The entire Northeastern region—recently placed in the highest earthquake-risk category by the Bureau of Indian Standards (BIS)—recorded a staggering 25 tremors in October alone, the highest among all regions in the country. In October this year, 25 earthquakes were registered in the Northeast: Assam reported seven quakes, followed by Arunachal Pradesh (six), Meghalaya (four), Manipur and Nagaland (two each), and Mizoram and Sikkim (one each). Nationwide, a total of 66 earthquakes were recorded in October 2025.
According to the Report on Real-Time Earthquake Location released by the National Center for Seismology (NCS) under the Ministry of Earth Sciences, a total of 304 earthquakes were located and disseminated by the Centre this year, of which 152 occurred within India and its neighbouring regions. In a major update, the entire Himalayan arc—from the Northeast to Jammu & Kashmir—has been upgraded from Zones IV and V to a newly created Zone VI, the highest hazard category reflecting extreme tectonic vulnerability and a high likelihood of major earthquakes. The new seismic map is based on an updated Probabilistic Earthquake Hazard Assessment (PEHA) by the BIS, incorporating detailed data on faults, tectonic structures, expected magnitudes, and ground-shaking intensity.
The revised zonation marks a departure from older maps that relied primarily on historical damage patterns. The updated approach uses modern probabilistic seismic hazard assessment (PSHA), factoring in active fault behaviour, strain accumulation, and ground-shaking attenuation. These scientific enhancements aim to guide more robust earthquake-resistant design and construction across India. Engineers and planners warn that, in view of recent findings, quake-prone regions will require stricter seismic design, improved structural detailing, and stronger enforcement of building norms. As India continues rapid urbanisation, the updated provisions are expected to strengthen nationwide resilience against future seismic events. Under the revised guidelines, any town located on the boundary of two hazard categories will automatically be assigned to the higher-risk zone to ensure greater safety.
With the reclassification, about 61% of India’s landmass is now categorised as moderate to high seismic-risk, necessitating updated building codes and stricter compliance. The National Center for Seismology operates a National Seismological Network of 169 stations equipped with state-of-the-art instruments across the country. Most earthquakes within India and neighbouring regions last month were recorded in the Hindu Kush region, North India (Ladakh, Jammu & Kashmir, Himachal Pradesh, and Uttarakhand), and Northeast India. Activity remained sparse across eastern and central India.
The updated national earthquake safety code, IS 1893:2025, introduces a four-zone seismic map covering 61% of India’s land area, home to more than three-fourths of its population. The revision marks the most significant overhaul of India’s seismic planning norms in nearly a decade. Moving from the earlier zone-factor method to a return-period-based probabilistic approach, the code brings India’s standards in line with global best practices.
The new framework expands design requirements to account for vertical ground shaking, soil flexibility, liquefaction potential, and enhanced protection for architectural elements and utilities—factors that have previously contributed to casualties and structural damage during major quakes. Experts say the changes will have far-reaching impacts on urban planning, infrastructure development, and disaster preparedness, especially in rapidly growing high-risk cities. According to BIS, earthquake-resistant detailing remains mandatory for all structures, even when other forces—such as wind loads—appear dominant in design considerations. Besides the eight Northeastern states, the high-risk category now includes the Andaman & Nicobar Islands, North Bihar, parts of Uttarakhand and Himachal Pradesh (higher Himalayas), the Kutch region in Gujarat, and portions of Jammu & Kashmir.
