Avalanches, know to avoid them

on Wednesday 20 February 2008
by Francesco Macchi

Avalanche danger is danger of death. In Italy in the last 20 years have on average 19 deaths a year due to the Avalanche. The vast majority of deaths occurs by suffocation, but many also perish as a result of injuries. The possibility of being found alive after an avalanche decreases dramatically over time: after 15 minutes, only one third of persons completely buried under the snow is still alive. The surest way to escape the death consists in not to be overwhelmed!

A sequence of an avalanche (look at the slideshow).
Photo by Club Parapendio Macugnaga

The danger of avalanches is determined by the reciprocal of the natural factors such as soil, the amount of fresh snow, the wind, the structure of snow cover and temperature. Snow lovers should know the significance of these factors, since 90% of people personally overwhelmed causes detachment of the avalanche.

Ground
The danger of avalanches increases proportionally to the slope of the land. An avalanche may have become detached from the slopes of 28 degrees of tilt.
The shady slopes are often more dangerous than those exposed to the sun.

Snow and wind

More snow has fallen, the greater the danger of avalanches. Especially critical is the first day of good weather after a period of bad weather. The wind can deposit snow on the slopes further downwind. The frames of snow on the ridges of the mountains often indicate the presence of such accumulations. Already 10-20 cm of fresh snow can - with unfavorable conditions - increasing markedly the risk of avalanches. The typical slope at risk of avalanches is steep, exposed in the shade, near the ridge and covered with heaps of snow brought by the wind.

Snowy cover

The weight of snow generates snow inside the large cutting forces in which often several layers of snow can not oppose the necessary resistance. In a slope at risk is usually small enough overload such as that caused by the passage of a person to break the balance and cause the detachment of an avalanche. A thick snow cover and small stones projecting not imply a lower risk of avalanches, indeed! The greatest danger is the so-called avalanche of snow slabs because within a few seconds an entire slab of snow sets in motion. The victims will be quickly overwhelmed and often completely buried. Avalanche of snow in recent slabs, cracks in the snow or deaf noise (Wümme) found on a slope are unmistakable warning signs.

Temperature

The low temperatures after a snowfall may slow the consolidation of the snow and keep unchanged for a long time the danger of avalanches. A first rise of temperature reduces the resistance of snow causing an increased danger of avalanches, but it fosters the consolidation of rule involving a certain period after a reduction of the danger of avalanches. In spring, the increased insolation and the resulting heat and damp snow burden, thereby increasing during the day, the danger of avalanches.

Avalanche danger

The avalanche bulletin may not take account of local situations. Those responsible for the slopes or the emergency services, constantly observe the evolution of the danger of avalanches and warn by warning boards (often accompanied by flashing lights) dall'avventurarsi not controlled in the area for winter sports, or barrier tracks, routes and trails for winter sports.
The areas outside the tracks and routes are considered non-controlled areas for winter sports and are neither insured nor demarcate the danger of avalanches. In case of doubt the cartel next informs the user if the descent is demarcated and secured or if it is part of the area not controlled.
As the degree of danger 'marked', the cartel and the next signal light flashing - exposed to the lifts - warn users. Stay on descents demarcate and open! Do not walk under any circumstances, tracks, routes and trails closed!

Out of piste/ Freeride

You wake and you go in the snow at your own risk.
The assessment of the danger of avalanches requires great care and expertise. Join a team so driven and attended a course for the freeride. In case of doubt to waive off and freeride.

• Observe the current avalanche bulletin and weather warnings as well as the services of the slopes and rescue.
• Take it upon himself to search an avalanche beacons (beacons) and place it on "release". Equipped with a shovel and avalanche probe.
• Do not ski or snow never go alone and only if the visibility is good.
• Do not follow any path other skiers or snowboarders who leads in unknown terrain.
• Avoid the accumulation of recent snow and wind brought by the steep slopes.
• Do not take the extreme steep slopes in a group, keep an eye on each other.
• To ensure the warning signs (of snow avalanches in recent slabs, cracks in the snow, noise deaf type Wümme).

ARVA, airbags and transponder (reflectors) do not offer any protection from avalanches! In favorable situations, however, may help to limit the damage. The safety rules also apply to those who are equipped with such systems.