Professional Observation

Basic Information

Observation Date:

December 18, 2022

Submitted:

December 18, 2022

Observer:

Geoff Unger | Key Observer

Zone or Region:

Mammoth Lakes

Location:

EQ Dome East Face Uptrack

Recent Avalanches?

None Observed

Cracking?

None Experienced

Collapsing?

None Experienced

Stability Rating:

Good

Confidence in Rating:

Moderate

Stability Trend:

Improving

Today we toured and skied on a variety of aspects of Earthquake Dome. We did not se any signs of instability. Snow depth and the thickness of the 11/30 Facet layer changed with aspect and elevation. As we moved around to the east and south the layer thinned to 15cm and then 0cm in the shallowest areas. In sheltered areas a thicker layer of faceted snow was easy to find with a probe under a thicker mid pack.

Advanced Information

Cloud Cover:

Clear

Temperature:

3.5 degrees C

Wind:

Light , SW

Mild conditions in the sun, but a chill to the wind in exposed areas and colder in the shade on sheltered north facing slopes.

Field Weather Observation

Location	EQ Dome
Time	11:00 AM
Elevation	8700
Aspect	E
Sky	CLR
Tair	3.5
Precipitation Type/Rate	NO
Wind	L -> SE
Blow Snow	None
Surface Form/Size	Melt Forms
HST	0
HS	75
Pen Boot/Pen Ski	30cm/10cm
Comments	Some roller balls, previous(see photo). Probe estimate 5-10cm of weaker basal snow in this location.

The eastern approach to Earthquake Dome allowed us to peer into the steep and unsupported terrain on the NE face of the dome on our way to skiing shallower angle north facing slopes. Though there were tracks in some of these features, it still didn’t seem like it was time for us to step it out that far given the concerns with persistent slab.