Glaciar Perito Moreno

The 250 km² ice formation, 30 km in length, is one of 48 glaciers fed by the Southern Patagonian Ice Field located in the Andes system shared with Chile. This ice field is the world's third largest reserve of fresh water. The Glacier is 5 kilometres wide, with an average height of 74 m above the surface of the water of Argentino Lake, in Argentina. It has a total ice depth of 170 m. A part of the terminus is seen here. Pressures from the weight of the ice slowly pushes the glacier over the southern arm ("Brazo Rico") of Argentino Lake, damming the section and separating it from the rest of the lake. With no outlet, the water level on the "Brazo Rico" side of the lake can rise by as much as 30 meters above the level of the main body of Argentino Lake. Periodically, the pressure produced by the height of the dammed water breaks through the ice barrier causing a spectacular rupture, sending a massive outpouring of water from the Brazo Rico section to the main body of Lake Argentina.