Danger of Earthquake in North India

Danger of Earthquake in North India

Important for Prelims:

Earthquake, Earthquake Zone, Richter Scale, National Center of Seismology (NCS), 'Indian Plate'

Important for Mains:

GS-1: Danger of earthquake in North India, causes, effects, earthquake zones of India.

October 20,2023

Context:

From recent surveys, geologists have expressed the possibility of a strong earthquake in North India.

Danger of earthquake in North India:

  • According to geologists, small earthquake tremors can be a sign of a big earthquake. Many experts have expressed the possibility of a major earthquake of 7.5 to 8.5 magnitude between Delhi and Bihar. Earthquake shocks have been occurring repeatedly in the National Capital Region of Delhi. Are the tall and luxurious buildings of Delhi in a position to withstand a major earthquake?
  • On October 8, 2023, more than two and a half thousand people died and several thousand were injured due to the strong earthquake in western Afghanistan. Recently, strong earthquake tremors were felt in Delhi-NCR including Uttarakhand, Uttar Pradesh, Haryana, Rajasthan, Madhya Pradesh, the epicenter of which was in Bajhang district of Nepal. The impact of this earthquake was felt in North India twice consecutively in a day.
  • On October 3, the first earthquake of 4.6 magnitude on the Richter scale and the second earthquake of 6.2 magnitude were felt. Although there was no loss of life or property due to this earthquake in India, this earthquake caused a lot of devastation in Bajhang district of Nepal, where hundreds of houses in the mountains were razed to the ground.
  • Due to the continuous earthquake tremors, this question is troubling the people whether these earthquake tremors from Afghanistan to Nepal and Delhi are a sign of some major disaster. In the same year, a very powerful and destructive earthquake of 7.8 magnitude occurred in Turkey, in which thousands of people lost their lives. That earthquake also shifted the land of Turkey by about three meters.
  • According to a study conducted by the National Center of Seismology (NCS), twenty cities and towns in India are most at risk of earthquakes, including the capitals of nine states including Delhi.
  • The Himalayan mountain range region is considered to be the most earthquake sensitive region in the world and according to a study by NCS, the most earthquake sensitive cities are located in this region.

Cause:

  • According to geologists, due to internal strain in the Delhi-Haridwar forest area, the earth is repeatedly vibrating. These tremors show that geological faults are active in this zone, due to which a major earthquake can occur in North India, but no prediction can be made.
  • The ‘Indian Plate’ extends from the Himalayas to the Antarctic, which is south of the Himalayas, while the Eurasian Plate is north of the Himalayas.

Impact of this earthquake on Delhi:

  • Many studies show that in 72 percent of the cases, mild earthquakes have been responsible for major earthquakes. Delhi-NCR is considered a very sensitive zone from earthquake point of view, which falls in the second most dangerous earthquake zone-4. According to NCS study, about 30 percent of Delhi falls in Zone-5, which is most sensitive from earthquake point of view.
  • According to the report of the Ministry of Earth Sciences, new buildings constructed in Delhi are capable of withstanding earthquakes of 6 to 6.6 magnitude, while old buildings can only withstand earthquakes of 5 to 5.5 magnitude.
  • According to a study by NCS, 90 percent of the buildings in Delhi are not capable of withstanding an earthquake stronger than magnitude six. Because these buildings in Delhi are made of concrete and rebar.
  • Experts are also estimating greater loss of life and property in Delhi in case of a major earthquake because the population of Delhi is around 1.9 crore and around ten thousand people live per square kilometre. The effect of any major earthquake is visible up to three to four hundred kilometers.
  • Due to the earthquake in Bhuj in 2001, there was a lot of devastation in Ahmedabad, about 300 kilometers away from there. Scientists of Indian Institute of Science have also warned of major earthquake in the areas of Delhi, Kanpur, Lucknow and Uttarkashi. According to him, almost the entire North India can be hit by earthquake.

Earthquake Zones of India:

  • Bureau of Indian Standards (BIS) has categorized India's earthquake sensitive areas from Zone-2 to Zone-5. According to 'Macro Seismic Zone Mapping', India has been divided into four zones from Zone-5 to Zone-2 to measure earthquakes. Among these, Zone-5 is considered the most sensitive and Zone-2 is considered the least sensitive. Zone-5 is the area where the risk of earthquake is highest, whereas in Zone-2 the risk of earthquake is the least.
  • Delhi and its surrounding areas have been kept in Zone-4 from this point of view, where an earthquake of up to 7.9 magnitude on the Richter scale can occur. This region includes Delhi-NCR, Haryana, Punjab, Jammu-Kashmir, Himachal Pradesh, Uttar Pradesh, Bihar, Sikkim and some areas of West Bengal.
  • Zone-5 includes Bhuj of Gujarat, some areas of Jammu and Kashmir, Andaman Nicobar, Uttarakhand and entire North-East India.
  • Zone-3 includes, apart from some areas of Uttar Pradesh, Bihar and Madhya Pradesh, some parts of West Bengal, Rajasthan, Maharashtra, Gujarat, Tamil Nadu and Kerala. The greater the intensity of the earthquake on the Richter scale, the greater the vibration.

Impact of earthquake based on intensity:

  • When an earthquake of 2 to 2.9 magnitude occurs, there is a slight vibration, whereas when an earthquake of 3 to 3.9 magnitude occurs, it feels as if a heavy truck has passed nearby.
  • In an earthquake of 4 to 4.9 magnitude, window glasses may break and frames hanging on the walls may fall. Earthquakes with intensity less than 5 on the Richter scale are considered mild and about six thousand such earthquakes occur in a year.
  • In an earthquake of 5 to 5.9 magnitude, even heavy furniture can move and in a 6 to 6.9 magnitude earthquake, the foundation of buildings can crack, causing significant damage to the upper floors.
  • When an earthquake of 7 to 7.9 magnitude occurs, along with buildings collapse, underground pipelines also burst. When an earthquake of 8 to 8.9 magnitude occurs, buildings and even big bridges collapse, whereas when an earthquake of 9 magnitude occurs, destruction is certain everywhere.

Conclusion:

  • Considering the effects of earthquake, we should start preparing buildings in sensitive areas for earthquake, so that the damage of major earthquake can be minimized.
  • According to NCS, there is a need not to panic about earthquake tremors, especially in Delhi-NCR region, but to emphasize on measures to reduce the risk. Because no such technology has been developed by scientists, which can accurately predict the time, location and intensity of earthquake.

 

mains question

Considering the possibility of earthquakes in North India, explain its causes and impacts.