On the fault line: How India stands vulnerable to earthquakes

25/Sep/2019 Srishti Choudhary, Live Mint e-paper

People gather near a damaged road after an earthquake of magnitude 5.8 in Mirpur (Reuters file)

  • The Indian subcontinent has suffered some of the largest earthquakes in the world
  • More than about 60% of its land area prone to shaking of intensity VII and above on the MMI scale, a seismic intensity scale

New Delhi: As a major 6.3 earthquake jolted neighbouring Pakistan, the tremors were felt up till the National Capital Region, while shaking the nearby region of Jammu and Kashmir and Punjab.

While the exact scale of damage and any loss of life is not fully known, it has raised concerns in Jammu and Kashmir which was closer to the epicenter and experienced its deadliest quake of 7.6 magnitude not less than a decade ago in October of 2005.

The Indian subcontinent has suffered some of the largest earthquakes in the world with more than about 60% of its land area prone to shaking of intensity VII and above on the MMI scale, a seismic intensity scale.

In fact, the entire Himalayan belt is considered prone to great earthquakes of magnitude exceeding 8.0, with Jammu and Kashmir among the most susceptible. The region lies on the boundary, where the small Indian plate that underlies most of India and Pakistan and the vast Eurasian tectonic plates that consist of Europe, Russia and most of Middle East collide.

In September itself, as many as 24 low to moderate intensity quakes have been reported in the country, out of which at least eight were recorded in the Jammu and Kashmir region bordering Chamba in Himachal Pradesh. At least five quakes were reported on September 8-9, as the region witnessed tremors which ranged from 2.7 to 5 on the Richter scale.

The highest recorded carried a magnitude of 5 on the Richter scale that hit this region at 12 pm on September 9, nearly 39 kms from Dalhousie in Himachal Pradesh. However, no major damage was reported.

The epicenter of the earthquake that shook Pakistan at 4:31 pm on Tuesday was in the India-Pakistan border region, barely 129 kms away from Jammu and 200 kms from Amritsar in Punjab, according to India Meteorological Department (IMD). The depth of the quake was 10 kms into the ground.

There are over 66 active faults of regional extent in the country, with the Himalayan belt, extending for 2400 km itself dissected by 15 major active faults, which participate in the strain accumulation and release. The Indo-Gangetic and Brahmaputra Plains has 16 tectonically active faults while the Peninsular India is marked by the presence of about 30 neo-tectonic faults.

But there are some of the hidden faults which have not been clearly identified.