Observation: Turnagain

Location: Tincan

Date:
Observer:
Route & General Observations

Weather:
Scattered clouds with plenty of sunshine. Windy – steady moderate southerly wind
from 2,000′ to ridgetop (3,800′). Temps in the low teens.

Signs of instability:
– Medium to large sluffs in steep terrain. Southerly aspects were more concerning
as the snow become damp from the sun in the afternoon. This caused them to entrain
additional snow, adding weight and momentum – enough punch to carry a person if
overrun from behind.

– Collapsing. Three small to medium size collapses felt at 2,800′ NW. This was
while ascending CFR ridge (prominent corniced west ridge of Tincan). We dug in
to see where the collapses took place and found it to be a thin scoured location
only 140cms deep. The collapses occurred in a 5cm layer of 1mm faceted grains
located 45cm below the surface and above the uppermost of the late January crusts.
Pit results were ECTP 22 sudden collapse. The block only popped forward a few
mm’s. See photos below.

– Wind loading. Winds were moving snow onto northerly aspects. Cracking was
quite minimal however and no sign of people triggering anything more but sluffs.

Concerns:
– Persistent slab problem with respect to the facet/crust combo between 1,900′
and 3,000′. The collapses and pit results got our attention. This is one of the
few places around Turnagain Pass we have found this facet/crust combo to be
reactive to any degree – and we have been digging. Seems we stumbled upon one of
these isolated areas. Could there be a dragon or two lurking? That’s the question.

Photos & Video
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