On 30 January 2020, a large PIDA (plan d'intervention de déclenchements des avalanches) took place for the Tour slopes service, Tête de Balme sector, Belleplace du Tour in Mont-Blanc massif, at 2,150 m altitude (7,053 ft).
Following the preventative release of the impressive wind slab, a huge break of 5.5 meters was photographed.
Wind slab avalanches are caused by a cohesive slab of wind‐deposited snow overloading the bond to an underlying weak layer or interface (more information on avalanche.ca).
Active avalanche control is the intentional triggering of slides. This control work is done to minimize the chance of natural avalanches into traffic. Avalanche control work is done all over the world; by highway departments, ski resorts, railroads, mining operations, utility companies, and other activities threatened by avalanches.
As an active avalanche control measure, an impressive wind slab of 5.5 m was created in the Tête de Balme sector, Belleplace du Tour in Mont-Blanc massif.
"In 40 years of profession I had never seen something like this", declares Serge Ducroz, head of safety on the Tour - Vallorcine ski area.
Serge Ducroz captured the huge break of 5.5 m on camera. "I didn't take this photo to brag, but to make people who venture off-piste think".
The triggered avalanche brought down the "whole layer of winter, accumulated since December", according to Serge Ducroz.
It confirms that the quantities of snow are very important at the moment in the Alps where the risks of an avalanche are 3/5.
More information on www.data-avalanche.org.
