Scientists warn of glacial lake outburst risk at Arunachal Pradesh's Khangri glacier

Guwahati: A team of scientists have issued a warning about potential threat of a Glacial Lake Outburst Flood (GLOF) in the downstream ecosystems and communities after they detected a "potentially dangerous" proglacial lake at an elevation of nearly 16,500 feet in the Mago Chu basin of Tawang district in Arunachal Pradesh.

The proglacial lake was detected during the Khangri glacial expedition to Mago Chi basin, a critical headwaters region of the larger Brahmaputra basin system. The expedition, which began on May 4, was carried out to assess the glacier health, cryosphere monitoring and climate hazard studies in the eastern Himalayas.

"During the ground-truthing studies, scientists and engineers observed that the Khangri glacier is undergoing rapid and alarming geomorphological transformation, indicating accelerated impacts of climate variability in the high-altitude Himalayan environment," director of Centre for Earth Sciences and Himalayan Studies (CESHS), Arunachal Pradesh, Tana Tage, told DH on Monday.

The team observed development of a significant glacier sinking zone within the study area, where the glacier snout is rapidly collapsing and creating unstable terrain conditions. The team noted that such geomorphological instability could substantially increase downstream vulnerability and landscape hazards in the Mago Chu Basin, Tage said.

This, he said, could lead to potential adverse impact in the downstream areas in Arunachal Pradesh, North (Tezpur)1 and Western Assam (Bodoland region) and in parts of Bhutan via Jang waterfalls.

The expedition was carried out by CESHS, in collaboration with the National Centre for Polar and Ocean Research (NCPOR) and North Eastern Regional Institute of Science and Technology (NERIST).

Climate variability

Tage said although the region experienced comparatively healthy winter snow accumulation this year, the expedition findings indicate that glacier melting continues at a critically high rate due to persistent climate variability and rising atmospheric temperatures across the eastern Himalayas.

To strengthen long-term glacier monitoring and cryosphere research, the expedition team successfully installed five new scientific monitoring stakes at elevations reaching nearly 17,000 feet using a steam ice-core drilling system integrated with precise Differential Global Positioning System (DGPS) technology.

"These installations will support continued glacier mass balance assessments and surface velocity monitoring in the coming years," he said.

Tage said the team also retrieved valuable datasets from the existing Automatic Weather Station (AWS) and Automatic Water Level Recorder (AWLR), including calibration and maintenance of both monitoring systems to ensure uninterrupted high-altitude environmental observations.

The collected datasets will contribute towards understanding extreme weather dynamics, hydrological responses, and glacier-linked climate interactions in the region, he added.