A snow profile is a snapshot from within the snowpack. In situations with persistent weak layers or when signs of instability are absent, a snow pit may get us excatly the information we need to take the right decisions.
This short video recalls the standard procedures:
- finding a safe and represetative location
- recording snowpack layering
- testing stability
To eventually assess snow instability we need combine 2 elements, the snowpack layering and the test results.
The snowpack layering is unfavorable, if …
- well-bonded layers sit on top of
- softer layers with large grains that are buried
- no deeper than 1 m in the snowpack.
Stability test results are unfavorable, if …
- clean fractures cross the test column
- during the first loading steps.
Single stability test results correctly predict slope stability in only
60 – 80 % of the cases. For a better guess, we need to combine snow profile
data with the test results.
Only the process-based thinking may allow for extrapolation. Knowing the origin of the problem, e.g. the weak layer type, we may tell how it formed and where the problem is present in the terrain.