Avalanche frequency and terrain characteristics at Rogers’ Pass, British Columbia, Canada.

Saturday, 8 January, 2005

M.J. Smith and D.M. McClung
Journal of Glaciology, 43(143), 165-171
The frequency of avalanches at a given location is the primary variable for calculating the risk as input to zoning applications and decisions about avalanche control options. In this paper, we present an in-depth study of avalanche frequency using an extensive data base of avalanche occurrence records from Rogers’ Pass, British Columbia (43 avalanche paths; 24 years of records). This study, the first of its kind for high frequency avalanche paths, yields the result that the frequency of avalanches may be described by a Poisson distribution. Study of the relationship between terrain variables and precipitation estimates shows that avalanche frequency is significantly correlated with path roughness, 30 year maximum water equivalent, east-west location from Rogers’ Pass summit, wind exposure and runout zone elevation and inclination. With the length of avalanche occurrence records and quality of the data, we believe our study is the most comprehensive in existence about avalanche frequency and its relation to terrain variables.