Watched Pete Groves a veteran ski patroller at Alta, throw in a ski cut in to the top of Cardiff Bowl, the ski cut appeared to nock out a small wind slab at his feet which in turn triggered a larger shallow wind slab a little ways below. Crown was 8 inches at its deepest point and about forty feet wide, ran down to where the slope angle eased up. These slides were starting in the density inversion in the new snow then running on the hard bed surface below. Photos.

Whole slide.

Crown.