Sunday, September 18, 2011

Earthquake Safe Zones in India

Seismic Zoning Map of India Courtesy : Wikipedia
The earthquake which has hit the north eastern state of India – Sikkim falls in zone five like Kutchh of Gujarat which faced the tragedy of deadly calamity in 2001. Geographical statistics of India shows  that major portion of the country is vulnerable to earthquakes. Therefore, while designing big structures like bridges, dams, flyovers and chimneys special care needs to be followed by the engineers to avoid casualties.

Seismic zoning map of India assigns four levels of seismicity for the country. Seismicity is the relative frequency and distribution of earthquakes and depends on the turbulence beneath the earth crust. According to this map, Zone 5 expects the highest level of seismicity whereas Zone 2 is associated with the lowest level of seismicity.

Zone five is  referred to as the Very High Damage Risk Zone. The state of Kashmir, Punjab,the western and central Himalayas, the North-East Indian region and the Rann of Kutch fall in this zone.Next, to it is zone four, which  is called the High Damage Risk Zone. The Indo-Gangetic basin and the capital of the country (Delhi), Jammu and some portions of Bihar& Maharashtra fall in Zone 4.

Very little portion which is in zone one are  Jaipur, Raipur, Hydrabad  and Bangluru.  From Jaipur  to some portion of Madhya Pradesh is the safest area in India. But the capital of Madhya Pradesh is in zone two. The major portion of India is in zone three with moderate risk of quake. These mapping are not  static but keep on changing  after some span of time due to movements of the plates causing earth quake.

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