During the winters of 2003 and 2004, 705 rutschblock tests in 29 separate arrays, and 930 prototype fracture propagation tests in 23 separate arrays were performed. Slopes with sources of variability typical of avalanche start zones were selected for the array sites. Fracture properties such as propagation energy, fracture character and release type, for rutschblock tests, were found to be less variable than stability. Correlation analysis with snowpack and terrain variables measured for each rutschblock test revealed that varying slab thickness and slope angle are major causes of spatial variability of point stability. Correlation analysis with snowpack and terrain variables measured for each propagation test revealed that varying weak layer thickness and depth is a major cause of variability of propagation energy. Ultimately, spatial variability is influenced by a combination of various causal processes with different scales and is, therefore, difficult to assess with current methods.
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