For a slab avalanche to occur, a sufficient amount of fresh snow (30 cm or more)—heavy enough to trigger a sliding motion—must have fallen. The terrain slope must be suitable, and the area must be free of trees or major surface irregularities. Slab avalanches typically occur during or immediately after fresh snowfall, usually within a day at most. As time passes, the factors causing instability between the fresh snow and the underlying snowpack diminish; the layers bond together, and no avalanche occurs. Other triggering conditions are also significant: following snowfall, temperatures may rise suddenly, or conversely, strong winds may begin to blow. Additionally, a skier or a shovel could cut into the snow mass and set it in motion. In the vicinity of Kholat, it is virtually impossible to encounter an avalanche event without a combination of heavy snowfall, meteorological factors (such as a sudden rise in temperature or strong winds), and human intervention.
In light of the data regarding slab avalanches described above, a possible explanation for the tragedy emerges: the final days of January had been quite calm until the Dyatlov group reached the slopes of Kholat. However, it is evident that the weather deteriorated starting February 1st; with the onset of fresh snowfall, the previously relatively easy traverse across the Auspiya plain became impossible. It became necessary to lighten their loads, and they attempted to follow a new route along the ridgeline before entering the forest.
Upon waking on the morning of February 1st, they noticed the fresh snowfall and waited for it to stop. The precipitation did not cease until midday. They set out without wasting any more time, leaving some of their equipment behind. In the afternoon, the snowfall intensified, forcing them to halt. They planned to spend the night on the slope and reach the summit of Otorten—a day's hike away—the following morning. Given that the snowfall, which had lasted all day, intensified after the tent was pitched (continuing from the 5:00 PM setup until 8:00 PM), it is evident that the two conditions necessary for a slab avalanche were met: a sufficient amount of snow had accumulated, and the natural anchor points holding the snow mass in place had been disrupted by human activity. That leaves meteorological factors. It would have been unrealistic to expect a rise in temperature on the slopes of Kholat at that time of year and day; a strong wind had likely sprung up. Indeed, it must have been a powerful wind that caused the group's tent to collapse under a slab avalanche, disrupted their progress through the forest, and prevented them from returning to the tent.
This scenario is the most consistent version regarding the unfolding and consequences of the Dyatlov tragedy. Naturally, it requires supporting evidence. If there had been no snowfall—or only very light precipitation—on the day the tent was pitched or the following days, the snow would have been blown away by the wind, and the tent fabric would have been found clean. Yet, there was approximately 20 cm of snow on the tent. In the photos showing the tent's setup, we see the tourists cutting into the snowpack—which reaches waist-height—to create a level platform and a wall directly in front of them. Yet, in the images taken when the tent was actually found, we see neither the debris from that excavation nor a tent embedded within a meter-high snow wall. It appears as though the tent was simply placed on the slope without any ground leveling. If we accept these photos as a valid reference—assuming the group members used sleds to dig through fresh snow and cut into the older, hard snow to reach that waist-deep level before lining up their sleds—then perhaps a slab avalanche swept away the fresh snow layer (which had accumulated to 30 cm, and later 50–60 cm, by the time the tent was pitched), leaving the tent exposed on the much harder snowpack from December or January. If the tent shows no signs of external interference, the most plausible reason for it being cut open and abandoned is that conditions inside made it impossible to stay there—such as a heavy weight pressing down that made re-entering and breathing impossible. They exited the tent and walked calmly downhill. They placed a lit flashlight on the tent's peak—which remained relatively exposed above the snow cover—and left another one along the path leading to the forest. This suggests the incident occurred early in the night; the plan was likely for some group members to descend to the forest and then return, using the flashlight beams to navigate and retrieve extra equipment from the tent. The flares signal that there is no human threat influencing their decision to return to the tent, that they have experienced a natural disaster, and that they have injured people who need to be urgently brought down to the forest.
Topic: 2 Chinese lanterns (Read 136 times)
