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Avalanche: Arrowhead Slide Path

Observer Name
Nalli
Observation Date
Sunday, January 2, 2011
Avalanche Date
Sunday, January 2, 2011
Region
Provo » Provo Canyon » Arrowhead Slide Path
Location Name or Route
Arrowhead Slide Path
Elevation
8,000'
Aspect
Southeast
Slope Angle
37°
Trigger
Skier
Trigger: additional info
Intentionally Triggered
Avalanche Type
Hard Slab
Weak Layer
Density Change
Depth
12"
Width
50'
Vertical
500'
Comments

While on my way to investigate a larger slide that occurred on Dec 29 in the Arrowhead slide path just east of Sundance I found another pocket of wind blown hard slab from our last storm. A carefully placed jump at the top of the cornice fractured and propagated 50' wide 4"-12" deep. It traveled 500' vertical before stopping mid track in some older debris from the 29th. I was not able to find any facets at the bed surface, just a change in density.

Comments

Looking further down the ridge in the photo you can see the crown from the 29th. That slide was approximately 800' wide and 2'-3' deep traveling 2000'vert. While I was also not able to find any type of facets at the interface, I suspect that the weak layer here was the old snow surface of small 1-2mm NSF that formed just after Christmas. There was a very widespread cycle in the Southern Wasatch that fits the pattern of S-E-N aspects mostly a few hundred feet below the ridgelines, SS-R4,D3+-I.

Comments

This is the East Ridge of Timp at 9400'. This one traveled about 2800' vert ending below Stewart's Falls.

Coordinates