Tsunamis







What are tsunamis?

The word tsunami comes from the Japanese word "harbor" and "wave."A tsunami is a series of waves of extreme length that is usually caused by an earthquake, an underwater volcano, a landslide, or a meteorite. These massive waves can travel up to hundreds of miles per hour and smash into land at a height of up to 100 feet. Tsunamis are sometimes falsely referred to as "tidal waves", but this is inaccurate because tsunamis have nothing to do with the earth's tides.

Causes of Tsunamis

What causes tsunamis? Tsunamis are usually caused by earthquakes from the sea floor, and sometimes by landslides or volcanic activity on the ocean floor. On a rare occasion, tsunamis will be caused by a meteorite impact on the ocean. The Ring of Fire, a ring of volcanoes surrounding the pacific ocean, creates some of the world's deadliest tsunamis because of all of the volcanic activity occurring in the ring. Tsunamis can be caused by any movement of tectonic plates on the ocean floor.

How tsunamis form


When a force causes movement of the ocean floor, large amounts of energy is released which pushes the ocean floor up hundreds of feet, causing a very large wave. Out in open ocean, a tsunami waves often pass as ordinary waves because the wave height is short-one to two feet at the most. The wave length is greater, sometimes reaches distances of 125 miles. However, as the wave nears the shore, the wave height gets higher and higher, while the wave length gets shorter. Waves can reach heights up to hundreds of kilometers. tsunami_formation.htmtsunami_graphic.gif
















Damage cause by tsunamis
Tsunamis can cause severe damage to the land that they encounter. These natural disasters can strip beaches of their sand, rip down trees, and erode land from a coast. They can flood areas hundreds of miles inland from the area that the tsunami hit. Tsunamis can tear down houses, buildings, or other coastal structures. Debris from tsunamis are a secondary risk. The debris can knock over over other objects in the path of the tsunami.
They can destroy entire towns and leave them looking like a nuclear war zone.


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Types of tsunamis



Meteotsunamis


In many ways, meteotsunamis and regular tsunamis are similar. They create the same destruction and create tsunami-like waves. Meteotsunamis are created when there is a change in air pressure which causes large masses of water to reach shores.

Local tsunamis
Local tsunamis that occur in shorter distances. A local tsunami can occur in a few minutes, in contrast to long distance tsunamis, which take much longer.





The Ring of Fire


The ring of fire is a an area surrounding the Pacific Ocean that contain a majority of the world's volcanoes and most tsunamis. This occurs because of several different factors. The Pacific Ocean has more water than any other ocean, there are stronger tidal waves and winds, there's more earthquake activity because of the ring of fire, and the Pacific is the deepest ocean.



Ways to stay safe during a tsunami.

Before:
1. Make an emergency supply kit that will allow you to survive for three days on your own.
2. If there is a noticeable water recession at the shoreline, leave the area immediately, because that is a sign of a tsunami
3. Move inland tom higher ground and stay there.
4. Know your community's evacuation routes where shelter can be provided.
After:
1. Don't go near any flooded areas.
2. watch out for debris in the water.
3. Boil water before you drink it in case it's contaminated.
4. Stay out of buildings that water has been surrounding for awhile because the building could collapse.


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Accountable Earthquakes

2004 Indonesian Tsunami
:

On December 26, 2004, a major earthquake occured in the Indian Ocean due to subduction on the ocean floor. This created several different tsunamis. This series of tsunamis affected fourteen different counties. The earthquake had a magnitude of 9.0, which is the second biggest earthquake recorded on a seismograph. The group of tsunamis killed more than 200,000 people and the damage cost more than $7 billion (U.S. dollars).

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1960 Hawaii Tsunami
:
The largest earthquake ever recorded occurred on May 22, 1960. Countries affected were United States Hawaii),Japan, Chile, and the Philippines. In Hawaii, Hilo Bay suffered the most from the tsunami. The 35 foot wave ruined more than 500 homes and buildings and cost $75 million.














http://science.jrank.org/pages/7009/Tsunami-Types-tsunami.html
http://www.tulane.edu/~sanelson/geol204/tsunami.htm


http://www.dosomething.org/tipsandtools/how-be-prepare-and-be-safe-during-a-tsunami