Wednesday, January 04, 2006

Forecasting the Future


Disaster Tomorrow

Likelihood of Earth Quake in Tamilnadu

Quakes are of two kinds by their characteristics: first occurs in nature and the other is developed by wrong human activities. When we build dams large quantities of water cause quakes. This type of quake is called man-made quakes. Natural quakes are caused by motion between plates in the crest. Countries and continents are made of different plates in the crest. India and China in Asian continent are made of two separate plates. The Indian plate is believed to move 2mm per year from the north to the south. The Chinese plate is stable and there is no quake risk. Yet the Indian plate is clashing slowly with the Chinese plate. It causes at one stage quake in India.

In India 85 percent of land surface is classified as to be affected by natural disasters. In the survey conducted in 2002 following the quake in Gujarat 17 states were identified as having more likelihoods of quakes. These 17states consist of 169 districts and 38 cities. India could be divided in to five zones on the basis of the likelihood of quake occurrence. The first zone is quake-free region. The following zones are believed to be hit by multiple increases in the shake. Central Tamilnadu is in the second zone, Coimbatore, Chennai, Thirunelveli and Kancheepuram cities are in the third zone. Nilgiri, Thiruvallur, Nagapattinam, Cudallore and Kanyakumari districts are also delicate. The Central India is the fourth zone whereas the Great Himalayas are the firth zone. Formerly Coimbatore, Chennai, Thirunelveli and Kancheepuram cities were in the second zone. Now these cities are classified as third zone as they are more likely to be shaken.

Professors Dr. S. Rajasekaran of Department of Civil Engineering and Dr. K. Ilangovan of Department of Geography at the PSG College of Technology have explored the possibilities of quake occurrences in Coimbatore. In the Southern part of India the Great Western Ghats are situated in the West of Tamilnadu. The Ghats are situated through all four states in the South and in Maharashtra in the Central India. At Palakad, a canal in the Ghats is looked at a fault which would cause quakes in Coimbatore and parts of Kerala state.

Those places having large dams are also likely to be met with quakes. The quake which occurred in Palakad region in 1900 took about 1,000 lives. The Idukki Dam in Kerala, Koina Dam in Maharashtra are also likely to cause quakes in the South. Some spots in the cities of Chennai, Kancheepuram and Thirunelveli are also identified as likely to be subject to quake menaces as these three cities are comprised mostly rocks which could lead to cracks in the crest and consequent quakes. The quakes which are expected to occur in these cities are believed to have been measured at 6 Richter Scale.

The expected quakes could not be estimated in advance before they occur. Yet some symptoms could be seen as to sign the occurrence of a quake. Just half a hour before the occurrence of a quake birds and snakes will feel it; some animals will react to the would-be quake moments in advance. A large scale awareness is required to minimise the damages of a would-be quake. Buildings should be strengthened as to withstand a quake. Civil engineers and construction masons should be specially trained in quake-prevention and control measures. The current buildings will be affected for 90 percent if a quake occur. Educational campaign at large is also necessary to sensitise people about the damages of a would-be quake, so that they will be able to protect their lives and properties in case of a quake. At the same time physicians, especially country medical practioners (as most ordinary people go to them for treatment to their ailments) should be trained and skill-enhanced to help people met with the danger of a quake.

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