Mammoth Rock

Trees west of Mamoth Rock
Submission Info
Monday, January 9, 2017 - 11:15pm
Red Flags: 
Recent avalanche activity
Whumphing noises, shooting cracks, or collapsing
Recent loading by new snow, wind, or rain
Mammoth Rock 37° 36' 46.0368" N, 118° 59' 36.366" W
Snowpit Observations
More detailed information about the snowpack: 

Skinned up from the end of Old Mammoth Road to above Mammoth Rock around 9250 ft and back down the same way. 

Passed two seperate debris fields.  Debris piled up around a foot above snow against the uphill side of trees, some blocks up to 1 ft by 1 ft visible under new snow.  Both were under steep cliff bands west of the Rock.  One started around 9,000ft the other around 9,400ft, both crowns were obscured by new snow.  There were settlement cracks around many trees throughout the approach.  Cracking around skis was common, no shooting cracks.  Isolated collapsing when I moved into a wind loaded area. 

I did two hand shear tests, both failed easily 25 and 30 cm down.  Seemed to be a thin layer of larger crystals where the failure occured.  In both locations I found 10 cm of fist hard new snow on the surface, 5 cm 1F wet snow under that, and 35 cm fist hard snow below that.

Weather Observations
Blowing Snow: 
Cloud Cover: 
100% of the sky covered by clouds
Air temperature: 
Below Freezing
Wind Speed: 
Accumulation rate: 
Less than 1 in. per hour
More detailed information about the weather: 

Winds were light to moderate and from variable directions. 

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