August 28, 2002
Moraine Lake, elevation 6,265 ft (1910 m), is located in Banff National Park, in the Rocky Mountains of Alberta, Canada. The beautiful cyan or turquoise color of the water is caused by fine rock powder, which is suspended in the water and reflects the blue wavelengths of light. The rock powder, or glacial flour, comes from the meltwater of nearby valley glaciers. As a glacier moves, it grinds the rock comprising the valley floor and walls, reducing it to a fine powder. This picture was taken on August 13, 2002.