Bonney moraines 1.5 skier triggered

We skied bigger Bonney moraine bowl. Moderate wind from the S on top of the run. Ski cut just under moraine ridgeline triggered size 1 1/2 soft slab. 30-40cm crow line of storm snow. Only travelled 50-100m in the moraine bowl but propagated about 200m wide along ridgeline all the way into skiers left slidepath. The slide ran from 2100 down to about 1700m in the main gully of the slidepath. No step down, just storm snow. The skier didn t get carried away in the slide.