New Delhi: An avalanche hit Chamoli district in Uttarakhand, trapping over 50 construction workers. The road is closed due to an avalanche near the Border Road Organisation (BRO) camp in the border area of the Mana village. The Indo-Tibetan Border Police (ITBP) and the Army are engaged in the rescue operation, while the State Disaster Response Force (SDRF) and National Disaster Response Force (NDRF) are about to reach the spot.
As an avalanche has hit Uttarakhand’s Chamoli, let us understand what an avalanche is and how it occurs.
Understanding Avalanche Formation and Triggers
An avalanche is a quick snow flow down a slope, like a hill or mountain. It can happen on its own due to heavy snowfall or weak snow layers or be triggered by people, animals, or earthquakes. Avalanches mainly consist of flowing snow and air. Large avalanches can also carry ice, rocks, and trees with them.
There are two main types of avalanches: slab avalanches, which are made of tightly packed snow and are triggered by the collapse of a weak layer beneath, and loose snow avalanches, which consist of looser snow. Once triggered, avalanches can pick up speed and grow bigger as they collect more snow. If they move fast enough, they can mix with air and create powder snow avalanches.
Although avalanches might seem similar to slush flows, mudslides, rock slides, or ice falls, they differ from these events. Avalanches can happen in any mountain range with a persistent snowpack. They usually occur in winter or spring, but they can happen at any time of year. In mountainous areas, avalanches are serious natural hazards that threaten lives and properties, leading to efforts to control them. There are various ways to classify avalanches based on their size, destruction potential, how they start, what they are made of, and how they behave.
Most avalanches happen during storms due to heavy snow or erosion. Changes in the snowpack, like melting from the sun, are the second largest reason for natural avalanches. Other natural triggers include rain, earthquakes, and falling rocks or ice. Human activities like skiing, snowmobiling, and controlled explosives can also trigger avalanches. Contrary to popular belief, loud sounds do not trigger avalanches; the pressure from sound is too weak to cause one.
Avalanches can start with a small amount of moving snow, especially in wet or dry, loose snow conditions. However, if snow has formed a stiff slab on a weak layer, fractures can spread quickly, causing much snow to move simultaneously.
An avalanche occurs when the snow’s weight exceeds the snowpack’s strength. The load is simply the weight of the snow, but measuring the strength of the snowpack is complex. It depends on the snow grain properties, like size, density, and moisture, and how these properties change over time due to humidity, temperature, and radiation. One goal of avalanche research is to create computer models to describe how the seasonal snowpack changes.
Climate Change and Avalanche Risk
Avalanche formation and frequency depend heavily on weather patterns and local climate. Snowpack layers form differently based on temperature and humidity conditions. Climate change can affect when, where, and how often avalanches occur and their types.
Climate change may lead to a higher seasonal snow line and fewer days with snow cover. Temperature increases and changing precipitation will affect mountain regions differently, impacting avalanches in various ways. For example, lower elevations may see a decline in avalanche frequency due to less snow cover. Higher elevations above the snow line may experience more avalanche activity from increased winter precipitation. Storms may become stronger, leading to more days with enough snowfall to make the snowpack unstable. Moderate and high elevations may also see wild weather swings and more rain may fall during snow events.
Impacts on Burial Survival Rate
Climate change may lead to warmer, wet snowpacks, making avalanche burials more dangerous. Warm snow has more moisture and is denser than cold snow. This dense snow can make it harder for someone buried to breathe and reduces their time to get oxygen. As a result, the risk of death from asphyxia increases in these situations. Additionally, thinner snowpacks can raise the chances of injury from trauma, like a skier hitting a rock or tree while buried.
A devastating avalanche near Mana village in Uttarakhand’s Chamoli district has trapped over 50 construction workers. The article explains avalanche formation, triggers (heavy snowfall, weak snow layers, human activity), and the influence of climate change on avalanche frequency and severity, highlighting the dangers of warmer, wetter snowpacks. knowledge Knowledge News, Photos and Videos on General Knowledge
