Avalanch Essay, Research Paper
Each year in the U.S. alone thousands of avalanches occur. The avalanches happen at many ski resorts, and sometimes killing and injuring people who went out of bounds or did not listen to the instructors. The avalanches also happen on other mountains that people are hiking and climbing on the mountains. In the Cascades every year lots of avalanches occur with out causing any damage to anything. This year alone in North America 32 people have died due to avalanches. Avalanches don’t have to happen on a mountain. They can happen were ever there is snow lying on ground of sufficient angle. In recent years there have been accidents with avalanches on the English Lakes, the Cheviots and the Pennines and Wales (Marchant 52-53, About Avalanches)
The rising amount of backcountry skiing and snowboarding is not good. That it because where they ski, the snow is not safe and is easily caused to slide. On Mount Baker in Washington a skier was 15 feet out of bounds and was covered by a 15-foot wave of snow. (Martinet 52-53)
Many things can and will cause avalanches. Many factors cause avalanches. Weather is the most important factor in determining whether avalanches are likely, and the evaluation of the snowpack is entirely dependent on this. The snowpack depends on the weather. One day it could be warm out, warming the snow to 0 degrees. Then the next day could 10 below. That would make the snow icy on top and kind of sugary underneath. That would be a likely problem for a hiker. They could cause some snow to slide and it would go fast. It would go fast because the sugary snow acts as ball bearings making the crusty layer slide in big sheets destroying things. An other weather factor is a storm. It is said that 90% of all avalanches occur
during snowstorms. Other weather factors also affect avalanche activity but not as much as storms and temperature.
Terrain also has an affect on how avalanches are caused. If the ground is rocky underneath the snow it is not a likely that an avalanche will start because the rocks will hold the snow between themselves and kind of packs the snow tighter. When the rocks are covered surface avalanche activity is unhindered. The terrain also consists of the Slope. When there is a slope between 25 and 45 degrees, you are more likely to have a large slab avalanche.
The snowpack is a very important factor in determining whether an avalanche may occur. When checking the snow layers there is no need to dig to the ground level, only the first reasonably thick layer of neve (refrozen old snow). Smoothing the back wall of the pit and probing with a finger all the way down may then identify the snow layer. Look for these features. Adjacent layers of different hardness, very soft layers, water drops squeezed out of a snowball made of any layer, layers of ice, layers of graupel (rounded heavily rimmed pellets), airspace, and layers of loose uncohesive grains.
The people on the mountains cause the avalanches too. They cause the avalanches by disrupting the snow by making loud noises, by skiing, snowboarding and snowmobiling also. All the carving in the snow by the people and their toys causes breaks in the snow and that creates a very likely factor for a slab avalanche. People all do other things that might not thing will cause an avalanche. (About Avalanches)
The physical characteristics of an avalanche can be broken down to the types of avalanches and what they do.
One avalanche is the slab avalanche. This kind of avalanche is large slabs of hard snow sliding on the surface of the graupel. The graupel works a ball barring for the slab to slide on. Allowing the snow to reach speeds of two hundred mile per hour. The slab of snow is often hard and destroys everything in its way.
The slab avalanche has a fracture of fault line where it breaks away from the other snow and starts to slide. The fault can be caused by almost anything, like a 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 on a small safe slope of similar orientation, it is safer. There will no need to dig to the ground level, only down to the first neve. (Refrozen old snow) Look for these following features.
? Adjacent layers of different hardness.
? Very soft layers (fist penetrates easily).
? Water drops squeezed out of a snowball made from any layer.
? Layers of ice.
? Layers of Graupel (Rounded heavily rimmed pellets) Acts as ball bearings in the snow pack.
? Feathery of faceted crystals.
? Layers of loose, uncohesive grains
? Airspace.
Any of the above might be the source of a dangerous weakness in the snowpack. You should perform this test every time before you climb or hike. This will help you to make an educated risk assessment.
The Lee slopes should be avoided after storms of heavy drifting. Their location will obviously vary according to wind direction, and will include sheltered side of ridges and plateau rims.
People on the mountain are really the main cause of the avalanche. Most of the people on the mountains are skiers, snowboarders, and climbers. The skiers and snowboarders make big cuts in the snow when they are turning going down the mountain. The grooves from the people can and do cause the snow to break apart and cause slab avalanches. The people do others things on the mountain, like cause loud noises and other things that they just don’t realize they did to tell others what might have caused the avalanche. The truth is that most of the avalanches are cause by the victims. It is said that 90% of avalanches are cause by the victims. (About Avalanches)
There are things a person can do to prevent being caught in an avalanche. One thing is keep a close watch on the weather and get the forecast before you go climbing. Do not climb or ski if there is a storm coming or it is drifting.
Be watching the temperature because that makes the snow loose or hard. If the snow gets to 0 degrees o day it will be loose and soft. Then the next day the snow will be hard and will slide in a big slab if breaks away. The loose warm snow would be more likely to give way than the hard snow so watch for that.
The wind is another factor. If it is drifting, the snow will be unstable because there will be new snow being placed in different places, and the snow will not have time to pack itself before you climb on it. Don’t climb when there is drifting and stormy conditions. The wind will also drop the temperature real fast when climbing or skiing watch for the warm snow turning to ice.
The snow layers also will help you prevent being caught in an avalanche. If you follow the checklist of layers that were said earlier you would have a good idea of the kind of risk you would be taking, if there were any of the dangers in the layers like that were said. If you head those warning signs of the snow layers you should be good in that area.
Check the terrain. When checking the terrain look for the type of slope on the mountain you will be climbing or skiing. What is underneath the snow? Is are there rocks underneath the snow is there, pits that drop out for a couple feet but have a thin crust over them. Ask a couple locals who have climbed the mountain before, and see what have to tell you about the terrain. (About Avalanches)
If caught in an avalanche you should try to do these things. The first thing you should try to do is try to delay your departure with the moving snow. You could do that by digging you climbing ax in to the snow or one of your ski poles, or try holding on to a tree or rock in you can. Also tie a rope your body, if you have on with you, then tie the other end to a tree or rock, this way you will not get carried very far down the mountain. (About Avalanches)
When you are being carried away by the snow scream, yell, shout, just try to make a lot of noise for people will be able to hear you and maybe find be able to locate you a lot faster. By doing that others can get an idea of where you might be on the mountain.(About Avalanches)
If you are near the fracture line try to run or jump up slope above the fracture line. You could also try to jump on a hard slab and try to remain on the top of it for a while, until the slide slows down.
Get rid of your gear, like your sacks, skis etc. This will help you maneuver better in the snow and will help your senses a little more.
Try rolling like a log with the snow it will help you be able to move around a little better. You can try a swimming motion because it sometimes helps you maneuver a little more. But every what you do, try to stay on the top of the moving snow, it will help save your life if everything else does not work. (About Avalanches)
If you get buried in the snow try to do some of these tricks or maneuvers. One thing keeps your hand in front of your face and tries to clear and maintain an air space. This will help you be able to breathe better. Also try to have a space near your chest for expansion, when you are breathing.
You should avoid panic and try and conserve your energy. Most likely your companions are probably looking for you. So stay calm; don’t waste all of your strength on trying to get out from where you are. If you try and get your hand out above the surface, other wise try and stay still, and try to breathe normally.
If you witness an avalanche burial you should proceed by doing the following.
? Observe the victim’s progress, and if possible mark the point of entry and point at which last seen.
? Check for further avalanche danger.
? Make quick search of the debris surface, look for signs of the victim and listen for sounds.
? Make a systematic search, probing the debris with axes or poles.
? Send for help.
? Keep searching until help arrives
? Remember, you are the victim’s only real chance of live rescue. (About Avalanches)
How people are trying to control avalanches, so that they can be prevented.
One way they are controlling avalanches is that they fire missiles in to the mountains and make little slides. The little slides move a lot of snow down the hill, so when there is a real avalanche there is not as much snow moving down the hill at once. They also use dynamite and other munitions to do the same.
Anther thing they do is, they put up nets to control the speed and amount of snow going down the mountain all at once. The nets hinder the snow’s momentum and amount. That helps cut down on damage done to property and forests. (Ready, Aim, Fire, 148)
Here is what has happened to a couple of people and what they did while being caught in an avalanche.
Mitch Edwards was snowmobiling in the winter of 1998-1999, when was driving in some powder and got stuck going up hill. He knew the avalanche danger was high so he was trying to steer clear of it. But while he was stuck and trying to get out, one of his friends yelled avalanche. So he got on his 97 t-cat thinking the snow would go around him and his sled, but he was wrong. The moment the snow hit his sled it flipped him and his sled all over the hill. He was trying swimming motions through snow like you are supposed too, while his sled was getting flipped around. When it finally stopped his feet were pinned under his sled and his whole body was covered as if buried in cement. The snow was up to his eye level, and he could not move an inch. All that was visible of his snowmobile was the tip of his ski.
Luckily his friends had seen the whole thing happen. He said after some shoveling he and his snowmobile started to emerge. He also said every one in his group wears avalanches transmitters. He said if you don’t have one and were buried like he was and no one was there to find him he could still be there he said. By the way, his sled started on the first pull. (Edwards, 16)
(Mitch Edwards and His 97 T-cat)
Andrew Murr and a group were hiking on Mount Rainier when it all started with one word, SNOW. When he looked up he saw a 150 wave of snow coming down at him and 9 other climbers. Their guide tried to hustle them to safety, but they were swept away. Gregg dug his ax into the snow but nothing would hold. He told himself he was dying. Then his rope caught a rope and brought him to a halt. A lady that was on his same rope came to a stop over the edge of a 500-foot cliff underneath a waterfall of glacial runoff. As it turned out all but one of the ten climbers lived. Patrick Nestler, was hanging beneath the lady even farther down the rope. He died of hypothermia, because he was pelted with 35-degree water for about 2 hours.
The climbers had been climbing when the temp was a bout 75 degrees and the snow just gave away because of the snow being to warm they figured. (Murr, 34)
A device that skiers and snowboarders can wear to help save them in an avalanche, it is called the AIR BAG. It is a 1 or 2 plastic balloons that people can wear on their back. The contents inside are 150 litres of a mixture of nitrogen and air. The skier or snowboarder triggers this by pulling a little string, that then causes a chemical reaction and the balloons fill.
What the air bag does is actually two things. One thing is that it decreases density of a human, which is much higher than the one of the snow. (From 1,000 fg/m3 to about 400 kg/m3.) (Air Bag)
The second thing it does is make the skier become a bigger particle. This helps the victim stay on or close to the top of the moving snow. Because smaller pieces stay under the surface, like a human by them self with out an air bag, would be under the surface the whole and probably never surfacing. The avalanche seams to sort the big pieces and put them on top, and the air bag makes the person bigger, it keeps them on the top. (Air Bag)
During 1991-1997 12 people with air bags survived the accident. But you can not be certain you will be completely buried. In cases of the person being buried the balloon remains on top of the surface making it easier to find the person.
In conclusion avalanches can happen to any one who takes the risk and there are many factors of witch can cause them to happen. The victim is one of the main causes that the avalanche starts in the first place. So when going hiking or skiing check the factors. Look at the weather, get an extended forecast, as some locals about the avalanche activity on that mountain this year. Check the snow layers, and just don’t think it can’t happen to you. Remember avalanches can occur where there is sufficient angle and enough snow to slide.
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