Earthquakes in India at three-year high in 2019

 

New Delhi, Mar 04: The Indian subcontinent has suffered some of the deadliest earthquakes globally, with more than 60% of its land area prone to shaking of intensity VII and above

A total of 768 earthquakes of magnitude 3.0 and above were located by the National Seismological Network from 2017 to January 31, 2020 according to a response to a question in the Rajya Sabha this week.

There were 226 earthquakes in 2017, 203 in 2018, and 309 earthquakes in 2019. Earthquakes of magnitude 4 and above nearly doubled from 78 in 2018 to 159 in 2019, the response from the Union Earth Sciences Ministry revealed.

India has been grouped into four seismic zones, that is, Zone II, III, IV and V. Zone V is considered to be the most seismically active, while Zone II is the least so.

The Indian subcontinent has suffered some of the deadliest earthquakes globally, with more than 60% of its land area prone to shaking of intensity VII and above on the Modified Mercalli Intensity scale.

Extremely vulnerable

The Himalayan belt is particularly susceptible to earthquakes exceeding 8.0 magnitude, with Jammu and Kashmir considered extremely vulnerable. The Indian plate consists of India and Pakistan and the vast Eurasian tectonic plates that comprise Europe, Russia and most of the Middle East. The Himalayas are a result of the collision of these plates, and because the Indian plate moves northwards into the Eurasian plate a few centimetres every year, this has led to a build-up of a lot of strain, that scientists say, has not been adequately released. A study published in the journal Nature Communications, in 2019, says that moderate earthquakes, that is less than 7 magnitude, may in fact be adding strain and priming the region for a massive quake greater than 8.5 magnitude. Though such a quake is imminent, scientists are not able to say when such a quake is likely.

Active faults

There are over 66 active faults in India, with the Himalayan belt, extending for 2,400 km, itself dissected by 15 major active faults. The Indo-Gangetic and Brahmaputra Plains have 16 tectonically active faults, while Peninsular India is marked with around 30 neo-tectonic faults.