President's Ridge on Marmot

Our goal was to ascend President's Ridge, do a crown profile, and gather information about the avalanche that was triggered on 1/13. Snow surfaces settled quite a bit today, with approximately 12" of dense snow that has accumulated since the 10th, sitting on top of weaker, sugary facets. Numerous hand shears on the tour revealed a cohesive slab sitting over weaker snow with poor structure, moderate strength, and propagation potential. Hand shears took moderate force to initiate on smooth, firm bed surfaces. Once we reached approximately 2800' we found firmer snow from recent strong winds with shallower slabs on windward aspects and thicker slabs on leeward aspects. New snow from the past few storms has definitely improved conditions, despite the fierce winds that are responsible for thin and scoured conditions on windward aspects. 

We dug adjacent to the avalanche on Presidents and found a 1-meter thick slab sitting over two separate weak layers which failed with propagation approximately 85 cm deep. See pit profile photo and video. The avalanche was human triggered at 3100' on 1/13  and was a persistent slab (HS-ARu-D2-O) with a crown ranging from 1ft to 3.5 ft thick on a NE/E aspect, approximately 40 ft wide and ran 50 ft. The persistent slab avalanche was 1F>P hard slab that failed 100 cm deep (thickest part of the crown) within a 12cm thick layer of weak facets and depth hoar. This avalanche sympathetically triggered a wind slab (SS-ARy-D2-O) on a SE/E aspect that was 12-16" thick, approximately 40 ft wide with a vertical fall of 200ft. The latter is the one visible from the road.