An avalanche is the flow of snow down the mountain side. Avalanche is one of the biggest danger in mountains for both life and property. The speed of the avalanche depends on the quality of snow. If the snow is very wet, the speed of the avalanche will travel with great speed. The angle of the slope on which avalanche occurs is an important factor in causing variations of speed as well.
(Picture 1: Avalanche falling down)
-------
What causes the Avalanche?
The causes of the avalanche is divided into 4 factors:
-Steep slopes of the mountain
-Heavyweight of snow
-The saturation of water within the snow
-Strong winds that blow on the snow
The steep of the mountain slopes are very important. The steep of the slope is the highest pressure that gravity "push" on. The slope with less than 22 degree is likely to have an avalanche. Not only the slope is being determine, but also the mass of the snow. This is common logic. Since the snow is on the mountain, the gravity will push pressure greatly on the high area. So if the snow is already heavy, the great pressure will cause the snow to fall down. The saturation of water can also affect the mass of the snow. Lastly, if the wind is very strong, it can eventually blow the snow to fall down.(Picture 2: graph of the mountain slopes)
-------
What effect does the avalanche cause?
- death of the people
- destruction to many buildings and other facilities such as transportation, bridges, communication etc...
- Many trees are being covered or unroot by the snow
- Due to the destruction, a lot of money have to be use in order to fix the facilities
- Hunger can over come among the people, since the shops are close.
- damage of the crops
(Picture3: graph of the survival time when buried under the snow)
-------
Areas of the world that are affect:
(The pink area is where the avalanche happens)
Most areas that are affect by the avalanche are countries that have snowfall. This is the list of continents from the most mojority areas to the minority areas:
1) Asia (upper nothern hemisphere)
2) Europe
3) North America( Alaska and greenland)
4) South America (Peru)
5) Africa and Australia
-------
What can we do for prevention?
The government in countries have decided to try and come up with the prevention. First of all, there is a warning sign in different ski resorts to warn about the avalanch risk. The government has forbidden everyone to go near the mountain, when there is a warning of the avalanche that might likely to happen. The government has ordered that huge trees (many as possible) are to be planted near the mountaina, because the huge trees can prevent the snow coming down. Lastly, they built a snow net barrier, this can also prevent the snow coming down a bit.
Picture 5: the snow net
-------
The worst avalanche that ever happen was in a LEDC country, Peru. It happened on 31 May 1970 when one of the strongest earthquake made the summit ice-cap on the lofty morth peak of Huascaran to collapse down. Thousands tonnes of rocks were displaced by the falling ice and as these crash down into the glacier, a gigantic debris flow was generated. This snow has swept the Rio Shacsha valley. This avalanche has caused 700,000 deaths. The problem for this might be because the communications were cut off. The building wasn't strong enough to stand the snow. Lastly, there wasn't any warning about the upcomin avalanche. After the avalanche, they were very desperate for money to build up the construction. It has cost them a fortune, therefore they got help from other countries. (UN)
One of the famous avalanche in MEDC country are Andermatt, Vals and Airolo, Switzerland in 1950-1951. This avalanche has caused Switzerland to pay 2.2 millino pounds to fix up all of the 650 facilities. There were a loss of livestock, the damage in agriculture, forest land, outlay in new buildings, communication and power lines. Overall deaths from these avalanches are 41 people.
Therefore, LEDCs country will be more effective than the MEDC because of money. LEDCs country are quite poor to provide better communication and protections againts the avalanche. The LEDC couldn't afford the amount that they have to pay.
Picture 6: Huascaran avalanche areas
Picture 7: Switzerland avalanche
-------
Why people live in hazard prone area?
In LEDCs country, people were too poor to move to another country. If they move they will not have any houses to stay, but in MEDc is a different story. Most of the people that got affected were tourists that going for the ski. Therefore, it is very sudden for the avalanche to happen. Most of the country in the MEDCs are wealthly country. For example: Alaska, Switzer, France etc... People didn't want to move because of that facts.
Picture 8: Ski resort
-------
Conclusion:
Avalanche might have been the least 'unconcern' to some part of the world, because the avalanche involved sonw only. But it actually has caused a huge impact to the world such as the lives of the people, damage to the properties etc... Therefore, we should consider that avalanche is one of the major disaster in the world!
Internet Sources: http://www.wikipedia.org/,
Book sources:
-FW. Lane. 1986. The Violent Earth. British Library. Italy. Pages 107-109
-Whittow,John. 1979.The anatomy of environmental hazards disasters. University of Geogia Press. Great Britain. Pages 137-140
