March 5, 2025: The 300-km-long Kopili Fault zone in Northeast India has been identified as highly active, raising concerns about the possibility of a major earthquake exceeding magnitude 7 in the near future. Researchers studying the region have linked the recent magnitude 5.0 earthquake on February 27 to the fault, noting its proximity to the epicenter of the 6.4 magnitude Sonitpur earthquake that struck on April 28, 2021.

The Kopili Fault has a history of generating large earthquakes, including the Cachar earthquake of 1869 and the Mikir Hills earthquake of 1943, both of which were above magnitude 7. Over the past few decades, the region has witnessed multiple tremors of magnitude 5.0 and higher, emphasizing its vulnerability to seismic activity. A study published in Pure and Applied Geophysics highlights that the fault extends from western Manipur to the Bhutan-Arunachal Pradesh-Assam tri-junction. The deep-rooted fault system, which existed in the Indian plate before its collision with the Tibetan plate, remains active due to ongoing tectonic stress from the Himalayas and the Indo-Burma subduction zone.

Between 1984 and 2019, the Kopili Fault zone produced at least eleven damaging earthquakes ranging between magnitude 5.0 and 6.7 due to strike-slip faulting. The 2021 Sonitpur earthquake, with a magnitude of 6.1, resulted in casualties, injuries, and widespread structural damage. Ground fractures, landslides, soil liquefaction, and other deformations were reported following the tremor. Scientists indicate that the central segment of the fault, which was responsible for the major earthquakes of 1869 and 1943, remains a concern as seismic patterns suggest a similar event could occur.

Seismologist Saurav Baruah acknowledged the high activity of the fault system and pointed out that smaller earthquakes help release accumulated energy, potentially delaying a larger quake. However, he emphasized the need for increased investment in seismic hazard research and mitigation strategies, especially in Assam’s capital, Guwahati, which is surrounded by multiple fault lines. He noted that while modern infrastructure follows seismic design standards, older buildings remain highly vulnerable. He also stressed the importance of strict enforcement of building bylaws to reduce the risks associated with a major earthquake.

With the potential for a devastating seismic event looming, experts are urging authorities to prioritize earthquake preparedness, reinforce infrastructure, and increase public awareness to mitigate the impact of future disasters.