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Avalanche

Recently, soldiers and civilians were killed due to Avalanche in the Northern part of the Siachen glacier.

Where is Siachen glacier located?

1. It is located around 20,000 feet above the mean sea level, in the Karakoram range.

2. It has hostile weather conditions where temperatures can drop as low as -60oC during winters.

3. Avalanches and landslides are common in the region.

What are Avalanches?

1. Avalanches are a mass of snow, rock and soil that slides down the mountain.

2. It can be sudden and deadly especially for those living in foothills or the base of mountains in cold climates.

Types of avalanches

1. Loose snow: When there a fresh snowfall and it’s unable to grip itself to the mountain, that time the snow moves down thus causing an avalanche.

2. Slab avalanche: Slab is the formation of ice into a large block of slab which slips down a mountain side.

Classification of avalanche components

1. Starting zone: These zones are usually unstable part and are generally, high-up on the mountain.

2. Avalanche track: It is the natural path of avalanche that proceeds downhill after the slide begins.

3. Runout zone: Avalanche finally comes to a stop at bottom of the slope or in the run of zone where the snow and debris pile up.

Which are the factors causing Avalanches?

1. A mountain slope and thick layer of snow, along with terrain, snowpack and weather conditions can cause avalanches.

2. The weak layer collapses causing the overlaying mass of snow to fracture and start to slide.

3. Earthquakes can also trigger strong avalanches.

4. Avalanches are natural occurrences, but human factors also contribute.

5. Human triggered avalanches start when somebody walks or rides over a slab with an underlying weak layer.

6. Warm winters in the Himalayas are increasing the frequency of avalanches.

7. In cold conditions, slopes shaded from direct sun stay cooler and prevent bonding between snow layers leading to more avalanches.

8. In spring season sunny mountain sides have a higher risk of avalanches because of rapid warming and melting.

The Himalayas are known as the third pole. The Himalayas, Tibetan plateau and Hindukush mountains are home to the largest permanent ice mass outside of the Arctic and the Antarctic.

When do avalanches happen?

1. In the northern hemisphere, avalanches generally occur in winter months between December and April. The highest risk period is during and immediately after the snowstorm.

2. During this time underlying snowpack comes under pressure by a quick flood of snow causing the weak layer beneath the slab to fracture.

3. In India, avalanches generally occur after the passing of the Western Disturbances which causes the snowfall.

Conditions for Avalanches

1. Snow slides can start on slopes that have at least 30-degree incline but occur most frequently on slopes of 35 to 50 degrees.

2. Large avalanches starts at slop and can accelerate downhill.

Why is the Indian Army posted in Siachen?

1. Pakistan under the Operation name Ababeel tried to occupy the Siachen region.  

2. In 1984, India’s counter Operation Meghdoot pre-empted these efforts.

3. It is known as the highest militarized zone in the world.

How is Army trying to tackle the avalanche problem?

1. Since April 1984, over 1000 Indian soldiers including officers have lost their lives in Siachen glaciers due to Avalanches.

2. The army is consistently researching and developing innovations to prevent avalanches or reduce their impact.

3. Some of these measures includes

a. Snow and Avalanche Study Establishment that detail the study of avalanches from normal to highly dangerous.

b. Avalanche mitigation walls.

c. Avalanche detection devices.

d. Venture route markers.