Tornado Facts: Causes, Destruction and Protection

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What is Tornado and Cause of Tornado ? How it is Formed ?

A tornado is a violent storm with a column of rapidly rotating winds, having the appearance of a dark, funnel-shaped cloud that reaches from the sky to the ground (see Figure). Most of the tornadoes form from thunderstorms. Before a tornado starts, large thunderclouds appear in the sky.

One area of the thundercloud becomes specially dark and dense. The air in this area is rotating quickly. A funnel-shaped cloud begins to form and extend downwards to the ground (see Figure).

The diameter of the narrow end of a tornado (which touches the ground) can be as small as a metre and as large as a kilometre (or even more). Due to very low pressure in it, the funnel of a tornado sucks dust, debris and everything else (including people and vehicles) near its base and throws them out near the top.

A tornado moves across the surface of land (or sea) producing very high speed winds. A violent tornado can travel at speeds of about 300 km/h. Most of the tornadoes are weak. Tornadoes are not very frequent in our country.

Destruction Caused by Tornadoes

The wind speed in a tornado may reach up to 300 kilometres per hour. Tornadoes cause much damage from the sheer force of its high speed winds. A tornado causes considerable damage as it passes over land. This happens as follows :

1. Tornado uproots trees, electric poles and telephone poles disrupting power supply and telecommunications.
2. Tornado lifts people and vehicles off the ground and hurls them hundreds of metres away. This causes death of many people and damage to vehicles.
3. Tornado can cause extensive damage to buildings. When a tornado passes over a building, it sucks up air from around the building. This makes the pressure on the outside of the building much lower than that on the inside, and the building can explode.

Protection from a Tornado

The following precautions should be taken for protection during a tornado.

1. Take shelter in a room situated deep inside the house having no windows or in a basement (underground room). This is the best tornado shelter.
2. If a room without windows or basement is not available, then shut all the doors and windows of the house and take shelter under a sturdy table (where falling debris cannot reach). Bend down on your knees and protect your head and neck using your arms (see Figure). Stay indoors until it is safe to come out.
   
3. If a person is in a vehicle when a tornado begins, he should get out of the vehicle, go to a ditch or low-
   lying area and lie flat in it.
4. Stay away from fallen electric wires and stay out of damaged areas.