Why is it in the news?

• The Indian Space Research Organisation (ISRO) has observed a notable expansion of glacial lakes in the Indian Himalayas from 1984 to 2023 through long-term satellite imagery.

More about the news

• The Indian Himalayas are often referred to as the Third Pole due to their extensive glaciers and snow cover, making them crucial for climate studies.
• Satellite remote sensing technology plays a vital role in understanding glacier retreat rates, assessing risks of Glacial Lake Outburst Floods (GLOFs), and studying the impacts of climate change.

Key observations

• Glacial lakes originate from the melting of glaciers and are grouped into four categories based on their formation process: Moraine-dammed, Ice-dammed, Erosion, and others.
• Material left behind by moving glaciers is called moraine, and it forms natural dams for some glacial lakes.
• Among 2,431 lakes studied, 676 glacial lakes have expanded since 1984, with 130 located within India in the Indus, Ganga, and Brahmaputra River basins.
• The majority of expanding lakes are Moraine-dammed, followed by Erosion-dammed glacial lakes.
• Glacial lakes serve as freshwater sources for rivers in the Himalayan region but also pose significant risks such as GLOFs.