Northern San Juan

Avalanche

Mark Gober · Jan 4, 2021 · Northern San Juan

Weather

Clear skies, mild temps, and calm winds.

Snowpack

We dug a pit on a 25 degree slope, SE aspect near treeline adjacent to a slope that appeared to have slid a storm ago as the crown and flanks were still partially visible. The pit was 95 cm and had 4 notable layers. After I had excavated the pit, isolated the sides but not the back of column, I had my partner ski down to me. As he stepped into the pit the slope collapsed and cracked a few feet above us. The ECT column that was not fully isolated failed on two layers simultaneously, with good propagation across the column. The lower layer was 40cm off the ground and was facets a couple cm's above a suncrust. The second was 65cm in small facets that appeared to be formed in between storm events. We went ahead and isolated the back of the column and on 12 taps it popped out dramatically with clean shears on both layers. This was repeated above the collapsed area and cracking as well with similar results. Was not confidence inspiring.

Avalanche

I triggered a small soft slab on the sunny side hill low in the main part of Irenes. This slope had previously slid and the old crown and flanks were still visible. Bed surface was facets on a suncrust. It had the potential to be a larger slide if I had continued farther on the slope.