Practical Implications of Regional Avalanche Survival Curves

An avalanche survival curve is a graphical illustration of survival probability during complete avalanche burial as a function of time. The purpose of calculating these curves is not only to illustrate that survival is time-dependent, but to deduce practical information from the course of the curve. The step-wise decrease of survival over time was first recognized in the original curve in 1994 using avalanche data from Switzerland; four distinct phases were identified in which the subsequent drop in survival probability could be attributed to a specific pathology. These results have had lasting practical implications for avalanche rescue and international guidelines. More recently, region-specific curves have been used to understand the factors contributing to differences in survival probability. In this paper, we summarize the background to calculating and interpreting survival curves and discuss practical implications of regional survival curves, referring to preliminary results from the first Austrian curve.