Avalanche: Little Water Peak

Observer Name
Kobernik - Hardesty
Observation Date
Monday, December 10, 2012
Avalanche Date
Monday, December 10, 2012
Region
Salt Lake » Mill Creek Canyon » Little Water » Little Water Peak
Location Name or Route
East facing Little Water Peak
Elevation
9,500'
Aspect
East
Slope Angle
40°
Trigger
Skier
Trigger: additional info
Intentionally Triggered
Avalanche Type
Soft Slab
Avalanche Problem
Persistent Weak Layer
Weak Layer
Facets
Depth
18"
Width
250'
Vertical
400'
Comments

A small thump with a ski on a small cornice produced a shallow wind slab avalanche that was around 6" deep and 20' wide. It ran probably 50' down the slope when the big collapse occurred and a real avalanche released. The collapse was felt up on the flat terrain we were standing on where we were not exposed to any danger. The crown face was up to 2' deep at the deepest spot.

We were easily able to get onto the bed surface without having any hangfire above us. The weakness revolved around the rain crusts from the 4th and the 5th of December, which, now have some faceted grains around them. The avalanche did not break into the deeper November facets.

Earlier in the day we looked at two other recent avalanches on Square Top along the Park City Ridgeline. Because of the wind and drifting snow we were not able to positively identify which weak layer failed there. After we triggered Little Water and considering Ev's avalanche on Reynolds on the 9th which both broke around the rain crusts, we are assuming that Square Top had the same weak layer.

The deal here is that the northwest winds formed a significant enough slab on the east facing slopes. North slopes were not wind loaded enough. We suspect that above around 9600' or 9800' the rain crust is not present and the danger is less pronounced. It seems that east facing slopes along ridges which have just been wind loaded and are sitting between 8500 and 9500 feet is where the hazard is.

Comments

It is imperative to note that we had a clear view of the bottom of the bowl on the way up and could positively identify that no people were around. There were no tracks anywhere on the top of Little Water Peak. It is crucial that you have this situation prior to any testing by kicking a cornice.

Coordinates