This is an update to my previous avalanche report as that was quick and dirty. This avalanche occured early in the morning Feb 1st as myself plus one were skinning just below the rocks on the Western side of Cardiac Ridge. Neither of us heard or felt the avalanche, but as I was checking behind to see where my partner was I saw a significant crown just behind him that had released right where the skin track was put in. The avalanche was roughly 200 ft wide by 200 ft long and slid about 400 vertical feet. Crown looked like it ranged from 1-3 ft deep. It was hard to estimate depth of debri pile, but looked deep enough to bury somebody.