An investigation of radiation-recrystallization coupling laboratory and field studies

Near-surface faceted crystals are often attributed as being the weak-layer in fatal slab avalanches. To gain a further understanding of these crystals Montana State University researchers collaborated with the Yellowstone Club Ski Patrol to investigate near-surface metamorphism. Detailed weather information as well as daily observations and grain-scale images were collected from January to April, 2008. Several radiation-recrystallization events were observed throughout this period. Near-surface facets were successfully developed using laboratory simulations of recorded field data. A comparison of measured data with a thermal model indicated that natural snow would likely have higher temperature gradients compared to the laboratory snow test given the same environmental conditions. This phenomenon indicates that low-density snow may be conducive, but not obligatory, to form near-surface facets. This work highlights that field and laboratory investigations may be coupled to reveal information not present in the individual studies alone.