While booting up the North Couloir I triggered a slide. The crown broke about two feet above me and did not affect me at all. It was lethargic in its motion and had very little energy. My partner was about 100' below me and he easily moved to the side before it passed him. The crown varied from 4"-12"'. It was a wind slab that slide on old facets. It was extremely slow and unconsolidated.