Probing a circle for crevasses, before unroping. Alaskan glaciers are among the biggest in the world, and have very deep crevasses, which are difficult to spot. Denali, Alaska

Subjects: Atmosphere and Sky, Geology, High Altitude, Ice and Snow, Mountaineering, Mountains, Outdoor Recreation, Outside, People and Activities, Permanent Snow, Scenics with Sky, Snowy Peaks, Sun