Obs-Snow Profile: Mt Raymond 1/20/2011

Observer Name: 
Kikkert, Manos
Region: 
Mt Raymond
Mill A
Big Cottonwood Canyon
Salt Lake
Observation Date: 
01/20/2011
Location or Route: 
Mt Raymond/Gobblers Knob
Weather
Sky: 
Clear
Wind Direction: 
Northwest
Wind Speed: 
Moderate
Weather Comments: 

Still some moderate wind gusts moving some snow around along the upper elevation ridgelines, but not enough to affect stability. 

Red Flags

Cracking
Collapsing
Red Flag Comments: 

Along the the east ridge of Mt. Raymond we noticed huge variability in the thickness and strength of the rain/rime crusts.  At times there were two crusts, each about 1/2 inch thick, with about 1/2 inch between them, and just 10 feet a way there would be just one solid crust about 11/2 inch thick.  Pits along the ridge, all on SE aspects, were showing preserved facets below the 2nd crust.  The uppermost crust (when there was two) was the weakest.  On our way up the ridge we were also getting several large collapses.  At first we wrote these off as possibly just the upper crust collapsing onto the 2nd.  However, we were also getting collapsing in areas where there was just the single, very stout crust.  Near the top of the ridge, the collapsing was accompanied by shooting cracks that were propagating about 30 feet.  The longest cracks were in areas with the stoutest crust, and included the crust and the faceted snow below.  We debated whether the lack of a cohesive slab above the crust made the cracks somewhat irrelevant, but basically the crusts were behaving as a slab and as the last 2 large shooting cracks arched out into the top of starting zones, we decided enough was enough and headed to a different aspect.  All collapses were on SE aspects, between 9800 and 10,000 feet, similar to the cracking reported in the UFO bowls, in fact rereading that observation, the whole scenario seemed quite similar.  

Elevation: 
9900'
Aspect: 
Southeast
100_4547.JPG
snow_profile_location: 
United States
40° 39' 45.6156" N, 111° 41' 51.558" W
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Comments - Photos - Videos (group 1)

 Sorry for the poor snowpit image.  Pit was from lower down on the Raymond ridge, on a SE facing slope.  It was in an area where there was essentially 3 crusts: an upper crust composed of both a rime and a rain crust, and a lower crust with preserved facets below (mostly near surface facets with some small surface hoar).  In many other places there was only 1 stout crust; however, the crust was still underlain by faceted snow.  On NW facing in Gobblers Knob, we also noticed the crusts to be very variable in thickness and strength.  However, we experiened no cracking and collapsing and although you could find facets about 25 cm down, they had gained considerable strength, only shearing out in test pits with some effort (CT19-20) and not very cleanly.  In general, on the NW facing slopes the snow underneath the crusts was not nearly as weak (finger hardness) as on the SE facing where we had collapsing.

Comments - Photos - Videos (group 2)

 Photo shows a portion of the snowpack that was cracking.  Here the crust was about 1 1/2 inch thick, but underlain by very weak snow.  My thoughts are that the cracking was being initiated in thiner spots along the ridge, but the propagation was still unnerving.  

DSCN3581.JPG
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