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Frequent tremors in HP not a precursor to major quake, say experts
IMD, the nodal agency of Government of India that monitors earthquakes activities, does not report the earthquakes of magnitude below 4.0
In the past 12 days, the hills have witnessed at least four mild earthquakes, with the recent being felt in Chamba district on early Tuesday morning. A mild intensity earthquake of 3.3 magnitude struck Chamba district at 1:27am, said Manmohan Singh, director, Meteorological Centre, Shimla.
But do these tremors indicate a big earthquake in future?
The experts said no. Director of Indian Meteorological Centre (IMD), Shimla, Manmohan Singh said that these tremors are a common occurrence in the region.
“All the previous quakes were of mild intensity measuring below 4.0 on the Richter scale and at a shallow depth of 5 to 10 kilometers. This is a common occurrence in the state,” said Singh.
IMD, the nodal agency of Government of India that monitors earthquakes activities, does not report the earthquakes of magnitude below 4.0.
‘Mild tremors, a common feature’
“Dozens of earthquakes of small magnitude occur in the region on a regular note and are reported only when they are felt, “ said Singh and added, “There is nothing to worry about.”
Professor at School of Earth and Environmental Sciences, Central University of Himachal Pradesh, Ambrish Kumar Mahajan said that the state witnesses dozens of mild earthquakes every year due to its geographical location.
Chamba and Kangra region witnesses more tremors due to a main boundary fault that runs up to Mandi. Apart from it, there are scores of smaller faults which causes some seismic activity beneath the surface.
“Movements along these faults result in building up of elastic strain and sudden release of this energy causes an earthquake activity,” said Mahajan, who had earlier worked at Wadia Institute of Geology, Dehradun.
“We can’t say that these small intensity earthquakes are precursor to a major earthquake in future,” he added.
Earthquake measuring more than eight are categorised as major earthquakes. “The situation can be said to be alarming, if the frequency of tremors is high and the magnitude measured on the Richter scale is five or above,” said Mahajan.
He, however, admitted that a major earthquake might occur in the Himalayan belt due to tectonic activity but its geological time can’t be predicted.
Tremors that jolted the state
Earlier, Kangra and Chamba region had experienced over two dozen similar small intensity earthquakes over a period of three months in the year 2013 alone.
A number of damaging earthquakes have occurred in the Himachal during the 20th century, major being the 1905 Kangra earthquake—measuring 7.8 on the Richter scale—that razed Kangra and Dharamshala towns, leaving 20,000 people dead.
Another big quake of 6.4 magnitude hit Kullu in 1906. In 1975, an earthquake measuring 6.8 had hit Lahaul and Spiti region.
At least, 75 tremors of magnitude above 4.0 have been recorded in Himachal from 1809 to 2000.
