AdvisorySAAC04

01-04-05 Showboat Area

We returned today to the same site as the one we visited on Thursday the 30th of December and Sunday the 2nd of January to track changes in the layers over time. We dug on the slope right next to the previous tests.

The slab lost the weak layer in the middle of it as it all changed into sugary faceted grains during the cold clear weather last week. The sugary grains were still dry except for the top 2 cm, which were turning to slushy melt freeze in the light drizzle, but they are becoming rounded and less sugary as the temperature becomes more uniform throughout the snowpack.

Test slopes produced no results except cinnamon rolls, snowballs that picked up a spiral of sticky moist snow as they rolled downslope. There were no shooting cracks or other signs of instability.

Yet the block test values showed both weakness and high spatial variability, and the slab test result of #2 indicates a slab that stores energy and propagates fracture well.

Why no slabs? It is likely that the slab layers have settled enough to have less stored elastic energy now and the rate of warming and wetting is slow enough to not disturb their equilibrium. Beware of any rapid thaw, heavy rain, or rapid loading.

We skied with caution today. With conflicting test results, it is best to not trust the snowpack.

Matt Beedle shears the Rutschblock on #5 (a second, hard jump) Quality 2 (average) on a 38° slope. This was one of the rare blocks that broke at the cut, not at the tester's skis or board.

Matt points to the immediately adjacent AK Block that sheared on #2 (aproach) Quality 2 (average). The block sheared so quickly that Matt's ski tips did not get all the way across it, leaving the chunk of snow behind that was not loaded. There was no visible reason why two adjacent blocks had such widely varying results, it is most likely a combination of the weak layer being partially blown away before the slab was deposited, the faceted melt freeze bed surface having high variability, and the slab being inconsistent or differentially stressed.

Matt Beedle on the descent. The snow surface was moist and chunky, yet the sugar powder beneath it still made for silky smooth turns.

Gerry Landry cuts a low telemark turn through a powdery opening in the alders.

Trevor Joyce skis the Alaskan bush. The alder thickets have not had enough wet snow to bend them down and bury them this year, so some runs require advanced brush dodging skills.