Photo No. 3 illustrates a masterful use of terrain in a shallow, rocky, continental snowpack—with a dangerous weak layer near the ground. Here is how the skiers here use terrain to lessen the risk:
1. The skiers descend one at a time.
2. The skiers leave just enough of a buffer zone on the upper slope to avoid the obvious trigger points (marked with an X) and avoid the cross wind-loaded unstable start zone.
3. Below the first slope, instead of turning downslope and increasing exposure, they travel farther skier’s left and place a protective piece of terrain (a bench and small ridge) between their line and the unstable slope above.
4. The descent line avoids travel through the lower slope and terrain traps, avoiding overhead hazard and increased consequences.
All three images are examples of how to apply a safety margin to our terrain choices. Never pass up the chance to place protective terrain, such as a bench or downslope ridge, between your line and a hazardous slope. And when you choose a line that you think has a reduced chance of avalanching and fewer consequences, don’t forget to build in that margin for error and place a buffer zone between what you think is likely safe and the more hazardous line.
Colin Zacharias is a consultant and educator in the avalanche and mountain guiding industries, and an IFMGA/ACMG mountain guide. He resides on Vancouver Island.