Third Tremor Hits Delhi-NCR In A Month. What's Behind The Frequent Earthquakes In The Region?

Delhi-NCR experienced third earthquake in the last one month. Here's what is causing frequent tremors in the national capital and other adjoining areas in the northern parts of the country.

The national capital and the adjoining areas along with other parts of north India once again experienced tremors jolting people out of their homes in panic. This is the third incident in the last one month when tremors hit Delhi-NCR. On October 15, an earthquake of magnitude 3.1 on the Richter scale hit the national capital with an epicentre located 9 kilometres east of Faridabad. 

On October 3, strong tremors were felt in Delhi and NCR after two earthquakes of magnitude 4.6 and 6.2 hit Nepal at an interval of 25 minutes. The quake was felt in parts of Uttarakhand and Uttar Pradesh capital Lucknow, Hapur and Amroha, lasting for nearly 40 seconds.

What Causes Frequent Earthquakes In Delhi-NCR 

National capital’s proximity to the Himalayas is one of the main reasons for frequent earthquakes in the Delhi-NCR, and adjoining parts of north India. The Himalaya range, which is roughly around 300 kilometres from Delhi, were formed due to collision between Indian and Eurasian tectonic plates. The ongoing tectonic activity is what triggers tremors making the region including Nepal, Uttarakhand and the adjoining Himalayan region prone to earthquakes. 

While Delhi-NCR is not located on a fault line, it is in proximity to Himalayan tectonic plate boundary,where the Indian and Eurasian plates collide which is majorly responsible for the seismic activities in the national capital. 

The Himalayas in Nepal are made of different seiesmotectonic setting which keeps on storing strain energy. When The sharing strength exceeds, the zone rock ruptures which causes tremors that we feel. 

"...Nepal Himalayas consist of different seismotectonic settings. There are different faults that are seismogenic faults...When one earthquake occurs it releases the strain energy," National Center for Seismology (NCS) Director OP Mishra told ANI. 

"That strain energy accumulates somewhere. And it keeps on accumulating and keeps on increasing. So once is the sharing strength or bearing strength of the rock material exceeded, then that zone or that zone rock ruptures and then an earthquake happens," he told further. 

India's Seismic Mapping 

Proximity to the Himalayan region places Delhi under seismic Zone IV whereas the Himalayan regions fall under seismic Zone V which implies highest risk of damaging earthquakes. 

In India, eight states along with Union Territories come under Zone V, prone to the risk of earthquakes with highest intensity. 

According to Government of India data, around 59 per cent of the country's land mass is prone to earthquakes  of different intensities. Approximately, 11% of the country’s area falls in zone V, 18% in zone IV, 30% in zone III and remaining in zone II.

Important cities in seismic zone V: Bhuj (Gujarat), Darbhanga (Bihar), Guwahati (Assam), Imphal (Manipur), Jorhat (Assam), Kohima (Nagaland), Mandi (Himachal Pradesh), PortBlair (Andaman and Nicobar), Sadiya (Assam), Tezpur (Assam). 

Parts of Uttarakhand, Haryana, Punjab, Uttar Pradesh, Bihar, West Bengal, Sikkim, Himachal Pradesh, Chandigarh, and New Delhi fall under Zone IV.