Parts of northern India have been rocked by several earthquakes over the past week, while the tremors in Bikaner were of magnitude 5.3 and those felt in Hyderabad were 4.0. New seismic mapping now shows that 59% of the country is subject to earthquakes of different intensities.
The new information was given by the Minister of Earth Sciences, Dr Jitendra Singh to Lok Sabha. In a written response, the minister said that according to the country’s seismic zoning map, the total area is classified into four seismic zones.
Zone V is the most active seismic region, while Zone II is the least.
While almost 11 percent of the country is in Zone V, 18 percent is in Zone IV, 30 percent in Zone III and the rest in Zone II. These seismic zones are classified based on the empirical law of seismic attenuation corroborated by historical seismicity and earthquake ground motions.
The National Seismic Center maintains a National Seismological Network (NSN) of 115 observatories spread across the country to detect these movements below the surface, which is disseminated to central and state disaster authorities to ensure preparedness and carry out work. rescue and rehabilitation if the tremors hit.
The government said in February that 965 earthquakes of magnitude 3 and above were recorded in 2020, and 13 of them were in and around the National Capital Region.
Here is the list of the most seismically active cities
The cities that belong to the most active Zone V are Bhuj, Darbhanga, Guwahati, Tezpur, Srinagar, Sadiya, Port Blair, Mandi, Kohima and Jorhat.
While those in Zone IV are Almora, Jalpaiguri, Kolkata, Ludhiana, Monghyr, Moradabad, Patna, Parganas, Pilibhit, Shimla, Roorkee, Ambala, Amritsar, Bahraich, Barauni, Bulandshahr, Chandigarh, Darjeeling, Dehradun, Deoria, Delhi, D Ghaziabad, Gangtok and Gorakhpur.
The then Minister of Earth Sciences, Harsh Vardhan, said the NCS had launched a magnetotelluric geophysical study, satellite image interpretation and geological field surveys in Delhi and the surrounding area in collaboration with IIT Kanpur to locate and characterize the main seismic sources or fault lines in Delhi and surrounding areas.
The center is also considering seismic microzoning of Indian cities with a population of 5 lakh to integrate the data into better urban planning. The development will generate inputs for the construction of earthquake resilient buildings in order to reduce the impacts of earthquakes and minimize loss of life.