New Delhi: The National Centre for Seismology (NCS) has unveiled a dramatically revised earthquake zoning map that places the entire Himalayan arc – from Ladakh to Arunachal Pradesh – in Zone VI, the highest seismic risk category ever assigned in India.
The upgrade means these regions must now prepare for quakes exceeding magnitude 8.0 with ground acceleration above 0.36 g, far deadlier than previously estimated.
The old 2002 map had capped most of the Himalayas at Zone V and parts at Zone IV. The new version, based on 25 years of fresh GPS data, micro-zonation studies and lessons from Turkey-Syria and Nepal 2015, paints a grimmer picture: the Indian plate is slamming into Eurasia 5 cm faster than thought, squeezing the world’s youngest mountain range like a vice.
Twelve states and Union Territories — Jammu & Kashmir, Ladakh, Himachal Pradesh, Uttarakhand, Sikkim, Arunachal, and all seven Northeastern Sisters — fall wholly or partially under Zone VI. Delhi-NCR stays in Zone IV, but its proximity to the Main Himalayan Thrust has officials sweating.
Construction codes will turn brutal: buildings must now withstand 50–100% higher lateral forces, mandated by deeper piles, shear walls, and base isolators. “Old structures will need urgent retrofitting; new ones will cost 15–25% more,” warns a Bureau of Indian Standards official.
Experts hail the map as “long overdue honesty”. “We were under-building for the real threat,” says Dr Harsh Gupta, former NCS head. With 59% of India already seismic-prone, this redrawing is a stark reminder: the next Big One may not be a question of if, but when.