TSUNAMI INFORMATION
A tsunami is a series of waves caused by an earthquake or other disturbance under the sea. Because there has been movement on the seabed, water is displaced, causing the waves to occur. It is a bit like when you jump into the bath or a swimming pool. The water around your body is being displaced causing ripples around where you are in the water. Of course, the sea is much bigger than a swimming pool or a bath, which is why you get waves instead of ripples.
Once a tsunami wave has been generated, it can travel at speeds of up to 500 miles per hour. That’s about the same speed as a jumbo jet. As it travels towards land, the wave can increase in height, sometimes becoming as tall as 10 metres.
As soon as a tsunami wave hits land, the force of the water can be massive, sweeping away anything in its path and damaging buildings and other structures like a bulldozer. Many people caught up in the force of the water will find it almost impossible to swim and stay in control. The only way they can survive is by holding onto something like a tree but, even then, the force of the water can be difficult to resist.
Remember that a tsunami is a series of waves. So after one wave has struck, several others will follow. The amount of big waves will depend on the scale of the original disturbance or earthquake. In the case of the tsunamis that hit southern Thailand, the earthquake (which happened in Indonesia) was one of the most powerful ever recorded.
Why is it called a tsunami?
The word tsunami comes from the Japanese tsu (harbour) and nami (wave). In Japan, tsunamis are more frequent but rarely as bad as the one experienced in this region.
Didn’t anybody know that the tsunami was coming?
This is an interesting question and one that is not easy to answer. Oceanographers have the technology to know when a tsunami has occurred. In theory, because a tsunami usually takes some time to reach land, the oceanographers can warn countries that may be hit, giving them enough time to evacuate endangered areas.
However, the speed at which local people can be warned depends upon the warning system that affected countries have in place. It seems that because the likelihood of a tsunami on this scale was so small, most of the countries had no real warning system at all.
According to reports, the tsunami hit the coast of Thailand one hour after it was generated. The weather department insists that it did send out a warning, although it was clearly ineffective as the tsunami took most people completely by surprise. Had a proper and swift warning system been in place, many lives could have been saved.
Countries where tsunamis occur frequently, such as Japan and Hawaii, all have proper official tsunami warning systems. When they occur, those stories hardly make the news because the loss of life is minimal.
Thailand and other countries are now working on a warning system that will soon be put into effect.
Can tsunamis be prevented?
No. Unfortunately, tsunamis are a direct result of a natural process which mankind cannot, as yet, do anything about. They are also completely unpredictable. The only way to minimize loss of life and damage is to have sufficient warning after a tsunami has occurred.
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tsunami
an extremely large wave in the sea caused, for example, by an earthquake
earthquake
a sudden, violent shaking of the earth’s surface
seabed
the bottom of the ocean
displace
to take the place of something
generate
to produce or create something
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bulldozer
a powerful motor vehicle with a broad steel blade in front, used for moving earth or knocking down buildings
resist
to use force to stop something from happening
scale
the size or extent of something, especially when compared with something else
oceanographer
scientists who study and monitor the ocean |
evacuate
to move people from a place of danger to a safer place
likelihood
the chance of something happening
ineffective
not having any effect
put into effect
to cause something to come into use
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