Earthquake And Seismic Zones of India

An earthquake, in simple words, is the shaking of the earth. It is a natural event caused due to the release of energy which generates seismic waves that travel in all directions. 

India’s Seismic Zone Map
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Measuring Earthquakes

  • Earthquakes are measured either in terms of the magnitude or intensity of the shock. Earthquake magnitude is measured on the Richter scale (named after the seismologist who devised it). The magnitude implies the energy released during the earthquake and is expressed in numbers 0 to 10.

  • Earthquake intensity is measured on the modified Mercalli scale, which ranges from 0 to 12 depending upon the intensity. The intensity scale takes into account the visible damage caused by the earthquake.

Seismic Zones of India

Earthquake-prone regions of the country have been identified on the basis of scientific inputs related to seismicity, earthquakes that occurred in the past and the tectonic setup of the region. On the basis of these inputs, the Bureau of Indian Standards (BIS) has grouped the country into four seismic zones viz. zones V, IV, III and II. Zone V expects the highest level of seismicity whereas Zone II is associated with the lowest level of seismicity.

  • Zone V (very severe intensity zone): Parts of Jammu and Kashmir (Kashmir valley); Western part of Himachal Pradesh; Eastern part of Uttarakhand, Kutch in Gujarat; part of Northern Bihar; all northeastern states of India and the Andaman & Nicobar Islands.

  • Zone IV (severe intensity zone): Ladakh; Remaining parts of Jammu & Kashmir, Himachal Pradesh and Uttarakhand; Some parts of Haryana, Parts of Punjab; Delhi; Sikkim; the northern part of Uttar Pradesh; small portions of Bihar and West Bengal; parts of Gujarat and small portions of Maharashtra near the west coast and small part of western Rajasthan.

  • Zone III (moderate intensity zone): Kerala; Goa; Lakshadweep islands; parts of Uttar Pradesh and Haryana; remaining parts of Gujarat and Punjab; parts of West Bengal, western Rajasthan, Madhya Pradesh; remaining part of Bihar; northern parts of Jharkhand and Chhattisgarh; parts of Maharashtra, Odisha, Andhra Pardesh, Telangana, Tamil Nadu and Karnataka.

  • Zone II (low intensity zone): Remaining parts of Rajasthan, Uttar Pradesh, Gujarat, Haryana, Madhya Pradesh, Maharashtra, Odisha, Andhra Pradesh, Telangana, Karnataka and Tamil Nadu.

  • Approximately, 11% of the country falls in zone V, ~18% in zone IV, ~ 30% in zone III and the remaining in zone II. A total of ~59% of the landmass of India (covering all states of India) is prone to earthquakes of different intensities