NEW DELHI: A deadly wall of muddy water that swept away an Indian Himalayan town this week was likely caused by a rapidly melting glacier exacerbated by the rising effects of climate change, experts said on Thursday (Aug 7).
Scores of people are missing after water and debris tore down a narrow mountain valley, smashing into the town of Dharali in Uttarakhand state on Tuesday.
Several people could be seen in videos running before being engulfed as waves uprooted entire buildings, leaving others smothered in freezing sludge.
At least four people have been confirmed killed, but at least 50 others are missing.
Government officials said shortly after the disaster that the flood was caused by an intense “cloudburst” of rain.
However, experts assessing the damage suggested that it was only the final trigger, adding to days of prolonged rains that had already soaked and loosened the ground.
PK Joshi, of New Delhi’s Jawaharlal Nehru University, an expert on Himalayan hazards, said it appeared the flood was caused by the collapse of debris – known as moraine – that had dammed a lake of meltwater from a retreating glacier.
“Given the persistent rainfall over preceding days and the sudden discharge observed, a glacial lake outburst flood (GLOF) or collapse of a moraine-dammed lake is suspected as the primary trigger,” Joshi told AFP.
That would have contributed to a “sudden high energy flash flood”, he said, noting that glacial terrain upstream of the town included “unstable sediment zones”.
Cloud cover has obstructed satellite imagery to check for the exact source of the debris, and Joshi cautioned that there was not enough satellite data for a “definitive confirmation”.
