Sknow as part of Advanced Avalanche Training
Our resident snow surveyor and geologist, Lars Christiansen, attended Tindeguide’s Advanced Avalanche Course led by Steinar Hustoft this past weekend in Voss. Alongside a group of snow enthusiasts, Lars spent the weekend surveying, studying, and understanding the snowpack through lectures and fieldwork. Lars had the opportunity to introduce Sknow to the group and discuss how it will supplement and advance the current snowpack evaluation methods in the field! Here’s a glimpse into some of the weekend’s studies.
While skiers at the resort like to describe snow with simple words like wet, heavy, powder — the details behind those descriptions are what every backcountry skier needs to know to conduct their own snowpack evaluation. New backcountry travellers should enroll in a beginner avalanche course to learn the basics. Snow-types, layering, and snowpack stability are crucial when evaluating avalanche conditions before a trip. An advanced avalanche course starts digging into more details. Steinar Hustoft shows the group how temperature and weather affects snow metamorphism. Snow comes in 9 different classes, ranging from new precipitation to homogenous spring snow, but many more subclasses.
Digging 1 or 2 snow pits only gives you a small view into the snow, especially when considering how the snowpack varies. Wind tends to transport snow away from hilltops and deposit it in topographic depressions. Snow layers will therefore distribute at different depths in the terrain, and the weight of a skier can affect a higher number of snow layers where the snow depth is low.
On Saturday, the team headed out to the field to learn how to dig snow pits according to the Canadian Avalanche Association standards. In this technique, a snow face parallel to the slope orientation is used to measure the snow profile whereas stability tests are conducted on the snow face perpendicular to the slope orientation.
Some snow crystals can be identified just by looking at them, but sometimes a magnifying lens is necessary. Crystal type can give indication of stability in the snow. Faceted crystals are less resistant to compression and shear stress as compared to coarse grained melt crystals.
A good snow profile reflects the main layering in the snowpack. The snow pit should be looked on from a distance, to get the main characteristics, and studied closely, to measure hardness, temperature gradient, crystal type and thickness of each layer. After documenting the layers, the team went on to test their strength! The team used the column compression tests to test the stability of the snow.
A compression test is a stability test used to find potential fractures in weak layers. The team found a fracture at 70cm depth. The crystals in the weak layer were partly rounded faceted crystals, laying on top of an ice crust and beneath a compact layer of wind-packed snow. Even though the team found a fracture during the compression test, they concluded the snowpack to be quite stable because of a 40cm thick melt-freeze crust in the upper snowpack.
Observations Sunday morning show how quickly the snowpack can changes! Saturday night, 10cm of snow fell on top of the old snowpack. Wind transported some of the snow and deposited it on top of new snow on leesides. These conditions resulted in a weak layer of precipitation particles underneath a layer of wind-packed fragmented particles. The regional avalanche hazard went from 1 to 3 over night, and the team found several danger signs along the way. The most prominent were propagating cracks in the snow and fresh avalanches in steep slopes.
Sknow thanks Tindeguide and the other participants of the course for an informative weekend learning more about avalanche safety! Most of the participants had already heard about Sknow and are following its development. A special thanks to all for joining in a conversation about how Sknow will fit into a backcountry traveler’s tool-set and its role in future avalanche training and prevention!
