India is mainly divided into 4 seismic zones. These are Zone 2, Zone 3, Zone 4, and Zone 5. Delhi lies in the very sensitive Seismic Zone 4. Other regions which lie in Zone 4 are Indo-Gangetic basin, Jammu and Kashmir, and Koyna region of Maharashtra. Areas under Zone 5 include western and central Himalayas, Rann of Kutch, and North-East India, and are even more vulnerable to massive earthquakes. In the list of 5 most earthquake prone cities in India, Delhi owns the third spot.
Zoning is done on the basis of the number of active fault lines on the earth’s surface which may or may not become the epicenter of an earthquake. A fault line is similar to a joint or a junction. It is basically a surface trail of a fault, formed as a result of a fracture in the earth’s crust, which is rocky in nature. Something similar to a hair-line fracture in human bones.
Now the main reason behind earthquakes in the Himalayas and adjoining areas has always been the friction between the Indian plate and the Eurasian plate. There’s a movement along the fault lines which releases huge amounts of energy thereby causing earthquakes.
Speaking of Delhi, the region is vulnerable to earthquakes in particular mainly because of its location. Delhi is situated on top of few active seismic fault lines. Moreover, its proximity to other active seismic fault lines further worsens the situation. Fault lines close to Delhi are Mahendragarh fault line, Moradabad fault line, Delhi-Haridwar ridge zone, and the Sohna fault line.
In addition to all this, Delhi’s high-density population is another cause of concern. We’re talking about a death toll in millions. There are several vulnerable structures in unauthorized colonies and other settlements. An earthquake with an epicenter in or around Delhi will surely prove to be catastrophic. Also, Delhi is built on a mix of hard and soft soil. The lack of uniform soil structure will lead to a variation in the impact of an earthquake. Moreover, Delhi is home to several ancient structures as well as modern high-rise buildings, which further complicate the matter.
It is a known fact that earthquakes cannot be predicted. But with proper measures of preparedness, mitigation of loss of life and property can be achieved. Then again, how many buildings in Delhi-NCR region are earthquake prone?
(Featured Image: iflscience.com)