Tuesday, March 24, 2009

Cyclones


We have been learning how to write explanations. This is our explanation of how Cyclones occur.

A cyclone is a severe storm that forms over the ocean in tropical areas.
Cyclones begin as areas of low pressure around which the winds rotate. The winds blow anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
The area at the centre of the storm which, surprisingly, is quite calm is called the eye of the storm. The winds rotate around the ‘eye’.

Cyclones involve winds of at least 125 kilometres per hour. The gale force winds can be up to 200 kilometres from the centre of a cyclone. When they come onto land, the heavy rain, strong winds and large waves can cause a great deal of damage.

If a cyclone originates in the Atlantic Ocean it is called a hurricane. Cyclones that develop in the Pacific are called typhoons. Hurricanes are most common in the Caribbean and around the Gulf of Mexico while the Philippine Islands and coastal areas of Japan and China experience many typhoons.

Cyclones are given names by meteorologists to help identify and track them as they move across the ocean onto land.

On August 28th 2005 Hurricane Katrina hit the Southern coast of the United States with devastating effect. It was reported that more than 1,800 people lost their lives and more than 81 billion dollars in damages occurred..