Big Island of Tierra del Fuego
The Isla Grande de Tierra del Fuego is located in the extreme south of America, a continent from which it is separated by the Strait of Magellan. By area, it is the 29th island in the world and the largest, by far, of the islands of the great Fuegian archipelago. It is bordered by the Beagle Channel to the south, the Atlantic Ocean to the east, and the Pacific Ocean to the west.
This island is shared by Argentina and Chile, countries that correspond to the eastern and western part, respectively. 18,507.3 km² belong to Argentina with 38.57% of the total, while 29,484.7 km² belong to Chile with 61.43% of the island's surface. The Argentine part of the island corresponds to the province of Tierra del Fuego, Antártida and Islas del Atlántico Sur, whose capital is the city of Ushuaia. The Chilean sector of the island corresponds mainly to the province of Tierra del Fuego, belonging to the region of Magallanes and Chilean Antarctica; the capital of the referred province is Porvenir. The rest of the Chilean section of the island corresponds to the Chilean Antarctic province, also belonging to the aforementioned region.
Geography and relief
The Big Island of Tierra del Fuego has two well-differentiated sectors, the northern two thirds are made up of plateaus and gently undulating plains. The south is occupied by the southern end of the Andes mountain range, which has an East-West orientation here. Its territory is 47,992 km². The Darwin mountain range in the southwestern (Chilean) sector has the highest points on the island. Of them Mount Shipton with 2469 m s. no. m., is the highest. Numerous glaciers develop on the higher and less sunny slopes of the mountain ranges. In some cases, these can descend to sea level, in the case of those that break off from the Darwin mountain range to the south, such as the Pía glacier on the Beagle channel. At the bottom of the valleys there are lakes and lagoons of glacial origin such as the Fagnano and Yehuin lakes. The climatic conditions favor the abundant development of peat bogs in almost the entire island, especially in the more humid environments of the southern half. The southern coasts, where the Andes are in contact with the channels of the Pacific Ocean, are high and very rugged, with numerous fjords. The northern coasts, on the other hand, are not very rugged, drawing attention to the almost circular San Sebastián Bay and the Useless Bay.
Extreme Points
Its northern end is located approximately at parallel 52°30' south — (Punta Anegada, Chile). As the southern end, the website of the Argentine National Geographic Institute indicates Cape San Pío in Argentina. However, the website of the Undersecretariat of Cadastre of Tierra del Fuego indicates that Punta Falsa is even further south than Cape Saint Pius.
Hydrography
In addition to lakes and glaciers, the island has numerous rivers. These drain into the Strait of Magellan, the Beagle Channel, the Pacific Ocean, and the Atlantic Ocean. The largest of these rivers is the Rio Grande which empties into the Atlantic. Fishing in the rivers of Tierra del Fuego is world famous, with the best fishing rivers being the Cóndor, Grande, Paralelo and Azopardo, where you can find various varieties of trout up to 10 kg [citation required].
Geology
The rocks exposed on the Isla Grande of Tierra del Fuego reveal a complex geological history, characterized by three main tectonic stages:
- During the late Jurassic to the Early Cretaceous (150-100 million years -Ma-), the south-west margin of the supercontinent Gondwana was subject to extensional efforts of the earth's crust. These resulted in the development of a narrow and elongated sedimentary basin, of NO-SE orientation (at current coordinates). This basin was constrained to the east by an arch of volcanic islands that continuously provided sediments, while by the opposite margin was present the continental mass of the supercontinent Gondwana, which began to fragment globally giving rise to the continent of South America. The configuration of the basin resembled what is now known as the sea of Japan, limited to one side by the volcanic island of Japan and the other by the Asian continent. This basin received, as has been said, abundant sediments mainly from the volcanic arch, which were filled in relatively deep marine environments. The anoxia conditions in the seabed and a relative proliferation of organisms that, when dying, constituted a high contribution of organic matter to the filling of the basin, were favourable conditions for this sedimentary filling to constitute the main hydrocarbon generating rock of the Southern basin.
- The second stage in the geological history of Tierra del Fuego resulted from a drastic change in the behavior of the tectonic plates involved in the region from the Late Cretaceous (100 Ma) and to the early Miocene (approx. 16 Ma), which caused the cortex to begin to compress and involved the progressive closure of the marine basin. In this way, the arch of volcanic islands began to move towards the NE, approaching the continental edge of the basin, compressing the sedimentary filling of the basin. This stage resulted in the formation of the Andes Fueguinos, where you can see thick successions of sedimentary rocks that, having formed part of the seabed, are exposed to hundreds of meters above sea level. A clear example of this phenomenon can be seen on Mount Olivia, where, when looking carefully, many folds are observed in the sedimentary layers. The closure of the basin involved a shortening and widening of the bark, manifested by the formation of a notorious mountain chain. The deformation spread beyond the current mountain front, occupying almost two-thirds of the island's southern regions. The weight of such a mass produced the partial sinking of the earth's crust in the environment adjacent to the mountain range, thus forming an ante-country basin, which bears the name of the Austral basin. This basin received an important amount of sediments mainly from the erosion of the Andes Fueguinos while they were rising, in addition to the continued contribution of the volcanic arch that was still active. Once the earth's crust stopped compressing, it culminated in the ascent and formation of the Fueguinos Andes and the Austral basin was completed during the Miocene.
- The third tectonic stage starts about 10 Ma, in the late Miocene, where the boundary between the South American and Scotia plates is formed. This limit, which crosses the Andes Fueguinos in Tierra del Fuego, remains active today and is manifested by the known "Fagnano-Magallanes failure", responsible for the active seism in the region.
From the Pliocene and during the Quaternary and until at least between 16 and 10 thousand years ago, Tierra del Fuego was covered by extensive glaciers, whose manifestation in relief is still observed today: ancient glacial valleys make up nowadays elongated depressions occupied by the sea (Beagle Channel, Almirantazgo Sound) or by fresh water (Fagnano, Blanco, Yehuin lakes). The deposits of moraines, kames, eskeres and drumlins associated with glacial dynamics covered a large part of the rocky massifs of the Fuegian Andes. After the thaw, the island began to take its current appearance; The melting of the glaciers generated important fluvial courses, with their associated glacifluvial deposits of gravel and sand. The associated fluvial valleys are currently occupied by rivers of much smaller magnitude, such as the Grande and the San Pablo, and most of the fluvial courses that are born in glacial cirques or in lagoons of glacial origin. During the Pleistocene, the The relative level of the sea suffered numerous transgressions and regressions, associated with the successive glaciations, until it acquired its current position during the Holocene (11,000 years to the present), thus configuring the Big Island of Tierra del Fuego as we know it.
Seismicity
The region responds to the Fagnano-Magallanes fault, a regional seismogenic fault system, with an east-west orientation that coincides with the transform boundary between the South American (to the north) and Scotia (to the south) plates, with medium seismicity; and its last expression occurred on December 17, 1949 (73 years old), at 22:30 UTC-3, with a magnitude of approximately 7.8 on the Richter scale.
The municipal Civil Defense must carry out an earthquake drill; and warn about listening - obey about
- Area
- Half seismic with 7.8 Richter, with seismic silence of 73 years, another lesser scent 13 years ago by the earthquake of Ushuaia of 2010 with 6,3 Richter
Demographics
The island has more than 130 thousand inhabitants distributed as follows:
| Sector | Population | Percentage | Density |
|---|---|---|---|
| TDF Argentina | 126 998 | 94.84 | 6.86 |
| TDF Chile | 6 904 | 5.16 | 0.20 |
| Total | 133 902 |
The population in Argentine territory is greater due to development and the successful Argentine plans in tourism and industry to encourage the settlement of people there. It is believed that the 2010 Census had several errors and that the Argentine sector has more than 180,000 inhabitants.
The main population centers are:
- Rio Grande (Argentina): 66 475 inhabitants (2010)
- Ushuaia (Argentina): 56 593 inhabitants (2010)
- Porvenir (Chile): 5 078 inhabitants (2002)
- Tolhuin (Argentina): 2 626 inhabitants (2010)
- San Sebastián (Argentina): 940 (2012)
- Cerro Sombrero (Chile): 687 inhabitants (2002)
- Puerto Almanza (Argentina): 100 inhabitants (2010)
Flora
The plains of the northern sector of the island are covered by steppes and cool semi-deserts, dominated by a formation of tussok (coironales or coirón steppe) whose characteristic species is the Festuca gracillima. Phytogeographically, they belong to the Fuegian Patagonian phytogeographic district of the Patagonian phytogeographic province.
The Andean summits present cold deserts that are included in the southern high Andean phytogeographic district of the Altoandina phytogeographic province.
Only 30% of the island is covered by forests, which belong to the Sub-Antarctic Phytogeographic Province. According to the dominant tree species, they are classified into two types; in those of the Magellanic sub-Antarctic phytogeographic district, evergreen species dominate, and they are located in areas close to sea level and with abundant rainfall. In the drier or higher altitude areas are the forests of the Sub-Antarctic Deciduous Forest Phytogeographic District, in which deciduous species dominate.
In the forests of Tierra del Fuego you can find 7 tree species: cinnamon (Drimys winteri), hardwood Maytenus magellanica, Guaitecas cypress (Pilgerodendron uviferum) —the southernmost conifer in the world—, notro (Embothrium coccineum), and 3 species of southern beech; ñirre Nothofagus antarctica, lenga Nothofagus pumilio and the evergreen Magellanic coigüe Nothofagus betuloides. In the open spaces of these forests, certain types of plants with edible fruits grow, such as the strawberry (Fragaria chiloensis var. chiloensis f. chiloensis ) and calafate (Berberis buxifolia), which were and are collected by the natives and peasants respectively. These forests are unique in the world for having developed in a climate with such cool summers (around 9°C). Tree cover extends very close to the southernmost tip of South America. The winds are so strong that areas exposed to the wind the trees grow twisted by the force of the winds, and people call them "flag-trees" because of the shape they need to take in their fight against the wind. Tree vegetation extends as far south as Isla de los Estados, Isla Navarino, and north to Isla Hoste. At altitudes close to 500 m s. no. m. dwarf communities of Nothofagus can be found.
The island's forests have ceased to have local importance, they have been the source of trees that have been planted in other parts of the world in places that have much the same climate but were originally devoid of trees such as the Faroe Islands and nearby archipelagos; most of the species were collected from the coldest parts of Tierra del Fuego in sites mainly adjacent to the tundra. The strong winds and cold summers did not allow the growth of trees in Faroe from other regions of the world, so the Fuegian species are now used as ornamentals, to form windbreaks and to fight against erosion caused by storms and the grazing.
Wildlife
Among the wild fauna, the following species are recognized:
Tetrapods: guanacos (which were of great importance for the economy of the Shelknam culture), the Fuegian culpeo or red fox, the tuco-tuco (rodent), and the huillín (native otter species) and smaller rodents such as mouses and mice. Among the introduced fauna are the chilla fox, the Castile rabbit, the muskrat, the Canadian beaver, and the American mink. The beaver, brought from Canada to influence the hunting of this animal and the sale of its skins, has caused severe ecological damage in the area.
Pinnipeds: The Fuegian coast is frequently visited by sea lions, leopard seals and elephant seals. Numerous colonies of the former are recognized, and a few of the latter two (elephant seals in Ainsworth Bay and leopard seals on the southern coast of the Darwin Range, in the Beagle Channel).
Cetaceans: Some species of mysticetes and toothed whales circulate in the seas surrounding the Big Island, including minke whales, southern right whales, bottlenose dolphins, killer whales, sperm whales, and pilot whales.
Birds: Among the numerous birds of both marine and terrestrial, lake and marsh habitats, we can list condors, eagles, falcons, woodcats, owls, sparrows, thrushes, doves, cauquens, cormorants, penguins (king, magellanic, chinstrap), oystercatchers or pilpilenes, macas or saplings, seagulls, terns, albatrosses, petrels, etc.
Reptiles: Only one species of reptile is known, the Magellanic lizard (Liolaemus magellanicus), which inhabits the steppe area north of the Rio Grande.
Amphibians: Only one species inhabits the island, and only in the Chilean sector, it is the three-striped toad, also being the southernmost amphibian in the world.
Climate
The climate in this region is quite inhospitable. It is subpolar oceanic (Köppen climate classification Cfc) with short, cool summers and long, wet, and cold winters: the northeast is characterized by strong winds and little precipitation; in the south and west it is very windy, misty and humid most of the year and there are few days of the year without rain, sleet, hail or snow. On Isla de los Estados, 230 km east of Ushuaia, it receives 1,400 mm of rain. Rainfall is heaviest in the far west, 3,000 mm per year.
Temperatures are very uniform throughout the year: in Ushuaia and Porvenir they barely exceed 9 °C in summer and average 1 °C in winter. Snowfall can occur in summer. The cold and humid summers help preserve the ancient glaciers. The southernmost islands have a typical sub-Antarctic Tundra climate that makes tree growth impossible. The annual thermal variation increases slightly in the northeast: while in Ushuaia the average temperature in summer is 10.5° and in winter 2°, in Río Grande it is 11° in summer and 0° in winter
There are some areas in the interior that have a polar climate. Regions in the world with climates similar to Tierra del Fuego are: Aleutian Islands, Iceland, Alaska Peninsula and Faroe Islands. The winters are very long and rigorous in which the snowfalls are continuous, during the winters, when the temperatures are constantly below -10 °C (10 degrees Celsius or Celsius below zero) the hours of sunshine are scarce (dawn towards the 9:30 a.m. and it gets dark around 5:00 p.m.), spring tends to have frequent drizzles and occasional snowfalls, summers are pleasant, although with temperatures that barely exceed 15 °C (exceptionally there have been a few days with temperatures that hovered around 30 °C), If in winter the hours with sun are few, on the other hand, during the Fuegian summer the sun rises early and only sets around 10:30 p.m. Throughout the year the winds (howlers or roarers) are frequent and strong, blowing from the southwest quadrant, bringing cold air and a lot of humidity that condenses and precipitates in the mountain ranges.
History
Original peoples of Tierra del Fuego
Regarding the pre-Columbian population, the Fuegian archipelago has been inhabited by Homo sapiens sapiens for about 10,000 years.
The first settlement was the work of Paleoamericans, who would have been the ancestors of the Yagans, who mainly inhabited the eastern region, and, perhaps partially, of the Kawésqar, who occupied the steep and rugged western coasts.
Around the XIV century, the Selknam —an ethnic group of the Amerindian group, the Pámpidos subgroup and the Tehuelche lineage, also called "Patagonians" - entered Tierra del Fuego. This new population settled mainly in the steppe region, approximately the northern half of the archipelago; The Selknam, also called "onas" by the Yagans, called the island Karukinka, 'our land'. Subsequently, a lineage of the Selknam group entered the extreme southeast of the territory and mixed with the Yagans, giving rise to the Mánekenk ethnic group, commonly known as "haush" or "aush".
The vast majority of the original population of the island perished between the end of the XIX century and the beginning of the XX, victim mainly of an extermination campaign carried out by Patagonian ranchers. Currently, a small number of descendants of the Fuegian peoples live on the island.
Colonial period
The first Europeans who had contact with this island were the members of a Spanish expedition under the command of Ferdinand Magellan, around August 21, 1520. The name is attributed to the vision these first European sailors had of it. they explored its coasts: from their boats they could see surprising and constant bonfires. Thus, it was named "Land of smoke", a name that Carlos I of Spain would modify to "Tierra del Fuego".
The bonfires were the way in which the natives protected themselves from the southern cold, indigenous Selknam (or Onas, in Yagán) and Yámanas (or Yaganes) who, despite the harsh climate, barely wore clothes. Only fire and their special metabolic adaptation (body temperature one degree higher than ours) kept them warm. They carried lit fires even in their lenga bark canoes, which they used to fish and hunt marine mammals.
On November 1, 1520, Magellan and his companions entered the strait they called "De Todos Los Santos" (currently called the Strait of Magellan), and made a reconnaissance of the northern coasts of the island, believing that it was a coastal region of the Terra Australis Incognita and not an insular group of America. The voyage lasted 19 days.
In 1525 Francisco de Hoces, in command of the caravel San Lesmes, separated from the García Jofre de Loaísa Expedition, discovered the arm of the sea that separates the southernmost part of America from the South Shetland Islands, and was the first to double Cape Horn and discover the passage between Antarctica and America (although he did not go into the Pacific, as he returned with the rest of the expedition, which would cross the Strait of Magellan), all this according to the relationship of the This trip was made by Andrés de Urdaneta, although there are authors who have studied the impossibility of Hoces and San Lesmes reaching so far south. in Spain, Argentina and other Spanish-speaking countries. Sixty years later, the Englishman Francis Drake crossed it, which is why it is called Drake Passage or Passage in the Anglo-Saxon world, in international cartography and also in Chile.
Around 1555, the Spaniard Juan de Alderete attempted to conquer Tierra del Fuego but, like Pedro Sarmiento de Gamboa, had to give up due to inclement weather.
On January 24, 1616, the Dutchman Jakob Le Maire from the expedition of the brothers Jan and Willem Schouten, discovered the Strait of Le Maire and gave its name to Isla de los Estados. On January 29, they discovered and passed Cape Horn, which they named after the ship Hoorn.
In 1619 the brothers Bartolomé and Gonzalo García de Nodal circumnavigated the Tierra del Fuego archipelago sent by King Philip III of Spain. The second returned to the Strait of Le Maire in 1622 but died before reaching Araucanía. On February 10, 1619, Diego Ramírez discovered the islands.
In 1620 the Spaniard Diego Ramírez de Arellano, confirming that Tierra del Fuego was not a continent, but an island, renamed it "Isla de Xativa", in honor of Játiva, the city where he was born.
In 1624 the Dutchman Jacques L'Hermite, returning from Peru, gave his name to the Hermite Islands and Nassau Bay and explored Tierra del Fuego.
In 1643 the Dutch corsair Hendrick circumnavigated the Isla de los Estados proving that it is an island.
In 1765 the shipwreck Purísima Concepción occurred in the Falsa cove (Argentine sector of the island). The first European settlement on the island was established there for three months, called Port Consolation. The castaways (193) built a boat that they called Our Royal Captain San José and Las Animas and returned to Buenos Aires.
Between December 11, 1768, and January 21, 1769, James Cook's first voyage expedition to the South Pacific, commanded by HMB Endeavour, toured the northeast coast of the island in its crossing of the Strait of Le Maire to pass to the Pacific around Cape Horn. Cook surveyed the coast of the island, made profiles of it and gave very exact references for the time of its coordinates. The passage of the strait was difficult. The expedition anchored for 5 days in Buen Suceso Bay, on the Miter peninsula, to stock up on wood and water before facing the passage of Cape Horn to the Pacific Ocean. There they had peaceful contacts with the Haush natives, of whom both Cook and the naturalist Joseph Banks, who was part of the scientific team of the expedition, made descriptions of their appearance, clothing and ways of life, and the cartoonist Sydney Parkinson several illustrations. And a party led by Banks and Daniel Solander, also a naturalist, went into the area to collect samples of plants and animals. A sudden change in weather that brought on a snowfall forced them to spend the night outdoors and two of Banks's servants died of hypothermia.
Republican era
After the independence of Argentina and Chile, the two new states discussed sovereignty over the island at length. In July 1876, the foreign ministers of both countries, Bernardo de Irigoyen and Diego Barros Arana, within a general agreement on the borders, decided to divide the island with an imaginary line that would separate the Chilean sector, to the west, from the Argentine sector, to the east. The border agreed by both countries by virtue of the Boundary Treaty of 1881 and the Boundary Protocol of 1893 extends from Cabo Espiritu Santo, at the mouth of the Strait of Magellan, to the Beagle Channel, following longitude 68º 34' EITHER.
Decades before (1840s) the settlement of the white population had already begun, initiated with the introduction of Anglican missionaries and Salesian Catholics. After them came the first ranchers, who began to put strong pressure on the indigenous population.
In 1881 gold seekers began to arrive in Tierra del Fuego, who, after some research, managed to find the precious metal on the island. The news spread quickly, giving way to a gold rush that attracted numerous European immigrants. Among them came Julius Popper, who managed to build a small mining empire, based on questionable methods, such as the genocide of the native population.
The sudden wealth of gold allowed the establishment of the main urban populations, such as Porvenir, in Chile, founded in 1894. In 1884, in the south of Isla Grande, on the Beagle Channel, the Ushuaia sub-prefecture in the vicinity of the Anglican mission founded in 1869. In the north, the Salesian mission was established in 1893 on the Río Grande, along which a town closely linked to livestock activity also began to grow. In 1908 the town of Puerto Yartou was founded. The Town of Río Grande was officially founded as an agricultural colony of Río Grande only in 1921.
In the last years of the XIX century, the first large sheep farms on the island were created, owned by the Menéndez families and Bridges.
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