Avalanch Essay Research Paper Each year in — страница 2

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skier, snowboarder or snowmobiler. The edges are perpendicular to the fault and will slide perpendicular with the fault. (About Avalanches) A surface avalanche is another feature of avalanches. This type of avalanche is started on the surface and just keeps sliding down picking up speed and more snow burying things in its way. The surface avalanche is not as bad as a slab avalanche because it does not have the large slabs of hard ice and snow sliding on top crashing though things. The snow in avalanches moves very fast down the hills. The snow averages a speed of 150 – 200 miles per hour! That is very fast especially when there probably about 15-foot wall of snow coming down the mountain at 200 miles per hour. The snow can only reach that speed when there is sufficient angle on

the mountain. (About Avalanches, Encarta 98) Avalanches damage property. The fast moving snow takes out trees and houses in it way. Not much can stop the snow except itself, because trees and house don’t stand a chance against the fast hard snow. In the picture below you can see that the snow will ruin the land by ripping the trees down and smacking them into the house. That also moved the house off its foundation and pushed it for a couple hundred feet before stopping the slide. (Marchant 52-53, About Avalanches) This year alone 70 people have died from avalanches in Europe. Mostly all of them were skiers, snowboarder and hikers. This year in North America 32 people have died. Most of them were snowboarders, skiers, hikers and maybe a snowmobiler. The reason most of the people

are killed in the avalanches are that they are skiing or snowboarding and don’t stay in bounds and go out in the backcountry were no one knows where they are and if they were in the avalanche or not. So most of the people in the backcountry that are caught in the avalanches died of being beat around by the snow and hitting things or die of hypothermia. So when going in the backcountry don’t go alone and invest in an avalanche transmitter. The transmitter sends out a signal for people can find you when you are buried in the snow in the middle of no where. So to avoid dying while skiing and snowboarding in an avalanche stay out of the backcountry and stay on the marked groomed trails. (Marchant 52-53, About Avalanches) How Avalanches are caused. There are four main reasons that

avalanches are caused. One main key factor is the weather. 90% of avalanches are caused during snowstorms. The weather in most important factor in determining whether an avalanche will happen, next to the evaluation of the snow. There are many variable in the weather that have an affect on the avalanche activity. For instance, if there is a SW wind of 25mph is indicated with freezing temperatures and snow is know to be lying then it may be assumed that some avalanche risk will be building on the NE facing slopes. The information provided on the temperature, wind speed and direction often enables people to make useful predictions before leaving home. When hiking after drifting and storms do watch out for cornices they look like this. This is a hazard and can be avoided if you are

watching where you are climbing and know the ground fairly good. The diagram shows the possible avalanche fracture line, so try to give them a wide berth to prevent starting an avalanche. Another Factor in avalanches is the terrain. The terrain consists of the slope profile and the ground surface. The slope profile consists of the type of slopes, and which ones are more dangerous. The most large slab avalanches run on the slopes between 25 and 45 degrees. This range includes the average angle of coire backwalls and approach slopes to crags. The convex slopes are generally more hazardous than uniform or concave slopes. The point of maximum convexity is a frequent site of tension fractures, with the release of the slab avalanches. Ridges or buttresses are better choices than open

slopes and gullies when avalanche conditions prevail. The crest of the mountain ridges is usually protected from avalanches, while climbing in situations, rock belays on ribs and buttresses can often provide security. (About Avalanches) Snowpack is another factor in causing avalanches. When there is adequate visibility, snowpack observations can begin from the roadside. The evidence of recent avalanche activity, main snow accumulation, and fresh loading snow and drifting can often be noted from below. When proceeding up the mountain take note of foot penetration, cornice build up, ease of release of small slabs and effect which localized wind patterns may have had on the slab. To get an accurate note on the snow layers you can dig a pit. Do not dig your pit on the main slope, but