Highest Mountains in Chile

Geography and geomorphology

Ojos del Salado is part of the High Andes and rises from the southern end of the Puna de Atacama, a high plateau next to the Atacama Desert with an average elevation of 4,000 metres (13,000 ft). The Argentina–Chile border runs across the summit of the mountain in an east-west direction. The Argentine part is within Catamarca Province and the Chilean in Copiapo Province of the Atacama Region. The highway Chile Route 31 runs between the city of Copiapo west of the volcano and the Paso San Francisco to Argentina, lying about 20 kilometres (12 mi) north of the volcano, making it more accessible than many other volcanoes there. The region is uninhabited and lacks water resources; many parts are only accessible through dirt roads.

Geology

In South America, there are about 200 volcanoes with evidence of eruptions during the Pleistocene and Holocene along the western coast, where the Nazca Plate and Antarctic Plate subduct beneath the South America Plate in the Peru-Chile Trench. Volcanic activity is localized in four major volcanic belts, the Northern, Central (CVZ), Southern and Austral Volcanic Zones; these are separated by belts without volcanic activity and form part of the Pacific Ring of Fire. Where volcanic activity occurs, the subduction process releases fluids from the downgoing slab which trigger the formation of melts in the mantle that eventually ascend to the surface and give rise to volcanism.

Eruption history

Volcanic activity probably commenced 3.3–1.5 million years ago or during the late Pleistocene. The 3.7±0.2-million-year-old Las Lozas Andesite may have been a precursor of Ojos del Salado. The oldest rocks of Ojos del Salado are 3.5–3.4-million-year-old dacites in the lower parts of the volcano. Argentine geological maps define a "Ojos del Salado basal complex", which consists of a number of Miocene volcanoes that have erupted andesite and dacite, partially in glacial environments.

The volcano developed in two stages, with the more recent one grown on top of the older. A somma volcano structure may have formed during an eruption that generated the pumice deposits on the lower slopes of the volcano, and there are potential air fall deposits north of it.

Climate

Detailed climate data do not exist for the area. The Puna de Atacama region has an extreme climate with strong wind, high elevation, a dry climate and high insolation; the area is in or just south of the Arid Diagonal.

Temperatures at lower elevations can exceed 10 °C (50 °F) but mean annual temperatures only reach −10 °C (14 °F). Mean winds at Laguna Verde reach maximum speeds of 8–10 metres per second (26–33 ft/s) in winter; on the mountaintops they can exceed 10 metres per second (33 ft/s) and can impede climbing attempts. Winds blow strongest in the afternoon.

Geography and geomorphology

Aucanquilcha is a compound volcano in the El Loa Province of Chile's Antofagasta Region.

Roads and railways, including a branch line of the Antofagasta-Bolivia railway going to the Collahuasi mine, pass near the volcano. A road with numerous switchbacks leads up to the Aucanquilcha mine; it was built in 1972 and is now impassable because of rock falls, and might have made the mine on Aucanquilcha the highest point on Earth accessible by road. The mountain was evaluated as a potential site for the European Southern Observatory and its surroundings for the Submillimeter Array observatory.

The main volcano is composed of an east–west 8 km long chain of at least six stratovolcanoes, some with well-preserved volcanic craters, that rise 1.4 km above a platform of andesitic rocks.

Geology

Off the western coast of South America, the Nazca Plate subducts beneath the South America Plate at a rate of 7 cm/year. As it descends, it releases fluids into the mantle that induce its melting and the onset of volcanism at the surface. This volcanism of the Andean Volcanic Belt is distributed over four arcs, including the Northern Volcanic Zone (NVZ), the Central Volcanic Zone (CVZ) and Southern Volcanic Zone (SVZ), which are separated by gaps without volcanic activity. Aucanquilcha is part of the CVZ, which contains more than a thousand volcanoes (including ignimbrites and compound volcanoes). During the past 28 million years, it has produced more than 3000 km3 of eruption products; the average rate of 0.11 km3/ka is one tenth of the global maximum rate of arc magma production.

Eruptive history

Volcanic activity of the Aucanquilcha cluster commenced 11 million years ago. From 6–5 million years ago, activity increased, and at the same time the magmas became more uniform in composition and strong hydrothermal alteration commenced. The Aucanquilcha cluster generated about 340±20 km3 of volcanic rock, with each centre being active for a few hundred thousand years. Over time, centres became less distributed and their magmas more uniform. Activity waned 2–1 million years ago: the Aucanquilcha volcano proper may be a waning stage of the overall cluster. Both the timing and the duration of volcanic activity of the Aucanquilcha cluster are comparable to that of the Altiplano–Puna volcanic complex.

Climate and vegetation

Temperatures at the summit are usually below freezing, but owing to the thin atmosphere at this altitude insolation is among the highest on Earth's surface and can cause sunburns. Mean annual precipitation at Aucanquilcha is unknown, but it did not exceed 100 mm per year at Ollagüe in 1963. It occurs mostly during summer as the so-called Bolivian winter.

Geography and geology

Cerro Tronador is in the Wet Andes, a zone of high precipitation of both snow and rain. The humid temperate climate of the southern Andes has allowed several glaciers to develop due to high accumulation rates. Most of the precipitation is produced by western frontal systems from the Pacific. Located in the middle of the Andean massif at a latitude of 41° S, Tronador is part of an alpine landscape of fjords, glacial lakes, and U-shaped valleys. The forming of the landscape took place during the Quaternary glaciations, periods during which the whole area was covered by the Patagonian Ice Sheet.

Mountaineering and tourism

Tronador was first climbed by Hermann Claussen solo on 29 January 1934, after several attempts. A mountain hut, Refugio Otto Meiling, is the destination of popular day hikes on the mountain, and is named after a German mountaineer who made dozens of ascents and spent years guiding people around it. The hut is located about 1200m vertically above Pampa Linda, at the mountain's base.

Most summers the Internacional or Anon peaks (the highest of Tronador's three peaks) is climbable. However, an unusually hot summer increased rockfall to dangerous levels during January and February 2008. The Argentine side risks becoming no longer accessible due to increasingly warm weather in the region destabilising the glaciers.

Geography

Argentina and Chile have agreed that their international border detours eastwards to pass over the main summit, but a large part of the border to the south of the summit, as far as Cerro Murallón, remains undefined. The mountain is the symbol of the Argentine Santa Cruz Province, which includes its representation on its flag and its coat of arms.

On February 27, 2014, Chile's National Forestry Corporation created the Chaltén Mountain Range Natural Site by Resolution No. 74, which covers the Chilean side of Mount Fitz Roy and the surrounding mountain range.

History

After the signing of the 1881 Treaty between Argentina and Chile, the boundary in the area was defined in 1898 by the boundary surveyors, Francisco Pascasio Moreno from Argentina and Diego Barros Arana from Chile. Huemul was declared a border landmark. The surveyors had no differences in the area between Mount Fitz Roy and Cerro Stokes, unlike other territories that were subject to arbitration in the 1902 arbitral award. The boundary was defined by the following mountain landmarks and their natural continuity: Mount Fitz Roy, Torre, Huemul, Campana, Agassiz, Heim, Mayo, and Stokes (nowadays Cervantes). Chile has defended it as a border landmark.

Tourism

Fitz Roy is a popular tourist destination for hikers, as a viewpoint between the Laguna de Los Tres and the Laguna Sucia can be reached by foot from the town of El Chaltén. The total trek is around 20 kilometers for the round trip, making it possible to do the out-and-back hike within a single day, while also passing by the Poincenot campground that is run by a local association, for people who want to take more time.

Geology

The range is made up of a yellowish granite underlain by grey gabbro-diorite laccolith and the sedimentary rocks it intrudes, deeply eroded by glaciers. The steep, light colored faces are eroded from the tougher, vertically jointed granitic rocks, while the foothills and dark cap rocks are the sedimentary country rock, in this case flysch deposited in the Cretaceous and later folded.

The radiometric age for the quartz diorite at Cerro Paine is 12 ± 2 million years by the rubidium-strontium method and 13 ± 1 million years by the potassium-argon method. More precise ages of 12.59 ± 0.02 and 12.50 ± 0.02 million years for the earliest and latest identified phases of the intrusion, respectively, were achieved using Uranium–lead dating methods on single zircon crystals.

Geography

Cerro de Los Inocentes is 1,000 m (3,300 ft) above sea level and is located on Alejandro Selkirk Island, the western-most island of the Juan Fernández Islands in the Pacific Ocean. The summit of the mountain is 1,319 m (4,327 ft) high. It is the tallest mountain in the Juan Fernández Islands and is located on the southern portion of Alejandro Selkirk Island.

The island is located on the remnant of a basaltic volcano from the Pleistocene.

History

There is currently no known evidence of Polynesians or indigenous peoples inhabitating the island prior to the arrival of Europeans. Europeans first arrived at Alexander Selkirk Island in 1574. In 1935, the entire island was declared a national park.