with field trips to Kicking Horse, Bow Summit area, and Rogers Pass.
Kicking Horse, Feb 11-13
The main story is a weak facet layer (no Xmas crust in this area) taking up the
bottom third or so of a snowpack that varies quite a bit in it's depth, from 120 to
220 cm. In deep areas there were no results from our testing on this weak layer,
while in shallow areas easy shears were recorded. This to me means we should stick
to fairly simple terrain features, not too steep and with few convexities or
starting points such as rocks. Stay in areas where the snow depth is at least 150
cm, preferably deeper. Surface windslabs are also a concern at Kicking Horse.
Bow Summit, Feb 14
Similar to Kicking Horse although for the most part the weak facet layer at the
bottom is actually stronger and shows harder test results. All the same, variability
is great in the Rockies and the cautions we had for Kicking Horse held here too.
Rogers Pass, Feb 15 (Fidelity area)
The only significant weaknesses observed in the upper snowpack was a weak layer 10
-20 cm from the surface, which at ridgecrests was reactive where there was a soft
windlsab on it. We saw an Rutshblock 2 sudden planar shear on this layer. Where
there was little wind effect this layer was not a problem at the moment. The deep
facet layers persist in the Pass but we did not dig down to test them. They are
buried 2 m or more deep. The occassional deep release still is occurring on these
layers in high elevation thin rocky areas. If it goes it goes big, with the most
recent natural avalanche being a size 3 on February 14.
Cornices
The one consistent thing in all these areas are the numerous recent cornice falls.
These often are triggering deep weak layers and large avalanches. Keep looking at
what's above you!
Mark Klassen
Mountain Guide
Corax Alpine Guides
mark@alpinism.com
www.alpinism.com
403/760-3337
_______________________________________________
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