Outline of Quelccaya in 2010
The Quelccaya (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 of Peru, the ice cap covers an area of 42.8 square kilometres (16.5 sq mi) with ice up to 200 metres (660 ft) thick. It is surrounded by tall ice cliffs and a number of outlet glaciers, the largest of which is known as Qori Kalis Glacier; the terrain surrounding the ice cap features lakes, moraines, peat bogs and wetlands and features a rich flora and fauna, including birds which have been observed to nest on the ice cap. Water from Quelccaya eventually nourishes the Inambari River and the Vilcanota River and is an important source of water.
A glacier is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. Glaciers slowly deform and flow due to stresses induced by their weight, creating crevasses, seracs, and other distinguishing features. They also abrade rock and debris from their substrate to create landforms such as cirques and moraines. Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
Coropuna is a dormant stratovolcano in the southern Peruvian Andes that belongs to the Central Volcanic Zone; it has several summits, the highest of which reaches an altitude of 6,377 metres above sea level. The volcano, located 150 kilometres from the city of Arequipa, is mostly made of ignimbrites and lava flows on a basement formed by additional ignimbrites and lava flows, some of which may have been formed by Coropuna itself. Coropuna has been active for at least five million years, with the bulk of the current cone having formed during the Quaternary. It has had three Holocene eruptions 6,000, 2,100 ± 200 and either 1,100 ± 100 or 700 ± 200 years ago which generated lava flows. Currently, activity occurs exclusively in the form of hot springs.
The section of the Cordillera Oriental in Peru is in the extreme south-west of the area of study, where manifestation like the spurs of the eastern flank. This unit has modelled itself on metamorphic rocks of the Paleozoic. The eastern limit is more or less uniform and Colorado is located in the beginnings of the tributaries of the valley of the river. It crosses for the average basin of the Marcapata River and goes out of the area of study for Lanlacuni Bajo.
A number of ice cores have been obtained from Quelccaya, including two ice cores in 1983 which are the first ice cores obtained outside of the polar regions. Past climate states, including evidence of the Little Ice Age, regional droughts and wet periods with historical significance and past and recent El Niño events, have been reconstructed from data in these ice cores. The ice cap is also regularly monitored and a weather station operates on it.
An ice core is a core sample that is typically removed from an ice sheet or a high mountain glacier. Since the ice forms from the incremental buildup of annual layers of snow, lower layers are older than upper, and an ice core contains ice formed over a range of years. Cores are drilled with hand augers or powered drills; they can reach depths of over two miles (3.2 km), and contain ice up to 800,000 years old.
The Little Ice Age (LIA) was a period of cooling that occurred after the Medieval Warm Period. Although it was not a true ice age, the term was introduced into scientific literature by François E. Matthes in 1939. It has been conventionally defined as a period extending from the 16th to the 19th centuries, but some experts prefer an alternative timespan from about 1300 to about 1850.
El Niño is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific, including the area off the Pacific coast of South America. The ENSO is the cycle of warm and cold sea surface temperature (SST) of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific. El Niño phases are known to occur close to four years, however, records demonstrate that the cycles have lasted between two and seven years. During the development of El Niño, rainfall develops between September–November. The cool phase of ENSO is La Niña, with SSTs in the eastern Pacific below average, and air pressure high in the eastern Pacific and low in the western Pacific. The ENSO cycle, including both El Niño and La Niña, causes global changes in temperature and rainfall.
Quelccaya was much larger in the past, merging with neighbouring glaciers during the Pleistocene. A secondary expansion occurred during either the Antarctic Cold Reversal or the Younger Dryas; then with the beginning of the Holocene the ice cap shrank to a size smaller than today until about 6,000 - 5,000 years ago, when 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.
The Pleistocene is the geological epoch which lasted from about 2,580,000 to 11,700 years ago, spanning the world's most recent period of repeated glaciations. The end of the Pleistocene corresponds with the end of the last glacial period and also with the end of the Paleolithic age used in archaeology.
The Antarctic Cold Reversal (ACR) was an important episode of cooling in the climate history of the Earth during the deglaciation at the close of the last ice age. It illustrates the complexity of the climate changes at the transition from the Pleistocene to the Holocene Epochs.
The Younger Dryas was a return to glacial conditions, which temporarily reversed the gradual climatic warming after the last glacial maximum started receding around 20,000 BP. It is named after an indicator genus, the alpine-tundra wildflower Dryas octopetala, as its leaves are occasionally abundant in the late glacial, often minerogenic-rich, like the lake sediments of Scandinavian lakes.
After reaching a secondary highstand during the Little Ice Age, Quelccaya has been shrinking concomitant with human-caused global warming; 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 aggressive climate change mitigation measures, Quelccaya is likely to disappear during the 21st-22nd century.
Global warming is the long-term rise in the average temperature of the Earth's climate system. It is a major aspect of current climate change, and has been demonstrated by direct temperature measurements and by measurements of various effects of the warming. The term commonly refers to the mainly human-caused increase in global surface temperatures and its projected continuation. In this context, the terms global warming and climate change are often used interchangeably, but climate change includes both global warming and its effects, such as changes in precipitation and impacts that differ by region. There were prehistoric periods of global warming, but observed changes since the mid-20th century have been much greater than those seen in previous records covering decades to thousands of years.
A flood is an overflow of water that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrology and are of significant concern in agriculture, civil engineering and public health.
Climate models use quantitative methods to simulate the interactions of the important drivers of climate, including atmosphere, oceans, land surface and ice. They are used for a variety of purposes from study of the dynamics of the climate system to projections of future climate.
Quelccaya lies in the tropical highlands of southern Peru, ten kilometres (6.2 mi) northwest of Quelccaya lies the Cordillera Vilcanota mountain range, which it is sometimes considered to be part of; occasionally Quelccaya is also linked to the Cordillera Carabaya range. East of Quelccaya, the Andes drop off steeply to the Amazon basin and the Amazon rainforest is only 40 kilometres (25 mi) away; supposedly it can almost be seen from the summit of Quelccaya. 120 kilometres (75 mi) south of Quelccaya lies Lake Titicaca. Politically, Quelccaya is part of the Cuzco Department.within the eastern Andes in the Cordillera Oriental.
Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the west by the Pacific Ocean. Peru is a megadiverse country with habitats ranging from the arid plains of the Pacific coastal region in the west to the peaks of the Andes mountains vertically extending from the north to the southeast of the country to the tropical Amazon Basin rainforest in the east with the Amazon river.
The Cordillera Vilcanota is a mountain range located in Peru southeast of Cusco, on the boundary between the regions of Cusco and Puno. It extends between 13°39' and 14°29'S and 70°31' and 71°20'W for about 80 km. It includes 469 glaciers.
The Cordillera Carabaya lies in the Andes of Peru. It extends between 14°00' and 14°22'S and 69°38' and 70°19'W for about 75 km. It is located in the Puno Region, Carabaya Province, between the Vilcanota mountain range in the north-west and the Apolobamba mountain range in the south-east, north and north-east of Macusani.
The Andes in Peru, Ecuador and Bolivia are subdivided into several separate mountain ranges, many of which are glaciated above 5,000 metres (16,000 ft) elevation. Peru contains about 70% of all tropical glaciers, and Quelccaya together with ice bodies in New Guinea and the Rwenzori Mountains in Africa is one of the few tropical ice caps in the world, or even the only one; during glacial times there were more ice caps which may have resembled Quelccaya. In 1968, the existence of two smaller ice caps south of Quelccaya was reported.
The Andes or Andean Mountains are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The Andes also have the 2nd most elevated highest peak of any mountain range, only behind the Himalayas. The range is 7,000 km (4,300 mi) long, 200 to 700 km wide, and has an average height of about 4,000 m (13,000 ft). The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Chile and Argentina.
Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. Ecuador also includes the Galápagos Islands in the Pacific, about 1,000 kilometres (620 mi) west of the mainland. The capital city is Quito, which is also the largest city since 2018.
Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in western-central South America. The capital is Sucre, while the seat of government and financial center is located in La Paz. The largest city and principal industrial center is Santa Cruz de la Sierra, located on the Llanos Orientales, a mostly flat region in the east of the country.
The ice cap, which is also known as Quenamari, 40 kilometres (25 mi) from the ice cap, which can be reached within three days with pack animals. 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 12 kilometres (7.5 mi) from the ice margin. Quelccaya is part of the Quelccaya National Sanctuary, a protected area, and the local population considers Quelccaya an important apu , a holy spirit. The cities of Cuzco and Sicuani lie 130 kilometres (81 mi) northwest and 60 kilometres (37 mi) southwest of Quelccaya, respectively.lies in a remote area. A road gets within
Quelccaya consists of an ice cap which extends up to 17 kilometres (11 mi) in north-south, 3–5 kilometres (1.9–3.1 mi) east-west direction between 5,200–5,700 metres (17,100–18,700 ft) elevation; it is thus a low-elevation ice cap by tropical standards but Quelccaya still rises above its neighbourhood. Unusually for glaciers the ice lies on a flat surface rather than on a mountain peak; the highest summit in the area of the ice cap is known as Joyllor Puñuna and reaches 5,743 metres (18,842 ft) elevation. Snowline elevation has been variously estimated at 5,250–5,300 metres (17,220–17,390 ft).
The ice forms a relatively thin 5,645 metres (18,520 ft) elevation. Close to the summit the ice is 100–150 metres (330–490 ft) thick, with a maximum thickness of about 200 metres (660 ft), and a total volume of over 1 cubic kilometre (0.24 cu mi). In terms of surface area, between 1975-2010, Quelccaya covered an area of 50.2 square kilometres (19.4 sq mi), decreasing over time; by 2009 it had shrunk to 42.8 square kilometres (16.5 sq mi) and was thus smaller than the ice on Coropuna volcano also in southern Peru, which is not declining as quickly. Previously, Quelccaya was long considered the largest ice area of the tropics.and flat structure with several ice domes, whose number is variously given as two, three or four; the highest of which reaches
The ice of the ice cap flows radially outward. 50 metres (160 ft) and often display banding in the form of 0.5–1 metre (1 ft 8 in–3 ft 3 in) thick layers, flutes or grooves and icicles. Over interfluves, the border of the ice cap is embayed. On the southern and western side parts of the ice cap end at steep cliffs like they are found in polar regions. From the ice falls, short glaciers up to 2 kilometres (1.2 mi) long descend to elevations of 4,900–5,100 metres (16,100–16,700 ft), with lower elevations reached on the eastern side. The largest of these glaciers is the Qori Kalis Glacier, which extends from the northern sector of Quelccaya westwards; in general there is a contrast between lobe-like glaciers that emanate into the shallow valleys of the south-western side of Quelccaya and steeper glaciers with crevasses that descend into deeper valleys elsewhere around the ice cap. On the southern side of the ice cap, the ice cap ends in four cirques with icefalls at their head and four sets of moraines downstream. Melting at Quelccaya occurs at the bottom and at the margins of the ice cap, where meltwater is discharged.Spectacular ice cliffs form most of the margin of Quelccaya, they reach heights of
Conditions on the ice cap are polar, 0.5–1 centimetre (0.20–0.39 in). Towards the summit, the plates are replaced with column- or less commonly needle-shaped crystals, and eventually by dendritic crystals on the summit. On the summit there are lenses of ice, probably from melting.and the ice surface has structures such as penitentes and sastrugi. Penitentes occur especially at lower elevations on the ice cap; at higher elevations they become smaller and eventually vanish, replaced with plate-shaped ice crystals with sizes of
Reconnaissance in 1974-1977 found glacier caves in the Quelccaya ice cap,including elongated caves where the ice has overrun an obstacle thus creating an empty space, and crevasse-associated caves that form when they roof over. Caves have fluted walls and contain cave corals, flowstones, stalactites and stalagmites; these speleothems are formed by ice.
The ice cap contains temperate iceand in 2003 the ice had similar temperatures through its whole thickness while according to a 1978 publication temperatures in the ice and its density increased with depth. Temperatures of the glaciers at the base of Quelccaya reach the pressure melting point, except at some locations. Radar data indicate the presence of water pockets in the ice.
The ice of Quelccaya does not appear to have been particularly erosive during the late Holocene, as indicated by the preservation of plants underneath of it;it is possible that the ice cap was in a temperate and erosive state when it was retreating such as during the early Holocene and cold-based and thus not very erosive during the expansion of the late Holocene. Cold-based glaciers do not produce much meltwater and do not erode the ground they rest on as they fluctuate.
Especially during the dry season, iron, silica and sodium accumulate on the ice cap in the form of microparticles, most of it originating in the Altiplano and possibly the sea.Sulfate and nitrate are also found and may originate in the Amazon; their concentrations at Quelccaya resemble these of snow in Andean regions. Particles are coarser when they are deposited during the wet season, perhaps due to wet-season storms. Diatoms, insects, their bodyparts and pollen have also been found in the ice.
During winter, the albedo of the ice is about 80%.As reported in 2013, 1979 and 1981, there is little energy available at the top of the Quelccaya ice cap as outgoing and incoming radiation are essentially balanced. This radiation pattern, along with temperature and wind, influence the appearance of the surface of the Quelccaya ice. Away from the ice cap, solar radiation is capable of quickly evaporating any snow.
The plateau that Quelccaya rises from features smooth bedrockwith a northeast to southwest slope and is relatively flat, meaning that even a small rise of the freezing level will result in a large change in the ice. The plateau is surrounded by an escarpment and a number of valleys emanate from the plateau.
On the western side of Quelccaya these valleys include the Qori Kalis valley northwest of the ice cap, Challpa Cocha valley south of Qori Kalis, 0.5 kilometres (0.31 mi) wide and flat Huancané and its tributary the "South Fork" valley south of Challpa Cocha valley. The Huancané valley runs southwestwards away from Quelccaya and is occupied by the Huancané River. Moraines from glaciers lie in the valleys radiating from the ice cap and contain alluvial deposits and peat bogs, ponds and wetlands within depressions. Clay and peat are also found incorporated in moraines, where peat has been exposed by erosion during floods. Blocky boulders with sizes of up to 7 metres (23 ft) dot the valley floors.the
West of Quelccaya lies a high plain that is formed by glacial outwash and till.The terrain features landforms such as drift deposits, lakes, moraines and moraine-dammed lakes, outwash fans, peat bogs, rocks bearing glacial striations, streams and wetlands.
A number of lakes occur in the region of Quelccaya and the Cordillera Vilcanota, including Sibinacocha south of the Cordillera Vilcanota. Among the lakes close to the Quelccaya ice cap area:
Quelccaya lies on a plateau is formed by ignimbrites/welded tuffs, which are of rhyolitic composition although the occurrence of andesite has also been reported. The rocks were emplaced during the Miocene 6 million years ago and only little erosion has taken place since then. The volcanics may correlate with the Quenamari volcanics farther east. West of Quelccaya a Holocene normal fault runs in north-south direction, part of the Ocongate fault system; this fault system extends across the Cordillera Vilcanota and has offset moraines, indicating it is active.
Annual precipitation at Quelccaya and the neighbouring Cordillera Vilcanota is about 0.8–1.0 metre per year (2.6–3.3 ft/a), with most of it originating from the Amazon and falling during austral summer during the summer monsoon when high insolation leads to intense convection and showers. Most snowfall occurs during the passage of cold fronts and cold air inclusions and the net amount is a function of the duration of the wet season. Overall, annually about 1,150 millimetres (45 in) of snow water equivalent accumulate on Quelccaya, in the form of about 2–3 metres (6 ft 7 in–9 ft 10 in) snow with rainfall sometimes occurring near its margins and also near its summit. This is much wetter than most of the tropical Andes, a consequence of Quelccaya's proximity to the Amazon. This moisture originates from the Atlantic Ocean and is transported to Quelccaya by trade winds; a temperature inversion and blocking effects of coastal topography prevent moisture from the Pacific Ocean from reaching the ice cap.
Unlike precipitation, temperatures are relatively stable throughout the year −4.2 °C (24.4 °F) -−4.8 °C (23.4 °F) Assuming a constant lapse rate mean temperatures of −3.3 °C (26.1 °F) (−6.3–0.9 °C (20.7–33.6 °F)) and −0.5 °C (31.1 °F) (2.9 – −3.1 °C (37.2–26.4 °F)) have been inferred for its margin during the dry and wet seasons, respectively. As a consequence of global warming, temperatures on the summit of Quelccaya sometimes rise above freezing, accelerating the shrinkage of the ice cap.with day-night temperature differences exceeding seasonal ones. Temperatures at the top of Quelccaya are inferred to be about
Winds are strongest during the dayand mostly blow from the west, except during the rain season when they also come from the east or north-east. The ice cap itself generates its own downslope katabatic wind, which blows over the ice and quickly peters out with distance from the ice margin.
The climate is influenced by the El Niño-Southern Oscillationand by the position of the Intertropical Convergence Zone; during El Niño years precipitation is much less as westerly winds suppress the transport of easterly moisture to Quelccaya. During the strong 2014-16 El Niño event, there was actually a net decrease in snow height on Quelccaya. Further, during El Niño there is a "front-loading" of precipitation with an earlier onset of the monsoon and decreased precipitation in its middle and late phase. Temperatures are also modulated by El Niño events, during which an increase is observed although winter temperatures decrease.
Ice cores show evidence of past climate variability, such as increased precipitation between 1870-1984, 1500-1720, 760-1040 and with drought such as between 1720-1860, 1250-1310, 650-730, 570-610 and 540-560.One of these wet periods has been correlated to the Medieval Climate Anomaly 1,000 – 700 years ago, while drought periods have been linked to cultural changes in the Moche culture and the collapse of Tiwanaku. However, apart of precipitation fluctuations climate at Quelccaya has been stable over the past 1500 years and precipitation has not fluctuated significantly over the past decades.
The terrain west of Quelccaya is sparsely vegetated 4,300 metres (14,100 ft) elevation it is defined as "super-Puna", and consists of herb and shrubs such as Plantago and trees like Polylepis which grow to the ice cap and often have a krummholz appearance. The only human use of the area is livestock grazing but agriculture has also been reported.with high elevation tundra vegetation. The vegetation in the region is known as puna, which is a kind of grassland; above
Aquatic plants are found in lakes.The glacial runoff and precipitation guarantee an ample water supply, leading to the development of wetlands known as bofedales and peat; Distichia muscoides is the dominant plant in the bofedales and these wetlands are hotspots of biodiversity. Tussock grasses have been expanding in the area. Other plants include Festuca orthophylla , jarava ichu and nettles; in total there are over fifty plant species. Lichens grow on rocks; 23 lichen species have been identified at Quelccaya.
Among animals are 60 species of birds,mammals in the surrounding region such as Andean foxes, deers, wildcats, vicuñas and vizcachas, while tadpoles and water fleas occur in lakes. Two birds, the white-winged diuca finch and the white-fronted ground tyrant are known to nest on the Quelccaya ice cap, mostly within cavities in the ice that are barely accessible to humans. The diuca finch is known to nest on ice elsewhere in the tropical Andes, and other bird species might also nest on the Quelccaya ice. Other than this finch, only emperor penguins are known to nest on ice; ice is an ill-suited environment for the raising of young birds and Quelccaya presents additional challenges linked to its high elevation. Other birds also nest in protected locations in the general Quelccaya area and some species also roost on the ice.
Glaciers in the region have been monitored since the 1970s. Sediment cores in lakes and peat, soil formation and cosmogenic isotope dating have been used to infer past states of the ice cap,and since 1976 Quelccaya is regularly reconnoitered. An automated weather station that records various meteorological parametres was installed in 2003 and reinstalled in 2004 after vandalism, and snow is sampled annually although continuous precipitation records do not exist. The American paleoclimatologist Lonnie Thompson and the Ohio State University have been monitoring Quelccaya since 1974 and the ice cap has been investigated for its glaciology and for both its past and present climate.
The layered appearance of the Quelccaya ice cap at its margins suggested to scientists that it could be used to obtain ice cores with annual resolution. 163.6 metres (537 ft) and 154.8 metres (508 ft) long ice cores from the central area of the Quelccaya ice cap. The ice cores were drilled with the help of a solar-powered ice drill specifically developed for the purpose of drilling into Quelccaya; it was developed because other power sources could not be brought onto the ice cap. These ice cores were then investigated by the Byrd Polar Research Center also at Ohio State University and cover a timespan of 1,500 and 1,350 years with the longer ice core going back farther in time; it goes back to 470 AD. Another, shorter ice core measuring 15 metres (49 ft) length and spanning 8 years was obtained in 1976, others followed in 1979, 1991, 1995, 2000, 2003 and 2014.After a summer field program that lasted between 1976 and 1984, in 1983 Lonnie Thompson and a team from the Ohio State University obtained two
Dust layers deposited during the dry seasonallow the determination of yearly layers, which characteristically thin downward. Additionally, volcanic ash deposited by the 1600 Huaynaputina eruption has been used to date the ice core.
A number of research findings have been made with the Quelccaya ice core:
The results of the Quelccaya ice core are widely used to reconstruct past climate states.Quelccaya is the first ice cap from which old ice cores have been obtained that lies outside of the polar regions, and the first annually resolved such record from the tropical Andes; it demonstrated the usefulness of tropical ice for ice core studies and has been called a "major step" in the sampling of high elevation ice in the world. It was selected as a site for extra-polar ice core research as it is located in the sparsely investigated tropics and Quelccaya lies at higher elevation than Puncak Jaya in Indonesia or the Rwenzori Mountains in Africa; thus the ice is less disturbed by percolating meltwater. Because of the lack of seasonal temperature variations and of synoptic weather patterns, tropical glaciers may primarily record secular climate change.
Moraines deposited by older glaciers indicate that during the Pleistocene and Holocene glaciers covered larger areas, 4,500 metres (14,800 ft) as the equilibrium line altitude decreased by 360 metres (1,180 ft); this change in the equilibrium line altitude is considerably less than the decrease found elsewhere in the Peruvian Andes and may reflect topographical controls on glacier expansion. The connection with the Vilcanota ice cap may have occurred during the last glacial maximum.such as the outwash- and till-covered plain west of Quelccaya, and connected with the Cordillera Vilcanota ice cap, covering the area with sandy drift derived from ignimbrites. During the maximum extent the ice reached down to elevations of
No direct evidence of glacier expansions in times preceding marine isotope stage 4 remainalthough an early glaciation of Quelccaya had ice advance to twice the distance it assumed during the Wisconsin glaciation. Maximum extent occurred either about 20,000 years ago or between 28,000 - 14,000 years ago. The maximum extent occurred during the Weichselian-Wisconsin glaciation and within marine isotope stage 2.
By 13,600 - 12,800 years ago Quelccaya had retreated concomitant with global glacier shrinkage at the end of the last glacial maximum. 12,500 years ago a readvance occurred, linked to a colder and wetter climate during the Younger Dryas. 12,400 years ago retreat recommenced and by 11,800-11,600 years ago the ice cap had reached a Little Ice Age-/modern-like extent.Another proposed chronology indicates a glacier expansion between 13,300 years ago and ending by 12,900 years ago, with Quelccaya reaching a size not much larger than during the Holocene by 12,800 years ago. A final scenario envisages an advance between 12,700 - 11,000 years ago. There might have been two readvances, one in the early Younger Dryas and the other around 12,600 years ago. A halt in retreat or an actual advance of Quelccaya may or may not have occurred at the same time as Lake Tauca existed on the Altiplano, and it is possible that the retreat occurred during the middle Younger Dryas.
During the Holocene, Quelccaya did not expand farther than 1 kilometre (0.62 mi) from its present position and early Holocene moraines have not been found. It is possible that during the mid-Holocene Quelccaya was ice-free altogether, peat deposits and ice cores indicate that it was reduced or even absent during that time. Until either 7,000 years ago or between at least 7,000 years ago and about 5,000 years ago, plants grew at its margins, including cushion mire vegetation. This shrinkage may relate to a warmer and drier climate at that time.
5,000 years ago, the ice cap began to grow again at a time of global climate change, which included the drying of the Sahara at the end of the African humid periodand wetter and colder conditions in the extratropics. This re-expansion was part of the global neoglacial; this pattern of a larger ice cap during the late Holocene than the early is similar to that of Northern Hemisphere glaciers and may reflect Northern Hemisphere insolation. The ice cap reached its Holocene maximum extent during the Little Ice Age.
About 4,000 years ago, a new retreat occurred under the influence of warmer and drier climates, 1 kilometre (0.62 mi) past its current limit, and about 0.8 kilometres (0.50 mi) past its limit 1,600 years ago.and another shrinkage also occurred between 3,000 - 1,500 years ago. Alternatively, 3,400 and 1,500 years before present the ice cap may have extended
Multiple moraines have been dated in the Huancané valley. 8 kilometres (5.0 mi), 4 kilometres (2.5 mi) and 1 kilometre (0.62 mi) from the 2002 ice margin and are also known as Huancane I, Huancane II and Huancane III, names which are sometimes applied to the glacial advances themselves. The moraines in the valley are terminal moraines and consist of sets of ridges up to 1 kilometre (0.62 mi) wide; boulders found on the Huancane III moraines have fresher appearances than these on the other moraines. Huancane III has also been subdivided into Huancane IIIa, IIIb and IIIc and Huancane II into Huancane IIa, IIb and IIc. These are all regressional moraines, as by the time of the emplacement of Huancane moraines, Quelccaya was shrinking and was already disconnected from the ice on the Cordillera Vilcanota. Finally, there is a set of moraines farther down the Huancané valley that appears to be the oldest. Equivalents of the Huancane moraines have been identified outside of the Huancané valley.Three separate glacial stages have been identified here, H1, H2 and H3, with H3 being the longest glacier, H1 the shortest and H2 in between the two. They have left moraines
About 16 late Holocene moraines are also found downstream of Qori Kalis glacier,with the largest advance occurring before 520 ± 60 years ago, followed by a progressive retreat and a readvance about 350 – 300 years ago. Similar glacier advance and retreat patterns have been observed in the Cordillera Blanca and Cordillera Vilcabamba in Peru, the Bolivian Andes and also in Patagonia and New Zealand and appear to reflect cold climate oscillations.
In general, estimating the ages of moraines is difficult. A retreating glacier will deposit successive moraines but an advancing one can destroy older moraines less extensive than the glacier advance. Dates obtained from organic material behind a moraine may be considerably younger than the moraine as its development occurs with a lag from deglaciation, while organic matter in or underneath a moraine may be considerably older.Changes in sediment fluxes to lakes west of Quelccaya appear to reflect advances and retreats of glaciers, with meltwater formed during retreats increasing sediment fluxes.
The extent of the Quelccaya ice cap does not appear to correlate with the amount of precipitation occurring on the ice capexcept in particular cases; temperature effects appear to dominate and warmer and wetter climates have been associated with retreat. This dominance of temperature over precipitation in determining ice cap size and glacier length has been replicated by modelling. Interannual climate variability does not have substantial effects on the extent of the ice cap.
The glaciers are melting at increasing rates, with rapid deglaciation underway during the late 20th century 0.57 ± 0.1 square kilometres per year (0.220 ± 0.039 sq mi/a) with a loss of 30% of its area between 1979 and 2014. Between 1990 and 2009, a southeastern branch of the ice cap disappeared altogether; parts of the northwestern ice cap have separated from the main ice body and by 2011 the retreat had reduced Quelccaya to a size it did not have since 6,000 years ago. There is some variation between retreat rates measured by different researchers as the Quelccaya ice cap is differently defined and due to differences between extents measured in seasons with and without snow cover. True fluctuations also occur, such as an advance of part of Quelccaya's southern margin reported in 1977 which bulldozed peat deposits, a pause of the Qori Kalis glacier between 1991-1993 probably linked with the global cooling caused by the Pinatubo eruption in 1991, a slow-down in the mid-2000s and an overall higher rate of retreat since 2000.at a rate that is comparable to or exceeds that of postglacial retreat rates. Between 1980 and 2010, the ice cap shrank at a rate of
The Qori Kalis outlet glacier has been observed since 1963, 6 metres per year (20 ft/a) and between 1991 and 2005 by about 60 metres per year (200 ft/a). The retreat has been accompanied by a thinning and volume loss of the ice cap, increasing from 290,000 cubic metres per year (10,000,000 cu ft/a) between 1963-1978 over 1,310,000 cubic metres per year (46,000,000 cu ft/a) between 1978-1983 to 2,200,000 cubic metres per year (78,000,000 cu ft/a) between 1983-1991. The rate of retreat is higher than at the end of the last ice age and the glacier responds quickly to climate alterations.and between 1963 and 1978 retreated by about
This retreat has been observed at other tropical glaciers as well and is linked to increasing global temperatureswhich are in turn caused by industrial greenhouse gas emissions. This warming is unprecedented by the standards of the late Holocene.
Meltwater lakesand proglacial lakes have formed in front of Qori Kalis glacier and other Quelccaya glaciers and expanded in size. These lakes could be sources of future glacial lake outburst floods, although the sparse population of the area mitigates against this hazard; one such flood occurred in March 2006 and drowned some alpaca. In addition, some lakes have drained and the course of streams has changed from the glacier retreat.
The freezing level regularly rises above the summit of Quelccaya,and in recent ice cores, meltwater infiltration has become apparent, to the point that oxygen isotope ratios are no longer preserved in the ice; while this infiltration has smoothened the record only to a certain depth, it illustrates the threat that climate change is creating for the existence of climate archives in ice cores. Alpine life is quickly advancing into the terrain left by ice, and the retreat has exposed plants that had been overrun during a glacier expansion that occurred 5,000 years ago.
Projected climate change is expected to involve a further 3–5 °C (5.4–9.0 °F) in the central Andes, with higher warming occurring at higher elevations. In "business-as-usual" climate change scenarios, during the 21st century the equilibrium line altitude will rise above the top of the ice cap; once the equilibrium line altitude has reached the top of the ice cap, the entire cap will become a zone of net ice loss and Quelccaya will disappear. In scenarios that include aggressive mitigation measures, the ice cap may persist, while intermediate scenarios predict a loss of the ice cap in the 22nd century. There is however some uncertainty owing to e.g. changes in precipitation, such as a potential future decrease thereof.
Glacial meltwater is an important source of water especially in dry years and during the dry season,including in the Altiplano and in the hyperarid coasts of Peru. For example, about 80% of Peru's hydropower sources are buffered by glacial meltwater. Avalanches and floods from glaciers have killed over 35,000 people and glacial retreat will likely increase their incidence. Enhanced melting may be contributing to streamflow, and past meltwater flows might have contributed to the formation of large lakes in the Altiplano.
Most of Quelccaya borders on the Inambari River watershed, especially on the east and south; the western parts of the ice cap conversely border on the Vilcanota River/Urubamba River catchmentof which it is an important part. Clockwise the Rio Chimboya, the Quebrada Jetun Cucho, the Quebrada Queoñani, the Rio Quelcaya Mayu, an unnamed river, the Rio Huancané, the Rio Ritiananta and the Quebrada Accoaysana Pampa emanate from the ice cap. The first four rivers eventually converge into the westward flowing Rio Corani, a tributary of the northward-flowing Rio Ollachea/Rio Sangabán which eventually ends into the Inambari River; the last four rivers eventually converge into the southwards-flowing Rio Salcca, which then turns west and ends into the Vilcanota River.
Quelccaya is the largest glacierized area in the watershed of the San Gabán hydropower plantand also of the catchment Rio Vilcanota watershed; its water is used by the Cusco Region. The water is used for both irrigation and hydropower production. The population in the region is for the most part rural with low socioeconomic status, which makes it highly vulnerable to the effects of climate change. Additionally, glaciers have important religious and social value for the local communities.
The Holocene is the current geological epoch. It began approximately 11,650 cal years before present, after the last glacial period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch.
An ice age is a long period of reduction in the temperature of the Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and greenhouse periods, during which there are no glaciers on the planet. Earth is currently in the Quaternary glaciation, known in popular terminology as the Ice Age. Individual pulses of cold climate within an ice age are termed "glacial periods", and intermittent warm periods within an ice age are called "interglacials" or "interstadials", with both climatic pulses part of the Quaternary or other periods in Earth's history.
The Last Glacial Period (LGP) occurred from the end of the Eemian to the end of the Younger Dryas, encompassing the period c. 115,000 – c. 11,700 years ago. This most recent glacial period is part of a larger pattern of glacial and interglacial periods known as the Quaternary glaciation extending from c. 2,588,000 years ago to present. The definition of the Quaternary as beginning 2.58 Ma is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Ma, in the mid-Cenozoic. The term Late Cenozoic Ice Age is used to include this early phase.
The Byrd Polar and Climate Research Center (BPCRC) is a polar, alpine, and climate research center at The Ohio State University founded in 1960.
The Last Glacial Maximum (LGM) was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Vast ice sheets covered much of North America, Northern Europe, and Asia and profoundly affected Earth's climate by causing drought, desertification, and a large drop in sea levels. According to Clark et al, growth of ice sheets commenced 33,000 years ago and maximum coverage was between 26,500 years and 19-20,000 years ago, when deglaciation commenced in the Northern Hemisphere, causing an abrupt rise in sea level. Decline of the West Antarctica ice sheet occurred between 14,000 and 15,000 years ago, consistent with evidence for another abrupt rise in the sea level about 14,500 ka ago.
Viedma is a subglacial volcano located below the ice of the Southern Patagonian Ice Field, an area disputed between Argentina and Chile. The 1988 eruption deposited ash and pumice on the ice field and produced a mudflow that reached Viedma Lake. The exact position of the edifice is unclear, both owing to the ice cover and because the candidate position, the "Viedma Nunatak", does not clearly appear to be of volcanic nature. Numerous ash layers in the Viedma lake indicate numerous past eruptions.
The Holocene Climate Optimum (HCO) was a warm period during roughly the interval 9,000 to 5,000 years BP, with a thermal maximum around 8000 years BP. It has also been known by many other names, such as Altithermal, Climatic Optimum, Holocene Megathermal, Holocene Optimum, Holocene Thermal Maximum, Hypsithermal, and Mid-Holocene Warm Period.
The Holocene glacial retreat is a geographical phenomenon that involved the global deglaciation of glaciers that previously had advanced during the Last Glacial Maximum. Ice sheet retreat initiated ca. 19,000 years ago and accelerated after ca. 15,000 years ago. The Holocene, starting with abrupt warming 11,700 years ago, resulted in rapid melting of the remaining ice sheets of North America and Europe. The retreat of glaciers altered landscapes in many ways and is currently still acting as a result of climate change.
Lonnie Thompson, is an American paleoclimatologist and Distinguished University Professor in the School of Earth Sciences at The Ohio State University. He has achieved global recognition for his drilling and analysis of ice cores from mountain glaciers and ice caps in the tropical and sub-tropical regions of the world. He and his wife, Ellen Mosley-Thompson, run the ice core paleoclimatology research group at the Byrd Polar Research Center.
The 4.2-kiloyear BP aridification event was one of the most severe climatic events of the Holocene epoch. It defines the beginning of the current Meghalayan age in the Holocene epoch. Starting in about 2200 BC, it probably lasted the entire 22nd century BC. It has been hypothesised to have caused the collapse of the Old Kingdom in Egypt as well as the Akkadian Empire in Mesopotamia, and the Liangzhu culture in the lower Yangtze River area. The drought may also have initiated the collapse of the Indus Valley Civilisation, with some of its population moving southeastward to follow the movement of their desired habitat, as well as the migration of Indo-European speaking people into India.
In climatology, the 8.2-kiloyear event was a sudden decrease in global temperatures that occurred approximately 8,200 years before the present, or c. 6,200 BC, and which lasted for the next two to four centuries. It defines the start of the Northgrippian age in the Holocene epoch. Milder than the Younger Dryas cold spell before it but more severe than the Little Ice Age after it, the 8.2-kiloyear cooling was a significant exception to general trends of the Holocene climatic optimum. During the event, atmospheric methane concentration decreased by 80 ppb, an emission reduction of 15%, by cooling and drying at a hemispheric scale.
Bond events are North Atlantic ice rafting events that are tentatively linked to climate fluctuations in the Holocene. Eight such events have been identified. Bond events were previously believed to exhibit a quasi c. 1,500-year cycle, but the primary period of variability is now put at c. 1,000 years.
Deglaciation describes the transition from full glacial conditions during ice ages, to warm interglacials, characterized by global warming and sea level rise due to change in continental ice volume. Thus, it refers to the retreat of a glacier, an ice sheet or frozen surface layer, and the resulting exposure of the Earth's surface. The decline of the cryosphere due to ablation can occur on any scale from global to localized to a particular glacier. After the Last Glacial Maximum, the last deglaciation begun, which lasted until the early Holocene. Around much of Earth, deglaciation during the last 100 years has been accelerating as a result of climate change, partly brought on by anthropogenic changes to greenhouse gases.
Bjørn Grothaug Andersen was a Norwegian professor of Quaternary geology and glaciology who made foundational contributions to glacial geology and the understanding of climate change.
The Northern Ice Field is near the summit of Mount Kilimanjaro in Tanzania, on the west slope of the peak. The Northern Ice Field and Eastern Ice Fields were connected to the Southern Ice Field and formed part of a continuous body of glacial ice atop Mount Kilimanjaro when first scientifically examined in 1912. By 1962 the Southern Ice Field separated from the Northern Ice Field and then by 1975 the Eastern Ice Field did as well. In 1912, the glaciated areas atop Mount Kilimanjaro covered 11.40 square kilometres (4.40 sq mi); by 2011 this had been reduced to 1.76 square kilometres (0.68 sq mi), an 85 percent loss. At one time, ice flowing off the Northern Ice Field fed numerous glaciers, including, north to south, the Credner, Drygalski, Great Penck and Little Penck Glaciers.
The Carbajal Valley is a valley in the Fuegian Andes of southern Tierra del Fuego Province, Argentina. The Carbajal valley is approximately 20 kilometres (12 mi) long, running west to east, between the Alvear mountain range to the north and the Vinciguerra range to the south. Andes peak heights in the region are generally less than 1,250 metres (4,100 ft) above sea level.
Lake Tauca is a former lake in the Altiplano of Bolivia. It is also known as Lake Pocoyu for its constituent lakes: Lake Poopó, Salar de Coipasa and Salar de Uyuni. The lake covered large parts of the southern Altiplano between the Eastern Cordillera and the Western Cordillera, covering an estimated 48,000 to 80,000 square kilometres of the basins of present-day Lake Poopó and the Salars of Uyuni, Coipasa and adjacent basins. Water levels varied, possibly reaching 3,800 metres (12,500 ft) in altitude. The lake was saline. The lake received water from Lake Titicaca, but whether this contributed most of Tauca's water or only a small amount is controversial; the quantity was sufficient to influence the local climate and depress the underlying terrain with its weight. Diatoms, plants and animals developed in the lake, sometimes forming reef knolls.
The African humid period (AHP) is a climate period in Africa during the Holocene during which northern Africa was wetter than today. It was caused by changes in Earth's orbit around the Sun, and involved changes in vegetation and dust in the Sahara that altered the African monsoon, the disappearance of much of the Sahara desert which was replaced by grassy vegetation, trees and lakes and the settlement of the former desert by various animals and humans, who lived as hunter-gatherers. It has had profound effects on present-day Africa such as the birth of the Pharaonic civilization and the pyramids and potentially also the development of widespread Golden Age myths.