India has introduced a major update to its seismic zonation map under the revised Earthquake Design Code of the Bureau of Indian Standards (BIS), classifying the entire Himalayan arc under a newly created highest-risk Zone VI. This marks one of the most significant changes in the country’s earthquake hazard assessment in decades.
According to the new map, 61% of India now falls under moderate to high earthquake-risk zones, expanding the list of vulnerable regions far beyond the Himalayan states.
Why the Himalayas Are in Extreme Danger
The update reflects the continuous collision between the Indian Plate and the Eurasian Plate, pushing against each other at roughly five centimetres per year. This tectonic movement, which originally formed the Himalayas and continues to elevate them, builds massive pressure beneath the surface. When this stress releases, it results in powerful earthquakes.
Multiple major fault systems run directly below the Himalayas — including the Main Frontal Thrust, Main Boundary Thrust, and Main Central Thrust — each capable of triggering destructive quakes. Scientists have also identified long-standing seismic gaps where major earthquakes haven’t occurred for nearly 200 years, indicating a buildup of high energy.
What’s New in the Seismic Map
The new BIS map does more than reassign hazard zones — it reshapes policy and safety requirements:
The outer Himalayas and foothill regions have been upgraded to high-risk status
Boundary towns between zones will now automatically fall under the higher-risk category
The risk line extends southward along the Himalayan Frontal Thrust, impacting cities like Dehradun near Mohand
Earthquake-resistant standards will now become mandatory for future urban and infrastructure planning
Experts say the redesigned map brings scientific accuracy to national safety frameworks and could help India better prepare for urban expansion in vulnerable states like Uttarakhand, Himachal Pradesh, and parts of Uttar Pradesh.
A Shift Toward Better Resilience
With new modelling and geological studies, authorities now stress the need for:
Retrofitting older buildings
Strengthened rules for construction on soft soil and fault zones
Higher disaster-preparedness and response plans across states
The updated map is expected to drive a nationwide recalibration of earthquake safety standards — a crucial step as India continues to urbanise rapidly in high-risk regions.
