The Union ministry of earth sciences admitted in Parliament on Thursday that the entire Himalaya arc stands extremely vulnerable to strong earthquakes.
“As per the updated seismic zonation map of India, the entire Himalayan arc falls within the highest seismic risk category, Seismic Zone VI, reflecting its extremely high tectonic activity and vulnerability to strong earthquakes,” reads the answer of the ministry in Parliament on Thursday responding to a question.
“Only a small portion of the Ladakh region in the north-eastern corner falls under Seismic Zone V, which is the second-highest seismic hazard category,” the response further adds.
Collision with Eurasian plate critical
India’s seismic activity is primarily due to the Indian Plate colliding with the Eurasian Plate, creating active faults in the Himalayas and Indo-Gangetic plain.
According to the earthquake zonation in the country as categorised in late 2025, the entire country is now divided in five seismic zones – II to VI – based on risk, with Zone VI being the most active and Zone II the least.
Previously there were four zonation categories, but an additional category has been added reflecting India’s ongoing collision with the Eurasian Plate, which has placed the entire Himalayan arc under the highest risk category for the first time.
“This revised zoning, using advanced probabilistic methods, aims to guide stricter earthquake-resistant building codes for a more resilient future,” points out the ministry response.
Studies confirm threat
The parliamentary response on Thursday vindicated what several recent studies claim.
A 2025 study, using interferometric synthetic aperture radar (InSAR) from the ALOS-2 satellite and ground-based GNSS data, examined an approximately 800 km stretch across the northwest and central Himalayas — from Himachal Pradesh to western Nepal – to reveal inter-seismic uplift rates of 5–8 mm per year in the higher Himalayas, indicating strong elastic loading on the locked Main Himalayan Thrust (MHT) fault.
The analysis shows higher plate convergence rates —15–20 mm per year — and a wider locking zone than previously estimated, amplifying seismic hazards.
Critically, 500–700 years of accumulated strain since historical megathrust events in 1505 and 1344 could trigger at least two magnitude 8.8 (Mw 8.8) earthquakes in the central Himalayan seismic gap to fully release the built-up inter-seismic strain.
“This aligns with India’s 2025 revised seismic hazard map, which classifies much of the region as the highest-risk Zone VI, with over 60% of the country facing moderate to high earthquake threats,” shares a senior government official.
Research presented at the American Geophysical Union, by analysing seismic patterns, suggested that the next major earthquake (Mw ≥ 7) in the Himalayas could occur before September 2036 (±3.16 years), with alternative timelines extending to June 2033 (±2.78 years) or May 2045 (±5.65 years), based on recurrence modeling.
“These studies collectively indicate that the Himalayas are accumulating strain at rates sufficient for megaquakes, with potential ruptures along the MHT capable of impacting millions in India, Nepal, Bhutan, and Tibet,” opines the report.