10-11

A dense wind slab sitting over a layer of small grained facets allowed the flanks of this slide to propagate outwards lower in the path.  The primary weak layer for this avalanche was weak facets around a rock outcroppings near the top of the slope.  The thin layer of facets in this photo required the heavy load of avalanche debris to break and is not a major concern by itself.  Photo: GNFAC

This slide was the result of a heavy wind load sitting over weak facets, which formed around the rock outcroppings in the upper part of the path.  A cornice drop was presumably the trigger.  The avalanche ran close to 1,000 ft vertical.  GNFAC

This debris pile was the result of a large slide that occured on Hardscrabble Peak in the northern Bridgers.   GNFAC

This slide on a NE aspect of Fan Mountain near Big Sky is very similar to one that occurred recently in the Bridger Range.  It appears to have been triggerd by a falling cornice.  The slide started in a steep rocky area that likely contained a thin, weak snowpack.  The resulting avalanche broke further downhill but did not propagate over a much wider area.  Photo: S. Reznicek

This avalanche was likely triggered by a falling cornice on Hardscrabble Peak in the northern Bridger Range near Fairy Lake.  A previous avalanche from Jan 22 can be seen to the right.  Photo: D. Jupka

Thin snow equals weak snow.  This photo was taken near Big Sky at the head of Middle Basin on a broad planar slope which faces south and southeast.  Without a significant load of new snow, triggerring an avalanche in these areas isn't likely but should be considered.  Stability test results on the facets were CT20 Q1 and ECTP20.  Find a deeper snowpack, and you will find much stronger snow. Photo: GNFAC