea surface, generating a wave 1 m high. However, this wave travels at a speed of 500-1000 km / h, and at a higher speed the greater the depth of the sea. As it approaches the coast, its height increases (more than 15 m), when it reaches it, the tsunami may not break and behaves like a large sudden tide, forming several waves that break or form a wall of turbulent water.
The damage caused by a tsunami will depend on the depth of the sea, distance to the seabed, shape of the fault, the typology of the coast and the existing vegetation. As well as the vulnerability of the population, which is located a few meters from the coast, in low-lying areas, with weak buildings, and the lack of a tsunami detection system and warnings to the population.
Tsunamis are rare and difficult to predict. Although the existence of a large underwater earthquake can be detected with the help of seismographs, it is difficult to predict whether or not the earthquake will generate a tsunami, since other factors, such as the topography of the seabed, are involved in this process.
In this XXI century, there are already three tsunamis that have occurred, surely they will not be the last. In 2004, a tsunami in the Indian Ocean devastated Thailand, Sumatra, Indonesia and other regions of Asia, causing a death toll of 226,000. Last year a strong tsunami hit the coasts of Chile as a result of an 8.8 earthquake on the coast off the town of Cobquecura.
And the most recent occurred in March of this month in Japan, an earthquake of magnitude 9.0, caused a tsunami on the Pacific coast of the Japanese country, for now there are more than 11,000 dead, and more than 16,000 people are still missing. The tsunami hit the coasts of Hawaii and the entire South American coast with minimal damage thanks to early warning systems led by the Pacific Tsunami Warning Center.
