The crumbling town of Joshimath in the Indian Himalayas has sunk by 5.4cm in less than two weeks, satellite images from the national space agency show.
Large parts of the town in Uttarakhand state were declared unsafe for habitation earlier this week after about 700 of its 4,500 buildings developed large cracks because of subsidence.
The town of about 20,000 people sits at an altitude of 2,000 metres in the Chamoli district of Uttarakhand and is the gateway to many popular Hindu pilgrimage sites. Experts say it is built on the deposits of a century-old landslide, making it vulnerable to being destabilised by even slight triggers.
The Indian Space Research Organisation’s National Remote Sensing Centre released a report on Thursday with satellite images showing parts of the Joshimath had sunk by 5.4cm between December 27 and January 8.
This was caused by "a rapid subsidence event" that was most likely triggered on January 2, the report said, citing eyewitness accounts.
The area affected by the subsidence also increased, but remains confined to the central part of Joshimath.
In comparison, the rate of subsidence from April to November last year was 8.9cm, said the report.
Cracks began to appear in buildings and roads in Joshimath months ago but have been widening at an alarming rate in recent weekss. Many of the buildings have brown, muddy water oozing from them.
More than 100 families have been moved to safer locations and authorities have started demolishing two hotels deemed dangerous.
Residents have been forced to spend nights outdoors in the winter chill over fears their homes may collapse on them in their sleep.
Many desperately prayed for the weather to remain clear of rain or snow, which would normally be welcome as they bring in tourists that boost the town's economy.
“We are having sleepless nights but at least it is not raining or snowing here, otherwise the structures would come down to the ground,” Himanshu Khurana, who runs a homestay, told The National.
Environment experts have blamed rampant infrastructure building work for damaging the ecological balance of the region.
Vimlendu Jha, an environmentalist, pointed to a hydroelectric project being built by the National Thermal Power Corporation in the area and said that the town was beyond repair.
“Joshimath has been brought down by engineers! ... there is no scope of repair, no reverse gear, engineers, because they have eschewed understanding of geology and geography, in their education or practice,” Mr Jha tweeted.
“Joshimath disaster is the result of puncturing of aquifers by the NTPC engineers, by their tunnel-boring machines, through tunnelling under Joshimath, muddy waters seeping out from homes and the ground is a testimony of the engineered crime leading to aquifer breaches."
Cracks have now started to appear in houses in the neighbouring town of Karanprayag.
Authorities have sent two contingents of national disaster forces. Army helicopters are monitoring the developments and have been put on stand-by for an emergency.
Geotechnical experts are conducting a study and a team of experts from the National Geophysical Research Institute will reach the town on Friday to study the underground water channel.