Hubbry Logo
Avalanche controlAvalanche controlMain
Open search
Avalanche control
Community hub
Avalanche control
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Avalanche control
Avalanche control
Avalanche control
View on Wikipedia
from Wikipedia
An avalanche snow bridge near a ski-resort in Vorarlberg

Avalanche control or avalanche defense activities reduce the hazard avalanches pose to human life, activity, and property.[1] Avalanche control begins with a risk assessment conducted by surveying for potential avalanche terrain by identifying geographic features such as vegetation patterns, drainages, and seasonal snow distribution that are indicative of avalanches. From the identified avalanche risks, the hazard is assessed by identifying threatened human geographic features such as roads, ski-hills, and buildings. Avalanche control programs address the avalanche hazard by formulating prevention and mitigation plans, which are then executed during the winter season. The prevention and mitigation plans combine extensive snow pack observation with three major groups of interventions: active, passive and social - sometimes more narrowly defined as "explosive", "structural", and "awareness" according to the most prevalent technique used in each.[1] Avalanche control techniques either directly intervene in the evolution of the snow pack, or lessen the effect of an avalanche once it has occurred. For the event of human involvement, avalanche control organizations develop and train exhaustive response and recovery plans.

Prevention and mitigation

[edit]

Prevention and mitigation begins with observing the snow pack to forecast the risk of avalanche occurrence. The forecast risk then determines the necessary interventions to reduce the hazard posed by an avalanche.

Observation and forecasting

[edit]

Snow pack observation studies the layering and distribution of the snow to estimate the instabilities of the snow pack and thus the risk of an avalanche occurring in a particular terrain feature. In areas of heavy human use the snow pack is monitored throughout the winter season to assess its evolution under the prevailing meteorological conditions. In contrast to heavily used avalanche terrain where forecasting is the goal of snow observation, in remote terrain, or terrain that is infrequently visited, snow pack observation elucidates the immediate instabilities of the snow pack.

Active interventions

[edit]
Avalanche blasting in the French ski resort of Tignes (3,600 m or 11,800 ft)
Gazex installation

Active techniques reduce the risk of an avalanche occurring by promoting the stabilization and settlement of the snow pack through three forms of intervention: disrupting weak layers in the snow pack, increasing the uniformity of the snow pack, and lessening the amount of snow available in snow pack for entrainment in an avalanche; this can be accomplished either by triggering smaller less hazardous avalanches, or by directly influencing the structure of the layering of the snow pack. Active avalanche control can be broadly classified into either mechanical or explosive methods. Mechanical methods are typically used in either remote terrain, smaller terrain, or less hazardous terrain; while explosive methods are used in accessible large high hazard terrain, or terrain with industrial, commercial recreational, urbanized, and transportation usage.

In the smallest terrain features the simplest method of avalanche control that disrupts weak snow layers by directly walking through them, a technique referred to as boot packing. For larger features this method can extended by mechanized redistribution of snow using large tracked vehicles called snow groomers. These two mechanical interventions can only be safely done as the snow is deposited and before it develops any instabilities. In terrain that can only be sporadically accessed, or in a highly developed snow pack that is too deep for boot packing, ski stabilization techniques are used. The first technique of ski stabilizing is a method of entering a slope called ski cutting. In this method a skier attempts to trigger a small avalanche by breaking the tensile support of the upper snow pack through a quick traverse along the top of the slope, the skier can be belayed on a rope to further protect them from being caught in an avalanche. A snow pack can then be further settled out, or stabilized, by further down slope ski traffic through it. Finally knotted cord can be used to saw through the roots of cornices, causing the cornice to drop onto the snow pack of the slope below. This has the combined effect of reducing the objective hazard posed by the cornice, and providing a large impact force on the snow pack.

U.S. Forest Service team using a 105mm recoilless rifle for avalanche control at Mammoth Mountain in the Inyo National Forest.

Explosive techniques involve the artificial triggering of smaller less destructive avalanches, by detonating charges either above or on the snow surface. The explosives may be deployed by manually hand tossing and lowering, by bombing from a helicopter, or by shelling with a howitzer, recoilless rifle, or air gun. In balancing the hazard to personnel with the effectiveness of the deployment method at accessing and triggering avalanche terrain, each method has its drawbacks and advantages. Among the newest methods, strategically placed remote controlled installations that generate an air blast by detonating a fuel-air explosive above the snow pack in an avalanche starting zone, offer fast and effective response to avalanche control decisions while minimizing the risk to avalanche control personnel; a feature especially important for avalanche control in transportation corridors. For example, the Avalanche Towers (Sprengmast) Austria, and Norway use solar powered launchers to deploy charges from a magazine containing 12 radio controlled charges. The magazines can be transported, loaded, and removed from the towers by helicopter, without the need for a flight assistant, or on site personnel.

Explosive control has proved to be effective in areas with easy access to avalanche starting areas and where minor avalanches can be tolerated. It is mostly unacceptable, however, in areas with human residence and where there is even a small probability of a larger avalanche.[1]

Permanent interventions

[edit]
Forest and structures to protect against avalanches.

Permanent techniques slow, stop, divert, or prevent snow from moving; either completely or to enough of an extent that the destructive forces are significantly lessened. Permanent techniques involve constructing structures and modifying terrain for purposes classified as:[1]

  • Snow retention structures (snow racks, avalanche snow bridges, snow nets), used in the upper path of probable avalanche paths
  • Avalanche barriers: The main part of the avalanche barriers is based on a high tensile strength steel wire mesh, extending across the slope and reaching to the surface of the snow. The supporting effect created by the retaining surface prevents possible creeping within the snow cover and sliding of the snow cover on the terrain surface. Breaking-away of avalanches is thus prevented at the starting zone, while occurring snow movements are restricted to the extent that they remain harmless. The forces resulting from the snow pressure are absorbed by the snow nets and carried off over the swivel posts and anchor ropes into the anchor points.
  • Snow guard devices (used to increase snow retention on roofs).
  • Snow redistribution structures (wind baffles, snow fences)
  • Snow deflection structures used to deflect and confine the moving snow within the avalanche track. They should not deflect the avalanche sharply, because in the latter case they may be easily overrun by snow.
  • Snow retardation structures (e.g. snow breakers), mostly used in small-slope parts of the avalanche track, to enhance the natural retardation
  • Snow catchment structures
  • Direct protection of important objects and structures, e.g., by snow sheds (avalanche sheds) or schneekragens (in mining areas).

A single intervention may fulfill the needs of multiple classes of purpose, for example, avalanche dams, ditches, earth mounds, and terraces are used for deflection, retardation, and catchment. Other passive methods include:

  • reforestation, up the natural tree line — forests serve all the functions of artificial avalanche defenses: retention, redistribution, retardation and catchment.
  • snow caves, as well as recessed, dug out, and snow walled quinzhees and bivouac shelters are used to temporarily protect bivouacking climbers and skiers by providing them with breathing space in the event of burial by avalanches.
  • Architectural streamlining and wedge shaping buildings, such as those found in the historic high mountain villages of the Alps.

Snow shed

[edit]
Trains passing in an avalanche gallery on the Wengernalpbahn in Switzerland.
See also: Rock shed

A snow shed or avalanche gallery is a type of rigid snow-supporting structure for avalanche control or to maintain passage in areas where snow removal becomes almost impossible. They can be made of steel, prestressed concrete frames, or timber.[2][3] These structures can be fully enclosed, like an artificial tunnel, or consist of lattice-like elements. They are typically of robust construction considering the environments they must survive in.

Snow protection is particularly important when routes cross avalanche "chutes", which are natural ravines or other formations that direct or concentrate avalanches.

Snow sheds or avalanche galleries are a common sight on railroads in mountain areas, such as Marias Pass and Donner Pass in the United States, or many of the Swiss mountain railways, where tracks are covered with miles of shedding. Although unused today, the Central Pacific Railroad had a complete rail yard under a roof on Donner Pass. They are also found on especially hazardous stretches of roadway as well. The Trans-Canada Highway between Revelstoke and Golden in British Columbia has several snow sheds covering both directions of travel to cope with the heavy snow.

East of Snoqualmie Pass in Washington in the northwest U.S., westbound Interstate 90 had a snow shed midway along the east shore of Keechelus Lake (47°21′18″N 121°21′57″W / 47.355°N 121.3658°W / 47.355; -121.3658, milepost 57.7); it was removed in 2014 in preparation for the construction of bridges to replace it.[4][5] The 500-foot (150 m) concrete structure covered two lanes on a curve and was constructed in 1950 for U.S. Route 10, then one lane in each direction; it marked the first time precast construction was used for a highway structure in a mountainous area and was the last remaining snow shed on an Interstate highway.[6]

Snow bridge

[edit]
Snow bridges in Switzerland.

A snow bridge, avalanche barrier, or avalanche fence, looks superficially similar to snow fences, but they act differently. Snow fences are built vertically and accumulate snow on their downwind side, while snow bridges are slanted or horizontal and hold snow on their top side.[7]

Snow bridges are fastened to the slope on the upslope side by tension anchors and on the downslope by compression anchors.[8]

Avalanche dam

[edit]

Avalanche dams (anti-avalanche dams, avalanche protection dams) are a type of avalanche control structure used for protection of inhabited areas, roads, power lines, etc., from avalanches. The two major types are deflection and catchment dams.[9]

Both types of avalanche dams are usually placed in the run-out zone of the avalanche and in the flatter parts of the avalanche path. In other parts of the avalanche they are ineffective because they may be easily overrun or overfilled.[9]

Avalanche net

[edit]

Avalanche nets (snow avalanche protection nets, snow nets) are flexible snow supporting structures for avalanche control, constructed of steel or nylon cables or straps held by steel poles, optionally supplied with compression anchors downhill. They are installed in the upper parts of potential avalanche paths to prevent snow from starting to slide into an avalanche, or to retard the slide.[1]

Snow avalanche nets have the following advantages compared to rigid supporting structures (snow fences, snow racks, snow sheds):

Avalanche nets have some drawbacks, as they are more difficult to anchor in loose ground.[compared to?]

Social interventions

[edit]

To mitigate the hazard of avalanches, social interventions reduce the incidence and prevalence of human avalanche involvement by modifying the behavior of people, so that their use of avalanche terrain is adapted to prevent their involvement in avalanches. Avalanche control organizations accomplish this by targeting awareness and education programs at communities that frequent avalanche terrain. Surveys of avalanche accidents have observed that most avalanches that involve people are caused by people, and of those victims many were unaware of the risk of avalanche occurrence. To address this observation, introductory awareness and education programs provide instruction in the avoidance of hazardous avalanche involvement through the recognition of avalanche terrain, the observation of snow pack instabilities, and the identification of human activities that cause avalanches. Avalanche control organizations also publicly disseminate forecasts, bulletins, warnings, and reports of avalanche activity to assist communities of avalanche terrain users.

Response and recovery

[edit]

Avalanche mitigation organizations plan for, and respond to, avalanches[12][13][14][15]. Typical responses span from clearing transportation corridors of avalanche debris, to repairing industrial and recreational facilities, to search, rescue, and recovery. To improve the outcome of human avalanche involvement avalanche control organizations offer training and education to both professionals and recreational amateurs in avalanche preparedness.

Professional preparedness

[edit]

Professional responses to avalanches are targeted at avalanches involving the general unprepared public. When avalanches are forecast to occur, avalanche terrain to which the general unprepared public is exposed will be closed, and after the avalanches have occurred the area is cleared of debris, and repaired. When unexpected avalanches occur that involve the general unprepared public, avalanche control organizations respond with large professionally organized search teams involving probe lines, and trained search and rescue dogs.

Amateur preparedness

[edit]

Recreational response to avalanches involves the rapid formation of an ad hoc search and rescue team. The ad hoc search and rescue teams rely on all the participants having prepared for a potential avalanche by carrying the correct search and rescue equipment, and undergoing the appropriate training.

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Avalanche control

View on Grokipedia
from Grokipedia
Avalanche control is the systematic practice of reducing the risk of snow avalanches in mountainous areas through proactive measures designed to prevent, trigger, or mitigate their occurrence, thereby protecting human life, , and economic activities such as transportation and . These efforts, applied worldwide including in the , , and , primarily involve artificial release of unstable snow slabs using explosives, construction of defensive structures to deflect or retain snow, and supportive techniques like snow compaction and . Common applications occur along highways, in ski resorts, and near settlements in regions with heavy snowfall, such as the Cascade and in . The core methods of avalanche control fall into active and passive categories. Active control employs explosives delivered via hand charges, shells from howitzers or recoilless rifles, or remote systems like avalanche launchers to intentionally trigger small under controlled conditions, often based on stability assessments and . For instance, 105mm howitzers fire projectiles with a radius of influence up to 122 , while remote avalanche control systems (RACS) allow detonation without personnel exposure to hazards. Passive control includes solutions such as snow sheds to shield roadways, deflection or mounds to redirect flows, and snow nets or fences to stabilize or catch debris in runout zones. Additional strategies encompass preemptive snow compaction by or grooming to densify weak layers and regulatory measures like public warnings and zoning restrictions to limit development in high-risk areas. Historically, avalanche control emerged in the early 20th century following catastrophic events, such as the 1910 Wellington avalanche in Washington state that killed 96 people, which highlighted the need for systematic measures. The U.S. Forest Service later adopted military surplus artillery for remote blasting in the 1940s. Techniques advanced through Swiss innovations beginning in the 1930s, with lightweight steel structures developed in the mid-20th century, and have since incorporated modern technologies like drones and automated systems to enhance safety and efficiency. Today, agencies like the Washington State Department of Transportation and Colorado Department of Transportation conduct seasonal operations on passes receiving over 450 inches of snow annually, minimizing closures—typically 30 minutes to two hours—while supporting millions of vehicle transits and freight movements. These practices underscore the interdisciplinary nature of avalanche control, integrating meteorology, engineering, and risk management to balance environmental challenges with societal needs.

Fundamentals of Avalanches

Types and Causes

Avalanches are classified into several primary types based on their formation mechanisms and physical characteristics. Slab s, the most dangerous type, occur when a cohesive layer of shears along a weak underlying layer, releasing as a single unit that can accelerate rapidly downslope. Loose avalanches, also known as point-release avalanches, begin at a single point where unconsolidated lacks sufficient bonding and propagates as a fan-shaped mass. Wet avalanches form when meltwater infiltrates the , reducing friction between grains and causing lubrication that leads to failure, often on slopes previously stable in dry conditions. avalanches involve dry, low-density that behaves like a fluid, typically resulting from the entrainment of loose, uncompacted during high-speed flow. The primary causes of avalanches stem from disruptions to snowpack equilibrium, divided into natural and human-induced triggers. Natural triggers include heavy snowfall, which adds excessive load to the snowpack and exceeds the strength of weak layers; rapid temperature increases that cause melting and bond weakening; and wind loading, where wind redistributes snow to form dense slabs on leeward slopes. Human-induced triggers commonly involve the added stress from recreational activities such as skiing or snowmobiling, where the weight of a person or vehicle propagates through the snow to fracture weak layers, often within 1-1.5 meters of the surface. Construction activities in avalanche-prone terrain, including road building or blasting, can similarly overload slopes and initiate releases by altering snow distribution or introducing vibrations. Snowpack structure plays a critical role in avalanche formation, consisting of layered variations in snow density, crystal type, and bonding that develop over time. Key layers include new snow, which accumulates rapidly and adds weight without immediate bonding; wind crusts, hardened surfaces formed by wind-compacted snow that can overlay weaker strata; and depth hoar, large, faceted crystals at the base of the snowpack resulting from strong temperature gradients that create fragile, poorly bonded interfaces prone to failure. Stability within these layers is assessed through indices that quantify the ratio of snow strength to load, such as those derived from field tests measuring shear resistance relative to slab weight, helping to identify persistent weak layers like depth hoar that contribute to slab releases. Globally, avalanches occur frequently in mountainous regions with sufficient snowfall and steep , with estimates of thousands annually across major ranges, though exact numbers vary due to underreporting in remote areas. In the European , avalanche activity is high, with around 500 to 1,500 avalanches recorded annually in the , driven by dense population and extensive monitoring. In contrast, the North American Rockies experience significant but regionally variable frequency, with tree-ring reconstructions indicating about 27 major avalanche years over a 94-year period in Glacier National Park, , reflecting influences like Pacific weather patterns that differ from the more maritime conditions in the .

Risk Factors and Assessment

Avalanches are influenced by a combination of environmental and factors that determine the likelihood of release. Slope angle is a primary , with avalanches possible on any steeper than 30 degrees and most frequent between 35 and 45 degrees due to the balance between gravitational pull and cohesion. Aspect, or the direction a faces, also plays a key role, as lee sides—those sheltered from —accumulate wind-drifted , forming unstable slabs more readily than windward aspects. affects risk through variations in snowfall accumulation, gradients, and wind exposure, with higher elevations often experiencing deeper and more intense storm cycles that heighten instability. history contributes significantly, as persistent weak layers—such as faceted crystals formed during prolonged cold, dry periods—can remain buried and prone to failure under added load. Weather patterns exacerbate these conditions; for instance, a sequence of prolonged cold followed by rapid warming can weaken surface layers through melt-freeze cycles, increasing slab potential. Human activities introduce additional risks by acting as triggers or increasing exposure in hazardous areas. recreation, such as or snowmobiling, often involves traveling on or below steep slopes during periods of instability, where skier weight or impact can initiate fractures in weak layers. Infrastructure placement, including roads, buildings, and power lines in avalanche runout zones—the lower areas where debris flows—amplifies vulnerability, as these structures can be directly impacted by even moderate slides if sited without adequate . Basic assessment methods allow individuals to evaluate site-specific stability before travel. Visual slope inspection involves observing signs of instability, such as recent avalanche debris, surface cracks, or "whumphing" sounds from collapsing weak layers, which indicate heightened risk across the slope. Snow profile digging requires selecting a representative slope of similar aspect and angle, then excavating a pit about 1.5-2 meters deep and 1.5 meters wide to expose the snowpack layers; examiners identify weak layers by hand hardness tests and probe for grain type and bonding. Stability tests performed within the pit provide quantitative insights into layer strength. The compression test isolates a 30 cm x 30 cm column adjacent to the profile wall; the tester places a shovel blade on top and applies 10 taps from the wrist, followed by 10 from the elbow, and 10 from the shoulder, recording the number of taps (CT score) required for the first and any propagating fractures in weak layers—lower scores suggest poorer stability. The extended column test (ECT) assesses propagation potential by isolating a 30 cm x 90 cm column cross-slope; after sawing three sides and the base, the tester loads it with the same tapping sequence as the compression test, noting the ECT score for propagation distance and any full-column failure, where propagation across the entire width signals high risk. Emerging influences like are altering traditional risk profiles by modifying dynamics. Warmer temperatures are projected to increase rain-on-snow events, which saturate the and boost wet avalanche frequency by up to 20% at higher elevations by mid-century. Avalanches are quantitatively classified on a 1-5 scale based on destructive potential, providing for . Size 1 avalanches are small, unlikely to bury a person except in traps; size 2 can bury or injure but destroy few objects; size 3 pose serious to people and vehicles with significant structural damage; size 4 cause major damage to buildings and forests; and size 5 devastate landscapes with catastrophic potential, such as entire villages.

Monitoring and Forecasting

Observation Techniques

Observation techniques in avalanche control involve a range of methods to detect unstable conditions, such as weak layers or recent fractures, which can indicate heightened avalanche risk. These approaches emphasize safe, systematic to identify early signs of instability without triggering events. Ground-based and remote methods complement each other, providing both detailed local insights and broader spatial coverage to support decision-making in avalanche-prone areas. Ground-based techniques form the foundation of direct snowpack assessment, allowing practitioners to evaluate stability through hands-on . Snowpit involves excavating a vertical profile of the , typically 1.5 to 3 deep, to examine layers for grain type, hardness, and bonding using tools like hand lenses and thermometers; this reveals weak interfaces prone to failure, such as depth hoar or surface hoar layers that contribute to slab . Protocols recommend digging pits on representative with similar aspect and to the area of interest, avoiding recent paths, and conducting stability like the extended column (ECT) or propagation saw (PST) to quantify and crack potential. Probe surveys complement snowpits by inserting lightweight probes at intervals across a slope to map snow depth variations and detect buried hazards like rocks or trees, with standard grids spaced 5-10 apart for efficiency. Fracture line observations focus on examining crown, flank, and debris zones of recent to measure slab thickness, fracture character, and release mechanisms, often documented with photos and measurements to inform ongoing assessments. These methods adhere to protocols, such as traveling in groups and using transceivers, to minimize risks during fieldwork. Remote sensing technologies enable non-invasive monitoring over larger areas, capturing data on environmental factors influencing snow stability. Automated weather stations, deployed at key elevations in avalanche basins, continuously record variables like wind speed, temperature, and precipitation to track loading on the snowpack; for instance, networks in the Swiss Alps integrate over 100 stations to detect rapid wind slab formation. Seismic sensors detect micro-tremors and infrasound from snow movement or settling, providing early warnings of instability; studies in the European Alps have shown these sensors can identify precursor vibrations seconds to minutes before fracture initiation in small slab avalanches. Infrared cameras map snow surface temperatures to identify refreezing or warming trends that weaken bonds, with applications at test sites revealing temperature gradients exceeding 10°C per meter in unstable profiles. Satellite remote sensing, using synthetic aperture radar (SAR) from missions like Sentinel-1, provides basin-scale snow depth and wetness estimates, with applications in the Alps and Rockies since 2023 to complement ground data in vast areas. As of 2025, these enhance forecasting by detecting buried weak layers over 1000 km². These systems often integrate with data loggers for real-time transmission, enhancing coverage in inaccessible terrain. Drone and LiDAR applications have advanced aerial surveys for precise and mapping since the early 2020s, particularly in the where deployments post-2020 have improved hazard zoning. Drones equipped with or LiDAR scan release areas to generate high-resolution digital elevation models (DEMs) with sub-meter accuracy, measuring depth variations that indicate drift accumulation or . In a case study, fixed-wing drones mapped depths across 10 km² of alpine , revealing uneven distributions up to 2 meters deep in wind-exposed zones, aiding in the identification of high-risk paths. LiDAR systems on drones or ground vehicles provide volumetric data for slab thickness estimation, with post-processing using structure-from-motion algorithms to differentiate from bare ground; Swiss deployments since 2021 have supported annual mapping campaigns, reducing fieldwork exposure in hazardous areas. These tools are particularly effective for pre-season analysis and post-storm surveys. Human observation networks leverage collective input from professionals and the public to build comprehensive situational awareness. In ski areas, avalanche patrols follow designated routes to conduct daily inspections, including visual scans for cracks, probing, and snow profiles at fixed plots; teams at resorts like those in the Rockies typically cover 50-100 km of runs per patrol, using skis or snowmobiles for access. Citizen reporting apps, such as the Colorado Avalanche Information Center's (CAIC) mobile platform, allow users to submit geotagged observations of snow conditions, recent slides, or weather via smartphones, aggregating thousands of reports annually to fill data gaps. Avalanche.org's reporting system similarly crowdsources field notes, including photos of instability signs, which forecasters use to validate automated data. These networks emphasize standardized reporting formats to ensure reliability. Despite their effectiveness, observation techniques face inherent limitations that can affect and applicability. Weather interference, such as heavy or high winds, often obscures visibility for ground and aerial methods, reducing accuracy in real-time assessments; for example, drone flights are typically grounded in storms exceeding 20 m/s winds. Coverage gaps persist in remote or vast areas, where deploying sensors or patrols is logistically challenging, leading to under-sampling of high-elevation zones. Field-based approaches also carry personal safety risks and potential biases toward accessible sites, underscoring the need for integrated multi-method strategies.

Forecasting Models and Predictions

Forecasting models for integrate observations, simulations, and historical to predict and issue danger ratings. Numerical models simulate physical processes in the , while statistical approaches analyze patterns from past events to estimate risk. These models form the basis for operational bulletins that guide users and managers. Numerical models like provide detailed simulations of snow layer evolution by solving equations for , settlement, and mass exchange. For instance, the model employs the instationary heat diffusion equation, ∂T∂t=κ∂2T∂z2,\frac{\partial T}{\partial t} = \kappa \frac{\partial^2 T}{\partial z^2}, where TT is , tt is time, zz is depth, and κ\kappa is , to compute temperature profiles and phase changes within the . This allows forecasters to assess weak layer formation and stability based on meteorological inputs such as , wind, and . is widely used in operational , particularly in , to simulate snowpack properties at multiple sites. Statistical models complement numerical simulations by deriving probabilistic forecasts from weather and snow data. Examples include and algorithms, which predict avalanche danger levels by correlating variables like new accumulation, speed, and stability metrics with historical avalanche occurrences. In , models have demonstrated strong performance in of avalanche days, emphasizing multi-day averages of new and as key predictors. These methods enable regional-scale predictions where direct simulations are computationally intensive. Predictions are standardized using the international five-level avalanche danger scale, developed by the European Avalanche Warning Services (EAWS), to communicate risk clearly. The scale ranges from 1 (Low) to 5 (Very High), with criteria based on triggering likelihood, natural avalanche potential, and terrain sensitivity.
LevelDescriptionTriggering ProbabilityNatural AvalanchesKey Signs
1 – LowGenerally stable conditionsPossible only from high additional loads in isolated very steep, extreme terrainOnly small and medium possibleNo signs
2 – ModerateHeightened conditions on specific terrain featuresPossible primarily from high additional loads on indicated steep slopesVery large unlikelyOften none; extra caution if persistent weak layer present
3 – ConsiderableDangerous conditionsPossible from low additional loads on indicated steep slopesSome large; isolated very large possibleRecent activity, cracking, “Whumpf” sounds; remote triggering typical
4 – HighVery dangerous conditionsLikely from low additional loads on many steep slopesNumerous large; often very large possibleWidespread activity, cracking, “Whumpf” sounds; remote triggering typical
5 – Very HighExtraordinary conditionsNumerous very large/extremely large even in moderately steep terrainNumerous very large/extremely largeWidespread shooting cracks, whumphing; numerous avalanches even on moderate terrain
This scale applies to avalanche terrain (slopes >30°) and is adjusted for elevation and aspect, with levels 4 and 5 issued rarely—about 2% and <1% of winter days, respectively. Recent advancements incorporate and to enhance prediction accuracy by analyzing vast historical datasets alongside simulated outputs. For example, the Open Avalanche Project uses algorithms trained on data from the Northwest Avalanche Center to forecast danger levels, improving and timeliness over traditional methods. Studies combining random forests with simulations have achieved up to 88% accuracy in susceptibility mapping, outperforming earlier statistical baselines by incorporating nonlinear interactions in snow and weather variables. Operational centers apply these models to produce daily avalanche bulletins. The Colorado Avalanche Information Center (CAIC) issues forecasts by 4:30 p.m. each day during the winter season (typically November to April), covering two-day outlooks by elevation zone and disseminating them via website, app, and email alerts. Similarly, the WSL Institute for Snow and Avalanche Research (SLF) in publishes interactive bulletins daily from early December to mid-April, integrating model outputs with observed data and distributing them through the White Risk app, which includes GPS-based risk assessment tools. These bulletins reference observation data inputs to refine model predictions. Model reliability is ensured through validation methods such as back-testing against historical avalanche events and quantifying . Back-testing involves comparing model outputs to recorded incidents, like tree-ring evidence of past , to verify long-term predictive skill. Uncertainty quantification accounts for variability in inputs (e.g., forecasts) and model assumptions, often using simulations or probabilistic outputs to express confidence intervals in danger ratings. Large-scale validations, such as those comparing simulations to forecaster assessments across regions, highlight areas of model bias and support iterative improvements.

Prevention and Mitigation Strategies

Active Triggering Methods

Active triggering methods involve intentionally initiating controlled avalanches to release unstable layers before they can build up into larger, more hazardous events. These techniques are employed in high-risk areas such as ski resorts, highways, and mountain passes to threats to and human activity. Traditional and modern approaches focus on delivering sufficient energy to fracture weak layers, often guided by real-time monitoring to target specific starting zones. Explosive methods remain a cornerstone of active avalanche control, utilizing high-energy charges to simulate natural triggers like wind or overload. Hand-thrown charges, typically consisting of 1-kg cylinders of cast pentolite—a mixture of 50% TNT and 50% PETN—allow operators to deploy explosives directly into suspected weak layers from relative safety. These charges release energy equivalent to TNT, with a standard detonation energy of E=4.184 kJ/gE = 4.184 \, \text{kJ/g}, enabling blast radii sufficient to disrupt slab formations up to several meters wide depending on snowpack conditions and charge placement. Artillery systems, such as the 105 mm Howitzer, extend this capability by firing explosive projectiles over distances up to 11 km, detonating on impact to cover larger areas inaccessible by foot. Aerial delivery via helicopters has historically supplemented these, dropping charges like 0.9-kg pentolite or TNT equivalents to achieve similar energy outputs and radial pressures that decay with distance, as measured in field tests showing peak overpressures exceeding 100 kPa within 10-20 meters. Mechanical remote avalanche control systems (RACS) have advanced safety by minimizing human exposure to hazardous terrain. The Wyssen Avalanche Tower, a mast-like structure that deploys tethered 5-kg charges via wireless control, has seen widespread 2025 deployments along U.S. highways, such as Colorado's I-70, where it replaces manual or methods and reduces operational risks associated with fieldwork. Similarly, Gazex exploders use fixed tubes to ignite a regulated propane-oxygen gas , generating a shockwave equivalent to approximately 8-15 kg of TNT that propagates up to 140 to trigger avalanches without residue from solid s. These systems allow for repeated use in fixed positions, with the gas 's force adjustable remotely to match varying conditions. Emerging technologies are enhancing precision and accessibility in triggering operations. Drone-dropped explosives, such as low-weight charges deployed by systems like Drone Amplified's MONTIS, enable targeted delivery in remote or steep terrain, as demonstrated in 2024 trials where drones successfully initiated two controlled slides, improving efficiency over traditional aerial methods. In , 2025 approvals for similar drone-based systems using eco-friendly payloads have shown potential for cost savings and reduced environmental impact compared to helicopter drops. Protocols for active triggering emphasize timing, safety, and to ensure effectiveness and minimize collateral risks. Operations are typically scheduled pre-storm to prevent snowpack instability buildup or post-storm to clear fresh accumulations, with decisions informed by forecasts. Safety zones, extending at least 500 meters beyond potential runout paths, are enforced to protect personnel and infrastructure, often verified through modeling and on-site observation. For drone operations, U.S. (FAA) rules under Part 107 require beyond-visual-line-of-sight waivers, remote pilot certification, and explosives transport approvals via concepts of operations (CONOPS) to mitigate hazards. A notable is the Washington State Department of Transportation's (WSDOT) 2025 implementation of a remote avalanche control system at , which allows for detonation of 1-2 kg charges in targeted starting zones along I-90 from a safe distance. This solar-powered system, resembling automated towers, enables precise, remote triggering in steep terrain, complementing existing cable-pulley trams and reducing closure times to 30 minutes to two hours during high-traffic winter operations while minimizing crew exposure to hazards.

Structural and Passive Defenses

Structural and passive defenses in avalanche control encompass engineered barriers and reinforcements designed to prevent accumulation from initiating slides or to intercept and redirect before they reach populated or infrastructural areas. These systems operate without human intervention during events, relying on physical structures to alter dynamics in starting zones, track paths, or areas. Common applications target high-risk transportation corridors and settlements in mountainous regions, where they provide long-term by deflecting, retaining, or supporting loads. Key snow control structures include snow sheds, which are roofed enclosures built over roads or railways to shield against falling snow and debris. For instance, snow sheds along the Trans-Canada Highway at Rogers Pass in Canada protect against frequent avalanches by preventing direct impacts on the roadway. Snow bridges, or overpasses, elevate transportation routes above avalanche paths, allowing snow to pass underneath without disruption; these are often constructed with steel frameworks to withstand lateral pressures from sliding masses. Avalanche dams, typically made of reinforced concrete, serve as retaining or deflecting barriers in runout zones to halt or redirect flows, with designs optimized for site-specific terrain slopes and avalanche volumes. Steel mesh nets, deployed in starting zones or along tracks, catch and hold loose snow or debris, preventing escalation into full slides by distributing loads across flexible wire rope systems. Design principles for these structures emphasize accurate modeling of avalanche forces to ensure stability under extreme conditions. A fundamental calculation for impact pressure PP on barriers derives from , given by P=12ρv2P = \frac{1}{2} \rho v^2, where ρ\rho is the (typically 300 kg/m³ for dense flows) and vv is the front (often 20–70 m/s based on and ). This estimates the dynamic from the of the moving mass, guiding the required structural resistance; for example, velocities of 30 m/s can yield pressures exceeding 100 kPa. To derive this, start with for incompressible flow, adapting it to dynamics by assuming the behaves as a granular , then multiply by a (around 1–3) for real-world adjustments from field measurements. Material specifications prioritize high-strength components, such as wire ropes in nets with tensile strengths of 246–386 kN/m to absorb and redistribute impacts without . Concrete dams incorporate reinforcement to handle peak forces up to 563 kN/m, factoring in Froude numbers (5–10) for supercritical flows. Modern passive systems extend these principles with snowpack-supporting structures, such as fences and rockfall netting in starter zones, to stabilize weak snow layers and inhibit fracture propagation. Snow fences, often 4–5 m high with mesh panels, trap wind-blown snow to build supportive mounds, reducing slab instability on slopes exceeding 30°. In starter zones, integrated rockfall netting—using double-twist steel mesh combined with high-tensile ropes—reinforces snow retention while also mitigating mixed debris events. In Canada, these systems have been increasingly adopted along highways like the Trans-Canada, with over 2,000 m of snowpack structures installed since the late 2010s to complement traditional barriers, enhancing overall mitigation in remote alpine areas. Maintenance of these defenses involves regular inspections to address , deformation, and overload, ensuring longevity in harsh alpine environments. Structures like nets and sheds require annual visual checks and post-event assessments, with repairs focusing on anchor integrity and replacement to maintain efficacy. In Alpine regions, operational costs include , adapting designs to evolving risks such as climate-driven changes in patterns. Historical examples illustrate their evolution; sheds at Switzerland's , first constructed in the late to safeguard the carriage road and later the 1882 railway, demonstrate early passive engineering, with ongoing updates to standards for debris loading and structural resilience.

Vegetation and Terrain Management

Vegetation and terrain management represent non-structural approaches to avalanche control, focusing on ecological and geotechnical modifications to enhance and reduce snow release in zones. These methods leverage natural processes, such as reinforcement and interception, to mitigate risks without relying on permanent barriers. By altering the and promoting resilient cover, they address both immediate hazards and long-term avalanche propensity, particularly in steep, treeless starter zones where weak snow layers form easily. Reforestation strategies involve planting dense stands of coniferous trees in avalanche starting zones to anchor snow and prevent slab formation. Species such as Swiss stone pine, mountain pine, and are selected for their ability to establish quickly in alpine conditions and develop interlocking root systems that bind soil and intercept drifting snow. In the Stillberg afforestation project in the , initiated in 1975 with 92,000 saplings, tree heights reached an average of 2.66 meters by 2015, surpassing twice the local snow depth and thereby stabilizing the through mechanical anchoring and disruption of weak layers. This resulted in a dramatic reduction in avalanche frequency, from 106 events in the to just 5 in the and 2010s, representing over a 95% decline in activity post-2000. Such afforestations provide cost-effective protection compared to engineered structures, with protective effects emerging after 20-30 years of growth. Terrain alteration techniques, including terracing, berms, and diversion channels, modify slope geometry to interrupt snow accumulation and redirect potential flows away from vulnerable areas. Terracing creates stepped contours that reduce effective slope angles, limiting snow gliding and promoting even snow distribution for greater stability. Berms, constructed from earth or reinforced materials, serve as low ridges to deflect or retard avalanche debris; typical heights range from 3 to 5 meters, designed to handle 30-year return period events by accommodating flow run-up without full overtopping. Diversion channels, often lined with concrete or vegetated slopes, guide debris laterally, with dimensions scaled to avalanche magnitude—such as widths of 10-20 meters and depths of 2-3 meters for medium-sized slides—to protect infrastructure like highways. These earthworks integrate with vegetation by providing microhabitats for regrowth, enhancing overall slope resilience. Erosion control measures, such as mulching and hydroseeding, are applied immediately after avalanche clearing or site disturbance to stabilize bare and prevent the formation of weak subsurface layers that could trigger future slides. Mulching involves spreading organic materials like or wood fibers to shield from wind and erosion, reducing loss by up to 90% on disturbed slopes. Hydroseeding sprays a of seeds, , fertilizer, and tackifiers onto the terrain, fostering rapid grass or establishment that binds particles and absorbs excess moisture. In avalanche-prone areas, these techniques are crucial post-event, as scoured surfaces are highly susceptible to rilling, which undermines regrowth and integrity. Long-term monitoring of planted assesses growth rates, , and stabilizing efficacy to ensure sustained . Annual measurements track tree height increments—typically 10-20 cm per year for in alpine settings—and development, with effective anchoring achieved when roots exceed 1 meter in depth after 10 years, providing tensile reinforcement against shear forces. In monitored sites like Stillberg, tree density above 800 stems per hectare correlates with minimal release, allowing such as to optimize canopy-snow interactions. These metrics guide replanting and confirm that mature forests can preclude continuous weak layers across slopes steeper than 30 degrees. Climate adaptation in these strategies emphasizes drought-resistant species to counter warming trends that may reduce snow cover and stress traditional conifers. European guidelines promote mixing native pines with tolerant provenances, such as drought-hardy or variants, selected for projected 2070-2100 conditions to maintain root vitality and snow-trapping capacity. In protective forests, this diversification enhances resilience against bark beetle outbreaks and prolonged dry spells, ensuring vegetation continues to mitigate amid shifting precipitation patterns.

Social and Policy Frameworks

Education and Awareness Programs

Education and awareness programs play a crucial role in reducing avalanche fatalities by equipping individuals with the knowledge to recognize risks, use essential gear, and apply strategies in environments. These initiatives target recreational users, such as skiers and snowboarders, emphasizing proactive behaviors to minimize exposure to -prone terrain. Organizations like the American Institute for Research and Education (AIARE) standardize curricula that progress from foundational concepts to advanced applications, fostering a culture of across communities. Structured training programs, such as AIARE's recreational courses, provide comprehensive instruction on avalanche safety. The AIARE Level 1 course, a three-day introduction, covers formation, recognition, evaluation, and basic rescue techniques, including the use of essential gear like beacons, probes, and shovels for companion rescue. Participants learn decision-making heuristics, such as observing weather patterns and slope angles, to assess risks during group travel. Building on this, the AIARE Level 2 course, also three days, focuses on advanced , in variable conditions, and applying skills in complex , while Level 3 emphasizes long-term and professional development. These certifications are widely recognized and delivered by over 100 providers in and internationally. Public awareness campaigns leverage digital tools and media to disseminate avalanche safety information broadly. Programs like Know Before You Go (KBYG), an initiative by the Colorado Avalanche Information Center and partners, offer free online modules and in-person presentations introducing core concepts such as terrain avoidance and emergency preparedness, targeting novice backcountry enthusiasts. In Canada, similar efforts through Avalanche Canada promote apps and resources for real-time risk assessment, enhancing accessibility for users planning winter outings. These campaigns encourage checking forecasts and carrying safety gear before entering avalanche terrain. Integration of avalanche education into schools and workplaces addresses broader societal exposure to risks. School programs, such as the U.S. Bureau of Land Management's Avalanche Awareness curriculum, teach students about avalanche triggers, slope measurement with inclinometers, and terrain factors through interactive activities, aiming to build early recognition among youth in mountainous regions. For backcountry workers, including ski patrollers and guides, employers in and the U.S. mandate professional training; for instance, WorkSafeBC requires avalanche protection plans with certified courses like Avalanche Operations Level 1, which includes 40% theory on hazard assessment and 60% field practice. In the U.S., AIARE Professional Level 1 serves as an entry point for operational roles, ensuring workers can mitigate s in employment settings. Research on human factors highlights cognitive biases that undermine avalanche safety, informing targeted educational interventions. A 2025 scoping review in Natural Hazards and Earth System Sciences analyzed 70 peer-reviewed papers and 81 conference proceedings, identifying 11 studies on biases such as overconfidence, where individuals overestimate their skills and underestimate terrain dangers, leading to risky choices. Other factors include heuristic traps like familiarity bias and social influences from group dynamics. The review codes these elements across studies, revealing growth in research since 2012 and gaps in addressing motivation and education's role in countering biases, advocating for curricula that explicitly teach bias recognition to improve decision-making. Evaluations of these programs demonstrate measurable improvements in participant outcomes. A study on an introductory avalanche course found that 78% of 184 backcountry users reported acquiring new knowledge in terrain assessment and rescue skills, with post-course surveys showing a medium-to-large increase in conservatism (effect size f²=0.29), particularly for uncertain slopes. Participants became less willing to enter high-risk areas, though confidence gains (f²=0.35) sometimes tempered this effect, underscoring the need for ongoing to align perceived with actual competence. Such findings validate education's impact on safer behaviors without over-reliance on numerical benchmarks.

Regulatory and Land-Use Policies

regulations for avalanche-prone areas typically involve hazard mapping to delineate zones of varying risk levels, guiding and building restrictions. In , under the Plan de Prévention des Risques (PPR) framework, avalanche hazard maps classify areas into red zones, where new construction is prohibited due to high-risk paths with return periods of 30-50 years for significant events, and blue zones, which permit development only with protective measures for less frequent but still hazardous s (return periods exceeding 300 years). These maps are developed using historical data, modeling, and field observations to define runout extents, ensuring that avoids direct exposure. Similarly, setback requirements mandate minimum distances from avalanche runout zones to buffer structures; for instance, in , additional setbacks beyond hazard lines are required based on site-specific assessments to account for variable avalanche dynamics. International frameworks provide guidance for harmonizing these approaches across borders, emphasizing climate-resilient planning. The European Avalanche Warning Services (EAWS) promotes standardized hazard assessment methods that inform land-use policies, including integration of projections into to anticipate shifting patterns. A 2024 assessment by the highlights ongoing gaps in adapting to natural hazards like avalanches, urging further incorporation into . In , the Canadian Geotechnical Society's guidelines outline -based for avalanche terrain, defining (high-hazard) and blue (moderate-hazard) zones with criteria for return periods and impact pressures, requiring no permanent structures in zones without . Although no unified EU directive specifically targets avalanches, the broader EU Strategy on Adaptation to (adopted in 2021) encourages member states to incorporate natural hazard s, including avalanches, into directives for resilience against intensified events. Enforcement of these policies occurs through permitting processes and liability frameworks to ensure compliance and accountability. In the United States, local governments enforce zoning via building permits that mandate avalanche impact assessments, often tying approvals to adherence to hazard maps; non-compliance can lead to denial or revocation. Liability laws, including U.S. Federal Tort Claims Act provisions, hold public land managers accountable for negligence in warning or controlling known avalanche risks, as seen in cases like Twohig v. United States, where failure to mitigate recreational area exposure resulted in liability. A notable is British Columbia's approach to avalanche zoning, refined through the Technical Aspects of Snow Avalanche Risk Management guidelines, which integrate Remote Avalanche Control Systems (RACS) into post-significant events like the 2012 Revelstoke incidents. These reforms emphasize mandatory RACS installations for in moderate-risk zones, balancing development with by requiring engineering reviews for all new builds in avalanche paths. Challenges in implementing these policies often revolve around balancing economic interests, particularly , with public safety. In ski resort areas like those in the European Alps, variances allow controlled development in blue zones to support winter , which generates billions in revenue, but require enhanced monitoring and defenses to mitigate risks—yet enforcement varies, leading to debates over economic prioritization versus stricter prohibitions. This tension is evident in U.S. resorts such as Vail, where accommodates expansion while mandating setbacks and triggering programs, illustrating the ongoing need for adaptive policies amid growing recreational demands.

Emergency Response and Recovery

Professional Response Protocols

Professional response protocols for avalanche incidents emphasize rapid, coordinated actions by trained teams to maximize rates, which exceed 90% if victims are located and extricated within the first 15-20 minutes of . operations typically begin with transceiver searches, where team members use avalanche beacons to detect signals from buried victims' devices, followed by coarse and fine signal refinement to pinpoint locations. If transceivers fail to locate a victim, probe lines are deployed, involving rescuers forming a systematic grid to manually probe the with collapsible poles, a method that, according to a 2004 study, has contributed to about 12% of organized search survivals. search dogs, trained to detect scent under , are then utilized for broader area coverage, accounting for roughly 11% of successful organized rescues according to the same study, often in conjunction with these techniques. Incident command systems (ICS), adapted from the (NIMS), provide a scalable framework for avalanche responses in the U.S., integrating multidisciplinary teams such as ski patrols, , and under FEMA guidelines. This structure designates roles like incident commander and operations chief to manage the three-stage rescue process—victim location, extrication and , and prolonged support—ensuring efficient during multi-agency operations. Forecasting models trigger these activations by issuing alerts for high-risk conditions, prompting pre-positioning of response teams. Key equipment includes reflectors, passive transponders integrated into clothing and gear that allow professional rescuers to detect victims rapidly using handheld or helicopter-mounted detectors, complementing searches. Thermal imaging drones have enhanced detection capabilities by identifying heat signatures under snow. Training for professionals involves rigorous certification programs, such as those standardized by the American Avalanche Association (), which include multi-agency exercises simulating full-scale incidents to practice , probing, and dog-assisted searches under ICS protocols. These drills, often conducted annually across agencies like teams and national parks, ensure compliance with A3 proficiencies in operational decision-making and rescue coordination. Post-2020 updates, influenced by the , incorporated adaptations from International Commission for Alpine Rescue (ICAR) guidelines, emphasizing remote coordination via telemedicine and drones to minimize on-site personnel exposure while maintaining PPE protocols and equipment disinfection during responses.

Community Preparedness and Recovery

Communities enhance resilience against through comprehensive preparedness measures, including the development of emergency kits stocked with essentials like food, water, first-aid supplies, and communication devices, alongside detailed and neighborhood plans. These plans outline evacuation routes away from high-risk slopes, designate assembly points, and incorporate regular drills to simulate responses, ensuring all members, including children and elderly, can evacuate swiftly. alert systems, such as electronic sirens installed in avalanche-prone valleys, provide audible warnings to prompt immediate action during heightened risk periods. For amateur enthusiasts, safety emphasizes hands-on training with transceivers, where users practice search modes and signal interpretation in controlled settings to improve efficiency. Group travel protocols mandate conservative decision-making, such as traveling one person at a time across potential slide paths, maintaining visual contact, and designating a leader to assess risks. Mobile applications from organizations like the Utah Avalanche Center enable real-time sharing of data, weather updates, and location tracking among group members, though they supplement rather than replace dedicated gear. Post-avalanche recovery unfolds in distinct phases, beginning with immediate that prioritizes temporary in centers or hotels, medical for injuries like or trauma, and distribution of essentials through local emergency services. Infrastructure repair follows, funded by programs such as FEMA's Public Assistance grants, which cover debris removal, road reconstruction, and hazard mitigation measures for eligible entities in declared disaster areas. Psychological support addresses the toll, with studies indicating PTSD prevalence around 15-16% among survivors, often managed through counseling referrals and support groups to mitigate long-term effects like anxiety and reduced . Notable community examples illustrate recovery strategies; in Blatten, , following the 2025 glacier collapse that partially buried the village, authorities debated full relocation of residents to safer sites while providing interim housing and financial aid, highlighting the challenges of rebuilding in unstable terrain. In , British Columbia's 2025 Disaster Resilience and Innovation Funding program allocated resources for geohazard projects, including avalanche monitoring and community in at-risk areas, to bolster long-term adaptability. Pre-planning significantly shortens recovery timelines, as evidenced by reduced highway disruption durations in hazard-prone regions.

References

  1. https://www.govinfo.gov/content/pkg/GOVPUB-A-PURL-gpo27529/pdf/GOVPUB-A-PURL-gpo27529.pdf
  2. https://wsdot.wa.gov/travel/operations-services/avalanche-control
  3. https://snowbrains.com/origins-u-s-avalanche-mitigation/
  4. https://www.codot.gov/projects/archives/i-70-avalanche-control-ejmt-berthoud-pass
  5. https://avalanche.org/avalanche-encyclopedia/
  6. https://avalanche.org/avalanche-encyclopedia/avalanche/trigger/natural-trigger/
  7. https://avalanche.org/avalanche-encyclopedia/avalanche/trigger/artificial-trigger/human-trigger/
  8. https://www.worldatlas.com/articles/what-causes-an-avalanche.html
  9. https://avalanche.org/avalanche-encyclopedia/snowpack/weak-layer/persistent-weak-layers/depth-hoar-basal-facets/
  10. https://avalanche.org/wp-content/uploads/2018/08/04_CRST_Landry_etal.pdf
  11. https://www.thelocal.fr/20170307/what-makes-the-frnech-alps-so-risky-for-avalanches
  12. https://bioone.org/journals/arctic-antarctic-and-alpine-research/volume-40/issue-1/1523-0430_06-069_REARDON_2.0.CO_2/Spatial-Reconstructions-and-Comparisons-of-Historic-Snow-Avalanche-Frequency-and/10.1657/1523-0430%2806-069%29%5BREARDON%5D2.0.CO%3B2.full
  13. https://avalanche.org/avalanche-tutorial/avalanche-terrain.php
  14. https://avysavvy.avalanche.ca/en-ca/slope-aspect
  15. https://avalanche.org/avalanche-encyclopedia/terrain/slope-characteristics/elevation/
  16. https://avalanche.org/avalanche-encyclopedia/snowpack/weak-layer/
  17. https://protectourwinters.org/how-does-climate-change-impact-avalanches/
  18. https://www.mountainskillsacademy.com/understanding-human-factors-in-avalanche-safety/
  19. https://planningforhazards.colorado.gov/avalanche
  20. https://avalanche.org/avalanche-tutorial/red-flags.php
  21. https://www.rei.com/learn/expert-advice/avalanche-snow-tests.html
  22. https://www.avalanchecourse.com/wp-content/uploads/2020/07/Snow-Pits-and-Stability-Tests-v2.pdf
  23. https://avalanche.org/wp-content/uploads/2018/08/09_CRST_Simenhois_ECT.pdf
  24. https://www.slf.ch/fileadmin/user_upload/WSL/Mitarbeitende/schweizj/Mayer_etal_Climate_warming_avalanches_ISSW2023.pdf
  25. https://www.avalanches.org/standards/avalanche-size/
  26. https://www.cnfaic.org/view-observations/interpreting-stability-tests/
  27. https://www.avalanchecourse.com/wp-content/uploads/2020/10/Snow-Pits-and-Stability-Assessment.Pro-1.pdf
  28. https://issuu.com/americanavalanche/docs/swag_2022_digital_small
  29. https://cdn.ymaws.com/www.avalancheassociation.ca/resource/resmgr/standards_docs/ogrs2024web.pdf
  30. https://www.slf.ch/en/about-the-slf/instrumented-field-sites-and-laboratories/natural-hazard-research-sites-and-facilities/investigating-snow-avalanche-dynamics/
  31. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020JF005741
  32. https://www.mdpi.com/2072-4292/16/5/872
  33. https://www.mdpi.com/2073-4433/15/11/1343
  34. https://nhess.copernicus.org/articles/25/1315/2025/
  35. https://www.slf.ch/en/about-the-slf/portrait/how-we-conduct-our-research/monitoring/remote-sensing/
  36. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020WR028980
  37. https://typolive03.wsl.ch/en/projects/capturing-snow-depths-by-using-drones/
  38. https://arc.lib.montana.edu/snow-science/objects/issw-1996-217-218.pdf
  39. https://avalanche.state.co.us/mobile-app
  40. https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observations/
  41. https://avalanche.state.co.us/observations
  42. https://www.slf.ch/en/avalanche-bulletin-and-snow-situation/about-the-avalanche-bulletin/capabilities-and-limitations-of-the-avalanche-bulletin/
  43. https://doi.org/10.1016/j.coldregions.2019.102910
  44. https://snowpack.slf.ch/
  45. https://arc.lib.montana.edu/snow-science/objects/ISSW2023_P1.17.pdf
  46. https://tc.copernicus.org/articles/19/1849/2025/
  47. https://www.avalanches.org/standards/avalanche-danger-scale/
  48. https://openavalancheproject.org/
  49. https://www.nature.com/articles/s41598-025-22051-w
  50. https://tc.copernicus.org/articles/17/2245/2023/
  51. https://avalanche.state.co.us/forecasts/tutorial/how-to-read-our-forecasts
  52. https://www.slf.ch/en/services-and-products/avalanche-bulletin/
  53. https://www.tandfonline.com/doi/full/10.1657/AAAR0014-047
  54. https://munin.uit.no/bitstream/handle/10037/33045/thesis.pdf?sequence=2&isAllowed=y
  55. https://arc.lib.montana.edu/snow-science/objects/issw-1994-580-582.pdf
  56. https://www.jstor.org/stable/1550755
  57. https://www.osti.gov/servlets/purl/15002352
  58. https://www.dir.ca.gov/oshsb/documents/petition-575-dosheval.pdf
  59. https://rosap.ntl.bts.gov/view/dot/63352/dot_63352_DS1.pdf
  60. https://www.codot.gov/news/2025/november/remote-avalanche-control-testing
  61. https://www.skyhinews.com/news/how-does-it-work-starting-an-avalanche-cdot-preps-gazex-avalanche-exploders-for-coming-winter-months/
  62. https://dronedj.com/2024/02/14/alaska-avalanche-drones-droneamplified/
  63. https://dronexl.co/2025/08/14/canadas-drone-powered-avalanche-control/
  64. https://www.wyssenavalanche.com/wp-content/uploads/2022/10/Guidelines-for-Artifical-Release-of-Avalanches_en.pdf
  65. https://parksandrecreation.idaho.gov/wp-content/uploads/Avalanche_Safety_Web.pdf
  66. https://downloads.regulations.gov/FAA-2024-2616-0001/attachment_2.pdf
  67. https://wsdotblog.blogspot.com/2025/10/new-technology-improves-avalanche.html
  68. https://www.slf.ch/en/avalanches/avalanche-protection/structural-avalanche-protection/
  69. https://nrc-publications.canada.ca/eng/view/object/?id=c276ab3a-c720-4997-9ad8-ff6f9f9a7738
  70. http://www.mairwilfried.it/steel-snow-bridges-and-sliding-snow-stands/
  71. https://www.preventionweb.net/files/10851_avalancheprotection.pdf
  72. https://trumerschutzbauten.com/products/avalanche-fences/static-defense-structures/ts-lv-snow-net/
  73. https://link.springer.com/article/10.1007/s40819-015-0056-4
  74. https://www.maccaferri.com/us/solutions/snow-fences-and-avalanche-protection/
  75. https://alpinesolutions.com/service/avalanche-protection-structures/
  76. https://www.maccaferri.com/us/wp-content/uploads/2023/04/Maccaferri-ROCKFALL-PROTECTION-AND-SNOW-BARRIERS.pdf
  77. https://www.researchgate.net/publication/349336856_Synthesis_Report_on_the_Use_and_Design_of_Snow_Sheds_to_Protect_Transportation_Corridors_Against_Avalanches
  78. https://www.alpconv.org/fileadmin/user_upload/Fotos/Banner/Organisation/thematic_working_bodies/Part_02/natural_hazards_platform_planalp/4_PLANALP_LCM_brochure_final.pdf
  79. https://www.slf.ch/en/about-the-slf/instrumented-field-sites-and-laboratories/mountain-ecosystem-research-sites/stillberg-afforestation-research/
  80. https://doi.org/10.1016/j.coldregions.2025.104612
  81. https://link.springer.com/article/10.1007/s10342-023-01640-2
  82. https://cdn.ymaws.com/www.avalancheassociation.ca/resource/resmgr/standards_docs/tasarm_english.pdf
  83. https://arc.lib.montana.edu/snow-science/objects/ISSW2018_P02.18.pdf
  84. https://www.nrcs.usda.gov/resources/guides-and-instructions/after-the-fire-hydromulching
  85. https://www.stoverseed.com/hydroseeding-a-cost-effective-erosion-prevention-practice/
  86. https://link.springer.com/article/10.1007/s10346-023-02178-5
  87. https://foresteurope.org/wp-content/uploads/2016/08/Adaptation_to_Climate_Change_in_SFM_in_Europe_compressed.pdf
  88. https://www.eea.europa.eu/en/newsroom/news/europes-adaptation-policies-advance-but-stronger-action-is-needed-to-address-growing-climate-risks
  89. https://avtraining.org/recprogram/
  90. https://avtraining.org/aiare-level-1/
  91. https://avtraining.org/aiare-level-2/
  92. https://www.kbyg.org/
  93. https://avalanche.ca/training
  94. https://www.blm.gov/sites/blm.gov/files/CCSC_SchoolProgram_Avalanche-Awareness.pdf
  95. https://calgaryherald.com/business/local-business/worksafebc-says-employers-need-avalanche-protection-plan-for-backcountry-workers
  96. https://www.avalancheassociation.ca/?page=Level_1
  97. https://nhess.copernicus.org/articles/25/929/2025/
  98. https://www.tandfonline.com/doi/full/10.1080/01490400.2022.2062075
  99. https://www.cambridge.org/core/journals/journal-of-glaciology/article/avalanche-zoning-in-france-regulation-and-technical-bases/B6CFF51EB1A150613F46C261FEEB2EE9
  100. https://nap.nationalacademies.org/read/1571/chapter/6
  101. https://pitkincounty.com/DocumentCenter/View/3470/chapter-07?bidId=
  102. https://www.eca.europa.eu/en/publications?ref=SR-2024-15
  103. https://coloradogeologicalsurvey.org/wp-content/uploads/woocommerce_uploads/SP-07.pdf
  104. https://law.justia.com/cases/federal/district-courts/FSupp/711/560/1655130/
  105. https://www.tranbc.ca/2018/02/20/ka-boom-4-types-of-remote-avalanche-control-in-bc/
  106. https://www.sciencedirect.com/science/article/abs/pii/S2213305423000401
  107. https://pmc.ncbi.nlm.nih.gov/articles/PMC3080544/
  108. https://journals.sagepub.com/doi/10.1016/j.wem.2023.05.014
  109. https://www.hqinc.net/wp-content/uploads/2012/05/ICPGR-AvalancheRescueUsingGroundPenetratingRadar2004.pdf
  110. https://arc.lib.montana.edu/snow-science/objects/P__8247.pdf
  111. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2824053
  112. https://recco.com/avalanche-rescue/
  113. https://advexure.com/blogs/news/thermal-drones-in-sar-critical-tools-for-saving-lives
  114. https://www.americanavalancheassociation.org/professional-avalanche-education
  115. https://www.9news.com/article/sports/outdoors/avalanche-rescue-training-technology/73-9d4570d4-c8fd-4529-b795-9f4ee56d6f0f
  116. https://www.juneauempire.com/news/disaster-strikes-repeatedly-as-do-rescue-efforts-during-large-scale-avalanche-exercise/
  117. https://icar-med.com/Research/Guidelines-for-Mountain-Rescue-During-the-COVID-19-Pandemic/
  118. https://pmc.ncbi.nlm.nih.gov/articles/PMC8558066/
  119. https://www.ready.gov/avalanche
  120. https://www.electronic-sirens.com/down-the-hill-to-safety-avalanche-warning/
  121. https://beready.utah.gov/family-preparedness/be-informed-family/
  122. https://www.rei.com/learn/expert-advice/avalanche-transceiver.html
  123. https://www.mtavalanche.com/blog/rules-game-safety-and-strategy-avalanche-terrain
  124. https://utahavalanchecenter.org/education/apps
  125. https://www.fema.gov/assistance/public
  126. https://sjtrem.biomedcentral.com/articles/10.1186/s13049-021-00912-3
  127. https://www.nytimes.com/2025/11/03/world/europe/switzerland-climate-change.html
  128. https://www2.gov.bc.ca/gov/content?id=76C1AA90A3844FDE9740B2E8B9355842
  129. https://www.sciencedirect.com/science/article/pii/S1361920924004942
Add your contribution
Related Hubs
User Avatar
No comments yet.