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Context: A study identified 219 hanging glaciers in Uttarakhand’s Alaknanda basin, warning that warming and permafrost thaw are increasing break-off risks — potentially triggering ice-rock avalanches and outburst floods.
What a Hanging Glacier Is
- A glacier that originates high on a mountain wall or valley flank
- And terminates abruptly at the edge of a steep precipice or cliff face
- Rather than flowing down into a main valley floor
- Its snout ends high above the valley trough
- Routinely shedding ice through calving, icefalls and avalanches
Where They Are Found
Globally: high-relief alpine environments — the European Alps, the Andes, the North American Rockies, and the Himalaya-Karakoram range
In India: heavily concentrated along the steep, glaciated slopes of:
- Garhwal and Kumaon Himalayas (Uttarakhand)
- Himachal Pradesh
- Ladakh
- Sikkim
How They Form — Three Processes
- High-altitude accumulation: Heavy snowfall collects in steep niches, ledges and cirques → compacts into firn → glacial ice.
- Glacial retreat: Warming causes trunk/valley glaciers to thin and retreat, disconnecting smaller tributary glaciers → leaving them perched high on mountain walls.
- Thermal destabilisation: Rising temperatures thaw permafrost and basal ice, producing meltwater that lubricates the glacier–bedrock interface → making hanging glaciers unstable and prone to collapse.
