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.
| About GLOFs
· Glacial Lake Outburst Floods (GLOFs) occur when glacial lakes release large volumes of meltwater due to the failure of natural dams, leading to sudden and severe flooding downstream. · GLOFs can be triggered by various factors including avalanches of ice or rock, extreme weather events, global warming, earthquakes, etc. · GLOFs are recognized as a potential climatological disaster in the National Disaster Management Plan 2019 of India.
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