Crack in thick ice across from Howard Luke's camp A large crack in a thick slab of ice across from Howard Luke's camp close to the river bank at Perkin's Landing, revealing the layers of ice and snow and how they form throughout the winter. Process Observed: Ice ThicknessIce ShelfIce LayersIce Formation Date Process Observed: Friday, February 12, 2010 Galleries: Across from Howard Luke's camp close to river bank at Perkin's Landing Gallery