In February, a series of fatal avalanches occurred in British Columbia, Alberta, California, and Utah, claiming the lives of five individuals in B.C. and Alberta, and more than a dozen in California and Utah, including a tragic incident with nine casualties. Across Europe, from Andorra to Slovakia, 125 avalanche-related fatalities have been reported this season.
These incidents underscore the persistent risks associated with backcountry activities, even for experienced individuals prepared for avalanche hazards. Understanding the timing of avalanches remains challenging. To shed light on this, CBC News engaged with three experts to explore avalanche formation, prediction difficulties, and the potential impact of climate change.
Avalanche formation involves a mass of snow moving visibly at speed, typically downhill due to a strong layer over a weak layer needing a trigger to initiate the avalanche. The composition of snow and ice is dynamic, with changing crystalline structures affecting stability. As snowpacks evolve with precipitation and temperature changes, conditions conducive to avalanches can develop.
Various types of avalanches exist, ranging from loose, non-cohesive sluffs to perilous slab avalanches that break off hillsides. Predicting avalanches remains complex due to the unique nature of each event, as snowpack structures vary over short distances. Forecasting involves a blend of art and science, incorporating interpretation and historical patterns to anticipate avalanche behavior.
The influence of climate change on avalanches is a topic of interest, with experts suggesting a likely impact as the planet warms. However, connecting specific weather events to climate change’s role in avalanches poses challenges. Changes in precipitation and snow levels due to rising temperatures could affect avalanche risks, particularly in altering snowpack stability.
Experts emphasize the importance of preparation, including staying informed with local forecasts, possessing appropriate gear, and undergoing avalanche safety training before engaging in backcountry activities. Additionally, establishing clear group rules and communication protocols can help mitigate risks and respond effectively to unforeseen situations.