The Quelccaya Ice Cap (also known as Quenamari Ice Cap) is the second largest glaciated area in the tropics, after Coropuna. Located in the Cordillera Oriental section of the Andes mountains in Peru, the cap covers an area of with ice up to thick. It is surrounded by tall ice cliffs and a number of outlet glaciers, the largest of which is known as Qori Kalis Glacier; lakes, moraines, peat bogs and wetlands are also present. There is a rich flora and fauna, including birds that nest on the ice cap. Quelccaya is an important source of water, eventually melting and flowing into the Inambari and Vilcanota Rivers.
A number of ice cores have been obtained from Quelccaya, including two from 1983 that were the first recovered outside of the polar regions. Past climate states have been reconstructed from data in these ice cores; these include evidence of the Little Ice Age, regional droughts and wet periods with historical significance and past and recent El Niño events. The ice cap is regularly monitored and has a weather station.
Quelccaya was much larger in the past, merging with neighbouring glaciers during the Pleistocene epoch. A secondary expansion occurred during either the Antarctic Cold Reversal or the Younger Dryas climate anomalies. At the beginning of the Holocene the ice cap shrank to a size smaller than present day; around 5,000 years ago, a neoglacial expansion began. A number of moraines – especially in the Huancané valley – testify to past expansions and changes of Quelccaya, although the chronology of individual moraines is often unclear.
After reaching a secondary highstand (area expansion) during the Little Ice Age, Quelccaya has been shrinking due to human-caused climate change; in particular the Qori Kalis Glacier has been retreating significantly. Life and lakes have been occupying the terrain left by retreating ice; these lakes can be dangerous as they can cause floods when they breach. Climate models predict that without climate change mitigation measures, Quelccaya is likely to disappear during the 21st or 22nd century.
Geography
The Quelccaya Ice Cap lies in the tropical highlands of southern Peru, in the Cordillera Oriental/eastern Andes. The Cordillera Vilcanota mountain range is northwest of Quelccaya, and Quelccaya is sometimes considered to be part of it; occasionally Quelccaya is also linked to the Cordillera Carabaya range. East of Quelccaya, the Andes drop off steeply to the Amazon basin. The Amazon rainforest – only away – is barely discernible from the summit of Quelccaya. Lake Titicaca is south of Quelccaya. Administratively, Quelccaya is part of the Cuzco Department.
The Andes in Peru, Ecuador, and Bolivia are subdivided into several separate mountain ranges, many of which are glaciated above elevation; Peru contains about 70% of all tropical glaciers. Together with the Coropuna volcano also in southern Peru and ice bodies in New Guinea and the Rwenzori Mountains in Africa, Quelccaya is one of the few tropical ice caps in the world; during glacial times there were more ice caps which may have resembled Quelccaya. The existence of two smaller ice caps south of Quelccaya was reported in 1968.
Human geography
The ice cap lies in a remote area. It is also known as Quenamari and is sometimes spelled Quelcaya. Since 2020, Quelccaya is part of the Área de Conservación Regional Ausangate, a protected area, and the local population considers Quelccaya an important , a holy spirit.
The region around the ice cap is sparsely populated. The city of Cuzco lies to the northwest of Quelccaya, and Sicuani is to the southwest. The closest road is still from the ice cap and the rest of the journey can take three days with pack animals to reach the ice cap. There are several camps at Quelccaya, including one close to the northwestern ice margin. A 1974 map shows a homestead on the Huancané River southwest from Quelccaya, about from the ice margin.
Ice cap
The Quelccaya ice cap extends up to from the north to south and between from east to west. Quelccaya is a low-elevation ice cap that rises above the surrounding terrain; the ice cap lies at elevation. The highest summit in the area of the ice cap is Joyllor Puñuna at elevation. Snowline elevation has been estimated at .
The ice forms a relatively thin and flat structure with several ice domes. The number of ice domes is variously considered to be two, three or four; the highest of which reaches elevation. Close to the summit of the ice cap the ice is thick, with a maximum thickness of about , and the ice has a total volume of over .