About Glacial Lake Outburst Flood:
- Glacial lakes are large bodies of water that sit in front of, on top of, or beneath a melting glacier.
- As they grow larger, they become more dangerous because glacial lakes are mostly dammed by unstable ice or sediment composed of loose rock and debris.
- In case the boundary around them breaks, huge amounts of water rush down the side of the mountains, which could cause flooding in the downstream areas. This is called glacial lake outburst floods or GLOF.
- It can be triggered by several reasons, including earthquakes, extremely heavy rains and ice avalanches
- These lakes are also often found in steep, mountainous regions, which means landslides or ice avalanches can sometimes fall directly into the lakes and displace the water, causing it to over-top the natural dam and flood downstream
Key facts about South Lhonak Lake
- This lake in northern Sikkim is situated about 5,200 metres above sea level.
- It formed due to the melting of the glacier.
- It is a moraine-dammed glacial lake at the snout of South Lhonak glacier, Sikkim Himalaya.
- It has become the largest and fastest-growing glacial lake in the state, with a glacial retreat of almost two kilometres in 46 years between 1962 and 2008.
