Summary:
An overview of tsunamis, caused by the displacement of the ocean floor or a disruption of a body of standing water. While tsunamis are most noticeably caused by earthquakes, they are also caused by underwater landslides, volcanic eruptions, meteorite impacts, underwater explosives, and many other disturbances to the earth's crust that happens underwater.
Imagine that you were sitting on a beach then suddenly you see water rushing at you at up to nine hundred and fifty kilometers per hour. You try to escape but this large wave strikes so fast without warning that you can't escape. This large wave is called a tsunami. The word tsunami comes from the Japanese words that mean "harbor wave."
A tsunami is a large under water wave caused by the displacement of the ocean floor or a disruption of a body of standing water. Tsunamis can be caused by earthquakes, under water landslides, volcanic eruptions, meteorite impacts, under water explosives, and many other disturbances to the earth's crust that happens under water. They are often most deadly when they are caused by earthquakes. Although tsunamis can be caused by many disruptions to the earths crust they are often caused by earthquakes. In order for an earthquake to cause a tsunami it has to measure up to at least a seven point five on the Richter scale.
All waves, including tsunamis, have a wavelength, a wave height, an amplitude, a wave velocity, and a wave frequency or period. The wavelength is the distance between two identical points. Regular waves have a wavelength of about one hundred kilometers to two hundred kilometers. Tsunamis, because they are larger, have wavelengths of two hundred kilometers to above five hundred kilometers.
The height of a wave or the wave height refers to the distances between the crest or peak of the wave and the trough of the wave. The height of the wave depends on the depth of the water in which the wave was formed. The amplitude of a wave refers to the height of the wave above the still water line. The wave amplitude is equal to one half of the wave height. The wave amplitude also depends on the depth of the water that the wave was formed in.
The wave frequency or period is the amount of time that it takes for one full wavelength to pass or cross a set stationary point. Regular waves have frequencies of five to twenty seconds. A tsunami on the other hand has frequencies from ten minutes to two hours.
The final characteristic of a wave is the wave velocity. The wave velocity is how fast the wave is going or the speed of the wave. The wave velocities of normal waves are about ninety kilometers per hour. The velocities of tsunamis can be up to nine hundred and fifty kilometers per hour. That is about the same speed that jet airplanes fly. The velocity of a wave equals the wave height divide by the wave period or V=L/D.
Since tsunamis are under water waves they usually rise only a few meters above the still water line in the deep ocean. It may not sound deadly but they are. Tsunamis are characterized as shallow water waves. This means that the closer they get to land or shallow water the larger the wave gets. As tsunamis approach shallow water they can rise up fifteen to forty meters high.
Not only are tsunamis large and fast but they can travel long distances. An average tsunami can travel ten thousand miles at the speed of nine hundred and fifty kilometers per hour without slowing down. This trait makes tsunamis even more deadly. Because of their speed and the long distances they can travel while maintaining their speed tsunamis are able to cross the Pacific Ocean in one day. This makes it very difficult for civilians in the Pacific to avoid tsunamis.
In many places such as Hawaii, Thailand, Alaska, South America, and many countries in Asia tsunamis are highly unavoidable. They strike so sudden that many can't escape. When tsunamis hit property and building structures are usually more devastating than the actual lose of life. In 1952 an earthquake that measured an eight point two on the Richter scale caused a tsunami that hit the Kamchatka peninsula in Russia. Luckily, for the people who live in Kamchatka no lives were lost. Unfortunately, the tsunami caused eight hundred thousand dollars in damage to their peninsula and raised a high panic for basic necessities such as food, clothing, and shelter.
In 1946 a very large earthquake hit the Aleutian Island of Alaska. This large earthquake generated a very deadly tsunami. This tsunami reached the Hawaiian Islands about four thousand miles away form the epicenter of the earthquake in almost five hours, this large deadly under water wave killed one hundred and fifty nine people. After this devastating event the people of the Pacific created a tsunami warning system. The system was a number of stationeries that was put up to measure wave frequency. An alarm would sound if a wave frequency was longer that the average five to twenty seconds.
In conclusion, tsunamis can be very dangerous and deadly. Since people can't usually detect tsunamis because they are under water waves that make them even more difficult to escape. Tsunamis can damage a lot of property and usually leave a panic for the human basic necessities. They are nothing to be taking lightly.
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