Layer cake

In the Wapiti for an AST1 course today and found a smidge of new snow! Once we got above 1600 m we found the scattered flurries had deposited between 5 and 20 cm of fresh snow on top of last weeks melt freeze crust. Snow is very light and we didn’t see any signs of wind or storm slab instability. Visibility was poor above 1600 m as well, so we couldn’t see into the alpine all day. Our pit had two layers reacting and propagating in the hard range, a snow layer that looked like decomposing stellars down 50 cm and the November crust down 110 cm. Both failed almost together on the 24th or 25th tap in column tests, and both propagated across the full extended column as well, on the 26th or 27th tap. Height of snow was 130 cm at the pit at 1650 m.

We had two layers of concern in our pit, a layer in the December storm snow down 50 cm that failed on what looked like decomposing stellars, 2-3 mm size. We also saw failures in facets above the November crust, which was 110 cm down at our pit location. Both layers had sudden planar failures on both compression and extended column tests, and both failed within one tap of each other. We did two tests two times each. (CTH24, 25 down 50 SP on stellars. ECT26 down 50 SP on stellars. CTH25 x2 down 110 SP on Facets. ECT27 down 110 on facets.) There is a significant melt/sun crust down about 8 cm from last weeks warming, but we saw no signs of activity on or around that crust and the new snow on top of it is very light.