Kolkata Shaken: Tracing the Epicentre of the Recent Quake

On Thursday afternoon, clocks around 2:45 pm IST, a tremor rolled through Kolkata, shaking windows, rattling doors and prompting a few startled calls to emergency services. The quake, measured at magnitude 5.0 by the India Meteorological Department (IMD), wasn’t powerful enough to cause major damage, yet it left many residents staring at swaying ceiling fans, wondering what had just happened.

Seismologists were quick to locate the epicentre – the point beneath the Earth’s crust where the rupture began – somewhere near the tri‑junction of Bhutan, Assam and North Bengal. While the exact coordinates are still being refined, the consensus places the focus roughly 30 kilometres south‑west of the town of Kokrajhar in Assam, at a depth of about 10 kilometres. That shallow depth is why the shaking was felt so vividly in Kolkata, even though the city lies over 250 kilometres away.

What does a 5.0 magnitude mean for a city like Kolkata? In layperson’s terms, it’s comparable to a heavy truck striking a building – enough to be noticeable, but not typically catastrophic. The IMD issued a brief advisory urging people to stay calm, avoid unnecessary travel, and keep an eye on official updates. So far, there are no confirmed reports of structural collapses, injuries or fatalities, and power supplies remained largely unaffected.

Local authorities acted swiftly. The Kolkata Police, in coordination with the West Bengal Disaster Management Department, dispatched teams to inspect critical infrastructure – bridges, hospitals and schools – to ensure nothing was compromised. Residents were reminded of simple safety steps: drop, cover, and hold on until the shaking stops, and stay away from glass panes or heavy furniture that could topple.

The tremor also rippled into neighbouring regions. In North Bengal districts such as Darjeeling and Jalpaiguri, people reported similar rattling sensations, and in Assam’s Kokrajhar and Dhubri, the shaking was more pronounced. Even across the border, parts of Bhutan registered the quake on their own seismographs, confirming the widespread reach of the seismic waves.

Why did this quake occur now? The Himalayan belt, a massive collision zone where the Indian plate pushes into the Eurasian plate, is perpetually under stress. Over time, this stress is released in the form of earthquakes. While the region experiences frequent minor tremors, a 5.0‑magnitude event is relatively uncommon for the plains surrounding Kolkata, making this incident a reminder of the broader tectonic forces at play.

Looking ahead, experts say the aftershock sequence will likely be modest – a handful of smaller quakes in the days to come – but they advise people to stay alert. The IMD will continue to monitor the situation and release updates as needed. For now, Kolkata can breathe a sigh of relief, but the episode underscores the importance of preparedness in a seismically active part of the world.