The Sikkim science and technology department, in collaboration with the mines and geology department, has completed a detailed scientific expedition to three high-risk glacial lakes in the remote corners of west Sikkim in a major step towards mitigating the threat of glacial lake outburst floods (GLOFs).
An eight-member multidisciplinary team comprising glaciologists, geographers, geologists and civil engineers carried out the expedition from June 19 to July 1 under the state’s ongoing comprehensive hazard assessment of high-risk glacial lakes.
The team studied the Tiklip Lake, the Bhaley Pokhri and the Doodh Pokhri, all located in Gyalzing district and accessible only through a strenuous four-to-five-day trek from Yuksom, the nearest motorable point, which is around 120km from Gangtok.
The mission comes in the wake of the devastating South Lhonak glacial lake outburst flood (GLOF) on the intervening night of October 3 and 4, 2023. The GLOF claimed over 100 lives, destroyed homes and washed away the 1,200MW Teesta Stage III hydel project.
In response, the Sikkim government launched a first-of-its-kind statewide glacial lake survey in October–November 2024, assessing 320 glacial lakes, 16 of which were identified as vulnerable to GLOF events.
During the latest expedition, the team conducted Electrical Resistivity Tomography (ERT) surveys on the
three lakes.
“These high-resolution geophysical investigations are aimed at understanding the internal structure and stability of the moraine dams holding these glacial lakes,” said a senior official.
The ERT data help detect buried ice, water-saturated zones, and potential seepage channels, all critical indicators of potential GLOF triggers.
The team also repaired hydro-meteorological sensors near the East Rathong glacier below the Bhaley Pokhri, restoring integration with the region’s Automatic Weather Station (AWS) network. These sensors will provide continuous data on temperature, rainfall, humidity, and wind, which are vital for long-term climate monitoring in the fragile Himalayan ecosystem.
Lake discharge measurements were also carried out at the Bhaley Pokhri, contributing to real-time hydrological assessment.