Ojos del Salado


Nevado Ojos del Salado is an active stratovolcano in the Andes on the Argentina–Chile border and the highest active volcano in the world at. It is also the second highest mountain in both the Western Hemisphere and the Southern Hemisphere behind Aconcagua at approximately 7,000 meters and it is the highest in Chile. Nevado Ojos del Salado is translated to Snowy Salty Eyes describing it being very snowy in the winter and salty with many lakes.
Due to its location near the Atacama Desert, the mountain has very dry conditions, with snow usually only remaining on the peak during winter, though heavy storms can cover the surrounding area with a few feet of snow even in summer. Despite the generally dry conditions, there is a permanent crater lake about in diameter at an elevation of on the eastern side of the mountain. This is most likely the highest lake of any kind in the world.
The ascent of Ojos del Salado is mostly a hike except for the final section to the summit which is a difficult scramble that may require ropes. The first ascent was made in 1937 by Jan Alfred Szczepański and Justyn Wojsznis, members of a Polish expedition in the Andes.
Its name, meaning roughly "Eyes of the Salty One" in Spanish, comes from the enormous deposits of salt that, in the form of lagoons or “eyes”, appear in its glaciers. An international highway between Chile and Argentina runs north of the mountain.

Geology and geomorphology

Regional

Ojos del Salado along with several other high volcanoes such as El Muerto, El Solo, Nevado Incahuasi and Nevado Tres Cruces lies at the southern end of the Central Volcanic Zone of the Andes.
Volcanic activity in the region commenced 26 million years ago in the Cordillera Claudio Gay, at the same time as the neighbouring Maricunga Belt volcanoes were active. Starting 18 million years ago, local subduction of the Nazca Plate beneath the South America Plate became increasingly shallower and this caused volcanism to shift from the Maricunga Belt to the Ojos del Salado region.
The Paleozoic basement crops out only northwest of Nevado Tres Cruces. Other geologic units in the region are Oligocene sedimentary units and volcanic rocks ranging from Oligocene age to less than 1.5 million years old. The area is part of a tectonic boundary between a volcanically active region north of the boundary and a less volcanically active region south of the boundary, which is also characterized by geographical differences, e.g. the presence of transverse valleys.

Local

Ojos del Salado like other major neighbouring mountains is a complex of lava domes and lava flows, with the main summit surrounded by peripheral domes such as El Solo and El Fraile and many other lateral centres. Fumaroles are encountered at the summit of Ojos del Salado within a depression. Potassium-argon dating has yielded ages of 1.2 ± 0.3 million years ago and less than 1 million years ago from rocks north of Ojos del Salado.
There are glaciers on the mountain, in the crater and in the form of penitentes which reach heights of. Other reports indicate the absence of glaciers on Ojos del Salado. Permafrost exists on the mountain and its melting nourishes several lakes; one lake fed by a creek lies at altitude.
Ojos del Salado is an active volcano, but the question of whether it should be considered currently active is arguable. According to the Smithsonian Institution's Global Volcanism Program, the most recent known eruption was about 1,300 years ago, with a large margin of uncertainty. However, there is also some evidence for a minor ash emission in 1993, which would definitely qualify the volcano as historically active. The presence of fumaroles high on the mountain and recent-looking lava flows, albeit of uncertain age, also argues in favor of a categorization as "active." By these definitions, Ojos del Salado is the highest historically active volcano on Earth. If the older date is accepted, the title of "highest historically active volcano" might reside instead with the somewhat lower Llullaillaco volcano, which certainly has erupted in historic times and is considered active.

Composition

Salado's rock is predominantly potassium-rich dacite and rhyodacite. Its lavas are high in biotite, hornblende, plagioclase, and opaques, with lower levels of augite, quartz, and hypersthene.

Elevation

The elevation of Ojos del Salado has been the subject of debate. The mountain is hidden behind other peaks and thus its height was not appreciated in early research until 1937, when the mountain was climbed by Polish climbers.
A 2006 article in Andes Magazine offered that Ojos del Salado may be higher than Aconcagua, although the argument was premised on older, less accurate altitude surveys. The results of these older surveys assigned Ojos del Salado an elevation of, which would have made it nearly higher than Aconcagua. As early as 1955, an estimate was made that the elevation of Ojos del Salado was, but that was "simply based on the altitude of the final camp, and the hours of ascent to the summit." In 1956, the first Chilean expedition led by the retired lieutenant René Gajardo measured the height of Ojos del Salado as with a pocket pressure altimeter. Apart from being an inexact method, the height shown by the altimeter was far too high as air pressure is generally lower in the afternoon, the time at which the team reached the summit.
An expedition to the area in the 1990s claimed that nearby Monte Pissis was even higher than Ojos del Salado. Later measurements using more precise equipment showed that Ojos del Salado is about higher than Pissis. Furthermore, in 2007 a Chilean–Argentine–European expedition organized by Andes Magazine and Azimut 360 performed a survey on both Ojos del Salado and Monte Pissis using more accurate instruments. It found the former to be and the latter Although this fits within recent handheld GPS surveys, which have estimated the mountain to be between and, the vertical error margin of the expedition's equipment,, leaves uncertainty as to the mountain's more precise altitude.
A DGPS study from Phillipe Reuter in 2007, measured Ojos del Salado as 6,891.7 meters.
Ojos del Salado has two summits, one in Argentina and the other in Chile. The difference in elevation of the two summits is less than

Motorized partial ascent

Ojos del Salado has been a popular mountain for attempts to attain the highest altitude aboard a land vehicle.
The previous long-standing record altitude for a four-wheeled vehicle was set on April 21, 2007 by the Chilean duo of Gonzalo Bravo G. and Eduardo Canales Moya. Reaching an altitude of 6,688 meters with a modified Suzuki Samurai, the duo beat the previous record of 6,646 m which had been set on March 13, 2007 by German Matthias Jeschke in a Jeep Wrangler Unlimited Rubicon.
Jeschke set the high altitude record for trucks reaching a height of 6,675 meters with a Mercedes-Benz Zetros truck on March 6, 2015. This is also a world record for a diesel-powered engine.
On April 19, 2015 Chilean Gianfranco Bianchi reached an altitude of 6,472 m with a Suzuki RMZ 450, setting the altitude record for a motorcycle.
On November 6, 2017, Matthias Jeschke, again, attempted to gain two world records, one for construction at altitude and the other by beating the then current 6,688 m record. A refuge hut was built at 6,100 m, but on December 19 it was announced the altitude record attempt had been called off at a height of 6,150 m for a combination of factors including an insurmountable rock barrier and adverse weather conditions.
On December 13, 2019, a 10-person team led once again by Matthias Jeschke finally succeeded in breaking long-standing record. They reached an altitude of 6,694 m in a modified Mercedes-Benz Unimog U 5023. It was part of an expedition to set up an emergency radio system on top of the volcano.