Résumé de l'incident
- Pine Pass - Bijou Falls
- Location Description
- Approximately 20 km east of Mackenzie, BC
- 55.29895 °, -122.72537 °
- 1680 m
- Several days of stormy weather with warm temperatures and winds dropped significant amounts of new snow in the days leading up to the accident. Skies broke and temperatures cooled on the morning of November 28th and SW winds strong enough to move new snow were recorded in the region.
Two snowmobilers were riding in the Bijou Falls riding area towards the east side in a portion of terrain overlooking highway 97. One rider climbed high on the slope gaining a wind-exposed ridge above a rock band.
The rider triggered a large avalanche, approximately 800 metres wide by 400 metres long. The crown was 55cm deep on the steep, rocky, windswept roll where the avalanche was triggered, but significantly more snow was involved at lower elevations where the snowpack was sheltered from wind and much deeper. The bed surface was a crust that formed in early November and the suspected failure layer was faceted grains on the crust.
The snowmobiler was caught in the avalanche and buried in a terrain trap near the base of the slide. Their partner, who was watching from below and was not caught by the avalanche, performed companion rescue to locate and dig out the victim. The buried person did not survive.
|Date/Heure||Taille||Type||Déclencheur||Altitude||Versant||Largeur de la plaque||Épaisseur de la plaque|
|3.0||S||Ma||1680 m||NE||800 m||55 cm|
|Température actuelle||Température maximale||Température minimale||Tendance 24h||Vitesse du vent||Direction du vent||Condition du ciel||Type et intensité des précipitations|
Commentaire météo: Weather recordings were taken from Link Creek Weather station (730 m) approximately 10 km north of incident location.
|Manteau neigeux||Neige 24 hrs||Neige de tempête||Date de la tempête|
Commentaire sur le manteau neigeux: 100 cm 1F+ to P resistance snow overlay a thick (20 cm) weaker layer (4F resistance) resting on a crust (I resistance). Compression tests yielded sudden planar failures down 110 cm in the easy/moderate range (one test gave 7 taps, one test gave 11 taps). In the snow profile, the snow failed on facets above the crust, which is consistent with the failure plane of the avalanche. The profile location was adjacent to the avalanche flank.
|Date du document||Titre||Source|
|2020-12-10||Google Earth image, annotated||Avalanche Canada||Vue|
|2020-11-29||Profile by SAR team||PG SAR||Vue|