Submitted by: Bob
| Location: | Snow study area, sf ski area |
| Date: | Feb 2, 2010 | Temp (C): | -5 |
| Wind Speed: | 0 | Wind Direction: | - |
Northwest aspect, 39 degree slope, under tree canopy.
30-70 cm - dry, decomposing and fragmented particles, 1 mm, fist resistance
15-30 cm - dry, solid faceted crystals, 2 mm, fist resistance
15 cm - dry ice masses, pencil resistance
10-15 cm - dry solid faceted crystals, 2 cm, fist resistance
5-10 cm - dry solid faceted crystals, 3-4 cm, fist resistance
0-5 cm - dry solid faceted crystals, 5-7 cm, fist resistance
Extended column compression test - CTN (no failure)
Shovel shear test - STM (moderate), fail at 15 cm, Q2 (average shear bed)
This pit was dug before the most recent storm, The results said to me that the newer snow is bonding but that the ice layer at 15 cm is still providing a shear plane.
One really notable thing was the shovel shear test - the resistance was moderate, but when it failed the column shot out from the snowpack dramatically. There was a lot of energy stored in the upper layer.
The bonding of the upper layer was good, but it seems to me that if there is a release it may be in a large area like a bowl or chute and be wall-to-wall. There wasn't any bridging to speak of between the layers at 15 cm. I'd still be uspect of open bowls and chutes, especially if there are rocks along the perimeter.
The snow below 15 is pure sugar - no cohesiveness.