It has been snowing heavily for some weeks now. Mama is getting worried, she have seen this happen before. This was exactly how he lost Matt last Christmas. Matt loves skiing, Mama learnt from the girls in the neighborhood that he was the best skier. Probably they said so because they were in love with him. Won't blame them, who wouldn't love Matt, with his muscles and fine look. He is the kind of man the girl in the neighborhood would die for.
Mama still remembers that day vividly. It was Charlotte, her neighbors daughter and one of Matt's admirers that came knocking.. "Mama, Mama... The snow took Matt.." That was enough to send Mama running down the street to the skiing resort, not minding the fact that she is old and feeble. A mother's love for their child.
On getting to the resort, it was quite clear that Matt wasn't there. All Mama could see what a track, those types left by a flood, but this time it was covered with snow. Quickly, Mama followed the track. It seems as if the track won't end. Though she got a lift from boys in the hood, Charlotte told them, when they finally got to the end of the town, all they saw was a mini-mountain of snow. Matt was buried deep inside it.
Pictures by dahu1 - Wikicommons CC BY-SA 3.0
Avalanche
Though this is a fictional story, quite a number of people that died due to an avalanche died this way. Imagine being suffocated and chilled to death.. Mehn.. Don't bother imagining it, doing so might even cause nightmares. We will be discussing about this natural disasters - avalanche. We will consider also, how it's formed, it's causes, it's effect and how to dig yourself up if you ever get trapped in it.
AVALANCHE
An avalanche is a rapid flow of snow down a slopy path. An avalanche always happens whenever the force of the snow acting on its starting zone becomes too much at its foundation. As the snow slides down the slope, the more it accumulates, as it carries others with it. By the time it gets downhill, it has developed enough power to cause destruction (i.e if it has not caused destruction already).
For an avalanche to occur, there must be a slight increase in temperature, because at lower temperature, the grip of the ice to the surface is strong but as the temperature increase, the grip weakens. A perfect example is what happens on your windshield after a snow fall. You will observe that snow flakes grip strongly to the windshield, but as the temperature rises, they slide down the windshield. Avalanche is also referred to as snowslide.
Don't let the name snowslide fool you, though it is composed mainly of snow and air, that's not the only thing it carries along with it as it travels. Snowslide also carries trees, rocks, and every other thing it meets in its path, thus, it's victims are not only subjected to severe cold from the snow, they are also at hit by these trees and rocks.
Unlike what happens in our windshield, avalanche are far more deadly and larger. A normal avalanche that occurs in North America can release snow of more than 230,000 cubic meters. (230,000 cubic meters is quite much, it's more like 20 times the size of Nou Camp filled up 3 meters high with snow!!!). This size of avalanche is mainly triggered by nature or by huge explosions. Those triggered by skiers and other recreationalist are small, but also deadly.
ANATOMY OF AN AVALANCHE
An avalanche is divided into three major parts. These parts are the starting zone, avalanche track and the run-out zone.
The Starting Zone:-
As you rightly guessed from the name, the starting zone is the point where the snow is unstable and easily susceptible to fracture. In the simplest words, it is where the avalanche begins. Due to pressure, this weakest point breaks loose from the surrounding cover and like that, the chain reaction begins. There is no limitation to where the fracture can occur, but most times, its always at a higher point in the slope.
The Avalanche Track
When the snow begins to slide down the hill, it follows a path. That path it follows as it slide down is what we refer to as an avalanche track. Tracks of an avalanche are easily noticed even after its been a while it happened. You can note them with signs like a chute-like clearing, track of trees missing from a slope. Another sign that indicates an avalanche track is this; a heap of snows and debris can be found at the bottom end of the slope.
The run-out zone:-
Every obstruction the avalanche meets obstructs it, and as it gets to a more level ground, the more it weakens. A point will reach when the avalanche becomes very weak and then finally stops. This point that it finally comes to a stop is what we call run-out zone. Some refer to this point as the deposition zone because it is at this point that all the snow and the debris carried by the avalanche are finally deposited. The pile at this point is the highest.
WHEN AND HOW OFTEN DO AN AVALANCHE OCCUR
Most people think that avalanche is one rare phenomenon that only occurs once in a specific area. Well, that is not correct. Avalanche can occur anywhere that is slopy, (especially, during winter or spring) and any time. The only thing needed is just something that would trigger it. In mountainous terrains, avalanche is the most dangerous natural disasters that occurs there. And whenever it does occur, anything on its way, both lives and properties are destroyed, because whenever it moves, it moves with great speed.
TYPES OF AVALANCHE
The classification of avalanches into types is done based on their different characteristics. The knowledge of these different types and their characteristics of great importance. The types of avalanches are; loose snow avalanches, slab avalanche, wet snow avalanche and powder snow avalanche.
Loose snow avalanche:-
This type of avalanche is more common in steep terrains, and they occur almost immediately after a snow fall. It may also occur in old snow surfaces when they get moistened by solar radiation. It starts from any point in the slope and slides down forming a shape that resembles a tear drop as it slides. Though the loose snow avalanches are not always so large, but when they are, it results to a slab avalanche.
Maxpixel.com: Loose snow avalanche
Slab Avalanche:-
Slab avalanche are those type of avalanche that are formed as a result of snow being deposited by the wind. They always appear like a snow block being cut out from its environment by fractures. The thickness of an avalanche may vary from few centimetres to a few metres, and about 90% of destructions caused by an avalanche is mostly done by the slab avalanche.
Powder Snow avalanche:-
This type of avalanche is known for its behavior of forming currents of turbulent suspension. The avalanche always has a cloud of powder on top of it. It can move at a high speed of 300km/h despite having a mass of about 10 million tons. Due to its speed, powder snow avalanche cab travel over a flat surface and even uphill, though it's for a few minutes.
Wet Snow Avalanche:-
Consisting mainly of water and snow, wet snow avalanches do have a slow speed when compared to other types of avalanche. There low speed is as a result of the fact that they are saturated with water, and also because of the friction between it and the surface it slides along. But don't mind the fact that it move at a very slow pace, it is as dangerous as the slab avalanche because of its large density and mass.
For instance, whenever a wet snow avalanche occurs, it uproots trees, pull down boulders and carry a huge mass of earth with it. They occur mostly at the end of the season, when there is an increase in the amount of sunlight. Due to the sunlight, the snow packs on the slopy surface are saturated with water, thus triggering it.
CAUSES OF AN AVALANCHE
In the early times, when science have not found reason or the causes of avalanche, because of the fact that avalanche always occurs without warnings, it was believed that that it was human voices that dislodges the first snow, which in turn result to the formation of an avalanche. It was also believed that a human's weight causes it too, as an additional weight at a weak spot will result to the fracture. But after some research into nature, we have now realized that environmental factors are also in play here. Let's take a look at some of those causes.
Snowstorm and Wind Direction:-
Whenever there is a heavy snowstorm, there is a likelihood of an avalanche occurrence. In places that are slopy, the 24 hours that proceeds after a storm are very critical. Another is the direction of the wind. Normally, the wind only blows from one side of the slope of the mountain to the other side, but whenever the wind blows from up to down, it is most likely to scrap off snow from the surface of the mountain, which may likely trigger an avalanche.
Heavy Snowfall:-
Heavy snowfall is a very crucial factor, as when it occurs, large amount of snow deposits are placed in very unstable areas, and this will put a huge amount of pressure on the snow pack. Assuming it didn't trigger it then, when summer months arrives, these snow packs dissolve, resulting to wet snow avalanche.
Human Activity:-
Within the last twenty years, humans have been the major reason of avalanche occurrence. In the name of winter sports, man mount so much pressure on snow packs. Most times, the snow packs can't bear this pressure, and the result of that is an avalanche. Also, deforestation and soil erosion makes the impact of an avalanche heavy, as the surface of the earth won't have any vegetation that would help slow it down.
Vibration or Movement:-
Too much vibrations from terrain veheciles and snowmobiles can easily cause a snow pack to fracture. Coupled with the action of gravity on the snow, a little fracture can cause the snow pack on the surface of the terrain to slide down. Another human action that is able to generate enough vibration to cause snow fracture is the use of explosives.
Layer of Snow and the steepness of the slope:-
When snow fall on mountains already covered by ice, it just settles without much grip on the surface, just a little event can cause it to slide down. The matter is aggregated if the slope is very steep. When an avalanche occurs in a slope with an 30° to 45°, it is dangerous, as not only that the only little events can trigger it, it's steepness causes water snow that slides down to do so at tremendous speeds.
EFFECTS OF AN AVALANCHE
The effects of an avalanche ranges from the destruction of crops animals and properties to loss of lives. Let's consider these effects.
Destruction of Life and Property :-
Whenever an avalanche occurs in a place, both lives and properties gets destroyed. The most pitiable are those that do enjoy skiing, snowboarding and snowmobiling. Since it happens without warning, most of them lose their lives while doing what they love. As the avalanche slides down, due to it weight, it destroys houses, cut down power supply, roads get blocked and even properties are carried away by it.
Economic Impact:-
Whenever avalanche occurs, it always causes roadblocks at it deposit zone, and that would require huge amount of money to clean up the mess it made. Houses, infrastructures and power lines destroyed by the avalanche needs to be fixed or rebuilt. That also cost a lot. Another set of people that are affected economically are ski resorts.
Every ski resort make profit from people visiting their resort, but whenever an avalanche occurs, ski resorts are forced to close down immediately till the situation becomes stable. But if the avalanche led to the death of someone, that's bad news for that result, as people may not want to patronize them again.
Flash Floods:-
Flash flood most times occur after an avalanche, and this is quite terrible for the inhabitants of those areas it occurred. As not only that the flood that follows after the avalanche would cause it's own destruction, it might also cause their crops to fail. Another danger that comes with flash flood is the spread of waste on those areas it occurred, resulting to the spread of disease.
Picture by CMBJ - Wikicommons CC BY-SA 3.0
flash flooding in the street
MAN AND AVALANCHE
There have never been a time an avalanche occurred without taking lives. Just like a vampire, the avalanche yearns for blood. Whenever it occurs, it leaves the whole world in mourning. In this article, I will be mentioning two major avalanche disasters that shook the world to its core.
1962 Huascaran Avalanche
This avalanche occurred in the 10th of January 1962. On that day, the Peruvian who dwelt around Mount Huascaran went about their business. It was winter, the body of the mountain was covered with snow. Then, all of a sudden a huge block of snow broke out of the mountain, falling down to the valley with great force, the next thing that followed was an avalanche. This wasn't the first time an avalanche occurred in that area, thus everyone knew to survive, he/she has to get to a higher ground before the avalanche releases its wrath on their homes.
It was quite unfortunate that they underestimated this particular avalanche. It came with great speed, covering more than 9.5 miles within 7 mins. None of them got a higher ground, none escaped it. This avalanche buried two towns, Ranrahirca and Huarascuho under snow of about 40 feet. When it got to Santa River, it blocked the ricer flow and then lead to the flooding of the nearby areas. The number of dead bodies that were recovered were 4,000. The economic loss ran in millions, no animal nor crop survived too.
1970 Huascaran-Ancash, Peru
Regarded as the worst avalanche disaster in human history. This avalanche occurred in May 31, 1970 and was triggered by the Great Peruvian Earthquake. More than 20,000 people died as a result of that avalanche. The Peruvian regions that were mostly affected by this disaster are Ancash and La Libertad. Immediately the earthquake destroyed the walls of Mount Huascaran, a huge avalanche struck the towns Yungay and Ranrahirca. It wasn't the disaster that caused the main destruction, it was the large chunk of ice and snow which was more than 1.6km long and 910 m in its width which broke itself from the mountain, speeding down it's path at a speed of 280 to 335 km/hr that caused the major destruction. Everything on its path were either leveled or destroyed.
HOW TO SURVIVE AN AVALANCHE
Most people that die from an avalanche disaster do as a result of hypothermia, trauma or from suffocation. The problem with avalanche is that, unlike a flood that just carried it's victim away and deposits him or her some place where it's victim can be found, an avalanche buries it's victim where ever it deposits him or her. And immediately it stops, it starts to solidify, becoming so strong like concrete, and digging out its victim by bare hands is impossible.
Having known this, the best way to survive an avalanche is to stay away from slopy areas. But if that is impossible, adhering to these few rules will help save your life.
What to do before an avalanche
Get yourself trained on how to recognize locations that are susceptible to an avalanche. Also sign up for disaster alerts so as to be per-informed of places that an avalanche just began. Whenever you are to go skiing, snowboarding, e.t.c, make sure you are wearing your helmet, and dress with all the protective gear that you need to survive even if you get carried by an avalanche. Never be alone in places susceptible to avalanche. Always have a friend around, as he might save you incase it occurs.
Go for first aid trainings so as to know signs of hypothermia, traumatic injury and know how to treat them or at least keep the person stabilized till the proper authorities arrives. Also learn how to use safety and rescue equipments like the shovel and probe. Make sure you always know more than one way to a particular location, as there is a likelihood of the road you want to take to a particular location being blocked by an avalanche.
During winter season, stay away from places with steepness of about 30° to 45°, if you must, put on a helmet, and air bag. Also wear an avalanche beacon to help rescuers locate you. Always pay attention to avalanche road warning and signs.
What to do if you get caught up by an avalanche
If you get trapped and carried away by an avalanche shielding you were skiing this is what you should do.
Do not struggle to hold your equipment like your skis, poles, snowboards,snowshoes e.t.c. Abandon them immediately as they may get in the way or hit, if you get caught up by the snow. After that, the next thing to do is to seek for shelter; a shelter can be behind rock. If you can, crouch down and turn your back over the avalanche, in such a way that it jumps over you from behind.
If unfortunately, you couldn't find shelter, and you get trapped in the flowing sea of snow, see if you can wade your way through it, but if it's too high and wading is impossible, scream for help. Once the snow starts to get very close to your mouth, stop screaming, take a deep breath, and then immediately cover your nose and mouth. Keep thrusting and kicking, try swimming upwards. Do not yell or open your mouth when you get hit by debris, to avoid debris and snow filling your mouth. Once you notice that the avalanche has slowed down, immediately, create an opening directly on top of you to the surface, so as not to get suffocated. Check if you can free yourself, if you can't wait for rescuers.
What to do after an Avalanche
Be safe.
**Note:-
Hypothermia means an unusual low body temperature. Some of its signs includes loss of memory, slurred speech, exhaustion, confusion, shivering e.t.c. To save the persons life, quickly take he or she to to a warm room or shelter. Warm the center of his/her body first, then the chest. After that, in this sequence warm the neck, head and groin. After then, wrap him/her in a blanket.
Picture by Tyler Finvold- Wikicommons CC BY-SA 3.0
Forest destroyed by an avalanche
CONCLUSION
I remember the last time I talked with Steve about the natural disasters. In the beginning, we both where of the opinion that probably, the reason why nature allow us to pass through disasters it to force out man's hidden abilities, but when we tried to analyze the avalanche, it seems as if that reasoning was out of place.
There is something peculiar about avalanche, starting from its formation to its end, it appears as if it's intention is to kill. It's starts without warning, and when it end, it quickly solidifies as if it doesn't want it's victim to survive. (Even though the avalanche and landslide behave alike, this is where they differ). But does this mean that nature is intentionally wicked? Have I been advocating for the wrong side all this while?
The truth is that no one knows what is going on in nature's mind. But we have seen so many nature inspired inventions to know that what ever height man have reached today is as a result of motivation it got from nature. Even though we might not see it yet, it is logical to think that man is currently going through a school. A school were nature is teaching him how to predict and overcome an avalanche. A school man will soon graduate from.
Till we meet again.
REFERENCES
Contributing factor to the occurrence of an Avalanche
Causes and Effects of an avalanche
How to Survive an avalanche1,How to survive an avalanche 2
Deadliest avalanches in history
