Arunachal’s Khangri glacier melting rapidly, lake poses flood threat

GUWAHATI: Rapid glacier melting in Arunachal Pradesh’s high-altitude Tawang district has triggered alarm bells among scientists, who have warned of unstable terrain and the emergence of a potentially dangerous glacial lake at Khangri.

The lake poses a serious flood threat to downstream areas in the Mago Chu basin, a critical headwater of the Brahmaputra system.

The findings were made during the 5th Khangri Glacier Expedition, conducted by the Centre for Earth Sciences and Himalayan Studies (CESHS) in collaboration with the National Centre for Polar and Ocean Research (NCPOR) and the NorthEastern Regional Institute of Science and Technology (NERIST), authorities said on Monday.

The expedition, which started on May 4, focused on glacier health assessments, cryosphere monitoring, and climate hazard studies in the eastern Himalayas.

In an official statement, CESHS stated that the team observed ‘alarming geomorphological changes’ in the glacier, including the development of a glacier sinking zone where the snout is collapsing, creating unstable terrain.

Scientists cautioned that such instability could heighten landscape hazards and increase downstream vulnerability.

The team also identified a newly formed proglacial lake at nearly 16,500 feet. Researchers warned that the lake could trigger a Glacial Lake Outburst Flood (GLOF), with cascading impacts on communities, ecosystems, and river systems across transboundary regions. Despite healthy winter snowfall, accelerated melting continues due to rising temperatures and persistent climate variability.

To strengthen long-term monitoring, five new scientific stakes were installed at elevations close to 17,000 feet using ice-core drilling and DGPS technology. Data was retrieved and calibrated from the existing Automatic Weather Station (AWS) and Automatic Water Level Recorder (AWLR), while moraine sediments and meltwater samples were collected for geochemical analysis.

CESHS said the expedition has reinforced cryosphere monitoring in the eastern Himalayas and will provide vital insights into glacier dynamics, water security, and climate hazards under a rapidly changing climate scenario.