12) Llosás

During the last glaciation (between 85,000 and 18,000 years ago), the Llosás Glacier occupied both the cirque between the Tempestades and Aneto Peaks (southern slope) and the entire basin delimited by the Margalida and Russell Peaks (eastern slope). At the level of the current Pleta de Llosás, at just under 2,000 m above sea level, this glacier converged with the Vallibierna Glacier in a single 9 km long tongue of ice, which was also joined by the Coronas Glacier, up to the current sector delimited by the Pla de Senarta and the Paso Nuevo Dam, to become a tributary of the Ésera Glacier. The latter reached a length of 36 km.

The Llosás glacier developed again as a cirque glacier during the Little Ice Age, under the protection of the great peaks that form its headwaters. A well-defined frontal moraine remains from its recent activity. Its most advanced point coincides with the shady area generated by Tempestades Peak in this sector of the old glacier.

During the Little Ice Age, its 28 ha of extension represented only 4% of the total ice extension of the Aneto-Maladeta Massif, as well as 26% of the ice on the southern slope of the massif. The fragments of the remaining ferns of this glacier were definitively extinguished in 1987.