Houses damaged in Nepal's devastating flash floods triggered by a glacier-mountain collapse in August. (AFP Photo)
The mountain section whose collapse triggered fatal floods in Nepal and China on August 26 had experienced unprecedented heat for the time of year, meteorological data analyzed by a researcher shows.
Average temperatures on the mountain glacier at an altitude of 5,200 meters were estimated at around 5 degrees Celsius between Aug. 21 and 26. This is exceptionally high.
They had not exceeded 4 degrees over the same period in more than 55 years of data recording, although no direct link to the collapse has so far been established.
This series of highly localized temperatures was reconstructed by Robert Rohde, chief scientist at the independent Berkeley Earth organization in California.
At the site of the collapse, the average temperature recorded over that six-day period has risen by about 1.8 degrees since the mid-20th century.
Without the additional heat brought by climate change, a comparable temperature pattern “would probably occur only once in a few thousand years,” Rohde calculated for AFP.
“These hot conditions can also explain permafrost thaw and combined slope and glacier collapse,” said French climatologist Valerie Masson-Delmotte.
Satellite images also showed significant snowmelt in the days before the disaster, providing “a substantial source of liquid water that can infiltrate fractures in the mountain and facilitate landslides,” said Etienne Berthier, a glaciologist at France’s CNRS research agency.
