Observation: Chugach State Park

Location: Ship Creek

Route & General Observations

I took the dogs for a ski-walk in Ship Creek midday. Dug a pit just to seen what lurked.

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

calm and temps near freezing. Bits of sunshine poking through

Snow surface

Mostly rain crust. Pretty terrible for skiing. I never took my skins off.


I dug to the side of a main slide path. Snow in the path was >1m deep, where I dug it ranged 65-85cm.

2600ft, SSW aspect, 31deg slope, depth of pit 80cm.

2-5mm rain crust on the surface. Where this crust formed over old stiff wind board it almost supported a skier, but in most places it was easily breakable.
The majority of the snowpack is a 4-finger density slab, but some parts of my pit wall were 1-finger for 40-50cm. I think this was the "waves" of old wind drifts and sastrugi buried mid-pack, since the thickness and depth varied across my pit.
The 10-15cm at the bottom was loose facets, fist-density or less.

ECTN 12, the top 30cm of the column mostly collapsed.
ECTP25 at 50-60cm down, this was a non-planar propagation.
The block came off with a very chunky base and I could not find a continuous weak layer. It looked like water from the rain event had percolated down through the snow pack and fanned out when it hit subtle density changes. I found a few frozen vertical "straws" linking the surface crust to mid-pack frozen lenses of various diameters, but very thin. These lenses were not connected, or even at a consistent depth. I think they were forming along buried sastrugi features. This was enough to cause propagation in my ECT, but I don't know if this would be enough to propagate on a larger scale, or if this percolated snowpack is widespread in Ship Creek.

No other signs of instability noted.