South Douglas - The Chute

Carte pour le rapport du Réseau d'information en montagne: South Douglas - The Chute

Information

Date/heure de l'avalanche
samedi 28 décembre 2024 à 18 h 00
Estimation de l'heure d’occurrence de l’avalanche
< 12 heures
Nombre d'avalanches dans ce rapport
1
Taille de l’avalanche
3
Largeur de la plaque
300m
Longueur d'écoulement de l'avalanche
400m
Caractère de l'avalanche
  • Plaque à vent
Type d'élément déclencheur
Motoneige
Sous-type d'élément déclencheur
Accidentel
Versant de la zone de départ
  • NO
Bande d'altitude de la zone de départ
  • Limite forestière
Altitude de la zone de départ
1 400m
Inclinaison de la zone de départ
50°
Altitude de la zone de dépôt
1 200m
Type de cristaux de la couche fragile
  • Grains à faces planes
Croûte près d'une couche fragile
Oui
Exposition au vent
Pente sous le vent
Couverture forestière
Pente dégagée

Commentaires

2 parties involved, 1st party were two skiers (including author) and 2nd party was a group of sledders (all friends for what it's worth). Skiers were on the lower apron of the chute and aiming for East Bowl via climbers right ridges/sub gullies to avoid the main chute when the sled group caught up. Both groups stopped and discussed options together, we felt comfortable using terrain on the climbers right to protect from any anticipated potential avalanche and the first sled proceeded up the chute. As he got to the upper third, the entire climbers left face let go above the sled and zippered to above the traditional safe spot on the moraine at the top. We thought we were still safe, but couldn't see that the crown had remoted/wrapped around the climbers right as well, entraining substantially more snow. With the compounding volume, the fast moving slide swept wider up the flanks than anticipated and crested the berm we (2 skiers) were sheltering behind. We both tried to dig in but I was blown out of my skis and lifted/thrown 3-5 meters then carried with the flank flow for another 100 meters. The impact of getting hit by the avalanche somehow deployed my airbag and I came to rest on the surface. The second skier was knocked off his feet and moved 20 meters or so but also was not buried. The sledder managed to stay just ahead of the slide but reported that he was almost pushed off the moraine at the top by the upper portion of the slide; the rear of his sled was surrounded by debris but not buried. The remaining 4 of the sled group were either out of range or able to turn out from a low point and get clear of the slide entirely. Thankfully there were no significant injuries (minor cuts and bruises) and the only loss was one pole. Cole's notes; the recent storm snow has not bonded to mid December crust in some areas and the storm slab is very reactive. We did not get near the bed surface to look for offending grains but suspect facets overlying the crust.