The Last Glacial Maximum (LGM) refers to the time of maximum extent of the ice sheets during the last glaciation (the Würm or Wisconsin glaciation), approximately 20,000 years ago. An ice sheet is a mass of Glacier Ice that covers surrounding terrain and is greater than 50000 km² (20000 mile²) "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. "Last glacial" redirects here For the period of maximum glacier extent during this time see Last Glacial Maximum The last glacial period This extreme persisted for several thousand years.
At this time, ice sheets covered the whole of Iceland and all but the southern extremity of the British Isles. Iceland, officially the Republic of Iceland ( ( Ísland or Lýðveldið Ísland ( The British Isles (Irish variously Na hOileáin Bhriotanacha, Oileáin Iarthair Eorpa, Éire agus an Bhreatain Mhór; Ellanyn Goaldagh Eileanan Northern Europe was largely covered, the southern boundary passing through Germany and Poland, but not quite joined to the British ice sheet. Northern Europe is a term for the northern part of Europe. The United Nations defines Northern Europe as (Finland Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Poland (Polska officially the Republic of Poland This ice extended northward to cover Svalbard and Franz Josef Land and eastward to occupy the northern half of the West Siberian Plain, ending at the Taymyr Peninsula. Svalbard is an Archipelago in the Arctic Ocean north of mainland Europe, about midway between Norway and the North Pole. Franz Josef Land, Franz Joseph Land, or Francis Joseph's Land ( Russ The West Siberian Plain (За́падно-Сиби́рская равни́на is a large Plain that occupies the western portion of Siberia and Russia Taymyr Peninsula (Полуостров Таймыр Таймырский полуостров is a peninsula in Siberia that forms the most northern part of mainland Asia In North America, the ice covered essentially all of Canada and extended roughly to the Missouri and Ohio Rivers, and eastward to New York City. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page The Ohio River is the largest Tributary by volume of the Mississippi River. The City of New York
In the Southern Hemisphere, the Patagonian Ice Sheet covered Chile and western Argentina north to about 41 degrees south. Southern Hemisphere is the half of a Planet that is South of the Equator —the word hemisphere literally means 'half ball' The Patagonian Ice Sheet was a large elongated and narrow Ice sheet that covered all of Chile south of approximately present-day Puerto Montt during the Chile, officially the Republic of Chile ( Spanish:) is a country in South America occupying a long and narrow Coastal strip wedged between the For a topic outline on this subject see List of basic Argentina topics. Ice sheets also covered Tibet (scientists continue to debate the extent to which the Tibetan Plateau was covered with ice), Baltistan, Ladakh and the Andean altiplano. Definitions of Tibet See also Definitions of Tibet Name In English The English word Tibet, like the word for Tibet in most European Baltistan (بلتستان, also known as بلتیول (Baltiyul in the Balti language, is a region in northern Pakistan,bordering Xinjiang Ladakh ( Ladakhi lad̪ɑks लदाख لدّاخ "land of high passes" is a region in the Indian state of Jammu and Kashmir between The Altiplano ( Spanish for high plain) where the Andes are at their widest is the most extensive area of High plateau on earth outside In Africa, the Middle East and Southeast Asia, many smaller mountain glaciers formed, especially in the Atlas, the Bale Mountains, and New Guinea. The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East. The Atlas Mountains ( Kabyle: Idurar n leṭles جبال الأطلس) is a Mountain range across a northern stretch of Africa extending about 2400 The Bale Mountains (also known as the Urgoma Mountains) are a range of Mountains in the Oromia Region of southeast Ethiopia, south of the New Guinea, located just north of Australia, is the world's second largest island, having become separated from the Australian mainland when the area now known
The Ob and Yenisei Rivers had their flows stopped by the vast ice sheets, creating huge pluvial lakes. Ob River (Обь also Obi, is a major river in West Siberia, Russia, the country's fourth longest Yenisei (Енисе́й is the greatest River system flowing to the Arctic Ocean, and at 5539 km (3445 mi is the fifth longest river in the world
Permafrost covered Europe south of the ice sheet down to present-day Szeged and Asia down to Beijing. This article is about frozen ground For other meanings see Permafrost (disambiguation. Szeged ( (approximate pronunciation Seg-ed (known also by alternative names) is the fourth largest City of Hungary, the Regional centre In North America, latitudinal gradients were so sharp that permafrost did not reach far south of the ice sheets except at high elevations.
The Indonesian islands as far east as Borneo and Bali were connected to the Asian continent in a landmass called Sundaland. The Republic of Indonesia ( (Republik Indonesia is a Country in Southeast Asia. Borneo is the third largest island in the world and is located at the centre of Maritime Southeast Asia. Bali is an Indonesian Island located at, the westernmost of the Lesser Sunda Islands, lying between Java to the west and Lombok to Sundaland is a biogeographical region of Southeastern Asia that comprises the Malay Peninsula and the Malay Archipelago islands of Sumatra Palawan was also part of Sundaland, while the rest of the Philippine Islands formed one large island separated from the continent only by the Sibutu Passage and the Mindoro Strait. Palawan is an Island province of the Philippines located in the MIMAROPA region. The Philippines ( Filipino: Pilipinas, officially known as the Republic of the Philippines (fil ''Republika ng Pilipinas'' RP Sibutu Passage is a safe and deep channel some 18 miles (29 km wide that separates Borneo from the Sulu Archipelago. Mindoro Strait is a strait in the Philippines,. separating Mindoro island from Palawan province  Australia and New Guinea were connected forming Sahulland. For a topic outline on this subject see List of basic Australia topics. New Guinea, located just north of Australia, is the world's second largest island, having become separated from the Australian mainland when the area now known Between Sundaland and Sahulland, Wallacea remained islands, though the number and width of water gaps between the two continents were considerably smaller. Wallacea is a biogeographical designation for a group of Indonesian islands separated by deep water Straits from the Asian and Australian
The formation of an ice sheet or ice cap requires both prolonged cold and precipitation (snow). An ice cap is an Ice mass that covers less than 50 000 km² of land area (usually covering a highland area In Meteorology, precipitation (also known as one class of hydrometeors, which are atmospheric water phenomena is any product of the condensation of atmospheric "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation. Hence, despite having temperatures similar to those of glaciated areas in North America and Europe, East Asia and parts of Alaska remained unglaciated except at higher elevations. Alaska ( Аляска Alyaska) is a state in the United States of America, in the northwest of the North American continent This difference was caused by the fact that the ice sheets in Europe produced extensive anticyclones above them. In Meteorology, an anticyclone (that is opposite to a Cyclone) is a Weather phenomenon in which there is a descending movement of the air and These anticyclones generated air masses that were so dry on reaching Siberia and Manchuria that precipitation sufficient for the formation of glaciers could never occur (except in Kamchatka where these westerly winds lifted moisture from the Sea of Japan). For airmass in Astronomy, see Airmass. In Meteorology, an air mass is a large volume of Air that Siberia (Сиби́рь Sibir) is the name given to the vast region constituting almost all of Northern Asia and for the most part currently serving Manchuria ( Romanized Manchu: Manju,, Маньчжурия Mongolian: Манж is a historical name given to a vast geographic region in northeast The Sea of Japan is a Marginal sea of the western Pacific Ocean, bordered by Japan, Korea, North Korea and Russia The relative warmth of the Pacific Ocean due to the shutting down of the Oyashio Current and the presence of large east-west mountain ranges were secondary factors preventing continental glaciation in Asia. The Pacific Ocean is the largest of the Earth 's Oceanic divisions The Oyashio Current (also named 'Oya Siwo' the Kurile current Japanese 親潮 is a cold subarctic Ocean current that flows south and circulates counterclockwise
In warmer regions of the world, climates at the Last Glacial Maximum were cooler and almost everywhere drier. In extreme cases, such as South Australia and the Sahel, rainfall could be diminished by up to ninety percent from present, with floras diminished to almost the same degree as in glaciated areas of Europe and North America. South Australia is a state of Australia in the southern central part of the country See also Sahel Tunisia, a region of eastern Tunisia. The Sahel or Sahel Belt (from Arabic ساحل sāḥil Even in less affected regions, rainforest cover was greatly diminished, especially in West Africa where a few refugia were surrounded by tropical grassland. Rainforests are Forests characterized by high Rainfall with definitions setting minimum normal annual rainfall between 1750–2000 mm (68-78 inches West Africa or Western Africa is the Westernmost Region of the African Continent. Grasslands (also called greenswards) are areas where the Vegetation is dominated by Grasses ( Poaceae) and other Herbaceous (non-woody The Amazon rainforest was split into two large blocks by extensive savanna, and it is probable that the tropical rainforests of Southeast Asia were similarly affected, with deciduous forests expanding in their place except on the east and west extremities of the Sundaland shelf. The Amazon Rainforest (Brazilian Portuguese: Floresta Amazônica or Amazônia; Spanish: Selva Amazónica or Amazonía A savanna or savannah is a Tropical or Subtropical Grassland or Woodland Ecosystem. Only in Central America and the Chocó region of Colombia did tropical rainforests remain substantially intact - probably due to the extraordinarily heavy rainfall of these regions. Colombia (kəˈlʌmbɪə officially the Republic of Colombia () is a country in northwestern South America.
Most of the world's deserts expanded. Exceptions were in the American West, where changes in the jet stream brought heavy rain to areas that are now desert and large pluvial lakes formed, the best known being Lake Bonneville in Utah. The Western United States &mdashcommonly referred to as the American West or simply the West &mdashtraditionally refers to the region comprising the westernmost Jet streams are fast flowing relatively narrow air currents found at the Tropopause, the transition between the Troposphere (where temperature decreases A pluvial lake is a Lake that experiences significant increase in depth and extent as a result of increased precipitation and reduced Evaporation. Lake Bonneville was a prehistoric Pluvial lake that covered much of North America 's Great Basin region The State of Utah (ˈjuːtɔː or) is a western state of the United States. This also occurred in Afghanistan and Iran where a major lake formed in the Dasht-e Kavir. Afghanistan /æfˈgænɪstæn/ officially the Islamic Republic of Afghanistan ( Pashto: د افغانستان اسلامي جمهوریت, For a topic outline on this subject see List of basic Iran topics. Dasht-e Kavir (دشت كوير in Persian) also known as Kavir-e Namak or Great Salt Desert is a large desert lying in the middle In Australia, shifting sand dunes covered half the continent, whilst the Chaco and Pampas in South America became similarly dry. For a topic outline on this subject see List of basic Australia topics. The Gran Chaco ( Quechua chaqu, "hunting land" dubbed by some as "the last South American frontier" is a sparsely populated hot and Laguna de Gomezjpg|thumb|left|240px|Lake Gomez near Junín in the heart of the Pampas grain belt Present-day subtropical regions also lost most of their forest cover, notably in eastern Australia, the Atlantic Forest of Brazil, and southern China, where open woodland became dominant due to drier conditions. The subtropics are the zones of the Earth immediately north and south of the tropic zone which is bounded by the Tropic of Cancer and the Tropic of The Atlantic Forest ( Mata Atlântica in Portuguese) is a region of tropical and subtropical moist forest, tropical dry forest, tropical |utc_offset = -2 to -4 |time_zone_DST = BRST |utc_offset_DST = -2 to -5 |cctld China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National Ecologically a woodland is an area covered in trees differentiated from a Forest. In northern China - unglaciated despite its cold climate - a mixture of grassland and tundra prevailed, and even here, the northern limit of tree growth was at least twenty degrees further south than today. In physical Geography, tundra is an area where the Tree growth is hindered by low temperatures and short growing seasons The tree line or timberline is the edge of the habitat at which Trees are capable of growing
In the period immediately before the Last Glacial Maximum, many areas that became completely barren desert were wetter than they are today, notably in southern Australia where Aboriginal occupation is believed to coincide with a wet period between 40,000 and 60,000 years BP (Before Present, a formal measurement of uncalibrated radiocarbon years, counted from 1950 AD). Indigenous Australians are descendants of the first known human inhabitants of the Australian continent and its nearby islands. Before Present (BP years are a time scale used in Archaeology, Geology, and other scientific disciplines to specify when events in the past occurred Radiocarbon dating is a Radiometric dating method that uses the naturally occurring Radioisotope Carbon-14 (14C to determine the age of