Ibantxo Photo with the avalanche triggered in this northern slope. To the left is the entrance to the rise of the group footprint, prompting the avalanche a few meters before reaching the crest.
Risk Confirmed Notable (3) plate avalanche in north faces this Saturday March 5
This risk has been confirmed by several avalanches plate, both sides note and both triggered by skiers (no esponáneos avalanches). Fortunately, no casualties have been. Remember
Risk 3 is the most victims were charged for mountaineers and skiers are not likely to change their route or their behavior (ski run) except when estimating Risk 4.
Risk 4 implies possibility of triggering avalanches spontaneously in a variety of slope and aspect, whereas when there is a risk 3 must pay attention to the text (the fine print) accompanying this bulletin, which describes susceptible slopes. In this case the risk was for the existence of plaques in sloping northern slopes, susceptible to rupture with severe overloads. This fact implies that there must be a necessary overhead to destabilize these plaques and that the inclination must be greater than 28 degrees, usually above 30 degrees. The two avalanches plaque displayed in this entry meet those characteristics.
On the one hand, the interesting blog of Freeskiing (Ibantxo, author of the book "Ski Free") Ibantxo recounts the experience they had on Saturday in a northern face above 2000m in the French Pyrenees that was, with the Val d'Aran, the most affected by recent snow.
The necessary conditions are met: Facing north over 2,000 m, slope of 30 º and strong overload, a group of 7 skiers where the avalanche took 5 of them. The use of ABS buoyed 3, 5 and partially buried the others, without major consequences shock.
In this case, the ABS was very helpful to avoid being buried.
But beware, the ABS is like a car aibag. You can save an accident, but do not always guarantee survival. It is best not to have to prove their effectiveness.
Many of the victims of an avalanche are the polytrauma and ABS does not always avoid it. The ideal is to avoid triggering an avalanche. Although not always a mathematical rule and mountain teaches you that there is "100% safe slopes." With
Ibantxo and colleagues for sharing their experience with everyone.
Then, the sample plate avalanche ski resort of Cauterets, the same days (Sector central French Pyrenees Haute Bigorre - Vignemale area)
photo another avalanche in the resort of Cauterets, drawn by J. Iciar
This plate also occurred Saturday in the ski resort of Cauterets (Vignemale sector). Iciar sent us (Thanks!).
It also conforms to the North direction, altitude and number of skiers overload.
can be seen above the plate in the footsteps of many skiers who entered this side (although we can not tell by the picture if entered several at once or is spaced and separated in time).
Set as right-hand corner of the photograph you can see another rise in z footprint by a similar channel orientation. Why shovel fell and the other not? The answer is uncertain, but possibly overloading the avalanche shovel was higher than many skiers go for it.
addition, you can see in the picture that the footprint of the right channel zetas ski passes to ski trail in the last minute. This reduces the load on the shovel and it's very possible that the group of skiers was lower.
It's also possible it was the same group that went to walk down the corridor after the cause avalanche if they decided skiing (all at once) by that avalanche shovel.
PLATE AVALANCHE NOTE: Remember
plates remain fragile while they remain cold . Despite being in March, the northern slopes see the sun only obliquely, do not change and remain fragile for much longer.
southern slopes, with the sun high in March, almost stabilized and the first 24 hours of sun, as are soft and moist, fading to its fragility. Plate behaves as any material that breaks with the cold.
Setting an example that taught me July Benede : Let's say, a piece plastic we put in the freezer. Take it out and give it a blow with a hammer. What happens? Jump to pieces. Is frozen and brittle.
We take another similar piece, place it next to the stove and heated. Softens. It is no longer fragile. Since we can paste a thousand blows, it will not break.
So this weekend we have had so much sun, the only slopes susecptibles plates were breaking up north. The slopes that were this high and generous sun March (E, S and W), were stabilized immediately at noon on Saturday, only increasing the other risk, the avalanche of merger, which rarely takes its toll, as there often match in time and place with people.
The plate avalanche is triggered by the skier himself or someone in your group, it causes many casualties. The fusion occurs when there is often nobody there but destroy buildings and trees, as falling Astun La Raca the bottom of the Canal Roya and destroys everything in its path. The northern slopes ... with that powder snow as appetizing ... eye with them. Go up separate, lower separated, enjoy all safely.
I thought interesting to share these notions, both as Ibantxo Icíar have shared with us and learn to prune both.
Jorge G ª-Dihinx
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