American Alpine Jounrna and Accidents in North American Climbing

Avalanche

Alaska, Eastern Alaska Range, Canwell Glacier

  • Accident Reports
  • Accident Year: 2016
  • Publication Year: 2017

On March 26, a group from a University of Alaska Fairbanks introductory mountaineering class was out for its final climb. The class consisted of nine students (ages 20–28), one lead instructor, and three volunteer assistant instructors. After 11 weeks of class, including nine days of hands-on field time, the students were tasked with developing and executing a trip plan for their final group climb. The class chose a snow climb on the northwest face of McCallum Peak, off the Canwell Glacier in the eastern Alaska Range.

This trip would involve a six-mile approach to a proposed campsite at around 4,500 feet on a glacier on the north aspect of McCallum Peak. From there, the climb would consist of glacier travel and climbing on moderate snow slopes, up to 50°, to the summit at 6,700 feet. The students’ plan was to leave early on Saturday to make the relatively flat approach to the campsite. If the avalanche conditions looked favorable, the plan was to wake up early on Sunday, climb the peak, descend back to camp, and then ski back out to the road. The eastern Alaska Range has a classic cold and thin continental snowpack. The class had been into this area several times during the weeks preceding the climb, on similar aspects and elevations as the proposed climb. We spent quite a bit of time doing snow assessment during those trips, and at that time the stability was relatively good in most locations.

Ten days before the attempted climb, a storm came through this part of the Alaska Range, bringing about 70cm of new snow and approximately 25 mph winds. Directly after this storm, an advanced avalanche course was taught in thevgeneral area of our objective. The folks in this Avy 2 course shared high-quality snow observations on the Eastern Alaska Range Avalanche Center website, about a week before our climb. The snowpack showed an existing wind slab, a potential weak layer of facets, and a melt-freeze crust at 25cm depth. The test results showed poor stability, with easy initiation and high propagation potential. The avalanche course students and instructors identified “considerable” avalanche danger on all aspects above treeline.


The mountaineering course students and instructors had read and discussed the forecast and had identified avalanche conditions as the main hazard in a pre-trip meeting on Thursday. The class made a decision to mitigate this hazard by avoiding avalanche terrain until extensive observations and snowpack assessment were possible. The route the students planned to follow during the approach would keep the group almost completely out of avalanche terrain, and they chose a camp location that provided access to representative terrain for snowpack assessment.

The group got to the trailhead at 8:30 a.m. It was about 24°F. The temperatures had been in the 20s and 30s and clear, with 5–15 mph winds, since the storm the week before. After a quick trailhead talk and beacon check, the group headed out. Everyone was wearing a working beacon and a helmet. Everyone also had a shovel and a probe along with their camping and climbing gear. Throughout the course, we had done 12–15 hours of avalanche education, which included work in the classroom and in the field. Two of the instructors had their Avy 2 certifications, and three of the other members of the group had taken Avy 1 prior to the class.

During the approach, navigation was left to the students, and it proved to be challenging and time consuming. The group strayed off the trail along the moraine bench on the south side of the Canwell Glacier and ended up out on the glacier. The instructor let the students go the less efficient way to reinforce the lessons of route-finding and navigation that had been taught in the course. We had proceeded about 1.5 miles along the glacier before the students realized they wanted to be on the large, flat moraine bench about 200 feet above them. The group gathered and briefly discussed the options, which were to retreat 1.5 miles to find the spot where the group had headed out onto the glacier and then travel back along the trail, or else to find the best spot along the north-facing lateral moraine feature to climb up to the flats and trail above them. The group decided to find a way up the relatively short moraine slope in front of them instead of backtracking.


While grouped up, we also discussed the snowpack observations we had made so far that day. No one in the group had seen or heard any red flags up to that point. The folks in the lead chose a line that followed a snow ramp up along a shallow rock band on a 25–30° slope most of the way up the moraine feature. This line had one short section (40–50 feet) of 35–40° open snow slope at the top before reaching flat ground. Upon reaching this slope, the lead group strapped their skis on their packs and started up. The rest of the group went up the slope in a staggered line. For the first half of the slope, the snow consisted of 30cm of unconsolidated sugar over scree. About halfway up, the snow began to have a wind crust/slab that thickened toward the rollover from the flats above.

The lead people were about 20 feet from the flats above, and the last folks were about 100 feet below them, when the lead climber triggered a wind slab that entrained all 13 members of the climbing party. The two people in the lead only traveled a short distance downslope; five people were carried downslope but remained on top; four people were partially buried; and two people were completely buried close to the surface. The avalanche had an R3 relative size and a D2 destructive force. The crown was between 6 and 12 inches thick. The slide path was 150 feet wide at the top and 250 feet wide at the bottom, with 250-foot vertical fall.

After the slide, rescue was initiated by several of the unburied students. One student took lead and did a count, one student yelled to everyone to turn their beacons to search, and two other students began looking for clues and limbs sticking out of the snow. (This student-led rescue was necessary due to the fact that all of the instructors were either at the top of the slope or partially/fully buried.) Only one person was not accounted for right away—miraculous with 13 people involved in the slide. After a few seconds, this victim’s fingers poked through the snow and were noticed by one of the students, who cleared the person’s airway. Within 30 seconds, this person and all the others were being helped out of the snow. Two folks had minor breathing difficulties after their burial. Other noncritical injuries included a small leg laceration on one of the students, a small facial laceration from one student’s sunglasses, and a minor hand laceration on one of the volunteer instructors. Several of the folks were cold from being buried and were given dry clothes and warmed up. After a brief discussion, the group packed up and skied several hours back to the vehicles.

ANALYSIS

Our group was extremely lucky that no one was seriously hurt or killed in this avalanche. The dangerous avalanche conditions persisted for the next couple of weeks. During that spring season, several human-triggered avalanches resulted in two fatalities within a few miles of our avalanche scene.

Here is a brief overview of some of the mistakes we made, contributing to our accident, along with strategies that we could have used to help mitigate the avalanche risks that we faced on our trip. This analysis is a combination of personal/in-house analysis in addition to a third-party assessment of the avalanche accident.

  1. Poor decision-making and communication as a group. The group didn’t acknowledge a distinct terrain change (entering avalanche terrain for the first time that day) by grouping up and discussing all available options. We didn’t follow the STOP rule: Stop, Think, Observe, Plan and Pre-Mortem. We didn’t keep everyone informed and involved in the decision to get onto that particular slope. We didn’t use a clear system for communication and decision-making.
  2. Poor group management—putting everyone on the same slope. We should have exposed only a minimum number of people to a hazard at one time.
  3. Not being flexible enough with the trip plan. We knew about the “considerable” avalanche risk and hoped to use terrain for protection instead of reconsidering the objective or changing the dates of the trip.
  4. Avalanche blindness. Had we been more sensitive to the hazard, we could have paused to acquire more information and/or backtracked to stay out of avalanche terrain completely.
  5. Time constraints, feeling rushed. We should have had more flexible time-management plans. (Source: Lead instructor of the class.) 
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