Puzzled? We went out and photographed for two hours on a ultra clear ice berg that is frozen in the Mendenhall lake. This is a pocket of sand that was inside the glacier. There are air bubbles radiating from the sand in a very cool pattern. No idea of the physics involved here. Very interesting phenomenon. This is a macro image focused inside of the ice giving testament to how clear this ice is. This little nodule is about 4 inches tall.