This test result of an extended column test shows
1. high strength of the weak layer – it took the 28th hit to cause failure
2. Propagation potential – the entire width of the block failed
3. A fast and clean high quality failure plane
The interpretation of this result means that an avalanche is unlikely to be
triggered, although possible on steeper slopes. However, if a collapse is
initiated, a relatively deep avalanche may propagate easily.
No collapsing or shooting cracks were observed.
Snowfall was light and intermittent throughout the day, then stopped by late
afternoon. Wind was light to Moderate across Turnagain Pass.
Other pit result at Seattle ridge – 2300 feet East facing aspect ~35 degree slope.
ECTN 26 Q2 at crust layer 85cm deep.
This result did not want to propagate. The block failed partially at the crust
layer. High strength was indicated.
This test result shows good stability and inspires more confidence than the
The take home point is that variability exists depending on location.
Avalanches may be possible in some places but not others.