Arunachal expedition charts Dharkha Tso, finds deep-water aquatic life in Rani Lake
Guwahati: A scientific team studying the Khangri Glacier has reported several major findings in Arunachal Pradesh’s Tawang district, including the first detailed survey of the high-risk Dharkha Tso glacial lake and the discovery of aquatic species 20 metres underwater in Rani Lake.
Centre for Earth Sciences and Himalayan Studies (CESHS) and the National Centre for Polar and Ocean Research (NCPOR) conducted the November 8–14 expedition as the latest in their 2023-launched series to track long-term glacier changes in the Eastern Himalayas.
According to CESHS Director Tana Tage, the programme aims to build a clearer picture of how Himalayan glaciers are responding to climate change and what this means for water resources in the region.
This year’s mission, led by glaciologist Dr. Parmanand Sharma and coordinated by Nyelam Sunil, included 11 specialists from CESHS, NCPOR Goa, Nagaland University, and NERIST.
Despite heavy and persistent snowfall blocking their route for summer mass-balance observations, the team used advanced drone systems to capture high-resolution aerial data of Khangri Glacier and Rani Lake.
A key outcome of the mission came from a sonar-based bathymetric study of Rani Lake, which detected aquatic organisms at a depth rarely observed in cold, high-altitude glacial environments.
The team also collected valuable information from an automatic weather station and a water-level recorder placed on the glacier, and carried out round-the-clock stream-discharge measurements to monitor meltwater patterns.
One of the most challenging tasks this year involved reaching Dharkha Tso, a lake identified by the NDMA as highly prone to glacial lake outburst floods.
Located at 16,145 feet in Mirathang Valley with no direct approach route, the site required the team to trek 3.8 kilometres through deep snow, uneven ridges, slippery slopes, and low-oxygen conditions.
Despite the hazardous terrain, the scientists succeeded in conducting drone mapping and collecting water and sediment samples, which will be used for a detailed assessment of potential GLOF threats.
CESHS stated that the conclusion of the fourth expedition marks a significant advancement in India’s research efforts to better understand glacier health, meltwater behaviour, and the increasing risks associated with unstable glacial lakes in the Eastern Himalayas.