Mt Fuji

We dug two pits near each other on a northwest aspect at 5700 ft on Mt Fuji today. In both pits, we found two surprisingly reactive layers of buried surface hoar. One was buried 38 cm deep, and the other was 64 cm deep. Both produced propagating results with moderate taps in extended column tests. Both layers were somewhat wind affected, with crystals partially blown over, but they still made obvious stripes in the pit wall. The layer buried 38 cm deep had 6-10mm crystals, and the 64 cm deep layer had 8-15mm crystals. The slab above the 38 cm deep layer is still relatively soft and seems to just barely be stiff enough to allow for propagation in tests (3 x ECTP, 1 x ECTN). The 64 cm deep layer is more stubborn and only failed in one test (ECTP17). There is uncertainty regarding the spatial variability of these surface hoar layers. 

We observed isolated stubborn cracking on unsupported small rolls. Some of the cracking was in the recent wind slab, and some of the cracking failed on the upper layer of surface hoar. We did not observe any collapsing/whumpfing. Snow surfaces today did not appear very wind affected, but we could feel stiffer wind slab layers buried beneath the recent snow on the upper wind affected ridge of Mt Fuji. 

The 6" of overnight snow was low density and sits on even more low density snow in most areas. We avoided steep terrain today, but I suspect that dry loose sluffing would be an issue in steep terrain.