Mountain Ranges, Deserts and Landforms of Chile

Geography

South America occupies the southern portion of the Americas. The continent is generally delimited on the northwest by the Darién watershed along the Colombia–Panama border, although some may consider the border instead to be the Panama Canal. Geopolitically and geographically, all of Panama – including the segment east of the Panama Canal in the isthmus – is typically included in North America alone and among the countries of Central America. Almost all of mainland South America sits on the South American Plate.

History

South America is thought to have been first inhabited by humans when people were crossing the Bering Land Bridge (now the Bering Strait) at least 15,000 years ago from the territory that is present-day Russia. They migrated south through North America, and eventually reached South America through the Isthmus of Panama.

Amongst the oldest evidence for human presence in South America is the Monte Verde II site in Chile, suggested to date to around 14,500 years ago. From around 13,000 years ago, the Fishtail projectile point style became widespread across South America, with its disappearance around 11,000 years ago coincident with the disappearance of South America's megafauna.

Economy

Since 1930, the continent has experienced growth and diversification in most economic sectors. Most agricultural and livestock products are destined for the domestic market and local consumption. However, the export of agricultural products is essential for the balance of trade in most countries.

The main agrarian crops are export crops, such as soy and wheat. The production of staple foods such as vegetables, corn or beans is large, but focused on domestic consumption. Livestock raising for meat exports is significant in Argentina, Paraguay, Uruguay and Colombia. In tropical regions the most important crops are coffee, cocoa and bananas, mainly in Brazil, Colombia and Ecuador.

Geography

The Altiplano is an area of inland drainage (endorheism) lying in the central Andes, occupying parts of northern Chile, western Bolivia, southern Peru, and northwest Argentina. Its elevation averages about 3,750 meters (12,300 feet), slightly less than that of the Tibetan Plateau. Unlike conditions in Tibet, the Altiplano is dominated by massive active volcanoes of the Central Volcanic Zone to the west, such as Ampato (6288 m), Tutupaca (5,816 m), Parinacota (6348 m), Guallatiri (6071 m), Paruma (5,728 m), Uturunku (6,008 m), and Licancabur (5,916 m), and the Cordillera Real in the northeast with Illampu (6,368 m), Huayna Potosí (6,088 m), Janq'u Uma (6,427 m) and Illimani (6,438 m).

Geology

Existence of weaknesses in the Earth's crust prior to tectonic shortening: Such weaknesses would cause the partition of tectonic deformation and uplift into the eastern and western cordillera, leaving the necessary space for the formation of the altiplano basin.

Magmatic processes rooted in the asthenosphere might have contributed to uplift of the plateau.

Climate has controlled the spatial distribution of erosion and sediment deposition, controlling the lubrication along the subducting Nazca Plate, hence influencing the transmission of tectonic forces into South America.

Climate

Due to its average elevation exceeding 3,800 meters above sea level, the climate of the Altiplano is cold and dry, characterized by marked daily temperature fluctuations; the region is sometimes used to identify the altitude zone and the type of climate that prevails within it is colder than that of the tierra fría, but not as cold as that of the tierra helada. Scientists classify the latter as commencing at an elevation around 4,500 meters (or about 15,000 feet). Alternate names used in place of altiplano in this context include puna and páramos.

Physical geography

Argentine Patagonia is for the most part a region of steppe-like plains, rising in a succession of 13 abrupt terraces about 100 m (330 ft) at a time, and covered with an enormous bed of shingle almost bare of vegetation. In the hollows of the plains are ponds or lakes of fresh and brackish water. Towards Chilean territory, the shingle gives way to porphyry, granite, and basalt lavas, and animal life becomes more abundant. Vegetation is more luxuriant, consisting principally of southern beech and conifers. The high rainfall against the western Andes (Wet Andes) and the low sea-surface temperatures offshore give rise to cold and humid air masses, contributing to the ice fields and glaciers, the largest ice fields in the Southern Hemisphere outside of Antarctica.

Climate

Patagonia's climate is mostly cool and dry year round. The east coast is warmer than the west, especially in summer, as a branch of the southern equatorial current reaches its shores, whereas the west coast is washed by a cold current. However, winters are colder on the inland plateaus east of the slopes and further down the coast on the southeast end of the Patagonian region.

History

Human habitation of the region dates back thousands of years, with some early archaeological findings in the area dated to at least the 13th millennium BC, although later dates around the 10th millennium BC are more securely recognized. Evidence exists of human activity at Monte Verde in Llanquihue Province, Chile, dated to around 14,500 years Before Present (~12,500 BC). The glacial-period ice fields and subsequent large meltwater streams would have made settlement difficult at that time.

The region seems to have been inhabited continuously since 10,000 BC by various cultures and alternating waves of migration, the details of which are as yet poorly understood.

Economy

The area's principal economic activities have been mining, whaling, livestock (notably sheep throughout) agriculture (wheat and fruit production near the Andes towards the north), and oil after its discovery near Comodoro Rivadavia in 1907.

In the western forest-covered Patagonian Andes and archipelagoes, wood logging has historically been an important part of the economy; it impelled the colonization of the areas of the Nahuel Huapi and Lácar lakes in Argentina and Guaitecas Archipelago in Chile.

Sheep farming introduced in the late 19th century has been a principal economic activity. After reaching its heights during the First World War, the decline in world wool prices affected sheep farming in Argentina.

Geography

The Southern Patagonian Ice Field extends from parallels 48° 15′ S to 51° 30′ S for approximately 350 kilometres (220 mi), and has an approximate area of 16,480 km2 (6,360 sq mi), of which 14,200 km2 (5,500 sq mi) belong to Chile and 2,600 km2 (1,000 sq mi) belong to Argentina.

The ice mass feeds dozens of glaciers in the area, among which are the Upsala (765 km2 or 295 sq mi), Viedma (978 km2 or 378 sq mi) and Perito Moreno (258 km2 or 100 sq mi) in the Los Glaciares National Park in Argentina, and the Pío XI Glacier or Bruggen Glacier (1,265 km2 or 488 sq mi, the largest in area and longest in the Southern Hemisphere outside of Antarctica), O'Higgins (820 km2 or 320 sq mi), Grey (270 km2 or 100 sq mi) and Tyndall (331 km2 or 128 sq mi) in Chile.

History

Thorough explorations include the expeditions of Federico Reichert (1913–1914), Alberto de Agostini (1931), and Harold William Tilman and Jorge Quinteros (1955–1956), as well as Eric Shipton (1960–61). The first (North-South) crossing of the field was accomplished in 1998 by Pablo Besser, Mauricio Rojas, José Montt, and Rodrigo Fica. Nevertheless, some areas of the field remain largely unexplored.

From the air, initial exploration was conducted in 1928–29 by Gunther Plüschow after whom a glacier is named. From April 1944 to April 1945, the United States Army Air Forces conducted an aerial survey using the Trimetrogon method at the request of the Chilean government.

Description

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.