Natural avalanches in GofS
By Sarah Goodnow
Date of Observation: March 6, 2019 10:00 AM
Location of Observation: Gulf of Slides #1, #2, South Snowfield
I found new debris in the bottom of Gully #1 and Gully #2. There was none in the south snowfield and I did not travel in any area north of #2. Debris in both gullies was wind affected but with some chunky wind slab evident. Debris pile in #1 was considerably less chunky and smaller than #2, leading me to think it was a softer slab that ran earlier in the period of wind loading than #2.
#2 had old surface (as in- the extra firm wind slab left after the 170mph wind event) as the primary surface in the lower 1/2 of the path. #1 had hardly any old surface exposed. #1 and the upper 1/2 of #2 had varying depths of 1F+ wind slab on top of a few cm of fist density snow and in places, up to 1 cm new snow blowing around on the surface. Pockets of softer wind slab could be found in the loosely treed ridges between gullies. Those pockets propagated cracks but weren’t inclined to slide.