Tolkien range observations

Summary of observations from 13-16 March at Brian Waddington hut. Snowpack, avalanche, and weather observations are recorded in the respective tabs. Photos are from 14 March pit on N slope at 1750m. Overall we observed enough concerning signals to keep our terrain choices mostly conservative. North slopes seemed to maybe be a bit stabler than South slopes in the zone due to better bonding on the early March melt-freeze crust.

Skiers triggered accidentally above some cliffs at the top of cabin hill. Skier was standing above steep terrain looking down at the line. A thick storm slab released below, cleaning off some small cliffs and steep slopes before fanning out into the small open bowl below. No one was caught by the sliding snow. We didn't get in near the crown to inspect the failure layer due to the potential hang fire and cliffs below. We suspect the failure was on a 11-12 March interface between two recent storm slabs.

We dug 3 pits over 4 days on South and North facing slopes. Test results as follows: 14 March, S aspect, circa 1750m large clearing below treeline, circa 30 degrees. We dug about 150cm down. Snowpack mostly rightside up above the early March melt-freeze crust, which we found buried at about 85cm down and about 5cm thick. ECT produced a storm slab failure 25cm down after 5 taps from the wrist. Failure was a planar break along a thin interface of small (<2mm) facets between 8-9 and 11-12 March storms. A second planar failure after 15 taps (5 from elbow) occurred on the early March melt-freeze crust. Later that day we triggered a large whumpf on an open bench at circa 1900m on the same aspect and scurried back into the trees. 14 March, N aspect, circa 1750m, large clearing in treeline, circa 30 degrees. We found the early March melt-freeze about 80cm down and the crust was thinner at about 3cm. ECT produced similar storm slab failure 25cm down after 10 taps. No failure was observed after 30 taps on the melt-freeze crust. (Attached photos are from this pit) 16 March, N aspect, circa 1850m, open alpine slope, circa 40 degrees. The melt-freeze crust was about 80cm down and thinner still at maybe 2cm. CT produced no sudden failures. In our travels around the zone we observed some shooting cracks while setting skin track up a 30 degree west facing slope. It wasn't clear if the cracks formed from the storm slab or the deep PWL.