Avalanche - orientation NE Avalanche Blackwood Canyon (USA), secteur Polaris Point, Near Stanford Rocks

01 mars 2012 13:30

skiers skinned up towards Stanford Rocks. When they reached this area where
they wanted to ski, they dropped a small piece of cornice onto the slope as a
test. This cornice drop released a slab a few inches deep that propagated
widely across the slope.  The first skier then started to ski the slope.
On his third turn, he triggered a slab avalanche about one foot deep that
failed within the storm snow. He grabbed onto a tree and was able to stop
himself from being taken down slope. The avalanche then stepped down another
15-20 inches to a lower persistent weak layer and pulled this skier away from
his tree and down the slope into the trees below."

"This deep slab avalanche failed within a layer of faceted snow sandwiched
between two crusts. This known persistent weak layer is located just below the
old/new snow interface.
"The fracture was 481 feet wide (environ 146m) and ran 1235 feet (environ 376 m) through the trees downslope".

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Observateur : Sierra Avalanche Center

Caractéristiques de l'avalanche

Rupture : épaisseur 60 cm, max ? cm, longueur 146 m. 2320 m. ? m.
Plaque friable
Origine principale
Skieur hors piste
Qualité de neige
Sèche poudreuse

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Indice de danger du bulletin

Image indice de danger Inconnu

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