Tiger in the skin of a lamb named innocent at first glance, the white snow Mathias Zdarsky - Austrian researcher who has studied the question of what an avalanche.Gently falling snow fascinates even those who does not like the winter - too beautiful picture, like a fairy tale.And slowly fly to the land of crystal stars create a false impression of fragility, defenseless tenderness.However, excessively active snowfalls are fraught with danger and serious.Because of the little snowflakes can grow not only snowdrifts and avalanches.So, what is an avalanche?The definition of this concept is shown below.And now a bit of history.
brief history
In all probability, the avalanche - a phenomenon that there are as many as there are steep slopes of the mountains, but the first large-scale convergence of snow, causing the death of hundreds of people, mentions even Polybius in the context of the history of the campaign Carthaginian troops acrossAlps.And in general, this mountain range, chosen by tourists and climbers, "behind" long record of accidents.No wonder that in the twentieth century in some areas served Mass in memory of the dead under the rubble of snow, because in this case an avalanche - it's a pain and grief for the relatives and friends of those affected by its descent.It is also noteworthy that one of the last winter of World War I by this natural phenomenon have killed more soldiers on the Austro-Italian front than directly in the hostilities.A December 16, 1916 went down in history as "Black Thursday" when were missing one day of six thousand people.Hemingway, who was in the Alps during the same time period and described his definition of what it means to avalanche noted that terrible winter avalanches, sudden and carry with them the instant death.
suffer from "white death" and residents of Norway, Iceland, Bulgaria, the United States, the Russian Federation, Canada and Asian countries: Turkey, Nepal, Iran, Afghanistan, and in the past and keeping the dead in the long run is not conducted.Tens of thousands of lives on account of avalanches, plucked from the mountains Huascaran in Peru.
What is an avalanche?The etymology of the word
ancient Romans called this phenomenon "a pile of snow."Each nation had its own definition.What do you mean - the avalanche?This is a beautiful, exciting and natural hazards.Interestingly, and the very meaning of the word "avalanche", the origins of which Latin root lab, which means "instability", although in the Russian language it fell after a German, because there were certain Germanic Lavine.Buddhist monk Xuan Zang poetically called them "white dragon", as in the days of Pushkin called avalanche collapses.In the Alps and the Caucasus, "speak" are the names of the individual, and has mountains, gorges and valleys.For example, forest or Lansky Zeygalan Hoch ("mountain, from which avalanches are always").Sometimes the ability to read onomastics though not tell all about the snow drifts, but unforeseen circumstances could keep.
What is
Avalanche Avalanche - is one of the types of landslides, a large mass of snow that moves or falls off the slopes under the influence of gravity.It creates a parallel wave of air, accounting, and accounts for a significant part of the destruction and damage that is almost inevitable in this disaster.
began to move, the avalanche can not stop, sinking lower and capturing on his way related rocks, blocks of ice, branches and uprooted trees, turning from ebullient white snow dirty mass remotely resembling a mudflow.His "fascinating journey" thread can continue as long as no stop on flat areas or on the valley floor.
Factors affecting the convergence of the masses of snow from the mountains
causes of avalanches, largely depend on the old snow - its height and density, surface conditions beneath it, as well as the growth of new mass precipitation.Also affects the intensity of snowfall, subsidence and seal cover and the air temperature.In addition, a fairly extended an open slope (100-500 m), ideal for the beginning of the path of the avalanche.
main "architect" of this natural phenomenon is often called the wind, because the convergence of snow is enough growth in the 10-15 cm. The temperature is also one of the most important factors that can trigger a disaster.And if at zero degrees instability of the snow, though there quickly, but not less active runs (it either melts or avalanches).And when the low temperature is stable, increasing avalanche period.
Activate toe snow and seismic vibrations can, which is not uncommon for the highlands.In some cases enough and flying jets over dangerous areas.
In general, frequent avalanches directly or indirectly linked to the violent human activities, which is not always reasonable.For example, now cut down forests previously served as natural protection against snow slides.
Frequency
Depending on repeatability distinguish Intra-toe (for winter and spring) and mean, which includes, respectively, the overall frequency of avalanche.Also highlights the systematic avalanche (annually or every 2-3 years) and sporadic, occurring maximum twice in a century, making them especially unpredictable.
movement, the focus of a natural phenomenon
nature of the movement of the masses of snow and the structure of the hearth define the following classification: chute avalanches, special and jump.In the case of the first snow is moving or on a tray or on a specific channel.Special avalanche in motion covers all the available land area.But with jumping more interesting - they are reborn from the gutter, appearing in places uneven flow.Snow weight falls like "bounce", to overcome certain areas.The last type is able to reach the highest speed, therefore, the danger is very significant.
Snow tricky and may well creep up unnoticed and quietly, hit an unexpected shock wave, destroying everything in its path.Features of the natural movement of the masses are the basis of a further division into types.It stands reservoir avalanche - is when the motion is on the snow surface located below and dirt - slides directly on the ground.
Scale
Depending on the damage caused by avalanches can be divided into particularly dangerous (they are natural) - the volume of material losses of the imagination with its scale and even dangerous - impede the activities of various organizations and jeopardize the peaceful measured life settlements.
Properties snow
Importantly and classification associated with the properties of snow, which is the basis of the avalanche.There are dry, wet and damp.For the first characterized by a high rate of convergence and powerful air wave breaking, and the masses themselves are formed at low temperatures after a significant snowfall.Wet avalanche - it snow, who likes to leave the cozy slopes at a temperature above freezing.Speed here is less than the previous ones, but the density and cover more.In addition, the base may regedit, turning in solid and hazardous formation.For wet snow avalanches raw material is sticky, wet, and the mass of each cubic meter of the order of 400-600 kg, and the speed - 10-20 m / s.
volumes
And the most simple division - small and almost harmless, medium and dangerous for humans, as well as large, are on their way razed buildings, trees, turn into a heap of scrap metal transport.
it possible to predict the occurrence of avalanches?
to predict the convergence of avalanches are more likely to be extremely difficult as the snow - it's the element of nature, which, by and large, virtually unpredictable.Of course, there are maps of dangerous areas and taken both passive and active methods of preventing this phenomenon.However, the causes and consequences of avalanches may be different and very tangible.Passive methods include special shield barriers, forests, observation points for hazardous areas.Active steps are as shelling areas of possible landslides from artillery and mortar units to provoke a convergence of snow masses in small batches.
slides from the mountain avalanches in any of the options are a disaster.No matter they are small or large.It is important to consider all the factors influencing the occurrence of snow masses and their movement on an uncertain route to unknown purposes, so as not to sacrifice the elements are too expensive gifts.
all about avalanches: interesting facts
- speed avalanche can reach 100-300 km / h.Powerful air blast instantly transforms a house in ruins, rock crushes, demolishes cable cars, uprooting trees and destroying all life around.
- Avalanches can go to any mountain.The main thing that they were covered with snow.If in a particular area 100 years there have been avalanches, then there is always the possibility that they may occur at any time.
- about 40 thousand. To 80 thousand. People during World War lost their lives, they were buried under avalanches in the Alps.These are approximate.
- In America (California) people have surrounded the mountain St. Gabriel deep moats.Their dimensions are football fields.Avalanche, coming down from the mountains, trapped in these pits and do not roll in the settlements.
- This devastating natural phenomenon is called differently in different nations.Austrians use the word "shneelaanen", which means "snow Stream", the Italians say "valanga", the French - "Avalanche".We call this phenomenon of an avalanche.
