Avalanche Report. 11.10.12. Raven Glacier Area.
Summary:
Skier triggered avalanche on a north facing aspect between the Raven and Milk
Glaciers at approximately 4000 feet. Skiers were skinning up a 30-35 degree
slope towards a saddle at approximately 3800 feet when the surface fractured
approximately 200 feet above their position. The slide knocked both skiers off
their feet carrying one skier 50 feet and the other 100 feet. The higher skier
was buried to his thighs while the lower skier was buried to his mid-stomach.
The time was 15:30. The weather was overcast. Temperature was approximately 20
degrees. No injuries.
Full Report:
Three skiers departed the Crow Pass Trailhead at approximately 12:30 with the
intent on camping in vicinity of the US Forest Service Cabin. At 14:30 their
camp was established and two skiers decided to tour the area to have a look at
the conditions. The skiers were aware that conditions were not good and
intended to stay on “safer” terrain.
The skiers proceeded north towards Crow Pass Proper and then veered northeast
onto the Raven Glacier. The two skiers progressed approximately 1/4 mile up the
glacier (eastward) before deciding to turn off the glacier at about 3800 feet
and head back to camp before nightfall.
The party was now traveling south towards a saddle that separated the two skiers
from their camp. From the base of the slope to the top of the saddle the skiers
needed to skin up approximately 400 feet at an average angle between 30-35
degrees. About half way up the slope the skiers heard a loud “whoomph” and then
noticed that the slope had fractured about 200 feet from their position. The
two skiers were separated by about 30-40 feet. Both skiers braced for the
impact of the oncoming snow and leaned into the slope in an improvised “self
arrest” position, but were still pushed off their feet and down the slope. The
lead skier traveled approximately 50 feet down the slope and completed one full
rotation underneath the slide before emerging on the surface with 1/4 of his
body still submerged. The lower skier traveled about 150 feet down the slope
and completed 3-4 full rotations underneath the snow before emerging on the
surface with 3/5 his body still submerged. Both skiers credit “swimming” and
“reaching for the surface” with enabling them to stay on top of the slide.
After the avalanche, both skiers were able to free themselves from their
positions under their own power. The lead skier lost both skis and one ski
pole. The second skier lost one ski, one whippet and one headlamp. The two
skiers conducted a quick search for the equipment but decided to vacate the area
and begin their post-holing boot pack back to camp.
A hasty assessment of the avalanche and the surrounding produced the following:
The crown of the avalanche was 1.5 feet at it’s shallowest and up to four feet
at it’s deepest and was approximately 200 feet wide. The crack continued
another 50 feet eastward and 200 feet westward from where the avalanche
occurred.