(2011) (1997) The
archipelago consists of a main island,
Isla Grande de Tierra del Fuego, often simply called Tierra del Fuego or Isla Grande, with an area of , and a group of smaller islands. Of the main island the westernmost 29,484.7 km2 (11,384, 61.43%) belongs to Chile, and 18,507.3 km2 (7,146, 38.57%) belongs to Argentina. The archipelago is divided by an east–west channel, the
Beagle Channel, immediately south of the main island. The largest islands south of the Beagle Channel are
Hoste and
Navarino. The western part of the main island, and almost all the other islands, belong to Chile. They are part of the
Magallanes y Antártica Chilena Region, the capital and chief town of which is
Punta Arenas, situated on the mainland across the strait. The largest
Chilean towns are
Porvenir, capital of the Chilean
Province of Tierra del Fuego, located on the main island, and, on Navarino Island,
Puerto Williams, which is the capital of the
Antártica Chilena Province.
Puerto Toro lies a few kilometers south of Puerto Williams. Arguably, it is the
southernmost village in the world. The mostly uninhabited islands north and west of the main island are part of
Magallanes Province. The eastern part of the main island and a few small islands in the Beagle Channel belong to Argentina. They are part of the
Tierra del Fuego, Antarctic Territory and South Atlantic Islands Province, whose capital is
Ushuaia. The other important city in the region is
Río Grande on the Atlantic coast, the largest in the archipelago. The
Cordillera Darwin in the southwestern part of the main island contains many glaciers that reach the ocean. While
Mount Darwin had previously been thought to be the tallest mountain in the archipelago, this distinction now belongs to the unofficially named
Monte Shipton at . The topography of Tierra del Fuego can be divided into four regions: an outer archipelago region () to the south and west, a mountainous region in the south (), a plains region () plus a sub-Andean zone in-between the last two zones ().
Geology The geology of the archipelago is influenced by the effects of the
Andean orogeny and the repeated
Pleistocene glaciations. The geology of the island can be divided into large east–west-oriented units. The southwestern islands of the archipelago, including
Cape Horn, are part of the
South Patagonian Batholith, while the
Cordillera Darwin and the area around the
Beagle Channel form the principal mountain range hosting the highest mountains. The Magallanes
fold and thrust belt extends north of
Almirantazgo Fjord and
Fagnano Lake, and north of this lies the Magallanes foreland, an old
sedimentary basin that hosts
hydrocarbon reserves.
Orthogneiss dated at 525 million years is known to underlie some of the oil wells in northern Tierra del Fuego. The
Magallanes–Fagnano Fault, a
sinistral strike slip fault crosses the southern part of the main island from west to east. It is an active
fault, located inside and parallel to the Fuegian
fold and thrust belt, and marks the boundary between a southern belt of
Paleozoic meta sediments and a northern
Mesozoic belt of sedimentary sequences. Fagnano Lake occupies a glacier-carved depression in a pull-apart basin that has developed along the Magallanes-Fagnano Fault zone.
Podzols and
inceptisols occur beneath
Nothofagus betuloides forests in Tierra del Fuego.
Climate (2009) The Tierra del Fuego region has a subpolar
oceanic climate (
Köppen climate classification Cfc) with short, cool summers and long, wet, moderately mild winters: the precipitation averages a year in the far west, but precipitation decreases rapidly towards the eastern side. Temperatures are steady throughout the year: in Ushuaia they hardly surpass in summers and average in winters. Snowfall can occur in summer. The cold and wet summers help preserve the ancient
glaciers. The southernmost islands possess a sub-antarctic climate typical of tundra that makes the growth of trees impossible. Some areas in the interior have a polar climate. Regions in the world with similar climates to southern Tierra del Fuego are: the
Aleutian Islands,
Iceland, the
Alaska Peninsula, the
Faroe Islands,
Macquarie Island, and the
Heard and McDonald Islands.
Flora Only 30% of the islands have forests, which are classified as
Magellanic subpolar. The northeastern portion of the region is made up of steppe and cool semi-desert. Six species of tree are found in Tierra del Fuego: canelo or winter's bark (
Drimys winteri);
Maytenus magellanica;
Pilgerodendron uviferum, the southernmost conifer in the world; and three kinds of
southern beech:
Nothofagus antarctica;
Nothofagus pumilio; and the evergreen
Nothofagus betuloides. Several kinds of fruit grow in open spaces in these forests, such as
beach strawberry (
Fragaria chiloensis var.
chiloensis forma
chiloensis) and
calafate (
Berberis buxifolia), which have long been gathered by both Native Americans and residents of European descent. They are the only forests in the world to have developed in a climate with such cold summers. Tree cover extends very close to the southernmost tip of South America. Winds are so strong that trees in wind-exposed areas grow into twisted shapes, inspiring people to call them "flag-trees". Tree vegetation extends to the southern tip of the region,
Isla Hornos, although the
Wollaston Islands are mostly covered by subantarctic
tundra except in wind sheltered areas where the trees can survive. File:Drimys winteri.jpg|
Drimys winteri flowers File:Nothofagus antarctica D.jpg|
Nothofagus antarctica File:Nothofagus pumilio.jpg|
Nothofagus pumilio File:Nothofagus betuloides.jpg|
Nothofagus betuloides Forests from Tierra del Fuego have expanded beyond local importance. These forests have been a source of trees that have been transplanted abroad in places with similar climate, but which originally were devoid of trees, such as the
Faroe Islands and nearby archipelagos. Most species were gathered from the coldest places in Tierra del Fuego, mainly sites with tundra borders. This effort resulted in positive changes, as the heavy winds and cool summers in the Faroe Islands did not allow the growth of trees from other regions in the world. The imported trees are used ornamentally, as curtains against wind, and to fight erosion caused by storms and grazing in the Faroe Islands.
Fauna s at Isla de los Lobos in the Beagle Channel, near
Ushuaia (2006) Among the most notable animals in the archipelago are
austral parakeets,
gulls,
guanacos,
South American foxes,
kingfishers,
Andean condors,
king penguins,
owls, and
firecrown hummingbirds.
Isla Grande de Tierra del Fuego is also home to the lizard with the world's southernmost distribution,
Liolaemus magellanicus.
North American beavers, introduced during the 1940s, have proliferated and caused considerable damage to the island forests. The governments have established a wide-reaching program to trap and kill beavers in Tierra del Fuego. Like the mainland of Chile and Argentina to the north, this archipelago boasts some of the finest
trout fishing in the world. Sea-run brown trout often exceed , particularly in rivers such as the Rio Grande and the San Pablo, and in the
Lago Fagnano. Waters adjacent to Tierra del Fuego are very rich in
cetacean diversity. Sightings of
southern right whales in Tierra del Fuego have increased in the 2000s,
humpbacks, and some others such as
blue whales,
southern fins,
southern seis, and
southern minkes. Beagle Channel is a prominent area to watch rare, endemic dolphins, and the less-studied
pygmy right whales.
Pinnipeds inhabiting the areas include
South American sea lions (
Otaria flavescens),
South American fur seals (
Arctophoca australis), the carnivorous and seal-eating
leopard seals (
Hydrurga leptonyx), and gigantic
southern elephant seals (
Mirounga leonine)the largest extant
marine mammal that is not a
cetacean.
Islands The following table lists islands over 1 . Area figures are from the USGS unless otherwise specified. == Economy ==