ASSESSMENT OF SPATIAL CORRELATION STRUCTURE OF PENETRATION RESISTANCE OF SNOW LAYERS USING RANDOM FIELD THEORY AND ITS IMPLICATION FOR SNOW STABILITY

ABSTRACT: Avalanche researchers have long recognized that stability information from specific snow pits may or may not represent the stability conditions on the entire slope. Although considerable theory exists for the probabilistic treatment of geo-technical materials, there has been little effort into identifying the nature of spatial stochastic variation in snow properties. A few years ago the mean and variance was sufficient but snow researchers are now becoming interested in rational snow correlation structures. This paper compares the spatial correlation structure of penetration resistance of two different snow layers, in layer perpendicular direction, using random field theory. Our data come from SnowMicroPen (SMP) measurements at Patsio in Greater Himalayas, India. Knowing that snow properties are spatially correlated, what is a reasonable correlation model? Are snow best represented using fractal models or finite scale models? These are questions that this paper addresses by examining a large number of Equi-Temperature (ET) fine grain and depth hoar snow signatures from SMP soundings. Analysis shows that one dimensional vertical penetration resistance may exhibit different spatial variability characteristics depending on the length of sampling window. The spectral densit