The Indian Space Research Organisation (ISRO) has discovered, through an analysis of decades of satellite imagery, that glaciers across the Indian Himalayas are melting at an alarming rate. This has led to the significant expansion of glacial lakes in the region.
These glacial lakes, formed by melting glaciers, serve as freshwater sources for rivers in the Himalayas. However, they also pose risks such as Glacial Lake Outburst Floods (GLOFs), which can cause devastation downstream. GLOFs occur when glacial lakes release large volumes of meltwater due to the failure of natural dams, such as those made of moraine or ice.
Research has shown that glaciers worldwide have been experiencing unprecedented rates of retreat and thinning since the Industrial Revolution. Using imagery from 1984 to 2023, ISRO noted that of 2,431 glacial lakes in the Indian Himalayas larger than 10 hectares, 676 have expanded since 1984.
The study further revealed that 89% of lakes have expanded more than twice, 10 lakes have grown between 1.5 to 2 times, and 65 lakes have expanded at 1.5 times their size in 1984. Among the 676 expanding lakes, the majority are Moraine-dammed (307) followed by Erosion (265), other (96), and Ice-dammed (8) glacial lakes.
The expansion of glacial lakes in the Indian Himalayas is a concerning trend that requires monitoring and mitigation measures to address the risks associated with GLOFs.
