Loaded PST failures on Stoney Ridge/Meeks Ridge.

We went back to the Stoney Ridge/Meeks Ridge area today to perform a loaded PST on the near surface facets located between the Jan 4 and Dec 12 rain crusts. Snowpit data for this location was collected on Jan 7 and the pit profile is posted in the Jan 7 observation. Since that time about 1 inch of new snow has accumulated in this area. The weak layer of interest does not have a sufficient overlying slab for standard snowpit tests so we used the Birkeland et al method to perform a loaded PST.

Using this technique we built a 15-20 cm thick artificial slab from F hard disaggregated snow (facets). We let this slab sit for 75 minutes to allow the slab to sinter. In this time the slab became 1F hard. The facets in between the crusts initially failed on column isolation. Performing a PST directly below the Jan 4 crust produced a second failure of Loaded PST 17/100 end at 132cm (see video).

This test and the results point towards a poor ability for this weak layer to handle a rapid new snow load. With two significant storms in the forecast for next week, we will continue to map and monitor this layer of concern.