Seismic Zones in India: UPSC Important Topic | 24 April 2023

Seismic Zones in India

▪️ There are four seismic zones (II, III, IV, and V) in India based on scientific inputs relating to seismicity, earthquakes occurred in the past and tectonic setup of the region.

▪️ Previously, earthquake zones were divided into five zones with respect to the severity of the earthquakes but the Bureau of Indian Standards (BIS) grouped the country into four seismic zones by unifying the first two zones.

▪️ Seismic Zone II:

Area with minor damage earthquakes corresponding to intensities V to VI of MM scale (MM-Modified Mercalli Intensity scale).

▪️ Seismic Zone III:

Moderate damage corresponding to intensity VII of MM scale.

▪️ Seismic Zone IV:

Major damage corresponding to intensity VII and higher of MM scale.

▪️ Seismic Zone V:

Earthquake zone V is the most vulnerable to earthquakes, where historically some of the country’s most powerful shocks have occurred.