It is a great sight when we witness an avalanche in the movies. But the hazards and far-reaching effects on human and animals living in areas that are prone to avalanches are life-threatening. To find oneself amidst an avalanche is the worst experience that anyone can have and in most cases such situations turn out to be fatal as no one can fight against nature.
Fact 1 What is an avalanche
When snow flows at great speed down the slope mostly of very high mountains it is called an avalanche. This occurs when the forces on the snow at the starting point is too heavy for its base. It cannot carry the weight smoothly and as it slopes downwards it grows more in mass as more snow accumulates on it. Apart from snow, an avalanche carries with it ice, rocks, trees and whatever comes across on its path and becomes very dangerous for travelers who are caught in such natural calamity.
Fact 2 How does it occur
An avalanche occurs when a layer of snow collapses and slides downwards along the hillsides. They are caused by namely four factors. The slope where the block of ice is standing may be very steep, snow cover cannot hold its weight, there may be weak layer in the snow cover or a trigger like vibrations from construction or machineries, skiers, hikers or snowmobiles may cause an avalanche. Other factors that cause avalanches are natural causes like heavy rains, winds and storms, snowing and earthquakes and also warming temperatures.
Fact 3 Kinds of Avalanches
Avalanches are natural events and happen suddenly and the warning signs too are not always the same. In most cases, the snow slides are caused by humans like skiers, snowmobiles etc and are responsible for killing more than 150 people every year.
Some avalanches are small slides and the snow is dry and powdery and do not have any forms when they move. These slides are not very hazardous as compared to the organized avalanches. When massive slabs of snow become loose and break from the mountainside, they race down the slopes like shattered broken pieces of glass. The speed of these moving masses is sometimes 130 km per hour. Those who are caught in these types of avalanches seldom return home.
Fact 4 When do they occur
Avalanches occur mostly 24 hours after other natural disturbances like heavy snowing, rains or winds when snow is dumped of about 12 inches on the slopes of the mountains or even fresh snow is deposited. The piled-up snow puts pressure on the underlying snowpack. This leads to the formation of a weak layer beneath the slab and causes a fracture or a deep crack. When the slab cannot retain the extra weight of the outer snow, it begins to slope down the hillsides and as it is huge and heavy as it nears the lower level, it gathers more speed and bangs against whatever obstructs its path. It is really difficult to ascertain how the layers have been formed and their bonding and when they will become weak and cause a slide.
Canada experiences thousands of avalanches every year in almost all regions with more frequent slides in the mountains of British Columbia, Alberta and Yukon. To avoid risks, railway tracks are changed for safety reasons.
If you are planning to visit the amazing countries of Canada and the nearby regions, it is best to travel in groups. It is wise to take avalanche safety training. It is good to follow traffic rules and obey hem especially in areas that are marked as avalanche-prone zone. Avalanches rush down the slopes on to the main tracks and can lead to fatal consequences if care is not taken.