Sikkim Records 41 Earthquakes in 18 Days as Seismic Activity Spikes

Sikkim recorded 41 earthquakes between February 9 and February 27, with the strongest measuring 4.6 magnitude near Yuksom in Geyzing district on the night of February 26, according to data from the National Centre for Seismology.

The cluster was part of 57 tremors detected across India, Bhutan and Nepal during the same 18-day period. The February 26 event occurred about four kilometres north-northeast of Yuksom at a depth of 10 kilometres, categorising it as a shallow-focus earthquake, which increases the likelihood of a stronger surface impact despite its moderate magnitude.

Spike In Seismic Activity

The earthquakes during the period ranged from magnitude 1.9 to 4.6. The lowest magnitude tremors, at 1.9, were recorded around February 20-21 in and around Gangtok.

Most events fell between magnitudes 2.3 and 3.5, with only a handful exceeding 3.8. Besides the 4.6 peak, relatively stronger tremors of 3.9, 3.8 and 3.7 magnitude were recorded between February 25 and 27, marking a noticeable escalation in activity.

February 26 saw the highest number of tremors in a single day, ranging from around 2.1 to 4.6 magnitude. The dense clustering suggests a swarm-like sequence rather than a classic mainshock followed by aftershocks. Activity persisted into February 27, though at slightly lower intensity.

Epicentre Distribution, Depth Analysis

Region-wise, North and West Sikkim reported the highest concentration of epicentres. Mangan appeared repeatedly in the dataset between February 15 and 27.

Yuksom and adjoining areas in Geyzing district recorded multiple tremors, including the strongest 4.6 event. Ravangla also experienced several earthquakes between magnitudes 2.5 and 3.8, while Gangtok and nearby locations saw consistent low-to-moderate seismic activity.

A few epicentres were traced northeast of Lachung and near the Nepal and Tibet borders, reflecting the broader tectonic dynamics of the Himalayan belt.

Depth analysis indicates most earthquakes occurred between 5 kilometres and 27 kilometres below the surface, with the majority clustered at shallow depths of five kilometres and 10 kilometres. The stronger tremors were predominantly shallow, including the 3.9 magnitude quakes at around five kilometres depth and the 3.8 and 3.7 magnitude events between five and 10 kilometres deep.

Official Response, Damage Assessment

State Disaster Relief Commissioner Rinzing Chewang cautioned against speculation, stating that earthquakes cannot be predicted with certainty.

“Everybody knows that earthquakes cannot be predicted. We cannot say with certainty why these tremors are occurring so frequently over the past couple of weeks,” he said.

He noted that Sikkim lies within the seismically active Himalayan belt, prone to tectonic movements due to geological faults and crustal interactions. While early warning systems in countries such as Japan can offer a few seconds of alert, he said, there is no scientific method globally to accurately predict the timing and magnitude of earthquakes.

On seismic zoning, Chewang said Sikkim was earlier placed under Zone IV bordering Zone V, but revised assessments by the Government of India have upgraded its vulnerability classification to Zone VI. He clarified that zoning indicates relative vulnerability and expected intensity, not certainty of occurrence.

The February 26 quake caused a false ceiling to collapse in a school building at Tashiding in Geyzing district while the district collector was on inspection. A few houses reported minor damage, and spot verifications are underway.

Authorities said assessments are being conducted and assistance for reconstruction will be extended wherever required. Officials confirmed there are no reports of major structural damage so far.

Appealing for calm, the Disaster Relief Commissioner said most of the recent tremors were minor. He urged residents to remain alert, follow safety protocols and refrain from spreading rumours.