On the right is rock debris from a landslide that occurred in 2002 after a 7.9 earthquake on the Denali Fault. The debris crossed the entire width of the glacier, 3 km wide. The debris insulates the ice, protecting it from melt which is why it is so much higher than the ice we were standing on. This provides a natural dam for water flowing down the streams on the glacier creating large ponds and lakes.
debrisblack rapids glacierlandslidelakealaska rangemountainsalaska