Donate to the 2024 Spring Campaign to help rebuild the UAC website.

Avalanche: Amazon Basin

Observer Name
Nate H-S
Observation Date
Tuesday, December 25, 2012
Avalanche Date
Monday, December 24, 2012
Region
Logan » Amazon Basin
Location Name or Route
Amazon Basin, viewed from Swan Flats Road
Elevation
Unknown
Aspect
Northeast
Slope Angle
35°
Trigger
Unknown
Trigger: additional info
Remotely Triggered
Avalanche Type
Soft Slab
Avalanche Problem
Wind Drifted Snow
Depth
2.5'
Width
150'
Vertical
40'
Comments
We observed a crown from a natural slide at the N/NE ridge of lower Beaver Envy from the Garden City approach. It appeared to be a wind slab on the ridge that ran down to the treeline 30-40 feet below. It may be natural or a remote trigger from the Swan Flats or in the - there was no sign of skier or sled activity from our distant vantage. It appeared to have gone after Monday's storm snow loaded up on a wind slab/cornice. Another member of my party has pictures of this slide. (photo from Brian Green) Once at Garden City, extended column tests failed between 10 and 15 taps on 35 degree slops. The rain crust failed all three times. Fast powder for riding, but the potential for hidden dragons on rollovers and steeper north-facing terrain is very real.
Comments

Forecaster's comments. Small natural wind slab released likely due to northwest winds and snow on Monday 12-24-2012.... Perhaps of more concern are the party's ECT results in Garden City Bowls, indicating the lingering potential of persistent slab avalanches on northerly facing slopes. Thanks Nate for the observation and getting back to me in timely fashion regarding my questions.