Toured up Corn Biscuit ridge today and found the buried surface hoar on northerly
aspects, which has been causing several shallow wind and soft slabs around Turnagain
Pass, is still sensitive.
We were able to ski cut this 6-12″ deep, ~50′ wide running 500′ avalanche in the
photos (N, 3100′, 38-40 degrees). While descending, two adjacent pockets pulled
out as well; the deepest section was around 16″ and strong/deep enough to push
This structure of buried surface hoar (BSH), sitting 6-12″ deep, was present the
entire slope but did not want to slide where slope angles were around 35 degrees.
Also, areas that slid had a harder winded surface under the BSH.
Southerly aspects: Two very stout layers of sun crust sit near the surface. One
on the surface(variably thick 15-20cm sandwich) and one about a foot deep(5cm
thick). The 5cm thick crust had moderate shears above it that did not propagate.
Westerly aspects: Much thinner sun crusts are present with scattered BSH, 6-10″
deep, that we could not get to react.