Sonamarg Avalanche
Kartavya Desk Staff
Source: ABP
Subject: Geography/Disaster Management
Context: Massive avalanches struck the Sonamarg tourist resort in Jammu and Kashmir, engulfing buildings and vehicles following heavy snowfall that disrupted the Jammu-Srinagar National Highway and forced the cancellation of all flights.
About Sonamarg Avalanche:
What is an Avalanche?
• An avalanche is a rapid downslope movement of a large detached mass of snow, ice, and associated debris, such as rocks and vegetation.
• It occurs when the force of gravity on the snow cover exceeds its mechanical strength, causing the snowpack to fracture and descend rapidly down a mountainside.
Types of Avalanches:
• Slab Avalanches: The most dangerous type, where a cohesive layer of snow reacts as a single entity and breaks free along a distinct fracture line.
• Loose Snow Avalanches (Sluffs): Formed in snow with little internal cohesion; they originate at a point and grow wider as they descend (inverted-V shape).
• Powder Snow Avalanches: Composed of dry snow that generates a turbulent dust cloud (aerosol) capable of reaching speeds up to 300 km/h.
• Wet Snow Avalanches: Triggered by melting or rain, these move more slowly but possess enormous destructive force due to high snow density.
• Ice/Rock/Debris Avalanches: Involve the sliding of massive chunks of ice (often from glaciers), rocks, or a mix of soil and loose stones.
Factors Causing Avalanches:
• Steep Slopes: Most dangerous avalanches originate on slopes with inclinations between 30° and 45°.
• Heavy Snowfall: Rapid accumulation (e.g., 1m in one day) overloads the snowpack faster than it can stabilize.
• Snowpack Layering: The presence of a weak layer beneath a cohesive slab creates a glide surface for potential release.
• Weather Changes: Rapid temperature rises or rain-on-snow events lubricate layers and decrease the mechanical strength of the snow.
• External Triggers: Seismic activity (earthquakes), human actions (skiing, construction), or loud vibrations (machine noise) can dislodge unstable snow.
Implications of Avalanches:
Primary Impacts:
• Loss of Life:Victims often die from suffocation, trauma, or hypothermia if not rescued quickly.
• Structural Destruction:Impact forces can crush buildings, power lines, and bridges not designed for such loads.
• Transport Disruption:Avalanches frequently block vital highways and railroads, sweeping away or burying vehicles.
• Secondary Impacts: Communication Isolation:Severed power and telephone lines can leave mountain communities disconnected for days. Economic Losses:Disruption to tourism, agriculture, and high-altitude developmental projects causes significant financial strain. Environmental Damage:Massive slides can result in the destruction of entire forests and alter local ecosystems.
• Communication Isolation:Severed power and telephone lines can leave mountain communities disconnected for days.
• Economic Losses:Disruption to tourism, agriculture, and high-altitude developmental projects causes significant financial strain.
• Environmental Damage:Massive slides can result in the destruction of entire forests and alter local ecosystems.
Initiatives Taken by the Government of India (GoI):
• Specialized Institutions: The Snow and Avalanche Study Establishment (SASE)—now under the Defence Geoinformatics Research Establishment (DGRE)—conducts cutting-edge research and provides daily forecasting.
• Advanced Monitoring: Deployment of 72 Snow Meteorological Observatories and over 100 Automated Weather Stations (AWS) to track snow stability in real-time.
• Modern Technology: Installation of India’s first Avalanche Monitoring Radar in North Sikkim, which can detect a trigger within three seconds.
• Strategic Infrastructure: Construction of avalanche-resistant tunnels like the Atal Tunnel and Zojila Tunnel to ensure all-weather connectivity.
NDMA Guidelines on Avalanche Management:
• Hazard Zonation Mapping: Systematic identification and mapping of avalanche-prone areas to guide land-use planning.
• Structural Control: Implementation of supporting structures in starting zones (nets, fences) and deflecting structures (walls, mounds) in run-out zones.
• Early Warning Systems: Integration of satellite remote sensing and ground-based sensors to provide at least 24-hour advance warnings.
• Community Preparedness: Educating local populations on self-survival techniques and equipping them with tools like beacons, probes, and shovels.
• Institutional Coordination: Strengthening the roles of the NDMA, SASE, and BRO to ensure rapid snow clearance and rescue response.
Conclusion:
The increasing frequency of avalanches in the Himalayas, as evidenced by the Sonamarg event, underscores the critical intersection of climate change and mountain development. Effective management relies on a shift from relief-centric activities to science-based planning, including real-time radar monitoring and resilient infrastructure.
Q. What are the key climatic and geomorphological factors contributing to avalanche formation in the Indian Himalayas? How do they differ from those in mid-latitude mountain systems? (10 M)