A collection of 100,000 striking high-resolution aerial photos of glaciers, photographed over 40 years with a 63-pound WW II surveillance camera.

As scientists study the effects of global warming, one of the most visible and alarming indicators is the rapid shrinking of glaciers. Government scientists have been documenting the size, shape, and movement of glaciers since the 1950s employing techniques ranging from direct field observations to aerial photography.

The United States Geological Survey (USGS) has one of the largest collections of aerial glacier photographs. Over 40 years, the USGS’ North American Glacier Aerial Photography (NAGAP) project captured thousands of striking high-resolution photos of glaciers and their surroundings.