8-March-2025-Editorial

AVALANCHE IN THE HIMALAYAS

Avalanches are a natural disaster that occurs when snow, ice, and debris rapidly slide down a mountain slope. The recent avalanche in Uttarakhand’s Chamoli district highlights the increasing risk of avalanches in the Himalayas due to climate change and rising temperatures.

What is an Avalanche?

• An avalanche is the rapid movement of snow, ice, and debris down a mountain.
• It can carry earth, rocks, and rubble, leading to large-scale destruction.
• Avalanches occur most frequently between December and April due to heavy winter snowfall and spring thawing, which weakens snow layers.

Types of Avalanches

Loose Snow Avalanche:

• Begins from a single point where snow is loosely bonded.
• Spreads in an inverted V-shape as it moves down.
• Less dangerous due to lower volume and speed.

Slab Avalanche:

• Occurs when a cohesive layer of snow breaks away from underlying layers.
• Can reach speeds of 50–100 km/h, causing extensive damage.

Gliding Avalanche:

• The entire snowpack slides over a smooth surface, such as rock or grass.
• Leaves a visible fracture line, separating it from remaining snow.

Wet-Snow Avalanche:

• Triggered by rising temperatures or rainfall, which weakens snow layer bonds.
• Often occurs in spring or during sudden warming events.

Causes of Avalanches

Natural Causes

• Heavy Snowfall: Accumulation of large amounts of snow increases weight and instability.
• Weak Snow Layers: Temperature fluctuations weaken snowpack bonds, making them prone to sliding.
• Sudden Warming: Rapid temperature rise leads to wet-snow avalanches.
• Earthquakes: Seismic activity can disturb snow layers, triggering avalanches.

Human-Induced Causes

• Deforestation: Tree roots provide natural slope stability; their removal increases avalanche risks.
• Adventure Tourism: Activities like skiing and mountaineering disturb the snowpack, potentially triggering avalanches.
• Climate Change: Rising global temperatures lead to frequent freeze-thaw cycles, increasing avalanche frequency.

Difference Between Avalanches and Landslides

Basis	Avalanche	Landslide
Definition	Movement of snow and ice down a slope	Movement of soil, rocks, or debris
Causes	Heavy snowfall, unstable snowpack, wind, temperature changes	Earthquakes, floods, deforestation, heavy rains
Material Involved	Snow and air	Soil, rocks, or mud
Occurrence	Snowy mountainous regions	Land with steep slopes
Speed	Very fast (up to 250 miles per hour)	Can be fast or slow

Why the Himalayas Are More Prone to Avalanches

Rising Temperatures:

• The Himalayas are warming faster than the global average, leading to glacier melt and shifting snow lines.
• Avalanches have increased in the western Himalayas since the 1970s.

Wetter Snow Conditions:

• Warmer temperatures cause more rain instead of snow, weakening snow layers.
• Rainwater infiltrates the snowpack, reducing friction and increasing avalanche risks.

Permafrost Melting:

• Thawing of permanently frozen ground leads to water accumulation, making snow layers more prone to sliding.

Increased Wind Speeds:

• Higher wind speeds transport snow, making fresh layers unstable.

Seismic Activity:

• The Himalayas lie in a tectonically active zone, where earthquakes can destabilize snow-covered slopes.

Karakoram Anomaly Unlike other Himalayan regions, glaciers in the Karakoram Range have remained stable or even gained mass. This anomaly contrasts with global trends of glacier retreat due to climate change.

Measures to Mitigate Avalanche Risk

1. Early Warning Systems (EWS)

• Monitor snow conditions using satellite data and sensors.
• Issue alerts when weak snow layers are detected.
• Example: India’s first avalanche monitoring radar was installed in Sikkim in 2022.

2. Snowpack Testing

• Conducting regular tests to assess the stability of snow layers and predict avalanche risks.

3. Defensive Structures

• Snow Sheds: Protect roads and railways from snow slides.
• Splitting Wedges: Divert avalanche flow away from settlements.

4. Artificial Avalanche Triggering

• Controlled explosions help trigger smaller, less destructive avalanches.
• Commonly used in ski resorts and mountain highways.

5. Afforestation and Land Stabilization

• Planting trees helps hold snow and reduce the likelihood of avalanches.
• Reducing deforestation in sensitive zones can enhance slope stability.

6. Dual-Purpose Infrastructure

• Constructing multi-functional dams to manage water flow post-snowmelt and prevent floods.

Conclusion

Climate change is intensifying the frequency and severity of avalanches in the Himalayas. Rising temperatures, melting glaciers, and increasing rainfall are making snowpacks more unstable. To protect lives and infrastructure, a combination of early warning systems, structural defenses, community awareness, and controlled snowpack management is essential. Proactive measures will ensure better disaster preparedness and resilience in avalanche-prone regions.