Avalanche: Catherine's Pass

Observer Name
Greg Gagne
Observation Date
Sunday, November 19, 2017
Occurrence Date
Saturday, November 18, 2017

Region:

Location Name or Route
Catherine's Pass Area
Elevation
10100
Aspect
North
Slope Angle
38
Trigger
Unknown
Avalanche Type
Soft Slab
Avalanche Problem
Persistent Slab
Weak Layer
Facets
Depth
2'
Width
70
Vertical
80
Comments

Noticed this slide in Catherine's Pass area on Sunday - second slide I found in this area this weekend. I did not notice it on Saturday (may have missed it) and there was no storm snow on top. No tracks above or adjacent to the slide, however I did see a single ski track below the slope, and am guessing it may have been remotely triggered.

This slide failed on a layer of facets sitting just above a thermal crust from September.

Comments

Photo of slide with an arrow pointing to the dirty graupel layer from the onset of Friday's storm.

Comments

This photo at the crown showing how stress cracks propagated widely, but did not avalanche as the angle of the slope lessened.

Comments

In a Sherlock Holmes moment, am guessing this was remotely triggered as if it was a natural during the storm, there would have been some storm snow on top of the bed surface and the debris from the tail end of the storm.

This also fits the characteristics of a persistent slab weakness: (1) remote triggering from the flats that (2) propagates widely.

Coordinates