AVALANCHE, POOR POSITION, WEATHER, DECISION MAKING
Alaska, Mount Huntington
Trapper Creek climber Johnny Soderstrom (26) was declared missing and presumed dead in an avalanche, which occurred on Tuesday, February 15th. Soderstrom was last seen alive by his climbing partner, Joe Reichert, on Tuesday morning, as the pair approached the mountain’s West Face Couloir route. After several hours of probing in avalanche debris in search of his partner, Reichert used a satellite phone to initiate search and rescue efforts.
There is no way to soften the blow or somehow mitigate the ramifications of this tragic loss. Yet any lessons or benefits of learning from hindsight, I believe, must be seized. Johnny’s death was felt far and wide by the climbing community, and many people can see themselves in this accident. It is only through the honest discussion of this incident that others might be safeguarded.
For the purposes of this report, the objective contributory causes will be discussed within the headings of terrain, weather, snowpack, and rescue. The subjective contributory causes will be discussed within the heading of decision-making/human factor.
Terrain. Based on statements made by the reporting party (Joe Reichert) and observations made during an aerial survey on February 16 and 17, the accident site appeared to have a slope angle from the high 30-degree range to the mid 20-degree range. Johnny appears to have entered the slide area at the steepest part of the slope.
Because it is at the base of the vertical West Face of Huntington, the slope lacks the typical windward (scouring) or leeward (loading) phenomena. Nevertheless, it is prone to snow slab formation, which results when snow sloughs from the adjacent cliffs and lands on the relatively flatter slopes below.
The slope is typical of a glacier in its lack of roughness or presence of sufficient anchoring. The slope is approximately 60 meters in height by 20 meters in width, is planar in shape, and lacks any compressive support from the snowpack below due to a large crevasse at the lower margin of the slab. The crevasse made the consequence of being caught in an avalanche a nearcertain fatality.
Weather. There are two parts of weather to consider. The first is the prior events and how those may influence the stability of the snowpack. The second is how current events are influencing the stability of the snowpack. The question to be asked: “Is the weather contributing to instability?”
The unstable layering within the snowpack had its probable origins two weeks prior to the accident. A period of clear skies with no snowfall and cold temperatures from January 31 to February 5 resulted in a layer of weak, poorly bonded (faceted) snow on the top of the snowpack. This weak layer was subsequently buried by light snowfall on February 6 and 10, and farther buried by an even heavier snowfall from February 13 through 15. February 11 and 12 were clear and cold, which continued to provide a sustained temperature gradient necessary to produce faceted snow.
The wind that Johnny and Joe experienced during the storm of February 13-15 (estimated 30+mph) did not seem to contribute significantly to this avalanche. The slope is situated to avoid direct wind loading due to the lack of adjacent ridges or ribs, as evidenced by the relatively shallow crown face of the avalanche. However, the wind may have played a slight role at this location by acting as a compactor, making the slab more cohesive and able to propagate a fracture.
The weather on the day of the accident was stormy with heavy snowfall at times. This additional loading on this slope would have increased the avalanche hazard. Most avalanches happen during a storm, when the stresses on the snowpack are greatest and natural releases are most common. Consequently, it is prudent to avoid traveling in avalanche terrain during or immediately after storms.
Further, the overall visibility was less than adequate. The collection of information about the terrain becomes more difficult during storms or flat lighting. Communication is more difficult during bad weather, and good discussions—crucial to good decision making—are often minimized or non-existent. Finally, if there is an accident, increasing hazard on unreleased slopes or rebuilding hazard at the accident site may preclude optimum search efforts.
Snowpack. The snowpack, consisting of a layer of weak snow capped over by a slab, had stored elastic energy provided by the snow falling from the above cliffs. The weak layer and subsequent snowfall were ubiquitous, but the weak layer, slab, and poor bonding found at the accident site existed primarily at the base of the cliffs. It only needed the slight additional stress supplied by a suitable trigger—in this case Johnny—to put the snow in motion.
On the day of the accident, while traveling on the lower portion of the route, Joe noted a lack of typical clues indicating an unstable snowpack, such as other avalanche activity, collapsing layers, shooting cracks, or hollow-sounding snow. For a slab avalanche to occur, there needs to be a relatively strong layer over a relatively weak layer, a critical balance between the strength and the stress of the snowpack, and enough elastic energy to propagate a fracture. In this scenario, the weather events contributed to the strong-over-weak layering; the slope angle, while shallow enough to collect snow, had enough steepness to allow the snow to slide; and the cliff faces above provided the mechanism that built the slab and supplied the needed elastic energy.
Further, the stresses at this particular site would have been higher due to the lack of compressive strength that is typically provided by the adjoining lower snowpack. The snowpack on any given slope derives some support from running into the snow below that is on a slightly less steep slope. Because the bottom of the avalanche slope adjoined the open crevasse, it lacked this component. It is possible that this difference allowed Johnny to cross the similar slope to the left of the slide path without triggering it.
Rescue. From talking to Joe and examining the site, it appears that Joe did everything that could be done to locate Johnny. Because they did not carry avalanche beacons, Joe could only search for surface clues and search the debris using an avalanche probe. Johnny was most likely swept into the crevasse on the leading edge of the slab. Consequendy, the probability of finding clues, because of the short distance Johnny traveled before entering the crevasse, was unlikely. Further, being on the leading edge would have made his burial very deep, so the chance of making probe contact was also low.
Joe first searched the debris that had not gone into the crevasse. This was a good strategy. The likelihood of a live recovery was highest there. He then concentrated his efforts in the main part of the debris in the crevasse, in the zone of highest probability of burial. Joe’s probe method, while not standard, was the approximate spacing of the three holes per step and, using proper technique, could yield about an 80 percent probability of strike. This is within the range of acceptable probe-line probabilities.
Joe searched for an estimated two hours and twenty minutes. Considering the hazard of the continuing snowfall, potentially reloading of the slope, and the large overhanging cornices that he was required to search under inside the crevasse, this was an appropriate amount of time. Statistics compiled from thousands of avalanche accidents tell us that even during shallow burials, it is rare to find the victim alive after one hour.
Decision Making/Human Factor. In 95 percent of avalanche accidents, the victim or someone in the victim’s party triggers the avalanche. In other words, the main cause of backcountry avalanche accidents is flawed decision making. Analyzing post-fatality decisions involves a certain amount of speculation. No one can know for certain the decision-making process that Johnny employed. Also, while retrospective judgments are easy to make, it is important to maintain a sense of humility. No one can predict with certainty how he or she might perform in a given situation, as many experts will attest. Even extensive experience and/or expertise do not provide absolute protection.
Based on the findings, it appears that the instability of the slope was underestimated, and the severity of the consequences was either not recognized or was underestimated. These judgments, particularly the latter, were the greatest contributory factors in this incident. Given the statement Johnny made immediately preceding the slide, it appears that he recognized the potential for an avalanche. However, he continued, either believing the snow would not avalanche, or that he would somehow be able to survive a slide.
Neither Johnny nor Joe dug a pit to investigate the layering and bonding of the snowpack. This is understandable given that a pit site that could provide the necessary information regarding slab formation, stress concentration, and layer bonding was exposed to the very hazard they were attempting to avoid. Sometimes in mountaineering “digging a pit” increases one’s exposure-time to the hazard. For this situation, however, the clues could have been garnered from a recollection of the weather, an examination of the snowpack lower on the route, knowledge of the slope angles they were likely to encounter, and an understanding of how slabs are built at the bottom of cliffs.
Joe and Johnny had spent longer on the route than anticipated, and the shorter amount of time they had remaining may have affected their decision to push forward on that day rather than wait for better conditions. They did, however, have a plan of calling for a flight to pick them up if time got short, though this was not their preferred option.
The entire mitigation of the avalanche hazard had to be the avoidance of avalanche slopes. This was not accomplished. Micro route selection was poor. On the macro scale, the route left little room for variation. The nature and location of the crevasses pushed the route up under the cliffs and above the crevasses. The route up to the point of the open crevasse was acceptable, but once Johnny stepped above the crevasse, the situation changed completely. To avoid being placed between a hammer and an anvil, as it were, it was necessary to skirt along the sides and upper edge of the slab. The margins of the slab are identifiable by the serac on the left side, the bergschrund above, and the lower slope angles on the right side.
The visibility was variable, so it may have been that Johnny couldn’t see the alternative option of ascending toward the bergschrund before he crossed above the open crevasse. Also, the alternative route could have necessitated taking off ones skis and post-holing, or at least making numerous switchbacks and side-stepping, all of which would be difficult in deep snow. Other factors may have influenced Johnny’s decision making. The distance from where he entered the avalanche slope to the safer lower angled slopes ahead is short. He was concerned about avalanches, which was demonstrated by his instructions to Joe. A predictable level of apprehension would have made the lower-angled terrain on the other side of the slope a very enticing focal point, a situation not conducive to looking around for alternatives.
It was unfortunate that visual contact was not maintained. This was an understandable product of the type of terrain they were attempting. From an avalanche perspective it is acceptable and often beneficial to travel unroped and farther apart. Being separated may have prevented both of them from being caught. It’s unknown how deep Johnny was pushed into the crevasse, but with the amount of snow involved, it is highly unlikely, had they been roped together, that Joe would have been able to arrest the fall and not be pulled in himself.
The decision to not take avalanche beacons deserves discussion. A beacon would probably not have made a difference in the outcome of this tragedy. However, a beacon would have provided more information about where exactly Johnny was buried and helped to eliminate the inevitable uncertainty and discomfort that occurs when a body cannot be found. Beacons also enable rescuers, including organized responders, to focus their efforts, shortening the search time and limiting their exposure to potential hazards.
Using an avalanche beacon in the big mountains has benefits other than body recovery. There are potentially survivable avalanches even in the big mountains and having a beacon does increase the odds of survival. The Mount St. Elias avalanche of June 10, 1981, provides a clear example of the potential benefits of wearing transceivers. Survivor of a burial Charlie Campbell said, “On my eight previous climbing expeditions, none of us ever used avalanche beacons. It was at my insistence that everyone had to wear one this trip. I guess I got smart just in time. Our choice of route, the intentional separation of our party, our avalanche beacons, and the fact we were trained to use them all helped stack the deck in our favor.”
The absence of beacons often represents an overestimation of one’s ability, or an underestimation of the hazard. It is not uncommon for experienced mountaineers to feel that if conditions make it prudent to wear a beacon, then the conditions are too dangerous to proceed. These climbers often claim that they “just won’t go” if it’s unsafe. Indeed, if wearing of a beacon encourages or allows the user to travel in more dangerous conditions than they might otherwise travel in, then there is a loss of overall safety. But to say that dangerous avalanche conditions will be totally avoided is a serious overestimation of any person’s ability to recognize and deal with the hazard. To say it another way, it is a serious underestimation of any person’s ability to make mistakes and not see the entire picture, or subconsciously to eschew the data that contradicts a desired result. Judging the hazard of any given slope is like shooting at a moving target. Conditions change over time, and what may be totally safe to cross on one day may not be safe on the next.
There are many factors that allow individuals to recognize the potentially serious consequences of avalanches and yet think that their personal situation is not so dangerous. In fact, studies on cognition have shown that people consistently rate their hazard evaluation skills significantly above average. We all feel we’re smarter than average and consequently feel the hazard is not as great for ourselves as it is for others. (Source: Blaine Smith, Alaska Avalanche School/Alaska Mountain Safety Center)