Context:
An ISRO study linked the August 2025 flash flood in Uttarakhand (Dharali village) to the collapse of an ice patch on the Srikanta glacier, highlighting new risks from Himalayan deglaciation.
Key Highlights:
Scientific Findings & Event Analysis:
• Flash flood caused by collapse of an exposed ice patch in the nivation zone of the glacier
• Located in the upper Bhagirathi basin, a region prone to extreme events
• Resulted in loss of lives and infrastructure damage
Emerging Glacier Risks:
• Exposed ice patches due to thinning snow and firn layers
• Increased vulnerability to melting, fragmentation, and sudden collapse
• Expands hazard scope beyond Glacial Lake Outburst Floods (GLOFs)
Role of Satellite Monitoring:
• Use of satellite imagery and topographic analysis to reconstruct events
• Identification of ice patch exposure during ablation period
• Enables early warning systems for cryospheric instability
Geomorphological & Climatic Factors:
• Nivation processes (freeze-thaw cycles) weaken glacier zones
• Rising temperatures and heavy rainfall accelerate instability
• Similar risks observed in Arctic and Greenland regions
Relevant Prelims Points:
• Cryosphere: Includes glaciers, snow, permafrost
• Ablation: Loss of glacier mass through melting/sublimation
• Nivation: Erosion under snow due to freeze-thaw cycles
• Firn: Intermediate stage between snow and glacial ice
• GLOF: Sudden release of water from glacial lakes
• Bhagirathi River: Major headstream of the Ganga
Relevant Mains Points:
• Climate Change and Himalayan Vulnerability:
- Accelerated glacial retreat and thinning
- Increased frequency of flash floods, landslides, and debris flows
- New Dimension of Disaster Risk:
- Small-scale instabilities like ice patch collapse often overlooked
- Need to broaden hazard assessment beyond GLOFs
- Importance of Technology:
- Remote sensing and GIS crucial for monitoring inaccessible terrain
- Integration into early warning and disaster preparedness systems
- Challenges:
- Limited ground-based monitoring infrastructure
- Lack of real-time data integration
- Increasing unpredictability due to climate variability
- Way Forward:
- Expand satellite-based glacier monitoring systems
- Map nivation zones and vulnerable cryospheric areas
- Strengthen community-based early warning systems
- Integrate findings into disaster management policies (NDMA framework)
UPSC Relevance:
• GS 1: Physical Geography (Glaciers, Himalayas)
• GS 3: Disaster Management, Climate Change