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Last Glacial Period

Topic: Earth

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"Last glacial" redirects here. For the period of maximum glacier extent during this time, see Last Glacial Maximum.
Short description: Period of major glaciations of the northern hemisphere (115,000–12,000 years ago)
Chronology of climatic events of importance for the last glacial period (about the last 120,000 years)

The Last Glacial Period (LGP), also known colloquially as the Last Ice Age or simply Ice Age,[1] 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.

The LGP is part of a larger sequence of glacial and interglacial periods known as the Quaternary glaciation which started around 2,588,000 years ago and is ongoing.[2] The definition of the Quaternary as beginning 2.58 million years ago (Mya) is based on the formation of the Arctic ice cap. The Antarctic ice sheet began to form earlier, at about 34 Mya, in the mid-Cenozoic (Eocene–Oligocene extinction event). The term Late Cenozoic Ice Age is used to include this early phase.[3] The previous ice age, the Saale glaciation, which ended about 128,000 years ago, was more severe than the Last Glacial Period in some areas such as Britain, but less severe in others.

During this last glacial period, alternating episodes of glacier advance, and retreat occurred. Within the last glacial period, the Last Glacial Maximum was between 26,000 and 20,000 years BP. While the general pattern of global cooling and glacier advance was similar, local differences in the development of glacier advance and retreat make comparing the details from continent to continent difficult (see picture of ice core data below for differences). Around 12,800 years ago, the Younger Dryas, the most recent glacial epoch, began, a coda to the preceding 100,000-year glacial period. Its end about 11,550 years ago marked the beginning of the Holocene, the current geological epoch.

From the point of view of human archaeology, the LGP falls in the Paleolithic and early Mesolithic periods. When the glaciation event started, Homo sapiens was confined to lower latitudes and used tools comparable to those used by Neanderthals in western and central Eurasia and by Denisovans and Homo erectus in Asia. Archaeological and genetic data suggest that the source populations of Paleolithic humans survived the LGP in sparsely wooded areas, and dispersed through areas of high primary productivity, while avoiding dense forest cover.[4]

Artist's impression of the last glacial period at glacial maximum[5]

Origin and definition

The LGP is often colloquially referred to as the "last ice age", though the term ice age is not strictly defined, and on a longer geological perspective, the last few million years could be termed a single ice age given the continual presence of ice sheets near both poles. Glacials are somewhat better defined, as colder phases during which glaciers advance, separated by relatively warm interglacials. The end of the last glacial period, which was about 10,000 years ago, is often called the end of the ice age, although extensive year-round ice persists in Antarctica and Greenland. Over the past few million years, the glacial-interglacial cycles have been "paced" by periodic variations in the Earth's orbit via Milankovitch cycles.

The LGP has been intensively studied in North America, northern Eurasia, the Himalayas, and other formerly glaciated regions around the world. The glaciations that occurred during this glacial period covered many areas, mainly in the Northern Hemisphere and to a lesser extent in the Southern Hemisphere. They have different names, historically developed and depending on their geographic distributions: Fraser (in the Pacific Cordillera of North America), Pinedale (in the Central Rocky Mountains), Wisconsinan or Wisconsin (in central North America), Devensian (in the British Isles),[6] Midlandian (in Ireland), Würm (in the Alps), Mérida (in Venezuela), Weichselian or Vistulian (in Northern Europe and northern Central Europe), Valdai in Russia and Zyryanka in Siberia, Llanquihue in Chile , and Otira in New Zealand. The geochronological Late Pleistocene includes the late glacial (Weichselian) and the immediately preceding penultimate interglacial (Eemian) period.

Overview

Vegetation types at time of Last glacial maximum
Last glacial period, as seen in ice core data from Antarctica and Greenland

Northern Hemisphere

Canada was almost completely covered by ice, as was the northern part of the United States , both blanketed by the huge Laurentide Ice Sheet. Alaska remained mostly ice free due to arid climate conditions. Local glaciations existed in the Rocky Mountains and the Cordilleran ice sheet and as ice fields and ice caps in the Sierra Nevada in northern California .[7] In northern Eurasia, the Scandinavian ice sheet once again reached the northern parts of the British Isles, Germany , Poland , and Russia, extending as far east as the Taymyr Peninsula in western Siberia.[8] The maximum extent of western Siberian glaciation was reached by about 18,000 to 17,000 BP, thus later than in Europe (22,000–18,000 BP)[9] Northeastern Siberia was not covered by a continental-scale ice sheet.[10] Instead, large, but restricted, icefield complexes covered mountain ranges within northeast Siberia, including the Kamchatka-Koryak Mountains.[11][12]

The Arctic Ocean between the huge ice sheets of America and Eurasia was not frozen throughout, but like today, probably was covered only by relatively shallow ice, subject to seasonal changes and riddled with icebergs calving from the surrounding ice sheets. According to the sediment composition retrieved from deep-sea cores, even times of seasonally open waters must have occurred.[13]

Outside the main ice sheets, widespread glaciation occurred on the highest mountains of the Alpide belt. In contrast to the earlier glacial stages, the Würm glaciation was composed of smaller ice caps and mostly confined to valley glaciers, sending glacial lobes into the Alpine foreland. Local ice fields or small ice sheets could be found capping the highest massifs of the Pyrenees, the Carpathian Mountains, the Balkan mountains, the Caucasus, and the mountains of Turkey and Iran.[14]

In the Himalayas and the Tibetan Plateau, there is evidence that glaciers advanced considerably, particularly between 47,000 and 27,000 BP,[15] but the exact ages,[16][17] as well as the formation of a single contiguous ice sheet on the Tibetan Plateau, is controversial.[18][19][20]

Other areas of the Northern Hemisphere did not bear extensive ice sheets, but local glaciers were widespread at high altitudes. Parts of Taiwan, for example, were repeatedly glaciated between 44,250 and 10,680 BP[21] as well as the Japanese Alps. In both areas, maximum glacier advance occurred between 60,000 and 30,000 BP.[22] To a still lesser extent, glaciers existed in Africa, for example in the High Atlas, the mountains of Morocco, the Mount Atakor massif in southern Algeria, and several mountains in Ethiopia. Just south of the equator, an ice cap of several hundred square kilometers was present on the east African mountains in the Kilimanjaro massif, Mount Kenya, and the Rwenzori Mountains, which still bear relic glaciers today.[23]

Southern Hemisphere

Glaciation of the Southern Hemisphere was less extensive. Ice sheets existed in the Andes (Patagonian Ice Sheet), where six glacier advances between 33,500 and 13,900 BP in the Chilean Andes have been reported.[24] Antarctica was entirely glaciated, much like today, but unlike today the ice sheet left no uncovered area. In mainland Australia only a very small area in the vicinity of Mount Kosciuszko was glaciated, whereas in Tasmania glaciation was more widespread.[25] An ice sheet formed in New Zealand, covering all of the Southern Alps, where at least three glacial advances can be distinguished.[26] Local ice caps existed in the highest mountains of the island of New Guinea, where temperatures were 5 to 6 °C colder than at present.[27][28] The main areas of Papua New Guinea where glaciers developed during the LGP were the Central Cordillera, the Owen Stanley Range, and the Saruwaged Range. Mount Giluwe in the Central Cordillera had a "more or less continuous ice cap covering about 188 km2 and extending down to 3200-3500 m".[27] In Western New Guinea, remnants of these glaciers are still preserved atop Puncak Jaya and Ngga Pilimsit.[28]

Small glaciers developed in a few favorable places in Southern Africa during the last glacial period.[29][upper-alpha 1][upper-alpha 2] These small glaciers would have been located in the Lesotho Highlands and parts of the Drakensberg.[31][32] The development of glaciers was likely aided in part due to shade provided by adjacent cliffs.[32] Various moraines and former glacial niches have been identified in the eastern Lesotho Highlands a few kilometres west of the Great Escarpment, at altitudes greater than 3,000 m on south-facing slopes.[31] Studies suggest that the annual average temperature in the mountains of Southern Africa was about 6 °C colder than at present, in line with temperature drops estimated for Tasmania and southern Patagonia during the same time. This resulted in an environment of relatively arid periglaciation without permafrost, but with deep seasonal freezing on south-facing slopes. Periglaciation in the eastern Drakensberg and Lesotho Highlands produced solifluction deposits and blockfields; including blockstreams and stone garlands.[29][30]

Deglaciation

Temperature rise marking the end of the most recent ice age, as derived from ice core data.
Main page: Earth:Holocene glacial retreat

Scientists from the Center for Arctic Gas Hydrate, Environment and Climate at the University of Tromsø, published a study in June 2017[33] describing over a hundred ocean sediment craters, some 3,000 m wide and up to 300 m deep, formed by explosive eruptions of methane from destabilized methane hydrates, following ice-sheet retreat during the LGP, around 12,000 years ago. These areas around the Barents Sea still seep methane today. The study hypothesized that existing bulges containing methane reservoirs could eventually have the same fate.

Named local glaciations

Antarctica

During the last glacial period, Antarctica was blanketed by a massive ice sheet, much as it is today; however, the ice covered all land areas and extended into the ocean onto the middle and outer continental shelf.[34][35] Counterintuitively though, according to ice modeling done in 2002, ice over central East Antarctica was generally thinner than it is today.[36]

Europe

Devensian and Midlandian glaciation (Britain and Ireland)

British geologists refer to the LGP as the Devensian. Irish geologists, geographers, and archaeologists refer to the Midlandian glaciation, as its effects in Ireland are largely visible in the Irish Midlands. The name Devensian is derived from the Latin Dēvenses, people living by the Dee (Dēva in Latin), a river on the Welsh border near which deposits from the period are particularly well represented.[37]

The effects of this glaciation can be seen in many geological features of England, Wales, Scotland, and Northern Ireland. Its deposits have been found overlying material from the preceding Ipswichian stage and lying beneath those from the following Holocene, which is the current stage. This is sometimes called the Flandrian interglacial in Britain.

The latter part of the Devensian includes pollen zones I–IV, the Allerød oscillation and Bølling oscillation, and the Oldest Dryas, Older Dryas, and Younger Dryas cold periods.

Weichselian glaciation (Scandinavia and northern Europe)

Main page: Earth:Weichselian glaciation
Europe during the last glacial period

Alternative names include Weichsel glaciation or Vistulian glaciation (referring to the Polish River Vistula or its German name Weichsel). Evidence suggests that the ice sheets were at their maximum size for only a short period, between 25,000 and 13,000 BP. Eight interstadials have been recognized in the Weichselian, including the Oerel, Glinde, Moershoofd, Hengelo, and Denekamp; however, correlation with isotope stages is still in process.[38][39] During the glacial maximum in Scandinavia, only the western parts of Jutland were ice-free, and a large part of what is today the North Sea was dry land connecting Jutland with Britain (see Doggerland).

The Baltic Sea, with its unique brackish water, is a result of meltwater from the Weichsel glaciation combining with saltwater from the North Sea when the straits between Sweden and Denmark opened. Initially, when the ice began melting about 10,300 BP, seawater filled the isostatically depressed area, a temporary marine incursion that geologists dub the Yoldia Sea. Then, as postglacial isostatic rebound lifted the region about 9500 BP, the deepest basin of the Baltic became a freshwater lake, in palaeological contexts referred to as Ancylus Lake, which is identifiable in the freshwater fauna found in sediment cores. The lake was filled by glacial runoff, but as worldwide sea level continued rising, saltwater again breached the sill about 8000 BP, forming a marine Littorina Sea, which was followed by another freshwater phase before the present brackish marine system was established. "At its present state of development, the marine life of the Baltic Sea is less than about 4000 years old", Drs. Thulin and Andrushaitis remarked when reviewing these sequences in 2003.

Overlying ice had exerted pressure on the Earth's surface. As a result of melting ice, the land has continued to rise yearly in Scandinavia, mostly in northern Sweden and Finland, where the land is rising at a rate of as much as 8–9 mm per year, or 1 m in 100 years. This is important for archaeologists, since a site that was coastal in the Nordic Stone Age now is inland and can be dated by its relative distance from the present shore.

Würm glaciation (Alps)

Main page: Earth:Würm glaciation
Violet: extent of the Alpine ice sheet in the Würm glaciation. Blue: extent in earlier ice ages.

The term Würm is derived from a river in the Alpine foreland, roughly marking the maximum glacier advance of this particular glacial period. The Alps were where the first systematic scientific research on ice ages was conducted by Louis Agassiz at the beginning of the 19th century. Here, the Würm glaciation of the LGP was intensively studied. Pollen analysis, the statistical analyses of microfossilized plant pollens found in geological deposits, chronicled the dramatic changes in the European environment during the Würm glaciation. During the height of Würm glaciation, c. 24,000 – c. 10,000 BP, most of western and central Europe and Eurasia was open steppe-tundra, while the Alps presented solid ice fields and montane glaciers. Scandinavia and much of Britain were under ice.

During the Würm, the Rhône Glacier covered the whole western Swiss plateau, reaching today's regions of Solothurn and Aargau. In the region of Bern, it merged with the Aar glacier. The Rhine Glacier is currently the subject of the most detailed studies. Glaciers of the Reuss and the Limmat advanced sometimes as far as the Jura. Montane and piedmont glaciers formed the land by grinding away virtually all traces of the older Günz and Mindel glaciation, by depositing base moraines and terminal moraines of different retraction phases and loess deposits, and by the proglacial rivers' shifting and redepositing gravels. Beneath the surface, they had profound and lasting influence on geothermal heat and the patterns of deep groundwater flow.

North America

Pinedale or Fraser glaciation (Rocky Mountains)

Map of Pleistocene lakes in the Great Basin of western North America, showing the path of the Bonneville Flood along the Snake River

The Pinedale (central Rocky Mountains) or Fraser (Cordilleran ice sheet) glaciation was the last of the major glaciations to appear in the Rocky Mountains in the United States. The Pinedale lasted from around 30,000 to 10,000 years ago, and was at its greatest extent between 23,500 and 21,000 years ago.[40] This glaciation was somewhat distinct from the main Wisconsin glaciation, as it was only loosely related to the giant ice sheets and was instead composed of mountain glaciers, merging into the Cordilleran ice sheet.[41] The Cordilleran ice sheet produced features such as glacial Lake Missoula, which broke free from its ice dam, causing the massive Missoula Floods. USGS geologists estimate that the cycle of flooding and reformation of the lake lasted an average of 55 years and that the floods occurred about 40 times over the 2,000-year period starting 15,000 years ago.[42] Glacial lake outburst floods such as these are not uncommon today in Iceland and other places.

Wisconsin glaciation

The Wisconsin glacial episode was the last major advance of continental glaciers in the North American Laurentide ice sheet. At the height of glaciation, the Bering land bridge potentially permitted migration of mammals, including people, to North America from Siberia.

It radically altered the geography of North America north of the Ohio River. At the height of the Wisconsin episode glaciation, ice covered most of Canada, the Upper Midwest, and New England, as well as parts of Montana and Washington (state) . On Kelleys Island in Lake Erie or in New York's Central Park, the grooves left by these glaciers can be easily observed. In southwestern Saskatchewan and southeastern Alberta, a suture zone between the Laurentide and Cordilleran ice sheets formed the Cypress Hills, which is the northernmost point in North America that remained south of the continental ice sheets.

The Great Lakes are the result of glacial scour and pooling of meltwater at the rim of the receding ice. When the enormous mass of the continental ice sheet retreated, the Great Lakes began gradually moving south due to isostatic rebound of the north shore. Niagara Falls is also a product of the glaciation, as is the course of the Ohio River, which largely supplanted the prior Teays River.

With the assistance of several very broad glacial lakes, it released floods through the gorge of the Upper Mississippi River, which in turn was formed during an earlier glacial period.

In its retreat, the Wisconsin episode glaciation left terminal moraines that form Long Island, Block Island, Cape Cod, Nomans Land, Martha's Vineyard, Nantucket, Sable Island, and the Oak Ridges Moraine in south-central Ontario, Canada. In Wisconsin itself, it left the Kettle Moraine. The drumlins and eskers formed at its melting edge are landmarks of the lower Connecticut River Valley.

Tahoe, Tenaya, and Tioga, Sierra Nevada

In the Sierra Nevada, three stages of glacial maxima (sometimes incorrectly called ice ages) were separated by warmer periods. These glacial maxima are called, from oldest to youngest, Tahoe, Tenaya, and Tioga.[43] The Tahoe reached its maximum extent perhaps about 70,000 years ago. Little is known about the Tenaya. The Tioga was the least severe and last of the Wisconsin episode. It began about 30,000 years ago, reached its greatest advance 21,000 years ago, and ended about 10,000 years ago.

Greenland glaciation

In northwest Greenland, ice coverage attained a very early maximum in the LGP around 114,000. After this early maximum, ice coverage was similar to today until the end of the last glacial period. Towards the end, glaciers advanced once more before retreating to their present extent.[44] According to ice core data, the Greenland climate was dry during the LGP, with precipitation reaching perhaps only 20% of today's value.[45]

South America

Mérida glaciation (Venezuelan Andes)

Map showing the extent of the glaciated area in Venezuelan Andes during the Mérida glaciation

The name Mérida glaciation is proposed to designate the alpine glaciation that affected the central Venezuelan Andes during the Late Pleistocene. Two main moraine levels have been recognized - one with an elevation of 2,600–2,700 m (8,500–8,900 ft), and another with an elevation of 3,000–3,500 m (9,800–11,500 ft). The snow line during the last glacial advance was lowered approximately 1,200 m (3,900 ft) below the present snow line, which is 3,700 m (12,100 ft). The glaciated area in the Cordillera de Mérida was about 600 km2 (230 sq mi); this included these high areas, from southwest to northeast: Páramo de Tamá, Páramo Batallón, Páramo Los Conejos, Páramo Piedras Blancas, and Teta de Niquitao. Around 200 km2 (77 sq mi) of the total glaciated area was in the Sierra Nevada de Mérida, and of that amount, the largest concentration, 50 km2 (19 sq mi), was in the areas of Pico Bolívar, Pico Humboldt [4,942 m (16,214 ft)], and Pico Bonpland [4,983 m (16,348 ft)]. Radiocarbon dating indicates that the moraines are older than 10,000 BP, and probably older than 13,000 BP. The lower moraine level probably corresponds to the main Wisconsin glacial advance. The upper level probably represents the last glacial advance (Late Wisconsin).[46][47][48][49][50]

Llanquihue glaciation (Southern Andes)

Main page: Earth:Llanquihue glaciation
Map showing the extent of the Patagonian ice sheet in the Strait of Magellan area during the LGP: Selected modern settlements are shown with yellow dots.

The Llanquihue glaciation takes its name from Llanquihue Lake in southern Chile, which is a fan-shaped piedmont glacial lake. On the lake's western shores, large moraine systems occur, of which the innermost belong to the LGP. Llanquihue Lake's varves are a node point in southern Chile's varve geochronology. During the last glacial maximum, the Patagonian ice sheet extended over the Andes from about 35°S to Tierra del Fuego at 55°S. The western part appears to have been very active, with wet basal conditions, while the eastern part was cold-based. Cryogenic features such as ice wedges, patterned ground, pingos, rock glaciers, palsas, soil cryoturbation, and solifluction deposits developed in unglaciated extra-Andean Patagonia during the last glaciation, but not all these reported features have been verified.[51] The area west of Llanquihue Lake was ice-free during the last glacial maximum, and had sparsely distributed vegetation dominated by Nothofagus. Valdivian temperate rain forest was reduced to scattered remnants on the western side of the Andes.[52]

Modelled maximum extent of the Antarctic ice sheet 21,000 years before present

See also

Historical names of the "four major" glacials in four regions
Region Glacial 1 Glacial 2 Glacial 3 Glacial 4
Alps Günz Mindel Riss Würm
North Europe Eburonian Elsterian Saalian Weichselian
British Isles Beestonian Anglian Wolstonian Devensian
Midwest U.S. Nebraskan Kansan Illinoian Wisconsinan

Notes

  1. ↑ Prior to the 2010s, considerable debate arose on whether Southern Africa was glaciated during the last glacial cycle or not.[29][30]
  2. ↑ The former existence of large glaciers or deep snow cover over much of the Lesotho Highlands has been judged unlikely considering the lack of glacial morphology (e.g. roche moutonnées) and the existence of periglacial regolith that has not been reworked by glaciers.[30] Estimates of the mean annual temperature in Southern Africa during the last glacial maximum indicate the temperatures were not low enough to initiate or sustain a widespread glaciation. The former existence of rock glaciers or large glaciers is, according to the same study, ruled out, because of a lack of conclusive field evidence and the implausibility of the 10–17 °C temperature drop, relative to the present, that such features would imply.[29]

References

  1. ↑ "The history of ice on Earth" (in en-US). https://www.newscientist.com/article/dn18949-the-history-of-ice-on-earth/. 
  2. ↑ "Glaciation of Wisconsin". Dept. Geology, University of Wisconsin. http://www.geology.wisc.edu/~davem/abstracts/06-1.pdf. 
  3. ↑ University of Houston–Clear Lake – Disasters Class Notes – Chapter 12: Climate Change sce.uhcl.edu/Pitts/disastersclassnotes/chapter_12_Climate_Change.doc
  4. ↑ Gavashelishvili, A.; Tarkhnishvili, D. (2016). "Biomes and human distribution during the last ice age". Global Ecology and Biogeography 25 (5): 563–574. doi:10.1111/geb.12437. 
  5. ↑ Crowley, Thomas J. (1995). "Ice age terrestrial carbon changes revisited". Global Biogeochemical Cycles 9 (3): 377–389. doi:10.1029/95GB01107. Bibcode: 1995GBioC...9..377C. http://www.agu.org/pubs/crossref/1995/95GB01107.shtml. Retrieved February 25, 2012. 
  6. ↑ Catt, J. A. (2006). "Quaternary: Ice Sheets and their Legacy". in Brenchley, P. J.; Rawson, P. F.. The Geology of England and Wales (2nd ed.). London: The Geological Society. pp. 451–52. ISBN 978-1-86239-199-4. 
  7. ↑ Clark, D.H. Extent, timing, and climatic significance of latest Pleistocene and Holocene glaciation in the Sierra Nevada, California (PDF 20 Mb) (Ph.D.). Seattle: Washington University.
  8. ↑ Möller, P. (2006). "Severnaya Zemlya, Arctic Russia: a nucleation area for Kara Sea ice sheets during the Middle to Late Quaternary" (PDF 11.5 Mb). Quaternary Science Reviews 25 (21–22): 2894–2936. doi:10.1016/j.quascirev.2006.02.016. Bibcode: 2006QSRv...25.2894M. http://www.geol.lu.se/personal/prm/PDF_papers%20full%20text/QSR-2007_SZ_Severnaya_Z.pdf. Retrieved February 9, 2008. 
  9. ↑ Matti Saarnisto: Climate variability during the last interglacial-glacial cycle in NW Eurasia. Abstracts of PAGES – PEPIII: Past Climate Variability Through Europe and Africa, 2001
  10. ↑ Gualtieri, Lyn (May 2003). "Pleistocene raised marine deposits on Wrangel Island, northeast Siberia and implications for the presence of an East Siberian ice sheet". Quaternary Research 59 (3): 399–410. doi:10.1016/S0033-5894(03)00057-7. Bibcode: 2003QuRes..59..399G. 
  11. ↑ Ehlers, Gibbard & 2004 III, pp. 321–323
  12. ↑ Barr, I.D; Clark, C.D. (2011). "Glaciers and Climate in Pacific Far NE Russia during the Last Glacial Maximum". Journal of Quaternary Science 26 (2): 227. doi:10.1002/jqs.1450. Bibcode: 2011JQS....26..227B. https://e-space.mmu.ac.uk/619060/1/Barr%20and%20Clark%20%25282011%2529.pdf. 
  13. ↑ Spielhagen, Robert F. (2004). "Arctic Ocean deep-sea record of northern Eurasian ice sheet history". Quaternary Science Reviews 23 (11–13): 1455–83. doi:10.1016/j.quascirev.2003.12.015. Bibcode: 2004QSRv...23.1455S. 
  14. ↑ "Glaciers of the Middle East and Africa – Glaciers of Turkey" (PDF 2.5 Mb). U.S.Geological Survey Professional Paper 1386-G-1. 1991. http://pubs.usgs.gov/pp/p1386g/turkey.pdf. 
    Ferrigno, Jane G. (1991). "Glaciers of the Middle East and Africa – Glaciers of Iran" (PDF 1.25 Mb). U.S.Geological Survey Professional Paper 1386-G-2. http://pubs.usgs.gov/pp/p1386g/iran.pdf. 
  15. ↑ Owen, Lewis A. (2002). "A note on the extent of glaciation throughout the Himalaya during the global Last Glacial Maximum". Quaternary Science Reviews 21 (1): 147–157. doi:10.1016/S0277-3791(01)00104-4. Bibcode: 2002QSRv...21..147O. 
  16. ↑ Kuhle, M., Kuhle, S. (2010): Review on Dating methods: Numerical Dating in the Quaternary of High Asia. In: Journal of Mountain Science (2010) 7: 105–122.
  17. ↑ Chevalier, Marie-Luce (2011). "Constraints on the late Quaternary glaciations in Tibet from cosmogenic exposure ages of moraine surfaces". Quaternary Science Reviews 30 (5–6): 528–554. doi:10.1016/j.quascirev.2010.11.005. Bibcode: 2011QSRv...30..528C. 
  18. ↑ Kuhle, Matthias (2002). "A relief-specific model of the ice age on the basis of uplift-controlled glacier areas in Tibet and the corresponding albedo increase as well as their positive climatological feedback by means of the global radiation geometry". Climate Research 20: 1–7. doi:10.3354/cr020001. Bibcode: 2002ClRes..20....1K. 
  19. ↑ Ehlers, Gibbard & 2004 III, Kuhle, M (2011-08-31). "The High Glacial (Last Ice Age and LGM) ice cover in High and Central Asia". Quaternary Glaciations - Extent and Chronology. Elsevier. pp. 175–199. ISBN 9780444534477. 
  20. ↑ Lehmkuhl, F. (2003). "Die eiszeitliche Vergletscherung Hochasiens – lokale Vergletscherungen oder übergeordneter Eisschild?". Geographische Rundschau 55 (2): 28–33. http://www.pgg.rwth-aachen.de/index.php?id=lef-abstracts. Retrieved February 9, 2008. 
  21. ↑ Zhijiu Cui (2002). "The Quaternary glaciation of Shesan Mountain in Taiwan and glacial classification in monsoon areas". Quaternary International 97–98: 147–153. doi:10.1016/S1040-6182(02)00060-5. Bibcode: 2002QuInt..97..147C. http://ntur.lib.ntu.edu.tw//handle/246246/173509. 
  22. ↑ Yugo Ono (September–October 2005). "Mountain glaciation in Japan and Taiwan at the global Last Glacial Maximum". Quaternary International 138–139: 79–92. doi:10.1016/j.quaint.2005.02.007. Bibcode: 2005QuInt.138...79O. 
  23. ↑ "Glaciers of the Middle East and Africa – Glaciers of Africa" (PDF 1.25 Mb). U.S. Geological Survey Professional Paper 1386-G-3. 1991. http://pubs.usgs.gov/pp/p1386g/africa.pdf. 
  24. ↑ Lowell, T.V. (1995). "Interhemisperic correlation of late Pleistocene glacial events" (PDF 2.3 Mb). Science 269 (5230): 1541–49. doi:10.1126/science.269.5230.1541. PMID 17789444. Bibcode: 1995Sci...269.1541L. http://www.uc.edu/geology/documents/lowell_abstracts/lowellsci.pdf. 
  25. ↑ Ollier, C.D.. "Australian Landforms and their History". National Mapping Fab. Geoscience Australia. http://www.ga.gov.au/education/facts/landforms/auslform.htm. 
  26. ↑ Burrows, C. J.; Moar, N. T. (1996). "A mid Otira Glaciation palaeosol and flora from the Castle Hill Basin, Canterbury, New Zealand" (PDF 340 Kb). New Zealand Journal of Botany 34 (4): 539–545. doi:10.1080/0028825X.1996.10410134. http://www.rsnz.org/publish/nzjb/1996/167.pdf. 
  27. ↑ 27.0 27.1 Löffler, Ernst (1972). "Pleistocene glaciation in Papua and New Guinea". Zeitschrift für Geomorphologie Supplementband 13: 32–58. 
  28. ↑ 28.0 28.1 Allison, Ian; Peterson, James A. (1988). Glaciers of Irian Jaya, Indonesia: Observation and Mapping of the Glaciers Shown on Landsat Images. United States Geological Survey. U.S. Geological Survey professional paper 1386. ISBN 978-0-607-71457-9. http://pubs.usgs.gov/prof/p1386h/indonesia/indonesia2.html. Retrieved February 9, 2008. 
  29. ↑ 29.0 29.1 29.2 29.3 "The cold climate geomorphology of the Eastern Cape Drakensberg: A reevaluation of past climatic conditions during the last glacial cycle in Southern Africa". Geomorphology 278: 184–194. 2017. doi:10.1016/j.geomorph.2016.11.011. Bibcode: 2017Geomo.278..184M. https://pearl.plymouth.ac.uk/handle/10026.1/8086. 
  30. ↑ 30.0 30.1 30.2 "Geomorphic and climatic implications of relict openwork block accumulations near Thabana-Ntlenyana, Lesotho". Geografiska Annaler: Series A, Physical Geography 86 (3): 289–302. 2004. doi:10.1111/j.0435-3676.2004.00232.x. 
  31. ↑ 31.0 31.1 Mills, Stephanie C.; Grab, Stefan W.; Rea, Brice R.; Farrow, Aidan (2012). "Shifting westerlies and precipitation patterns during the Late Pleistocene in southern Africa determined using glacier reconstruction and mass balance modelling". Quaternary Science Reviews 55: 145–159. doi:10.1016/j.quascirev.2012.08.012. Bibcode: 2012QSRv...55..145M. 
  32. ↑ 32.0 32.1 "The shape of glacial valleys and implications for southern African glaciation". South African Geographical Journal 92 (1): 35–44. 2010. doi:10.1080/03736245.2010.485360. 
  33. ↑ "Like 'champagne bottles being opened': Scientists document an ancient Arctic methane explosion". The Washington Post. June 1, 2017. https://www.washingtonpost.com/news/energy-environment/wp/2017/06/01/like-champagne-bottles-being-opened-scientists-document-an-ancient-arctic-methane-explosion. 
  34. ↑ Anderson, J. B.; Shipp, S. S.; Lowe, A. L.; Wellner, J. S.; Mosola, A. B. (2002). "The Antarctic Ice Sheet during the Last Glacial Maximum and its subsequent retreat history: a review". Quaternary Science Reviews 21 (1–3): 49–70. doi:10.1016/S0277-3791(01)00083-X. Bibcode: 2002QSRv...21...49A. 
  35. ↑ Ehlers, Gibbard & 2004 III, Ingolfsson, O. Quaternary glacial and climate history of Antarctica. pp. 3–43. http://www.hi.is/~oi/AG-326%202006%20readings/Antarctica/Ingolfsson_SUMMARY.pdf. 
  36. ↑ Huybrechts, P. (2002). "Sea-level changes at the LGM from ice-dynamic reconstructions of the Greenland and Antarctic ice sheets during the glacial cycles". Quaternary Science Reviews 21 (1–3): 203–231. doi:10.1016/S0277-3791(01)00082-8. Bibcode: 2002QSRv...21..203H. https://epic.awi.de/id/eprint/4507/1/Huy2002a.pdf. 
  37. ↑ OED
  38. ↑ Behre Karl-Ernst, van der Plicht Johannes (1992). "Towards an absolute chronology for the last glacial period in Europe: radiocarbon dates from Oerel, northern Germany". Vegetation History and Archaeobotany 1 (2): 111–117. doi:10.1007/BF00206091. https://pure.rug.nl/ws/files/14450372/1992VegetHistArchaeobotBehre.pdf. 
  39. ↑ Davis, Owen K. (2003). "Non-Marine Records: Correlations with the Marine Sequence". Introduction to Quaternary Ecology. University of Arizona. http://www.geo.arizona.edu/palynology/geos462/07nonmarin.html. 
  40. ↑ "Brief geologic history". Rocky Mountain National Park. http://www2.nature.nps.gov/geology/parks/romo/index.cfm#geology. 
  41. ↑ "Ice Age Floods". U.S. National Park Service. http://vulcan.wr.usgs.gov/Glossary/Glaciers/IceSheets/description_ice_sheets.html. 
  42. ↑ Waitt, Jr., Richard B. (October 1985). "Case for periodic, colossal jökulhlaups from Pleistocene glacial Lake Missoula". Geological Society of America Bulletin 96 (10): 1271–86. doi:10.1130/0016-7606(1985)96<1271:CFPCJF>2.0.CO;2. Bibcode: 1985GSAB...96.1271W. http://vulcan.wr.usgs.gov/Glossary/Glaciers/IceSheets/Waitt85GSA/abstract.html. 
  43. ↑ Ehlers, Gibbard & 2004 II, p. 57
  44. ↑ Funder, Svend"Late Quaternary stratigraphy and glaciology in the Thule area, Northwest Greenland". MoG Geoscience 22: 63. 1990. http://www.dpc.dk/sw3590.asp. 
  45. ↑ Johnsen, Sigfus J. (1992). "A "deep" ice core from East Greenland". MoG Geoscience 29: 22. http://www.dpc.dk/sw3551.asp. 
  46. ↑ Sánchez Dávila, Gabriel (2016) (in es). La Sierra de Santo Domingo: "Biogeographic reconstructions for the Quaternary of a former snowy mountain range". doi:10.13140/RG.2.2.21325.38886/1. https://www.researchgate.net/publication/339498574. 
  47. ↑ Schubert, Carlos (1998). "Glaciers of Venezuela". US Geological Survey (USGS P 1386-I). http://pubs.usgs.gov/pp/p1386i/venezuela/text.html. 
  48. ↑ Schubert, C.; Valastro, S. (1974). "Late Pleistocene glaciation of Páramo de La Culata, north-central Venezuelan Andes". Geologische Rundschau 63 (2): 516–538. doi:10.1007/BF01820827. Bibcode: 1974GeoRu..63..516S. 
  49. ↑ Mahaney, William C.; Milner, M.W., Kalm, Volli; Dirsowzky, Randy W.; Hancock, R.G.V.; Beukens, Roelf P. (April 1, 2008). "Evidence for a Younger Dryas glacial advance in the Andes of northwestern Venezuela". Geomorphology 96 (1–2): 199–211. doi:10.1016/j.geomorph.2007.08.002. Bibcode: 2008Geomo..96..199M. 
  50. ↑ "Glacial Quaternary geology of las Gonzales basin, páramo los conejos, Venezuelan andes". http://www.cprm.gov.br/33IGC/1349672.html. 
  51. ↑ Trombotto Liaudat, Darío (2008). "Geocryology of Southern South America". in Rabassa, J.. The Late Cenozoic of Patagonia and Tierra del Fuego. Elsevier Science. pp. 255–268. ISBN 978-0-444-52954-1. https://archive.org/details/latecenozoicpata00raba. 
  52. ↑ "South America during the last 150,000 years". http://www.esd.ornl.gov/projects/qen/nercSOUTHAMERICA.html. 

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