Avalanche: No No Name

Observer Name
Primomo
Observation Date
Sunday, February 12, 2012
Avalanche Date
Sunday, February 12, 2012
Region
Salt Lake » Park City Ridgeline » No No Name
Location Name or Route
No-No Name Bowl
Elevation
9,700'
Aspect
East
Slope Angle
Unknown
Trigger
Natural
Avalanche Type
Soft Slab
Depth
8"
Width
500'
Vertical
400'
Comments

Noticed a very fresh soft slab avalanche in No-No Name while digging some pits with the class today. Crown was very wide and wrapped from the main E facing bowl to a SE aspect, and connected through aspen trees to the right out of frame of the photo.

No Name Bowl also slid with a wide crown, but didn't get a great look at it with limited visibility.

Remotely triggered a small slope while skiing down the SE ridge of No Name from 60ft. away.

Weakest layer seemed to be a combination of buried surface hoar and near surface facets. Both diurnal recrystallized and radiation recrystallized noted.

-Test results on SE aspect at 9400ft, at NSF/crust 15cm down; CTE Q1 (Sudden Planar) down 15cm. ECTP: 11 down 15cm. PST 25/100 (End).

-Test results on NE aspect at 9400ft at SH/NSF layer 10cm down; CTE Q1 (Sudden Planar). ECTN 5. RB2 80%.

at basal facet layer 80cm down; CTH Q1 (Sudden Collapse). ECTP: 30. RB5 100%.

Interesting combination of weak layers demonstrated by the Rutchblock test. The upper layer failed first, then with some additional loading (jumping) the basal facets failed completely. This makes me think after a slide runs within the upper snowpack, the bedsurface should not be automatically assumed to be safe.

Coordinates