Load vs. Strength: The snowpack is a layered structure, and its stability depends on a delicate balance between the downward force of its weight (load) and its internal strength (cohesion and friction between snow grains and layers).
Weak Layers: Often, there are weaker layers of snow (e.g., from different snowfall events, temperature changes, or crystal types) buried within the snowpack that have less cohesion.
Triggering Event: When the added load from new snow, wind-blown snow, rain, or an external force (like a skier, snowmobile, or even seismic activity) exceeds the strength of these weak layers or the overall snowpack, a fracture can propagate.
Gravitational Pull: Once this bond breaks, gravity takes over, pulling the unstable mass of snow rapidly down the slope.
