New Delhi: Over the last 200 years less than 50 % of the Himalayan arc has been damaged due to tremors, which includes the Garhwal-Kumaon belt of Uttarakhand, and a major earthquake cannot be ruled out in the region, a parliamentary report has said.
In response to queries of Parliamentary Committee on Science and Technology, Environment and Forest, Shailesh Nayak, Secretary Ministry of Earth Sciences told the panel that an Earthquake Early Warning System in Uttarkhand is being undertaken.
The warning time will range from a few seconds to a little less than a minute.
Nayak said the northward movement of the Indian plate and its "under-thrusting" beneath Eurasian plate since last 50 million years ago is storing strain energy across the Himalayan region thereby making it seismically active.
This energy is periodically released during the large and great earthquakes.
"It has been observed that during the period of past 200 years, less than 50 % of the Himalayan arc has ruptured during the great earthquakes. Large earthquakes in these unbroken segments cannot be ruled out.
"The part of the Himalayas between the ruptures of 1905 Kangra and 1934 Nepal-Bihar earthquakes has not released strain in the past few years and is named as the Central Seismic Gap. GPS measurements in the region has provided unequivocal evidence of strain accumulation in the region.
"The Gharwal Kumaon Himalaya of Uttarkhand fall in this gap region and thus have a high seismic hazard potential," Nayak told the committee, a report of which was tabled before the Rajya Sabha today.
He, however, added that it was unknown when will the accumulated strain energy be released through a great or major earthquake.
Elaborating on the earthquake early warning system, Nayak told the committee that 100 sensors will be installed in IIT Roorkee.
"These sensors will detect the ground motion radiating from an earthquake rupture and estimate the resulting in ground shaking that will occur later either at the same location or some other location," he added.
The committee also recommended establishing an institutional mechanism for better planning, forecasting and SOPs (standard operating procedures) for dealing with a catastrophe of earthquake.