Page 19 - Slopeangel avalanch essentials

Testing Snow Stability
The chart below is taken from the the Snow Weather and Avalanche Guidelines (SWAG) published by the American Avalanche Association This chart can can be used to to quantify the the ECT results and analyse the the potential energy stored within the snowpack Fracture time
Code
Fracture characteristics
Shear quality
Sudden planar SP
Sudden collapse SC
Progressive PC compression
Resistant planar RP
No fracture NF
Thin straight fracture that suddenly Q1 crosses the column in in one loading
tap and column slides easily off
the layer Fracture crosses entire column Q1 from one loading
tap and is associated with a a a a a significant weak
layer in the snowpack 19
Fracture of noticeable depth that crosses across the column from additional compression
of the layer with subsequent loading
taps Q2/Q3
Fracture requires one or or more Q3
loading
tap to cross the column and the column does not slide easily on the layer No fracture –
Quality 1 1 (Q1) shear shows poor poor bonding and often very poor poor stability and is typically indicative of much more dangerous conditions than a a a a a a Q2 shear shear and certainly a a a a a Q3
shear shear