why do tsunamis occur in the pacific ocean
Earthquakes that generate tsunamis most often happen where Earth's tectonic plates converge, and the heavier plate dips beneath the lighter one. Part of the seafloor snaps upward as the tension is released. The entire column of seawater is pushed toward the surface, creating an enormous bulge. As the water flattens out, giant ripples race outward. Landslides, Volcanic Eruptions, Meteorites
Submarine landslides, which often occur during a large earthquake, can create a tsunami. During a submarine landslide, the equilibrium sea level is altered by sediment moving along the sea floor. Gravitational forces then propagate the tsunami given the initial perturbation of the sea level. Similarly, a violent marine volcanic eruption can create an impulsive force that displaces the water column and generates a tsunami. Above water landslides and space borne objects can disturb the water from above the surface.
The falling debris displaces the water from its equilibrium position and produces a tsunami. Unlike ocean-wide tsunamis caused by some earthquakes, tsunamis generated by non-seismic mechanisms usually dissipate quickly and rarely affect coastlines far from the source area. Come and visit the Pacific Tsunami Museum to learn more about the science of tsunamis! [ Tsunamis occur most frequently in the Pacific, particularly along the Pacific Ring of Fire. This zone is found at the northern edge of the Pacific Plate and refers to the geologically most active fields of the earth. Several times a year, strong earthquakes of at least 7 on the Richter scale result in tsunamis. Japan, for example, is hit by a tsunami at least once a year. Due to its geographical situation, it is also the country where the most casualties have been claimed in the last thousand years.
In this period, more than 160 000 people have been the victims of tsunamis. As a result, Japan has developed an effective tsunami warning system and many Japanese villages and cities protect themselves by means of gigantic dykes. Other states in the tsunami danger zones are, however, not as well equipped as Japan. In order to limit damages by tsunamis, seismographs were installed under water all over the world. The Pacific Warning Centre (PTWC) in Honolulu, Hawaii plays an important role in the analysis of the data. Originally set up for the protection of the US population, there are currently 26 member states that take part in the tsunami warning system in the Pacific, which became multinational in 1965. However, erroneous alarms can be costly if evacuations are unnecessary, and can undermine the trust that people have in the warnings. 17 July 1998: A seaquake caused a flood wave on the north coast of Papua New Guinea. 2 000 people lost their lives. 12 December 1992: A wave of 26 meters high flooded the Flores Islands and approximately 1 000 people were injured.
No deaths were reported. 2. September 1992: A flood wave of 10 metres high killed about 180 people on the Pacific coast of Nicaragua. The epicentre was 120 km off the coast. 28 March 1964: An earthquake off the coastline of Alaska caused a tsunami that claimed 122 lives on the western coast of Alaska and the USA. The damage to property amounted to about 100 million dollars. 22 May 1960: On Hawaii a whole village was evacuated in time because of the first warning system. In spite of this, 61 people were killed. In Chile, the point of origin of the tsunami, 1 000 people lost their lives through a wave of eleven metres high. 09 July 1958: Due to a landslide in Lituya Bay in Alaska, a tsunami developed that rose up to 520 metres high in the narrow fjord-like bay.
Because the region is sparsely inhabited, there were few casualties. 1. April 1946: In Alaska a flood wave washed a lighthouse into the sea and the five-man crew were swept away. After 3 700 km, the wave reached Hawaii and claimed the lives of 159 people. 02 March 1933: A 20 meter high wave that rose off the coast of Japan caused 3 000 casualties. 31 January 1906: During a flood wave that broke on the coasts of Colombia and Ecuador 500 to 1 500 people died. 15 June 1896: During religious ceremonies, tens of thousands of Japanese were surprised by a 23-meter high wave. The so-called Saraiko tsunami claimed 26 000 human lives. Read more about: - - - - Sources, follow-up links:
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