Ben Reuter, Jürg Schweizer
Geophysical Research Letters, 45, 7019–7027.
Snow instability is a generic term describing the propensity of a snow slope to avalanche. Inneed of a concise mechanics-based concept we suggest a framework based on failure initiation, crackpropagation, and slab tensile support. Following these three steps we modeled three metrics frommechanical data, which we derived from snow micropenetrometer signals. Verifying the metrics withfieldmeasurements confirmed that slab thickness and weak layer strength typically influence failure initiation,elastic modulus and weak layer fracture energy largely control crack propagation, and slab thicknessand tensile strength provide the required tensile support. For all three metrics, considering slab layeringwas essential. Validation with signs of instability showed that the most accurate model includes all threesteps–suggesting that snow instability can be described by failure initiation, crack propagation, and slabtensile support. Further validation is needed to assess the framework’s potential for operational use.