Northern Patagonian Ice Field | |
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Location | Aysén Region, Chile |
Coordinates | 47°00′S73°30′W / 47°S 73.5°W Coordinates: 47°00′S73°30′W / 47°S 73.5°W |
Area | 4,200 km2 (1,600 sq mi) |
The Northern Patagonian Ice Field, located in southern Chile, is the smaller of two remnant parts in which the Patagonian Ice Sheet in the Andes Mountains of southern South America can be divided. It is completely contained within the boundaries of Laguna San Rafael National Park.
The Northern Patagonian Ice Field is a vestige of the Patagonian Ice Sheet, an extensive ice sheet that covered all of Chilean Patagonia and the westernmost parts of Argentine Patagonia during the Quaternary glaciations. Today, with its glaciers largely in retreat and only an area of 4,200 km2 (1,600 sq mi), it is still the second largest continuous mass of ice outside of the polar regions. Its survival depends on its elevation (1,100 to 1,500 m (3,600 to 4,900 ft)), favorable terrain and a cool, moist, oceanic climate. The ice field has 28 exit glaciers, the largest two — San Quintin and San Rafael — nearly reach sea level to the west at the Pacific Ocean. Smaller exit glaciers, like San Valentín and Nef, feed numerous rivers and glacially carved lakes to the east.
Eric Shipton accompanied by Spaniard Miguel Gómez and Chileans Eduardo García and Cedomir Marangunic crossed the icecap from the San Raphael Glacier into Argentina in the summer of 1963–64. In 1972/73 a Joint Services expedition led by Captain CH Agnew of Lochnaw yr, now Sir Crispin Agnew of Lochnaw, spent 5 months carrying out scientific research on and around the ice cap, including on the Benito Glacier, and three members of the expedition carried out a north-to-south crossing from the foot of Monte San Valentín down to the snout of the Steffen Glacier. [1] Martin Session, the glaciologist on the 1972/3 expedition returned to the Benito Glacier with others in 2007 and 2011 to continue his research. [2]
The Northern Patagonian Ice Field lies in fault-bounded crustal block that has been uplifted. To the west lies the Liquiñe-Ofqui Fault Zone, to the north the Exploradores Fault Zone and to the east the Cachet Fault. To the south there is possibly a zone of extensional faults around Tortel Fjord. [3]
Patagonia refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and glaciers in the west and deserts, tablelands and steppes to the east. Patagonia is bounded by the Pacific Ocean on the west, the Atlantic Ocean to the east, and many bodies of water that connect them, such as the Strait of Magellan, the Beagle Channel, and the Drake Passage to the south.
The Last Glacial Period (LGP), also known colloquially as the last ice age or simply ice age, 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. 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. The term Late Cenozoic Ice Age is used to include this early phase. The previous ice age, the Saalian 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.
Viedma is a subglacial volcano whose existence is questionable. It is supposedly 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.
The Patagonian Ice Sheet was a large elongated and narrow ice sheet centered in the southern Andes that existed during the Llanquihue glaciation. The ice sheet covered all of Chile south of Puerto Montt plus the western fringes of Argentine Patagonia.
The Holocene glacial retreat is a geographical phenomenon that involved the global retreat of glaciers (deglaciation) 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.
General Carrera Lake or Lake Buenos Aires is a lake located in Patagonia and shared by Argentina and Chile. Both names are internationally accepted, while the autochthonous name of the lake is Chelenko, which means "stormy waters" in Aonikenk. Another historical name is Coluguape from Mapuche, a derivative of this name is applied to Colhué Huapí Lake after Argentine explorer Francisco Moreno reached this lake in 1876 conflating it with Coluguape.
The Southern Patagonian Ice Field, located at the Southern Patagonic Andes between Chile and Argentina, is the world's second largest contiguous extrapolar ice field. It is the bigger of two remnant parts of the Patagonian Ice Sheet, which covered all of southern Chile during the last glacial period, locally called the Llanquihue glaciation.
Torres del Paine National Park is a national park encompassing mountains, glaciers, lakes, and rivers in southern Chilean Patagonia. The Cordillera del Paine is the centerpiece of the park. It lies in a transition area between the Magellanic subpolar forests and the Patagonian Steppes. The park is located 112 km (70 mi) north of Puerto Natales and 312 km (194 mi) north of Punta Arenas. The park borders Bernardo O'Higgins National Park to the west and the Los Glaciares National Park to the north in Argentine territory. Paine means "blue" in the native Tehuelche (Aonikenk) language and is pronounced PIE-neh, while Torres means "towers". It was established as a National Park in 1959.
Melimoyu is a stratovolcano in Chile. It is an elongated volcanic complex that contains two nested calderas of 1 kilometre (0.62 mi) and 8 kilometres (5.0 mi) width. An ice cap has developed on the volcano with a couple of outlet glaciers. Melimoyu has not erupted in recent times, but during the Holocene two large eruptions took place and ejected ash at large distances from the volcano.
The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American Plate. The belt is subdivided into four main volcanic zones which are separated by volcanic gaps. The volcanoes of the belt are diverse in terms of activity style, products, and morphology. While some differences can be explained by which volcanic zone a volcano belongs to, there are significant differences within volcanic zones and even between neighboring volcanoes. Despite being a type location for calc-alkalic and subduction volcanism, the Andean Volcanic Belt has a broad range of volcano-tectonic settings, as it has rift systems and extensional zones, transpressional faults, subduction of mid-ocean ridges and seamount chains as well as a large range of crustal thicknesses and magma ascent paths and different amounts of crustal assimilations.
The geology of Chile is a characterized by processes linked to subduction such as volcanism, earthquakes and orogeny. The buildings blocks of Chile's geology assembled during the Paleozoic Era. Chile was by then the southwestern margin of the supercontinent Gondwana. In the Jurassic Gondwana began to split and the ongoing period of crustal deformation and mountain building known as the Andean orogeny began. In the Late Cenozoic Chile definitely separated from Antarctica, the Andes experienced a great rise accomplained by a cooling climate and the onset of glaciations.
The Chile Triple Junction is a geologic triple junction located on the seafloor of the Pacific Ocean off Taitao and Tres Montes Peninsula on the southern coast of Chile. Here three tectonic plates meet: the South American Plate, the Nazca Plate and the Antarctic Plate. This triple junction is unusual in that it consists of a mid-oceanic ridge, the Chile Rise, being subducted under the South American Plate at the Peru–Chile Trench. The Chile Triple Junction is the boundary between the Chilean Rise and the Chilean margin, where the Nazca, Antarctic, and South American plates meet at the trench.
Tortel is a Chilean commune located at the outflow of the Baker River and Pascua River to the Pacific Ocean. It lies between the Northern and Southern Patagonian Ice Field in the Capitán Prat Province in the Aysén Region. The commune is administered by the municipality in Caleta Tortel, the principal settlement.
Reclus, also written as Reclús, is a volcano located in the Southern Patagonian Ice Field, Chile. Part of the Austral Volcanic Zone of the Andes, its summit rises 1,000 metres (3,300 ft) above sea level and is capped by a crater about 1 kilometre (0.62 mi) wide. Close to the volcano lies the Amalia Glacier, which is actively eroding Reclus.
The Weichselian glaciation was the last glacial period and its associated glaciation in northern parts of Europe. In the Alpine region it corresponds to the Würm glaciation. It was characterized by a large ice sheet that spread out from the Scandinavian Mountains and extended as far as the east coast of Schleswig-Holstein, northern Poland and Northwest Russia. This glaciation is also known as the Weichselian ice age, Vistulian glaciation, Weichsel or, less commonly, the Weichsel glaciation, Weichselian cold period (Weichsel-Kaltzeit), Weichselian glacial (Weichsel-Glazial), Weichselian Stage or, rarely, the Weichselian complex (Weichsel-Komplex).
The Scandinavian Mountains or the Scandes is a mountain range that runs through the Scandinavian Peninsula. The western sides of the mountains drop precipitously into the North Sea and Norwegian Sea, forming the fjords of Norway, whereas to the northeast they gradually curve towards Finland. To the north they form the border between Norway and Sweden, reaching 2,000 metres (6,600 ft) high at the Arctic Circle. The mountain range just touches northwesternmost Finland but are scarcely more than hills at their northernmost extension at the North Cape.
The last glacial period and its associated glaciation is known in southern Chile as the Llanquihue glaciation. Its type area lies west of Llanquihue Lake where various drifts or end moraine systems belonging to the last glacial period have been identified. The glaciation is the last episode of existence of the Patagonian Ice Sheet.
Monte Burney is a volcano in southern Chile, part of its Austral Volcanic Zone which consists of six volcanoes with activity during the Quaternary. This volcanism is linked to the subduction of the Antarctic Plate beneath the South America Plate and the Scotia Plate.
Fueguino is a volcanic field in Chile. The southernmost volcano in the Andes, it lies on Tierra del Fuego's Cook Island and also extends over nearby Londonderry Island. The field is formed by lava domes, pyroclastic cones, and a crater lake.
Cachet Fault is a dextral strike-slip fault in Aysén Region, Chile. The fault runs in north–south direction right to the east of the Northern Patagonian Ice Field. Various west-east glacial valleys have been displaced the movement of the fault. The existence of the fault and its movement has been linked to the Chile Triple Junction and the oblique subduction of Nazca Plate. The fault exhibits present-day seismicity. Together, Exploradores Fault Zone and Liquiñe-Ofqui Fault Zone and Cachet Fault makes up the boundaries of a crustal block that has been uplifted hosting at present the Northern Patagonian Ice Field.