Introduction 
An avalanche occurs when a big amount of snow flows down a mountainside. Avalanches also pass through rocks slides and debris flows. It is also known as the biggest dangers and harm in the mountains because many lives were lost from this disaster. There are many factors that lead to an avalanche. Point-release avalanches happen when the internal strength of the snow layers cannot support the weight of the outer most layers. It occurs most often on steeper terrain. In contrast, slab avalanches occur when there is a strong and firm layer of snow, which is also called a slab. When large amount of snow are deposited on the lee slope, it can be deduced that a slab avalanche has occurred recently. Last but not least, the last starting type is a slush avalanche. It happens due to the saturation of snow of water.
When the avalanches move down the slope, the snowpack would grow in its size. It may alloy with air and transform into a powder cloud, which is known as a powder snow avalanche. It is a destructive snow particle that drifts as gravity current. Power avalanches are the largest avalanches that can reach 300km/hr and 10,000,000 tonnes of snow and can drift for a long distance along flat valley bottoms and also uphill for short distances.
The three main parts of an avalanche are the starting zone, the avalanche track and the run-out zone. The initial stage where the snow detaches from the entire layer is the process of the starting zone. This deformation of the original snow structure causes the starting zone to be the most unstable area, nearest to the summits of the snow mountain.
This is followed by the vertical path taken by an avalanche, ranging from the starting zone (usually near the summit), all the way down to the foot of the mountain (possibly at sea level). If the avalanche track can be distinguished by the naked eye, it infers that it is a track where large avalanches occur frequently. This is possibly because of an easy observation of the absence of trees or clearings resembling chutes.
At the very bottom of the avalanche track is the run-out zone, where large amounts of snow and debris are deposited and collected in a heap. This is the area of greatest danger: if people were to get caught in the path of an avalanche track, the sheer force would completely immerse them in the run-out zone, thus burying them. This could be fatal due to the coldness of the collected snow.
An avalanche occurs when a big amount of snow flows down a mountainside. Avalanches also pass through rocks slides and debris flows. It is also known as the biggest dangers and harm in the mountains because many lives were lost from this disaster. There are many factors that lead to an avalanche. Point-release avalanches happen when the internal strength of the snow layers cannot support the weight of the outer most layers. It occurs most often on steeper terrain. In contrast, slab avalanches occur when there is a strong and firm layer of snow, which is also called a slab. When large amount of snow are deposited on the lee slope, it can be deduced that a slab avalanche has occurred recently. Last but not least, the last starting type is a slush avalanche. It happens due to the saturation of snow of water.
When the avalanches move down the slope, the snowpack would grow in its size. It may alloy with air and transform into a powder cloud, which is known as a powder snow avalanche. It is a destructive snow particle that drifts as gravity current. Power avalanches are the largest avalanches that can reach 300km/hr and 10,000,000 tonnes of snow and can drift for a long distance along flat valley bottoms and also uphill for short distances.
The three main parts of an avalanche are the starting zone, the avalanche track and the run-out zone. The initial stage where the snow detaches from the entire layer is the process of the starting zone. This deformation of the original snow structure causes the starting zone to be the most unstable area, nearest to the summits of the snow mountain.
This is followed by the vertical path taken by an avalanche, ranging from the starting zone (usually near the summit), all the way down to the foot of the mountain (possibly at sea level). If the avalanche track can be distinguished by the naked eye, it infers that it is a track where large avalanches occur frequently. This is possibly because of an easy observation of the absence of trees or clearings resembling chutes.
At the very bottom of the avalanche track is the run-out zone, where large amounts of snow and debris are deposited and collected in a heap. This is the area of greatest danger: if people were to get caught in the path of an avalanche track, the sheer force would completely immerse them in the run-out zone, thus burying them. This could be fatal due to the coldness of the collected snow.
Causes
Snow avalanches occur when the outermost layer is unable to support the mass of the inner layers of snow. There is a low timber line that will worsen the threat because when it begins to move, the trees help to hold the snow and decrease the pace. Avalanches are caused by a surplus of materials, which increases the chance of causing an avalanche. It is caused by a number of factors, which include terrain, snow structure and characteristics, and weather.
Snow avalanches occur when the outermost layer is unable to support the mass of the inner layers of snow. There is a low timber line that will worsen the threat because when it begins to move, the trees help to hold the snow and decrease the pace. Avalanches are caused by a surplus of materials, which increases the chance of causing an avalanche. It is caused by a number of factors, which include terrain, snow structure and characteristics, and weather.
There is a low risk of avalanche when slopes are flatter than 25 degrees and steeper than 60 degrees. Snow does not aggregate on steeper slopes and also does not flow easily on flatter slopes. The angle of repose can be very effective. Avalanches are gre
at between 35 and 45 degrees and greatest on 38 degrees. The more man-made modifications like skiers are applied to a snow mountain, the more likely an avalanche will occur at greater frequencies. Many different snow composition and deposition characteristics affect the likely of an avalanche. In order for an avalanche to occur, a snowpack must have an instable layer below the surface. Weather can be a big influence of an avalanche. Avalanche occurs when the temperature is high and gentle free-thaw cycles take place. This cycle is the melting and refreezing of water in the snow, which strengthens the snow when freezing and weakens when melting. If there is a sudden rise in the temperature, an avalanche would occur.
at between 35 and 45 degrees and greatest on 38 degrees. The more man-made modifications like skiers are applied to a snow mountain, the more likely an avalanche will occur at greater frequencies. Many different snow composition and deposition characteristics affect the likely of an avalanche. In order for an avalanche to occur, a snowpack must have an instable layer below the surface. Weather can be a big influence of an avalanche. Avalanche occurs when the temperature is high and gentle free-thaw cycles take place. This cycle is the melting and refreezing of water in the snow, which strengthens the snow when freezing and weakens when melting. If there is a sudden rise in the temperature, an avalanche would occur. Effects
On November 13th, 1995, an avalanche occurred in the Mount Everest region, Nepal. It is known as Nepal's worst accident. This accident killed 26 people, 50% were Japanese. The wave of snow buried 11 porters and guides. Also, it buried 2 of the Pangka region, which is known as the world's highest peak. Mr. Miyahara: "The area was completely covered by snow. We could only see rooftops of the huts where the trekkers were staying."
On November 13th, 1995, an avalanche occurred in the Mount Everest region, Nepal. It is known as Nepal's worst accident. This accident killed 26 people, 50% were Japanese. The wave of snow buried 11 porters and guides. Also, it buried 2 of the Pangka region, which is known as the world's highest peak. Mr. Miyahara: "The area was completely covered by snow. We could only see rooftops of the huts where the trekkers were staying."
Protection Measures
There are ways to prevent avalanches from happening, for example "Explosives". Large avalanche disasters are prevented by the use of explosives on small snow mountains to reduce the build up of snow. Snow fences and light walls are built direct of snow. Snow is built around the fence and facing the prevailing winds, causing the snow build-up to be less. Besides, when there are many trees, they can decrease the strength of the avalanches. When there is an avalanche, the tree causes the snow to slow down. Furthermore, artificial barriers can be effective to reduce avalanches. There are few kinds, which include snow net, which is a composed of guy wires that strengthen their foundations in the earth, thus increasing their capacity, to prevent avalanches. Snow net can be constructed of steel, wood, or concrete. Also, earth mounds are placed on the path of the avalanches to slow the pace.
There are ways to prevent avalanches from happening, for example "Explosives". Large avalanche disasters are prevented by the use of explosives on small snow mountains to reduce the build up of snow. Snow fences and light walls are built direct of snow. Snow is built around the fence and facing the prevailing winds, causing the snow build-up to be less. Besides, when there are many trees, they can decrease the strength of the avalanches. When there is an avalanche, the tree causes the snow to slow down. Furthermore, artificial barriers can be effective to reduce avalanches. There are few kinds, which include snow net, which is a composed of guy wires that strengthen their foundations in the earth, thus increasing their capacity, to prevent avalanches. Snow net can be constructed of steel, wood, or concrete. Also, earth mounds are placed on the path of the avalanches to slow the pace.Conclusion
The rate of global warming will weaken the snow and making it easier to melt. The impact that this will have on snow-mountains is that it will increase the tendency of an avalanche to occur. In addition, if the population of a snow-mountainous country continues to increase, then the amount of man-caused disturbance will also impact on the frequency of avalanches.
The rate of global warming will weaken the snow and making it easier to melt. The impact that this will have on snow-mountains is that it will increase the tendency of an avalanche to occur. In addition, if the population of a snow-mountainous country continues to increase, then the amount of man-caused disturbance will also impact on the frequency of avalanches.
Sources:
http://query.nytimes.com/gst/fullpage.html?res=9A00EEDD1539F931A25752C1A963958260&sec=&spon=&pagewanted=print
http://www.sarinfo.bc.ca/Library/Rescues/Everest.NEP
http://en.wikipedia.org/wiki/Avalanche
http://query.nytimes.com/gst/fullpage.html?res=9A00EEDD1539F931A25752C1A963958260 http://www.sarinfo.bc.ca/Library/Rescues/Everest.NEP
http://query.nytimes.com/gst/fullpage.html?res=9A00EEDD1539F931A25752C1A963958260&sec=&spon=&pagewanted=print
http://www.sarinfo.bc.ca/Library/Rescues/Everest.NEP
http://en.wikipedia.org/wiki/Avalanche
http://query.nytimes.com/gst/fullpage.html?res=9A00EEDD1539F931A25752C1A963958260 http://www.sarinfo.bc.ca/Library/Rescues/Everest.NEP
