Avalanche Essay, Research Paper
What is a avalanche? To most of you it is the fall of snow from the top of a slope. Well you are partially right. It is snow but it can also be several other things such as soil, rock, ice, or volcanic lava. Although most of the time a avalanche is snow it can be rock or soil.
Most avalanches occur on slopes exceeding 30 degrees (Encarta 1.) They are caused by temperature, creeping snow , or vibrations. There are three main types of avalanches (Walker 6-7.) They are slab, dry-snow, and wet-snow. Slab avalanches occur when a slab of packed snow or ice breaks away from the mountain side and travels down the side destroying anything in its way. The aftermath of the avalanche is usually covered under snow. This is because when the slab is traveling downhill it hits objects, like trees, and it starts to break up at the front and covers anything it passes over. It also puts out a huge blast of air that can over turn cars and knock down trees.
According to Jane Walker a more deadly avalanche is the wet-snow avalanche (6-7.) These avalanches form into huge boulders and will collect trees and other objects on the way down the hill. They travel at 20 miles per hour. Once at the bottom they can set as hard as cement. They mostly occur in the spring in rocky areas. A dry-snow avalanche is even more deadly then a wet-snow. When a dry-snow avalanche occurs it mostly stays close to the ground but can swirl hundreds go feet into the air. Like a slab avalanche it to puts out a blast of air, but more powerful. Its blast can equal hurricane forces.
As for where avalanches occur, it can be about anywhere. If you get some snow and have a slope more than 30 degrees you can have a avalanche. All that is needed for a avalanche to occur is snow and a slope. In the Alps avalanches count for the highest death toll. They can be very deadly. For example in Alaska some skiers triggered a avalanche but were lucky they did not die. Although the people in India were not so lucky, 23 people died 10\16\98(www.csac)
When do they occur? Scientist have narrowed this down to winter and spring. In the spring the snow melts and water get under a layer of snow and breaks it lose. In the winter a lot of snow fall on top of the old snow and does not have the time to cohere with the old snow. There are people that trigger avalanches with explosions or loud vibrations. This keeps avalanches from happening at the spur of the moment and putting peoples lives in danger. Avalanches are natures way of clearing land and if you are in the way you will be cleared to. So now you know what a avalanche is and where they happen so watch out where you live or where your going because you can get a rude awakening.