From an email: "Lower elevation snowpack was a wallow through deep and unsupportable facets. We were sinking 12" - 18" on skis... straight to the ground off skis. Off the road, our sled tracks were dropping down almost to the ground.
At 8200'+ the snow was a bit more supportable. No collapsing, cracking, woomphing until...
We got to 8800' and were running out of time so decided to ski out. I was going to dig a pit on a 15 degree adjacent to a steeper pitch and as soon as I stepped out on to a more cohesive slab from the shallow snowpack I was on, the whole slope collapsed and shifted downhill a few inches (See photo). Didn't dig the pit... turned around, traversed to the trees, and slid home. Based pole and hand pit, the slab seemed to be about 1F - 4F over 18" - 24" Fist hardness facets.
The difference between the slope that collapsed and the rest of the tour was the slab . There had been recent windloading and the slab was more cohesive."