Observation: Hatcher Pass

Location: Independence Mine

Date:
Observer:
Route & General Observations

Traveled from IM parking lot to a small steep sidehill behind the upper mine buildings where an avalanche was reported on 11/9 on an easterly aspect around 3600′. Investigation of weak layer and snowpack.

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Avalanche Details

I suspect natural trigger but could have been remotely triggered as trail systems are close by.
Recent persistent slab avalanche cycle 11/7-8 with storm load, 10" new low-density snow at 3000'. Recent remotely triggered avalanches 11/8-9. Improved stability, but poor structure will persist and allow for human-triggered avalanches to be possible in specific locations on slopes 30 degrees and steeper. This PWL (persistent weak layer) will continue to be problematic for a long time and reactivated with new loads. The faceted PWL is sitting on a patchy, slippery ice crust bed surface at the ground . Variability in test results today were due to increased stability and variability in slab cohesion and a slab that is barely cohesive enough to act as a slab.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Observer Comments

We did not experience shooting cracks or whumphing, but other groups did this same day, and one group triggered an avalanche on Marmot SW Face without involvement.

Photos & Video
Please upload photos below. Maximum of 5 megabytes per image. Click here for help on resizing images. If you are having trouble uploading please email images separately to staff.