Cryoturbation landforms were not conspicuous according to Nagy et al. 2019, presumably because wind-driven phenomena overprint the effects of cryoturbation. Mass movements have left traces on the mountain. Lakes Ojos del Salado hosts the highest lake in the world in the form of the crater lake in the summit crater. Fed by permafrost and snowfields, it lies at - elevation. It is surrounded by fumaroles and covers an area of . Waters in a creek flowing into this lake reach temperatures of . There are two lakes at elevation on the northeastern slope, away from the higher lake. Each has an area of and an estimated depth of . Ephemeral lakes occur at elevation, when meltwater from permafrost accumulates in closed depressions. Such ponds may form in depressions at elevation. Some of the lakes may be permanently frozen. Lakes might disappear with climate change owing to the breakdown of permafrost. Surroundings The landscape is dominated by volcanoes, many of Pleistocene or Holocene age, and is the highest volcanic region in the world. Young volcanoes have conical shapes and often feature summit craters. Travellers have compared the region to a "moonscape". There are hot springs in the region, such as the Termas Laguna Verde at the shores of Laguna Verde, which are frequented by visitors. The volcano lies in the middle of an over long east-west trending chain of volcanoes that form a drainage divide and includes the volcanoes Nevado Tres Cruces, Incahuasi and Cerro Blanco. This chain of volcanoes appears to be part of the Ojos del Salado-San Buenaventura tectonic lineament, which corresponds to a geographic (southern boundary of the Puna de Atacama) and tectonic discontinuity in the region. The lineament may be a consequence of the subduction of the Copiapo Ridge at this latitude. An alternative view is that the subducting Copiapo Ridge is actually located north of the lineament; this would be more consistent with the theory that the subduction of such ridges gives rise to gaps in the volcanic chain. Ice and glaciers Except for firn and small glaciers in sheltered parts of the mountain, Ojos del Salado lacks substantial ice cover. This is due to the arid climate of the region, which causes the equilibrium line altitude of ice to rise above the top of the mountain and keeps most peaks in the area ice-free. Glacier areas shown on maps are often actually immobile firn fields.