Hanging glaciers: 219 found in Alaknanda basin
Why in the news
Researchers mapped 219 hanging glaciers across the Alaknanda basin of Uttarakhand and warned that a warming climate makes break-offs likelier.
Key facts
- Hanging glacier: ice that starts high on a mountain wall and ends abruptly at a cliff edge, its snout far above the valley floor; sheds ice by calving, icefalls and avalanches.
- World belts: Alps, Andes, Rockies, Himalaya-Karakoram.
- India: Garhwal and Kumaon (Uttarakhand), Himachal, Ladakh, Sikkim.
| Process | Mechanism |
|---|---|
| Accumulation | Snow packs into firn, then ice, in steep cirques and ledges |
| Retreat | Thinning trunk glacier strands its tributaries on the walls |
| Thermal destabilisation | Thawing permafrost and basal ice; meltwater lubricates the bed |
Concerns
- Higher break-off risk, leading to ice-rock avalanches and outburst floods.
Exam angle
- Basin and count: Alaknanda, 219.
- Three formation processes; term firn.