Perito Moreno Glacier

The Perito Moreno is one of the most important glaciers that break off from the Southern Patagonian Ice Field located in the southern chain of the Andes (Argentina and Chile). This icefield is the last reliect of the greatest glacial expansions that occurred form the late Miocene to the late Pleistocene. This glacier is approximately 30 km long. Its front is 5 km long and has walls up to 60 m high (Aniya and Skvarca, 1992; Stuefer et al., 2007). The glacier penetrates Argentino Lake, but its base maintains contact with the rocky substratum. It´s a temperate or humid base glacier with a unique dynamic behavior. In this sense, its front presents a condition of stability (Stuefer et al., 2007; Ciappa et al., 2010), with brief oscillations (advances) that, when colliding with the western end of the Magallanes Peninsula, periodically causes the temporary blockage of Brazo Rico (as a dam), raising its water level. This situation generates differential stresses at the end of the glacier and causes the progressive transfer of water to the Argentino lake through a tunnel excavated in the ice. The roof of the tunnel collapsed in 1995, which was a spectacular event that made the glacier famous internationally (Del Valle et al., 1995).