The Avalanche theory, particularly the slab avalanche hypothesis, is one of the most widely accepted scientific explanations for the Dyatlov Pass Incident, which claimed the lives of nine experienced hikers in the Ural Mountains in February 1959. This theory posits that a small but powerful slab avalanche triggered the catastrophic events that led to the hikers’ deaths, explaining the violent injuries, the chaotic scene, and their seemingly irrational behavior.
In late January 1959, a group of nine hikers from the Ural
Polytechnical Institute, led by Igor Dyatlov, set out on a skiing
expedition to reach Otorten Mountain in the northern Ural Mountains. On
the night of February 1–2, 1959, they pitched their tent on the slope of
Kholat Syakhl (“Dead Mountain” in the Mansi language). For reasons
unknown at the time, the hikers cut their tent from the inside and fled
into the freezing night, inadequately dressed and without shoes. Their
bodies were later found scattered across the area, some with severe
injuries, including chest fractures, skull trauma, and one missing her
tongue and eyes. The Soviet investigation concluded that a “compelling
natural force” caused the deaths, but the lack of clarity sparked
numerous theories. The Avalanche theory gained traction in recent years
due to scientific modeling and historical re-examination.
The
Avalanche Theory
The Avalanche theory suggests that a small slab
avalanche—a cohesive layer of snow sliding down a slope—struck the
hikers’ tent on the night of February 1–2, 1959. This event caused
panic, injuries, and forced the group to flee without proper clothing,
leading to their deaths from hypothermia, trauma, and exposure. The
theory was revitalized in 2021 by Swiss researchers Alexander Puzrin and
Johan Gaume, who used advanced modeling to demonstrate that a slab
avalanche was plausible under the specific conditions of Kholat Syakhl.
Mechanism of a Slab Avalanche
Definition: A slab avalanche occurs
when a cohesive layer of snow (the slab) breaks away from the underlying
snowpack and slides down a slope. Unlike loose-snow avalanches, slab
avalanches are more dangerous because the slab moves as a single, heavy
mass, capable of exerting significant force.
Conditions at
Dyatlov Pass:
The hikers pitched their tent on a slope with an
incline of about 15–20 degrees, which is within the range (typically
15–45 degrees) where slab avalanches can occur.
The Ural Mountains
are prone to heavy snowfall and strong winds, which can create unstable
snow layers. Wind-blown snow can accumulate on leeward slopes, forming a
slab over a weaker layer of snow.
The hikers dug a snow platform to
level their tent, potentially weakening the snowpack and increasing the
risk of a slab release.
Proposed Sequence of Events:
A small
slab avalanche, possibly triggered by wind loading, shifting snow, or
the hikers’ activity (e.g., digging), struck the tent.
The impact
injured some hikers, damaged the tent, and created panic, prompting the
group to cut their way out and flee downslope.
Disoriented and
underdressed in subzero temperatures (as low as -25°C), the hikers
succumbed to hypothermia, with some dying from their injuries.
Post-avalanche processes, such as scavenging animals or decomposition,
explain secondary findings like missing tissue.
Historical
Context
Avalanches were a known risk in the Ural Mountains, and the
hikers, as experienced mountaineers, would have been aware of them.
However, they may have underestimated the danger on Kholat Syakhl due to
its relatively gentle slope.
Soviet investigators initially
considered an avalanche but dismissed it, citing the lack of obvious
avalanche debris and the slope’s moderate incline. This dismissal
contributed to decades of speculation until modern science revisited the
hypothesis.
Violent Injuries:
Several hikers sustained severe trauma
consistent with a heavy impact:
Lyudmila Dubinina and Semyon
Zolotaryov had multiple rib fractures, likened by coroner Boris
Vozrozhdenny to injuries from a car crash.
Nikolay Thibeaux-Brignolle
suffered a fractured skull.
The coroner noted that these injuries
lacked soft tissue damage, suggesting a broad, forceful impact rather
than a targeted blow. A slab avalanche could deliver such force, as a
moving snow slab can weigh hundreds of kilograms.
Puzrin and Gaume’s
2021 study used simulations inspired by Disney’s Frozen snow physics to
model how a small slab (e.g., 5 meters by 5 meters) could generate
forces sufficient to cause these injuries without leaving extensive
debris.
Tent and Scene:
The tent was cut from the inside,
indicating a desperate exit. An avalanche striking the tent could have
caused panic, especially if it partially buried or compressed the
structure.
Footprints showed the hikers fled downslope in a
disorganized manner, consistent with escaping an immediate threat like
an avalanche.
The tent was partially collapsed but not buried, which
aligns with a small, localized slab avalanche that dissipated quickly.
Scientific Modeling (Puzrin and Gaume, 2021):
Published in Nature
Communications Earth & Environment, the Swiss study addressed key
objections to the avalanche theory:
Slope Angle: Although the slope
was only 15–20 degrees, the researchers showed that slab avalanches can
occur on such inclines, especially with wind-loaded snow.
Delayed
Trigger: The study proposed that strong katabatic winds (high-speed
downslope winds) accumulated snow above the tent over hours, creating an
unstable slab. A minor disturbance, such as a hiker’s movement or wind
shift, could have triggered the slide 9–13 hours after the tent was
pitched.
Injury Simulation: Using crash-test dummy models and snow
physics, the researchers demonstrated that a slab impact could fracture
ribs and skulls without bruising soft tissue, matching the autopsy
findings.
Lack of Debris: Unlike large avalanches, a small slab
avalanche would leave minimal traces, especially after weeks of wind and
snow, explaining why search parties found no obvious signs.
Environmental Conditions:
Weather reports from February 1–2, 1959,
indicate strong winds and snowfall, ideal for forming wind slabs. The
hikers’ diaries noted worsening weather, supporting the buildup of
unstable snow.
The tent’s location on an exposed slope increased its
vulnerability to wind-driven snow accumulation.
Hikers’ Behavior:
The hikers’ decision to flee without shoes or coats, while seemingly
irrational, is consistent with avalanche survivors’ accounts of panic
and disorientation. If the tent was struck or partially buried, they may
have feared further slides or believed their gear was inaccessible.
Some hikers attempted to build a fire and climb a cedar tree, suggesting
efforts to survive after escaping the initial danger, but hypothermia
set in rapidly.
Secondary Findings:
Lyudmila Dubinina’s
missing tongue and eyes are likely due to natural processes, such as
scavenging by small animals or decomposition, as her body was found in a
stream after months of exposure.
Paradoxical undressing, where
hypothermic individuals remove clothing due to a false sensation of
warmth, explains why some hikers were found partially undressed.
Soviet Investigation Reassessment:
In 2019, Russian authorities
reopened the case and concluded that an avalanche was the most likely
cause, citing the injuries and scene. This aligned with the Swiss
study’s findings, lending official support to the theory.
Lack of Obvious Avalanche Signs:
Critics note that search parties,
arriving weeks later, found no clear evidence of an avalanche, such as
displaced snow or debris. The slope appeared undisturbed, and the tent
was not fully buried.
Response: Puzrin and Gaume argue that a small
slab avalanche would leave minimal traces, especially after wind and
snowfall erased evidence over three weeks. The tent’s partial collapse
is consistent with a localized event.
Moderate Slope Angle:
The 15–20-degree slope is below the typical 30–45-degree range for
avalanches, leading skeptics to question the likelihood.
Response:
The Swiss study showed that slab avalanches can occur on gentler slopes
under specific conditions, such as wind-loaded snow and a weak
underlying layer. The hikers’ snow platform may have further
destabilized the snowpack.
Hikers’ Experience:
As experienced
mountaineers, the hikers should have recognized avalanche risks and
avoided pitching their tent in a vulnerable spot.
Response: The group
may have underestimated the risk due to the slope’s moderate incline and
their fatigue after a long day. The decision to dig a snow platform
suggests they prioritized a level campsite over avalanche safety.
Footprints and Scene:
Footprints were preserved in the snow,
suggesting no major snow movement after the hikers fled. A large
avalanche might have obliterated these tracks.
Response: A small slab
avalanche would not significantly disrupt the snow beyond the immediate
impact zone, and wind could have smoothed the surface, preserving
footprints.
Alternative Injuries:
Some argue that the
injuries, particularly the chest fractures and skull trauma, resemble
those from an explosion or human attack, not a snow impact.
Response:
The Swiss simulations demonstrate that a slab’s force can mimic
high-impact trauma without soft tissue damage, ruling out the need for
explosives or assailants.
Radiation and Other Anomalies:
Trace
radiation was found on some hikers’ clothing, and reports of “fireballs”
or lights in the sky fueled alternative theories (e.g., military tests).
Response: The radiation was likely from a lantern with a thorium mantle,
common in camping gear. The fireballs may have been atmospheric
phenomena or unrelated military activity, but they do not negate the
avalanche’s role.
Alternative Theories:
Other hypotheses, such
as katabatic winds (proposed by a 2019 Swedish-Russian expedition), a
military cover-up, or the Criminals/Former Inmates theory, compete with
the avalanche explanation.
Response: While katabatic winds could
explain disorientation, they don’t account for the specific injuries as
well as the avalanche theory. Human-attack theories lack evidence like
additional footprints, and military conspiracies are speculative.
The Avalanche theory gained significant credibility with Puzrin and
Gaume’s 2021 study, which addressed long-standing objections through
rigorous modeling. Their use of snow physics, inspired by animation
technology, provided a novel way to simulate the dynamics of a small
slab avalanche. The study’s findings were consistent with the 2019
Russian reinvestigation, which prioritized natural causes over
conspiracies.
Key strengths of the theory include:
Injury
Explanation: The slab avalanche accounts for the severe, localized
trauma without requiring human or supernatural intervention.
Environmental Fit: The weather, slope, and snow conditions align with
avalanche risk.
Simplicity: It avoids the complexity of conspiracy
theories, adhering to Occam’s razor by favoring a natural event.
However, the theory is not without limitations:
Lack of Direct
Evidence: The absence of avalanche debris remains a weak point, though
explained by the small scale and time gap.
Behavioral Questions: The
hikers’ extreme reaction (fleeing without gear) is plausible but not
definitive, as panic responses vary.
Compared to other theories, the
Avalanche hypothesis is the most scientifically grounded, supported by
data and simulations. It contrasts with speculative ideas like UFOs or
military tests, which rely on anecdotal reports, and human-attack
theories, which lack physical evidence.
The Avalanche theory has helped demystify the Dyatlov Pass Incident,
shifting focus from sensational conspiracies to natural explanations.
However, its acceptance is not universal, as the incident’s eerie
details—cut tent, missing tongue, scattered bodies—continue to fuel
public fascination. Books like Dead Mountain by Donnie Eichar (2013) and
documentaries have explored the avalanche hypothesis, but some Russian
investigators and enthusiasts prefer alternative explanations,
reflecting the case’s cultural significance in post-Soviet Russia.
The theory’s rise reflects advancements in avalanche science and a
broader push to resolve Cold War-era mysteries. Yet, the incident’s
haunting ambiguity ensures that even a robust explanation like the slab
avalanche cannot fully extinguish speculation.