From Nat Geo’s photo set “Rock and Roll…How a glacier pushed a boulder to a place near you:”  A melting iceberg, calved from the snout of Alaska’s Mendenhall Glacier, carries a passenger just a bit farther. This rock tumbled onto the glacier back in the mountains and rode the escalator down to Mendenhall Lake. Photograph by Fritz Hoffmann.

From Nat Geo’s photo set “Rock and Roll…How a glacier pushed a boulder to a place near you:” 
A melting iceberg, calved from the snout of Alaska’s Mendenhall Glacier, carries a passenger just a bit farther. This rock tumbled onto the glacier back in the mountains and rode the escalator down to Mendenhall Lake. Photograph by Fritz Hoffmann.