13-14

This slide was remotely triggered Tuesday (2/11) along the route into Sheep Creek just north of Cooke City. Remotely triggered means it was triggered from the flats under these steep slopes and a serious sign of unstable conditions. The snowpack in this are is relatively thin and this avalanche broke near the groud. Photo: GNFAC

This slope collapsed with a large "whumph" as we postholed downhill.  It moved  3" but was not steep enough to slide; about 33 degrees steepess.  Approximately 75 feet away a small rollover avalanched with this collapse.  The soft slab broke on a layer of buried surface hoar. Photo: GNFAC
 

Karl Birkeland measures the 50cm slab sitting above the buried surface hoar layer. It propagated in 21 of 24 stability tests with ECTP12-14. Photo: GNFAC

This layer of surface hoar is buried 50cm deep on Lionhead.  It is breaking easily in stability tests and we were able to collapse a slope and remotely trigger a small avalanche on this layer. Photo: GNFAC

These slides were triggered by two skiers on Monday (2/10/14) on a south facing slope at 8,000 feet.  They broke about 2 feet deep, likely on the facets formed two weeks ago. Photo: L. Hinck

A layer of near surface facets was found 40 cm's below the surface in the Flanders drainage up Hyalite.Ths layer produced unstable results in some stability tests but not all. It is not a major problem at the moment, but could become more reactive if stressed by a new load. Photo GNFAC