Entire Northeast now in Zone VI, India’s top earthquake hazard category

Guwahati: India has introduced a major overhaul to its earthquake safety rules, and the message is clear—much of the country, especially the Northeast, must brace for stronger seismic preparedness.

The updated national code, IS 1893:2025, now divides the country into five seismic zones, and a striking 61% of India’s land area is classified as being at moderate to high earthquake risk. In simple terms, most Indians live in places where strong tremors are a real possibility.

The biggest change comes with the creation of a new top-risk category, Zone VI. The entire Northeast—already known for its frequent tremors—now falls under this highest hazard zone. This upgrade follows a detailed scientific study of the region’s faults, past quakes, and how seismic waves move through the ground. The new map finally puts data and lived experience on the same page.

But the update isn’t just about renaming zones. The code transforms how engineers design buildings in India. Moving away from older models, the new system uses advanced probabilistic methods—approaches followed in earthquake-prone countries worldwide—to assess how powerful future shaking could be.

The fresh guidelines also push for stronger and smarter construction. Builders must consider not only horizontal shaking but also vertical jolts, soil behavior, and the possibility of ground liquefaction during severe earthquakes. The rules also highlight a commonly ignored danger: unsecured architectural elements and equipment that can topple, causing injury even when buildings remain structurally sound.

Urban planners say the new norms will have major consequences for rapidly growing cities like Guwahati, Imphal, Shillong, and Aizawl. BIS has made one point very clear—earthquake-resistant detailing is mandatory for buildings in Zones III to VI, no matter what other design forces may appear more dominant.

“With the entire Northeast placed in Zone VI, the region must adopt tighter seismic design standards, better detailing, and strict monitoring of all construction activities,” an expert noted.

As India continues its fast-paced growth, the revised earthquake code aims to ensure that homes, schools, offices, and public infrastructure are built to withstand stronger shocks—making communities safer and more resilient in the decades ahead.