Tremors in Delhi-NCR spark concern: Seismologists warn of catastrophic Himalayan quake

A 4.0 magnitude earthquake jolted Delhi-NCR early February 17 morning, startling residents from their sleep. Videos of swaying water tanks and wires surfaced on social media as many reported feeling the tremors across the region. Some residents also described hearing a loud sound, adding to the momentary panic. While there were no reports of damage or injuries, the event has once again raised concerns about the seismic vulnerability of Delhi and the looming threat of a major Himalayan earthquake.

For years, scientists have been warning that the Himalayan belt is overdue for a massive earthquake. Since the 2015 Nepal earthquake, experts have said that a tremor of magnitude 8 or higher is inevitable in the region, with potential repercussions for the densely populated Gangetic plain. Renowned geophysicist Roger Bilham has reiterated that it is not a matter of 'if' but 'when' such a seismic event will occur.

Delhi sits in Zone IV of India’s seismic map, making it one of the high-risk areas for earthquakes. The city’s vulnerability stems from the Delhi-Hardwar Ridge, a geological structure that extends from the Aravalli range under the Ganga basin. This fault line places not just Delhi but also cities like Shimla at heightened risk. 

Seismologists caution that a future mega quake in the Himalayas will be particularly devastating due to its land-based setting. Unlike oceanic earthquakes that can trigger tsunamis, a Himalayan quake would shake heavily populated areas directly, impacting over 300 million people. Urban infrastructure, especially in older cities, remains ill-equipped to withstand violent tremors, increasing the risk of widespread destruction.

Why did Delhi residents hear a loud sound?  

Many residents also reported hearing a deep, booming noise. Experts say this was due to the quake’s shallow depth. According to the US Geological Survey (USGS), shallow-focus earthquakes produce high-frequency vibrations that generate sound waves as the ground shakes. The closer the quake is to the surface, the more energy and noise it releases. Even when tremors are mild, these quakes can create loud, unsettling sounds.