TSUNAMI

--->A tsunami (pronounced soo-nah-mee) is a series of waves that is very long and occurs over a long period of time.

--->Tsunami are often caused by earthquakes orunder water landslides. The word ‘tsunami’ is a Japaneseword that means ‘harbour wave’.

--->A tsunami can travel great distances - 17,000km or more - a tsunami can be more than 100km in length. It can also travel very fast, atabout 400 km an hour in some cases.

--->Everything about the tsunami is big, fast andwide. Tsunami are not normal waves and are not tidalwaves either; they are giant waves that move separatelyfrom the tides. Tsunami can occur at any time, day ornight.

--->An earthquake began in the ocean. Two parts of the earth moved and ground against each other. This caused part of the earth to drop down and all the water dropped as well. The movement caused a big wave to start. The wave as so-o-o-o big that it traveled thousands of kilometers and got bigger and bigger and wider and wider until it began to hit countries and coastlines.

--->There is usually more than one wave in a tsunami. Sometimes after the first wave has hit, people think it is allover and head back to the beach; this is a dangerous thing to do. More waves will keep on a coming for a few hours.

--->All low lying coastal areas can be affected by tsunami.

--->A tsunami is recorded on average in Australia every two years but they are usually too small to be noticed by people.

--->Tsunamis occur frequently in Japan and over the centuries, many thousands of Japanese have been killed by them. Tsunamis are sometimes incorrectly called tidal waves but have nothing to do with tides.

--->A tsunami can also be generated by an enormous meteor impact with the ocean. Scientists have found traces of an asteroid-collision event that they say would have created a giant tsunami that swept around the Earth several times, inundating everything except the mountains 3.5 billion years ago. The coastline of the continents was changed drastically and almost all life on land was exterminated.

--->A tsunami is not a single wave but a series of waves, also known as a wave train. The first wave in a tsunami is not necessarily the most destructive.

--->When the ocean is deep tsunamis can travel unnoticed on the surface at speeds up to 500 miles per hour (800 kilometers per hour), crossing the entire ocean in a day or less. Scientists are able to calculate arrival times of tsunamis in different parts of the world based on their knowledge of when the event that generated them occurred, water depths, and distances.
Flooding can extend inland by a thousand feet (300 meters) or more. The enormous energy of a tsunami can lift giant boulders, flip vehicles, and demolish houses.

--->While a tsunami cannot be prevented; it can be anticipated by being wary about the signs.

--->Earthquakes are the main cause of this surge, so if you are near a body of water and a strong earthquake has occurred, chances are a tsunami is already building up.

--->It is a common occurrence that if a tsunami does occur, a trough, or a draw back occurs first, then a dramatic receding of the water happens in the shoreline exposing even those parts not normally seen during low tides. After this event expect a dramatic surge in the form of fast climbing of the tides to maximum heights, this is the main wave and the best way to avoid it is, to get to a higher ground.

--->Today, tsunami warning devices are already in use and are constantly worked on, for improvement. The most common device in use now is the bottom pressure sensors. These are attached to buoys and measure the pressure of the water. This is an accurate device that conveys if a tsunami is really on the way or if the earthquake did not do any shift in the water to produce a tsunami.

--->A number of national and international organizations cooperate to provide tsunami information and early warnings of tsunamis, including the United Nations and the National Oceanic Atmospheric Administration.

--->Many communities on the Pacific Coast of the United States participate in early warning systems like the West Coast/Alaska Tsunami Warning Center and the Pacific Tsunami Warning Center in Hawaii.