Observation: Other Regions

Location: Widowmaker Peak Seattle Ridge

Route & General Observations

We spent the day digging pits along Seattle Ridge. Once again,
the pit on Widowmaker had the most unstable results. Other pits
from 2/8/2010 included: 3000′ on Warm Up Bowl, 2900′ on the
Sunnyside on “Main Bowl Chute” heading back down towards the
highway, and at about 2000′ on Repeat Offender.

The Widowmaker pit failed with a Q1, which is a unusually clean
and smooth shear plane where the slab on top slid out rapidly.
This happened on top of the same melt-freeze layer that we saw
on the other side of the highway on Tincan, where this layer was
responsible for two small skier-triggered avalanches. This
layer is also most likely the failure plane for the natural
avalanche that ripped out on Widowmaker on Saturday 2/6/2010.

Additionally, we continue to see a clean shear plane on top of
the Jan 7 rain crust with moderate failures. It appears that it
will take a big trigger to start an avalanche on this rain
crust, but this deep instability has not gone away. It is still
showing signs of life.