The Andean Glacier and Water Atlas

Andes glaciers Glaciers are thick masses of ice which flow slowly due to gravity. Glaciers, including the ice sheets of Greenland and Antarctica, cover about 10 per cent of the world’s land surface and store about 75 per cent of global freshwater (National Snow and Ice Data Center, 2018). In the Andes, the greatest number of glaciers is found along the border between Chile and Argentina (approximately 4,000). A smaller number are found in the Tropical Andes, which constitute more than 95 per cent of the world’s tropical glaciers (Vuille et al., 2008). The largest number of tropical glaciers is located in the Peruvian Andes, with the Quelccaya Ice Cap located in the Cordillera Vilcanota being the largest single ice body in Peru (Hastenrath, 1998). In the Andes, glaciers only form above the snowline, where snow persists throughout the year. Their formation depends on latitude, altitude, and annual precipitation. As snow accumulates it compresses the underlying snow, creating a layer of dense snow, called a firn. As the snow continues to accumulate the pressure increases, further compacting the firn, which develops into solid

This complex topography, coupled with elevation, altitude and climatic gradients has made the Andes one of the most ecologically diverse mountain systems in the world (Borsdorf & Stadel, 2015). The wide variety of ecosystems with their rich flora and fauna, have long provided support for human settlements. Features include high-land plateaus, sometimes referred to as mountain knots, that are formed where mountain chains meet. Some of the highest cities in the world, such as La Paz in Bolivia and Quito in Ecuador are found on these high plateaus. The Andes cryosphere The cryosphere, originating from the Greek word for cold, kryos, consists of areas where water is frozen. It includes places that are either seasonally or year-around below freezing. The cryosphere on land includes areas of snow cover, glaciers, ice caps, ice sheets, river and lake ice, permafrost and seasonally frozen ground. The cryosphere plays an important role in climate with many direct links and feedbacks. These influence surface fluxes of energy and moisture, cloud formation, precipitation and atmospheric and oceanic circulation (Khromova, 2010). In the Andes, the freezing and melting regime of snow and ice has a significant impact on alpine hydrology and ecology (Diaz et al., 2003).

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