Τετάρτη 6 Φεβρουαρίου 2013

TSUNAMIS


Tsunamis  are a series  of large waves that strike a coastal  area. They are usually  extremely destructive and can travel very quickly. They can cause great devastation and can easily kill thousands of people. The word 'tsunami' is a Japanese  word. When translated,  it literally  means 'harbour  wave'. 'Tsu' means  'harbour'  and 'nami' means  'wave'. Very often they are called tidal waves, but this is an inaccurate term because tides do not cause  a tsunami to occur. Tidal waves are requlated by the gravitational pull of  the  moon, which means that the movement of tides is regular.

A tsunami is sometimes  created  when  there is an earthquake  under the  sea. After the earthquake, the floor of the  sea moves up and down and, and as  a result,  a huge wave is formed. A tsunami wave moves at a very high speed and is virtually unstoppable. Travelling at a speed of up to 1,ooo kilometres an hour, it can go across an entire ocean in only a few hours.When tsunami reaches the shore, it could be as high as a hundred  metres. Very often, first tsunami wave to hit the coast is followed by others, which  are sometimes  more destructive than the first.

How do we know when a tsunami is coming? Sometimes we can feel  the erthquake and this may be the first clue.However, if the earthquake is in the deep  sea, then very  often there  is no indication  that  it  has happened or that a tsunami will occur.
The most obvious sign of  tsunami when the  water on the shoreline goes out to sea very quickly. It could be as  soon as five minutes. In places where this might happen, there  are usally  warning systems such as sirens on the beach. Also, in some coastal regions, there are machines that detect seismic activity  in  the  water, which cause the sirens to go off.

What can you do if you know that a tsunami is coming? The first thing to do is abandon everything. Do not take anything with you because you might not have enough time. Go towards higher ground, a hill or a mountain and just keep  climbing. Never go down to the beach to watch  the spectacle. Yoy may not live to tell the tale. Most importantly , if you have managed to escape the wave, do not believe that you are save, because the second or third wave could be even more devastating. If you are fortunate enough to escape with your life, never return to your dwellings until the 'all  clear'  has  been  announced.

On the 26th  December   2004, the  most deadly tsunami ever to be recorded occurred in the  Indian Ocean. The earthquake, which started the tsunami measured  a  themendous  9.15  on  the Richter scale. All the countries  which surround the  Indian Ocean were affected, especially  Indonesia. In this particular case, there was a much longer delay before the tsunami hit  the coast and, therefore, most of  the inhabitants  were taken  by  surprise. On  that  day,  approximately  283,000  people lost their lives, and 168,000 of  them were in Indonesia alone. Apart  from the loss of human lives, it resulted  in resulted  in an  enormous enviromental  tragedy, which will affect this particular  area  for  years  to come.

Δεν υπάρχουν σχόλια:

Δημοσίευση σχολίου