Geophysical scientists to do subsurface physical mapping of sinking Joshimath

A team of experts from CSIR-National Geophysical Research Institute (NGRI) in Hyderabad is set to leave for Joshimath in Uttarakhand to carry out a subsurface physical mapping of the town affected by subsidence, a senior scientist has said.

The 10-member team headed by NGRI’s senior principal scientist Anand K Pandey is expected to reach the Uttarakhand town on January 13 and start working from the following day. The tests are expected to continue for two weeks, and the collated data will be analysed to ascertain the reason for the sinking of the ground.

Joshimath, the gateway to famous pilgrimage sites like Badrinath and Hemkund Sahib and international skiing destination Auli, is facing a major challenge due to land subsidence.

What the team will do

“Our equipment is already on the way. On January 13, the whole team will move to this site. And from 14th onwards, we will be there for at least two weeks to do the survey of that area. We are planning to conduct shallow subsurface physical mapping for water saturation and soil characteristics,” Pandey told PTI.

Also read: Explained: What is land subsidence, reason why Joshimath is sinking

He said they will do an electrical survey, which is very important in such seismic zones. They will use multi-channel analysis of surface waves (MASW), a non-destructive seismic method to evaluate material layer thickness and its shear wave velocity, to measure the thickness of the soil.

The team will also use ground penetration to find out minor cracks, water saturation of smaller size or fractures in the subsoil or cavities using ground penetrating radar. “In addition to that, we are also using field mapping,” he said.

Situation at Joshimath

NGRI is one of the largest scientific networks working in Uttarakhand and, in future, the institute will be able to provide early warnings about floods also, Pandey said. He added that NGRI has been conducting several research projects in Uttarakhand for the past four years in areas prone to earthquakes, floods, and landslides.

Watch: After Joshimath, fresh cracks reported from houses in Karnaprayag

The number of subsidence-affected homes has risen to 678 while 27 more families have been evacuated to safety, a bulletin from the Disaster Management Authority in Chamoli said on January 9, adding that 82 families have been shifted to safe locations in the town so far.

The Centre on Tuesday announced that it will install micro-seismic observation systems in Joshimath.

(With agency inputs)