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02-15 Fish Creek Knob

We went to check the strengthening and settlement of the snowpack over the last few days of moderate temperatures and light new snowfall. We found strong snow in most locations, including slope tests on 60°+. On all but north aspects, the powder of last weekend has settled to a shallow, dense surface layer. On steeper south aspects, it has a sun crust.

The only instability we found was in windloaded areas near the ridges, where freshly transported snow was sensitive and poorly bonded to underlying rime and melt freeze crusts.

The new snow was dry up high and damp on the surface below 500 m. There was less than 5 cm of new snow over the weekend's powder. The near surface facets that formed over the weekend were already rounded, and we did not find the surface hoar in our test areas.

The December 23 - 24 faceted melt freeze and associated facets are still present and sugary, but did not react in our tests. However, we were only able to cut the Rutschblock to 1 m depth. The AK Block was deeper, but we barely reached the December crust at the bottom of our test pit. So deep weakness remains in the snowpack, but cannot practically be evaluated with snowpit tests. The best indicator, though, is that it did not react in the Feb 9 - 10 cycle, the largest avalanche cycle in the area this winter, which was confined to the new snow and the new - old snow interface.

Bill Glude checks the shear on our AK Block. The Rutschblock would not fracture at all (#7), and the AK Block took repeated very hard jumps (#6) to get a release at Q3 (a rough, poor quality shear) on 42°.
Mike Janes samples the snow on a north aspect. We found windblown crust on the ridges, a few areas of sensitive windslab in loaded areas near the ridges, shallow and very dense powder on south, east, and west aspects, and deeper but dense (150 kg/m3) powder on north aspects. Steeper south aspects had a 1 cm sun crust from the 13th.
Slabs from the Feb 9 - 10 overnight wind and snow cycle on the North Face of Fish Creek Knob D002. These may have been several smaller slabs, but probably occurred as one big release 0.5 - 1.5 m deep and some 300 m wide, from 1000 down to 600 m.The next photo shows fractures lower on the right side of the face.
The fractures on the lower right side of the North Face of Fish Creek Knob D002. We classified these as one big slide, as the whole face probably released simultaneously, SS-NO-R3D3-I.