Perito Moreno Glacier Calving

Iceberg calving from the 70m-high face of Perito Moreno Glacier in Argentinian Patagonia. I identified this unstable-looking part of the glacier by its large cracks and trained my telephoto lens on it for several hours to catch the decisive moment. Constant vigilance was required. Although the splitting ice makes a noise like a peal of thunder, by the time the sound reached me after almost three seconds the ice had already hit the water. Seven frames per second, each 1/2,500th second at F/11 and ISO 320.