March 18, 2020
March 19, 2020
Zone or Region:
Galena Summit and Eastern Mtns
Did you trigger any avalanches? Yes
Was it intentional? Yes
Size 1: Relatively harmless to people
This slide was relatively small and isolated on a convexity at the top of one of the lower Gnarnia chutes and was around 45 cm deep, 10 feet wide, and ran 20 feet into the trees . It released with a ski cut and seemed like it was a buried wind slab from the 3/14 storm that was sitting on top of facets. The fresh snow on top from the day and night before was cohesion-less and seemed to have very little wind transport. Even though it was a small slide it still broke into blocks big enough to carry someone into the trees.
Did you see shooting cracks? Yes, Isolated
Did you experience collapsing or whumpfing? No
We dug a pit in the Gnarnia chutes higher up from the slide we triggered and got CTM 13 and CTM 14 with Q1 failures on this layer that was 30 cm's down. We did get an ECTN30 that did not propagate all the way through but after several hasty pits in multiple areas that all had the same set up (new snow on top of the 3/14 slab on top of facets), we decided the problem was widespread enough to not ski the steeper chutes in the area around the pit area. We skied mellow slopes to see if the 3/14 layer was still slabbed up in the lower more protected chutes where we triggered the slide and found the same set up with hasty pits. Therefore, we decided to ski more inconsequential slopes below 35 degrees not on the north aspect.