Tsunami or tidal wave is a giant wave series, which are formed mainly through seismic tremors. Tsunamis have an enormous destructive power, as they gain a lot of strength when they reach coastal regions, forming waves over 30 meters high.
Etymologically, tsunami is a term of Japanese origin, where tsu means "port", and nami "wave", therefore "port wave". Tsunamis form when shocks occur at the bottom of the sea or near the ocean, and end up causing a great disturbance in the water.
Tsunami waves travel along the ocean, and on the high seas they are practically imperceptible, however when they break. approach the earth, cause friction with the bottom, causing the wave size to increase a lot and destroy everything that is around. Tsunami can also be caused by volcanic activity on land, but generally have less power than those from the sea.
It is very difficult to predict when tsunamis might occur. Some countries, with higher incidences and risks of being hit by giant waves, have an alert center, but it is not always possible to be sure.
Countries located in coastal regions, such as the Philippines, Indonesia, Japan, Fiji, the United States, and Hawaii, have a history of episodes involving large tsunamis. To facilitate prediction, it is possible to use underwater sensors, radio and satellite telemetry and other instruments that try to measure the behavior of waves and their size.
Usually, about ten minutes before a tsunami hits the coast, the sea recedes, and depending on whether it's too much or too little, it's about the power of the waves to come. Initially the waves are long and low, hardly bigger than 0.3 to 0.6 meters, and their energy can decrease or even disappear as they travel thousands of kilometers.
Tsunamis have already claimed hundreds of victims around the world, devastated entire cities and even with technology, no country is 100% prepared to help the population when the phenomenon occurs.
See also the meaning of Earthquake.
