Avalanche: Shingle Mill Canyon

Observer Name
BN
Observation Date
Saturday, January 11, 2014
Avalanche Date
Saturday, January 11, 2014
Region
Provo » Provo Canyon » South Fork Provo R. » Shingle Mill Canyon
Location Name or Route
Shingle Mill
Elevation
9,100'
Aspect
East
Slope Angle
38°
Trigger
Skier
Trigger: additional info
Unintentionally Triggered
Avalanche Type
Soft Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
18"
Width
200'
Vertical
2,000'
Comments

We triggered this slide along the Big Springs-Shingle Mill ridge line remotely while approaching the cornice. It highlights the sensitivity of any wind loaded slope with buried facets. It propagated 200' and moved down hill very fast. This was not a survivable avalanche. We had no intention of skiing the slope and were just trying to get a look into Shingle Mill. It traveled all the way to the valley floor about 1900' vertical with a big powder cloud.

The structure is the same that has has been thoroughly documented all throughout the Wasatch. Very weak snow that has been sitting around for far too long is not buried under a 1 Finger hard wind slab that is strong enough to support its own weight but not much more. The storm that is on our doorstep now is sure to tip the balanceon many slopes, but not all.

Comments

Comments

The above slide was not the first that we triggered along our uptrack. This one was triggered intentionally lower down at 8800', NNE on another exposed subridge. We chose less exposed terrain to ascend that was connected to steeper slopes to allow assessment along the way and easy escape. Quickly we realized that most of the upper elevation terrain in our area was wind loaded and not safe to travel in. The snowpack structure is not to be taken lightly anywhere steep enough to slide.

Coordinates