Over a third of Kumaun Himalayas susceptible to moderate damage in case of major quake: Study

New Delhi, June 28

More than a third of the Kumaun region of the Himalayas is susceptible to moderate damage in case of earthquakes of magnitudes ranging from 7 to 8.6, says a new study by scientists at the Wadia Institute of Himalayan Geology.

Kumaun Himalayas is in the west-central section of the mountain range and lies mostly in Uttarakhand.

Several studies suggest that this region is prone to earthquakes of magnitude 8 or higher. In this context, mapping of the co-seismic landslide—which is caused by earthquakes—has become important.

Co-seismic landslides are one of the prime hazardous phenomena in the hilly and seismically-active mountainous region. Often, destruction due to earthquake-induced landslides is much greater than that caused directly by shaking of the ground.

A team of scientists, including Sandeep Kumar, Vikram Gupta, Parveen Kumar and Y P Sundriyal, from the Wadia Institute of Himalayan Geology in Dehardun, carried out a probabilistic assessment of co-seismic landslides for the Goriganga Valley in the Kumaun Himalaya.

The Valley lies in the highest seismically active area in the seismic zoning map of India.

The scientists estimated the Newmark permanent displacement which provides the distribution of predicted slope failure in the area.

“It was found that more than one-third of the area was vulnerable to co-seismic landslides and that earthquakes of 7, 8 and 8.6 magnitudes might moderately damage an area of 1,459 square km, 1,256 square km, and 1,134 square km in the study region respectively,” the research found.

The study has been recently published in the ‘Bulletin of Engineering Geology and the Environment’.

This work is the first of its kind in the Himalayas region, in which earthquake-induced landslides have been explored in view of future major to great probabilistic earthquakes. PTI