The 30-km-long Perito Moreno glacier is the most famous glacier in Argentina’s Los Glaciares National Park because of its rupture process: it is one of the few glaciers in the park not retreating or advancing but rather in equilibrium, going through cycles of retreats and advances. Located on a narrow channel that separates the main body of Lake Argentino from its southern arm (Brazo Rico), Perito Moreno forms an ice dam when it advances to the extent that it reaches the land on the other side of the channel, creating two separate bodies of water.