Why in News?

Rising temperatures and changing precipitation patterns are destabilising Himalayan glaciers, increasing the risk of glacier collapse, avalanches and downstream hazards. A 2026 study identified 219 hanging glaciers in the Alaknanda basin of the Garhwal Himalayas, highlighting their growing threat potential.

What are Hanging Glaciers?

Definition:

  • Hanging glaciers are masses of ice located on steep mountain slopes, often detached from the main glacier system
  • Due to their unstable position, they can suddenly break off and trigger hazardous ice and rock avalanches

Formation Process:

  • Rapid warming: Climate-induced temperature rise alters glacier structure and movement
  • Glacier retreat: Causes geometric changes in ice distribution
  • Structural weakening: Ice redistribution leads to development of unstable formations on steep slopes
  • Climate variability: Changing precipitation patterns accelerate destabilization

Global Context:

  • Hanging glaciers have been extensively studied in the Alps
  • Basin-scale assessments in the Himalayas remain limited due to:
  • Difficult terrain
  • Inadequate monitoring infrastructure
  • Limited accessibility for researchers

Risks Associated with Hanging Glacier Collapse

1. Avalanche Hazards

  • Break-off of hanging glaciers can generate massive ice avalanches
  • Simulations indicate avalanche flows in the Badrinath–Mana sector of Uttarakhand could exceed 50 metres in height
  • Potential to damage settlements and infrastructure downstream

2. Glacial Lake Outburst Floods (GLOFs)

  • Glacier collapse can trigger secondary hazards including GLOFs
  • Sudden release of water from glacial lakes causes destructive downstream flooding
  • Moraine dam failures pose significant threat

3. Cascading Hazards

  • Collapsing glaciers carry rocks, snow and sediments downhill
  • Generate compound hazards:
  • Debris flows
  • River blockages
  • Sudden floods
  • Landslides

4. Infrastructure Threat

Vulnerable infrastructure includes:

  • Hydropower projects
  • Roads and bridges
  • Settlements in valley areas
  • Pilgrimage routes (e.g., Char Dham yatra routes)

Study Findings: Alaknanda Basin

Key Statistics:

  • 219 hanging glaciers identified in the Alaknanda basin (April 2026 study, published in Nature)
  • Nearly one-third of unstable hanging ice mass concentrated in Upper Alaknanda basin

Risk Projections (2000-2030):

  • 120% increase in avalanche-risk exposure for buildings and infrastructure land area
  • 17% increase in population living in risk-prone areas
  • Significant threat to downstream settlements and infrastructure

Related Concepts

Glacial Lake Outburst Floods (GLOFs)

  • Sudden releases of large volumes of water stored in glacial lakes
  • Caused by failure of natural ice or moraine dams
  • Can cause catastrophic downstream flooding

Disaster Management Framework

  • National Disaster Management Authority (NDMA) guidelines address cloudburst and glacier-related hazards
  • Focus on mitigation measures for Himalayan regions
  • Emphasis on early warning systems and infrastructure resilience

UPSC Previous Year Questions

Prelims (2020): Siachen Glacier is situated to the North of Nubra Valley

Mains (2016): Discuss measures to mitigate impact of cloudburst incidents in Uttarakhand with reference to NDMA guidelines