61-584: Chachani is a volcanic group in southern Peru , 22 kilometres (14 mi) northwest of the city of Arequipa . Part of the Central Volcanic Zone of the Andes, it is 6,057 metres (19,872 ft) above sea level. It consists of several lava domes and individual volcanoes such as Nocarane , along with lava shields such as the Airport Domes. Underneath Chachani lies a caldera . During
122-409: A caldera, possibly an ash-flow caldera. The volcanic activity of Mars is concentrated in two major provinces: Tharsis and Elysium . Each province contains a series of giant shield volcanoes that are similar to what we see on Earth and likely are the result of mantle hot spots . The surfaces are dominated by lava flows, and all have one or more collapse calderas. Mars has the tallest volcano in
183-400: A diameter of 290 km (180 mi). The average caldera diameter on Mars is 48 km (30 mi), smaller than Venus. Calderas on Earth are the smallest of all planetary bodies and vary from 1.6–80 km (1–50 mi) as a maximum. The Moon has an outer shell of low-density crystalline rock that is a few hundred kilometers thick, which formed due to a rapid creation. The craters of
244-503: A large eruption occurred in 1600, Ticsani , Tutupaca , Yucamane and Casiri . Some of these volcanoes are among the highest in the world, and on average, there is one eruption of a Peruvian volcano every 13 years. The Peruvian volcanoes are part of the Central Volcanic Zone of the Andes, one of three separate volcanic belts in that mountain chain; the Central Volcanic Zone contains 44 named stratovolcanoes . Chachani
305-471: A magma chamber whose magma is rich in silica . Silica-rich magma has a high viscosity , and therefore does not flow easily like basalt . The magma typically also contains a large amount of dissolved gases, up to 7 wt% for the most silica-rich magmas. When the magma approaches the surface of the Earth, the drop in confining pressure causes the trapped gases to rapidly bubble out of the magma, fragmenting
366-601: A noticeable drop in temperature around the world. Large calderas may have even greater effects. The ecological effects of the eruption of a large caldera can be seen in the record of the Lake Toba eruption in Indonesia . At some points in geological time , rhyolitic calderas have appeared in distinct clusters. The remnants of such clusters may be found in places such as the Eocene Rum Complex of Scotland,
427-557: A present-day volume of about 154–248 cubic kilometres (37–59 cu mi); this makes Chachani one of the largest volcanoes of the Andes. Glacial erosion and landslides have affected the volcanic complex, forming cirques and U-shaped valleys and removing much of the original shape of the individual volcanoes. Some moraines have been overrun by lava flows. Chachani drains into the Rio Chili . The Quebrada Canchero, Quebrada Cabrería and Quebrada Traccra drain south to eastward into
488-403: Is a concern at Chachani. Chachani is the protector mountain spirit of Cayma The people of Arequipa sometimes refer to Chachani as the "father" of El Misti (Pichu Pichu is the "mother") and ascribed to it the ability to influence the gender of newborn children, making them daughters. The Inca worshipped Chachani and its neighbouring mountains and turned its summit into a mountain sanctuary that
549-410: Is a large cauldron -like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption . An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the structural integrity of such a chamber, greatly diminishing its capacity to support its own roof, and any substrate or rock resting above. The ground surface then collapses into
610-480: Is an about 2 kilometres (1.2 mi) high and 17 kilometres (11 mi) wide complex of lava domes , stratovolcanoes and volcanic cones ; the highest summit is 6,057 metres (19,872 ft) high, making Chachani the 84th highest peak in the Andes. The Chachani complex has an arcuate shape encompassing both the main Chachani volcano and the 5,784 metres (18,976 ft) high Nocarane to the north of Chachani, while
671-405: Is ejected, the emptied chamber is unable to support the weight of the volcanic edifice above it. A roughly circular fracture , the "ring fault", develops around the edge of the chamber. Ring fractures serve as feeders for fault intrusions which are also known as ring dikes . Secondary volcanic vents may form above the ring fracture. As the magma chamber empties, the center of the volcano within
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#1732783708186732-644: Is occasionally covered in snow. The zero degree elevation at Chachani lies at about 5,000 metres (16,000 ft). The diurnal temperature range is large and can reach 20 °C (36 °F), while ground temperatures are much more stable and higher than air temperatures. A meteorological observatory installed by the Harvard College Observatory was active on the mountain in the latest 19th century. From 3,500 to 3,900 metres (11,500 to 12,800 ft) elevation cacti , herbs , Peruvian feather grass , yareta but also lichens and mosses grow on
793-540: Is relatively young (1.25 million years old) and unusually well preserved, and it remains one of the best studied examples of a resurgent caldera. The ash flow tuffs of the Valles caldera, such as the Bandelier Tuff , were among the first to be thoroughly characterized. About 74,000 years ago, this Indonesian volcano released about 2,800 cubic kilometres (670 cu mi) dense-rock equivalent of ejecta. This
854-652: The Andes of southern Peru , 22 kilometres (14 mi) northwest of Arequipa and north of the Arequipa Airport ; the city of Arequipa is situated on the foot of Chachani and El Misti volcanoes. The road from Arequipa to Chivay runs along the southeastern foot of Chachani, and a dirt road reaches to an elevation of 5,000 metres (16,000 ft). It is considered to be one of the most easily climbed mountains between 6,000 - 7,000 m high, although acclimatization and good physical health are required to ascend it. In
915-578: The Holocene . Chachani has erupted andesite and dacite , which define a potassium -rich calc-alkaline suite with unusual adakite characteristics; adakites are magmas that form when the downgoing plate in a subduction setting melts. Phenocrysts include augite , biotite , hornblende and hypersthene ; the rhyolites of the Arequipa ignimbrites additionally contain ilmenite , magnetite , plagioclase , quartz and sanidine . The composition of
976-649: The Huaylillas Ignimbrite of southern Peru. Later, during the Quaternary the Chachani volcanic complex grew in the caldera. The older activity formed the older volcanoes Chingana northeast, Estribo east and Nocarane north of Chachani as well as the Colorado lava domes north-northwest from Nocarane and the volcanoes Chachani Base and El Angel; argon-argon dating has yielded ages ranging between 1,000,000 - 500,000 years ago for these volcanoes. Later
1037-746: The Pliocene and early Pleistocene , the volcanic group produced large ignimbrites such as the La Joya, Arequipa Airport and Yura Tuff ignimbrites; afterwards the volcanic group proper grew in the caldera until about 56,500 years ago. There have not been any eruptions during historical time, but the volcano is considered to be only dormant and due to its closeness to the city of Arequipa is considered high risk. The name means "brave" in Aymara or "mountain of man"/"mountain of male"; alternative spellings "Cacheni" and "Charchani" are also known. The volcano lies in
1098-508: The San Juan Mountains of Colorado , where the 5,000 cubic kilometres (1,200 cu mi) Fish Canyon Tuff was blasted out in eruptions about 27.8 million years ago. The caldera produced by such eruptions is typically filled in with tuff, rhyolite , and other igneous rocks . The caldera is surrounded by an outflow sheet of ash flow tuff (also called an ash flow sheet ). If magma continues to be injected into
1159-530: The Sencca Formation and the "Barroso" volcanics developed; Chachani is classified as part of the Barroso volcanics although the oldest volcanism might belong to the "Sillapaca" unit. The terrain of the volcano is formed by volcanic rocks of Eocene to recent age, which overlie a Precambrian basement and include widespread Neogene - Quaternary ignimbrites . Chachani straddles the margin between
1220-500: The airport , hydropower plants and reservoirs are within range of Chachani and human settlement has spread around its base. As of 2023, about 349000 people live on its slopes and infrastructure such as schools are within the volcano's reach. The western suburbs of Arequipa are 3 kilometres (1.9 mi) below and less than 25 kilometres (16 mi) away from the volcano and in case of renewed eruptions they would be threatened by pyroclastic flows . In addition, melting ice and snow on
1281-544: The 18–20 cubic kilometres (4.3–4.8 cu mi) 1.65 million years old Arequipa Airport, and less certainly the 1.5 cubic kilometres (0.36 cu mi) early Pleistocene Yura Tuff as well as the Capillune Formation ignimbrites appear to have been erupted by Chachani or (in the case of the Yura Tuff) from a vent north of it. Together with lava flows these form the "Pre-Chachani" units and probably are
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#17327837081861342-547: The 5,484 metres (17,992 ft) high La Horqueta together with El Rodado to its west and Chachani proper to its east forms an east–west trending ridge. La Horqueta has a young appearance and resembles an ash cone with a crater . Additional peaks are the northerly 5,852 metres (19,199 ft) high los Ángeles and the southeasterly 5,820 metres (19,090 ft) high Trigo. In total, Chachani is made up of more than 12 edifices. The Colorado lava domes which are also known as Cerro Penones in turn are located northwest from Nocarane. To
1403-711: The Arequipa area may be located underneath Chachani; to the north its outline is marked by a 20 kilometres (12 mi) wide amphitheatre while its southern part is continuous with the Arequipa depression and is generally poorly recognizable. The El Misti volcano later arose on the margin of the Chachani caldera, where it intersects the border of the Altiplano . The volcanic complex is formed mainly by aa and block lava flows that rarely reach lengths of about 10 kilometres (6.2 mi); additionally pyroclastic flows and tephra occur. The volcanic complex covers an area of about 600 square kilometres (230 sq mi) and has
1464-559: The Cabrería lava domes; formerly the Airport Domes/Los Angeles/Pampa de Palacio were considered to be the youngest and of Holocene age. However, Volcancillo may be even younger, and a post-glacial lava flow descends the western slope of Chachani between Chachani and Nocarane and phreatic eruptions may have formed Holocene-age craters on Chachani. No historical eruptions are known at the volcanic complex, and
1525-417: The Earth's volcanic activity (the other 40% is attributed to hotspot volcanism). Caldera structure is similar on all of these planetary bodies, though the size varies considerably. The average caldera diameter on Venus is 68 km (42 mi). The average caldera diameter on Io is close to 40 km (25 mi), and the mode is 6 km (3.7 mi); Tvashtar Paterae is likely the largest caldera with
1586-683: The English term cauldron is also used, though in more recent work the term cauldron refers to a caldera that has been deeply eroded to expose the beds under the caldera floor. The term caldera was introduced into the geological vocabulary by the German geologist Leopold von Buch when he published his memoirs of his 1815 visit to the Canary Islands , where he first saw the Las Cañadas caldera on Tenerife , with Mount Teide dominating
1647-514: The Moon have been well preserved through time and were once thought to have been the result of extreme volcanic activity, but are currently believed to have been formed by meteorites, nearly all of which took place in the first few hundred million years after the Moon formed. Around 500 million years afterward, the Moon's mantle was able to be extensively melted due to the decay of radioactive elements. Massive basaltic eruptions took place generally at
1708-633: The Rio Siguas. The volcano underwent five stages of glaciation in the past. During the last glacial maximum extensive glaciers formed well-developed moraines at 3,150–3,600 metres (10,330–11,810 ft) elevation; lateral moraines marking the limit of glaciation are located at 3,440 metres (11,290 ft) elevation on the southern flank. Glaciers may have also formed during the Little Ice Age , where there are moraines at 5,100–5,300 metres (16,700–17,400 ft) elevation; presently however
1769-678: The San Juan Mountains of Colorado (formed during the Oligocene , Miocene , and Pliocene epochs) or the Saint Francois Mountain Range of Missouri (erupted during the Proterozoic eon). For their 1968 paper that first introduced the concept of a resurgent caldera to geology, R.L. Smith and R.A. Bailey chose the Valles caldera as their model. Although the Valles caldera is not unusually large, it
1830-726: The Solar System, Olympus Mons , which is more than three times the height of Mount Everest, with a diameter of 520 km (323 miles). The summit of the mountain has six nested calderas. Because there is no plate tectonics on Venus , heat is mainly lost by conduction through the lithosphere . This causes enormous lava flows, accounting for 80% of Venus' surface area. Many of the mountains are large shield volcanoes that range in size from 150–400 km (95–250 mi) in diameter and 2–4 km (1.2–2.5 mi) high. More than 80 of these large shield volcanoes have summit calderas averaging 60 km (37 mi) across. Io, unusually,
1891-411: The base of large impact craters. Also, eruptions may have taken place due to a magma reservoir at the base of the crust. This forms a dome, possibly the same morphology of a shield volcano where calderas universally are known to form. Although caldera-like structures are rare on the Moon, they are not completely absent. The Compton-Belkovich Volcanic Complex on the far side of the Moon is thought to be
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1952-587: The caldera atop Fernandina Island collapsed in 1968 when parts of the caldera floor dropped 350 metres (1,150 ft). Since the early 1960s, it has been known that volcanism has occurred on other planets and moons in the Solar System . Through the use of crewed and uncrewed spacecraft, volcanism has been discovered on Venus , Mars , the Moon , and Io , a satellite of Jupiter . None of these worlds have plate tectonics , which contributes approximately 60% of
2013-676: The collapsed magma chamber, the center of the caldera may be uplifted in the form of a resurgent dome such as is seen at the Valles Caldera , Lake Toba , the San Juan volcanic field, Cerro Galán , Yellowstone , and many other calderas. Because a silicic caldera may erupt hundreds or even thousands of cubic kilometers of material in a single event, it can cause catastrophic environmental effects. Even small caldera-forming eruptions, such as Krakatoa in 1883 or Mount Pinatubo in 1991, may result in significant local destruction and
2074-526: The date of the last activity is likewise unclear. The existence of solfataras in the summit region and of hot springs at Socosani and Yura has been reported, and frequent seismic activity occurs on Chachani's southwestern flank; this activity may relate to either geothermal or tectonic phenomena. Currently, the volcano is considered to be dormant . Occasionally, mudflows descend its slopes and cause damages at lower elevations. The city of Arequipa with about one million inhabitants and infrastructure such as
2135-597: The downgoing Nazca plate falls steeply into the mantle. Volcanic activity in the Chachani region appears to have begun during the Cretaceous - Paleocene in the form of the "Toquepala" volcanics. The oldest volcanic rocks of the Western Cordillera are known under the name "Tacaza", and underwent erosion and folding before the next phase which is known as "Sillapaca". Finally, during the Miocene - Quaternary
2196-403: The emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater , the feature is actually a type of sinkhole , as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur over the course of a century,
2257-437: The foot of tall cliffs . Some of them (about six in total) are still active and are located above 4,810 metres (15,780 ft) elevation, while the lowest inactive ones end at 4,160 metres (13,650 ft) elevation. Permafrost is expected to be continuous above 5,420 metres (17,780 ft) with discontinuous occurrence above 5,050 metres (16,570 ft). Other periglacial phenomena such as needle ice are also encountered on
2318-464: The formation of a caldera is a rare event, occurring only a few times within a given window of 100 years. Only eight caldera-forming collapses are known to have occurred between 1911 and 2018, with a caldera collapse at Kīlauea , Hawaii in 2018. Volcanoes that have formed a caldera are sometimes described as "caldera volcanoes". The term caldera comes from Spanish caldera , and Latin caldaria , meaning "cooking pot". In some texts
2379-462: The higher-elevation Altiplano and the Arequipa basin at lower altitude. The younger El Misti volcano lies southeast of Chachani, across the Rio Chili . Other volcanoes in the region are Ampato and Jollojello northwest, Baquetane, Hucullani and Nevado Calcha north, Yanarico east and Pichu Pichu southeast from Chachani. Of these, Misti, Pichu Pichu and Chachani are aligned on normal faults that trend northwest–southeast and has been active during
2440-467: The human species was reduced to approximately 5,000–10,000 people. There is no direct evidence, however, that either theory is correct, and there is no evidence for any other animal decline or extinction, even in environmentally sensitive species. There is evidence that human habitation continued in India after the eruption. Some volcanoes, such as the large shield volcanoes Kīlauea and Mauna Loa on
2501-429: The island of Hawaii , form calderas in a different fashion. The magma feeding these volcanoes is basalt , which is silica poor. As a result, the magma is much less viscous than the magma of a rhyolitic volcano, and the magma chamber is drained by large lava flows rather than by explosive events. The resulting calderas are also known as subsidence calderas and can form more gradually than explosive calderas. For instance,
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2562-484: The landscape, and then the Caldera de Taburiente on La Palma . A collapse is triggered by the emptying of the magma chamber beneath the volcano, sometimes as the result of a large explosive volcanic eruption (see Tambora in 1815), but also during effusive eruptions on the flanks of a volcano (see Piton de la Fournaise in 2007) or in a connected fissure system (see Bárðarbunga in 2014–2015). If enough magma
2623-533: The largest eruptions experienced by Chachani. They occur in the wider region of Chachani and crop out in the Arequipa area and in river valleys. Their emplacement took place in the form of fast-moving hot streams of rock. An additional ignimbrite is the 13 million years old Miocene Rio Chili Ignimbrite; the vents of the Miocene units are unknown and the Rio Chili Ignimbrite appears to be related to
2684-458: The late 19th century, the good sight from Chachani was remarked upon. Politically, it lies in the Cayma, Yura and Cerro Colorado districts. Volcanoes in the southern part of Peru include from north to south Auquihuato , Firura , Coropuna , Andagua volcanic field , Sabancaya , Ampato , Chachani, El Misti , Pichu Pichu , Ubinas which has erupted intermittently since 1954, Huaynaputina where
2745-561: The magma to produce a mixture of volcanic ash and other tephra with the very hot gases. The mixture of ash and volcanic gases initially rises into the atmosphere as an eruption column . However, as the volume of erupted material increases, the eruption column is unable to entrain enough air to remain buoyant, and the eruption column collapses into a tephra fountain that falls back to the surface to form pyroclastic flows . Eruptions of this type can spread ash over vast areas, so that ash flow tuffs emplaced by silicic caldera eruptions are
2806-467: The mountain lacks glaciers and only has a snowfield . In general, glaciers in the tropical Andes have been shrinking after the end of the Little Ice Age, and especially after the 1970s. Permafrost and rock glaciers however still exist at Chachani, especially close to Nocarane, and reach lengths of 1.8 kilometres (1.1 mi); they are characterized by lobate appearances and their location at
2867-476: The only volcanic product with volumes rivaling those of flood basalts . For example, when Yellowstone Caldera last erupted some 650,000 years ago, it released about 1,000 km of material (as measured in dense rock equivalent (DRE)), covering a substantial part of North America in up to two metres of debris. Eruptions forming even larger calderas are known, such as the La Garita Caldera in
2928-573: The other two hazard scenarios. Chachani is considered to be a high-risk volcano and the Geophysical Institute of Peru in 2018 installed a monitoring station on Chachani. Several volcano hazard map exist: One shows three levels of danger depending on the distance from the edifice, the other two show areas threatened by mudflows and pyroclastic fall . Chachani is monitored with seismometers and tiltmeters . Apart from eruptions, volcano-induced pollution of neighbouring water resources
2989-462: The ring fracture begins to collapse. The collapse may occur as the result of a single cataclysmic eruption, or it may occur in stages as the result of a series of eruptions. The total area that collapses may be hundreds of square kilometers. Some calderas are known to host rich ore deposits . Metal-rich fluids can circulate through the caldera, forming hydrothermal ore deposits of metals such as lead, silver, gold, mercury, lithium, and uranium. One of
3050-528: The river which flows around the southeastern side of Chachani and has cut a canyon between Chachani and El Misti . The Rio Sumbay, one of its tributaries, runs along the eastern side of Chachani. The Rio Yura flows southward along the western side of Chachani, and upon reaching the then westward-flowing Rio Chili becomes the Rio Vitor , which eventually discharges into the Pacific Ocean together with
3111-473: The slopes of Chachani and other regional volcanoes. Vegetation is scarce to absent above 4,500 metres (14,800 ft) elevation, and much of its lower slopes were stripped of their vegetation during the colonial era. The dry soils are not suitable for agriculture . Part of the volcano is in the Salinas y Aguada Blanca National Reserve . Lizards on the mountain are the highest-altitude known reptile population in
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#17327837081863172-416: The south of Chachani lie the Airport Domes, a 8 kilometres (5.0 mi) wide lava shield with two discernible vents and a pristine appearance. The lava shield consists of overlapping lava flows with a wavy and rugose texture and a steep front which reaches heights of 1.2 kilometres (0.75 mi); evidently these were formed by viscous lava flows. A volcanic caldera associated with widespread ignimbrites in
3233-424: The summit could generate mudflows , and pyroclastic flows , lava flows and tephra falls are additional hazards. Four hazard scenarios have been established: An effusive eruption would cause serious physical damage, but only little threat to humans. Lava dome forming eruptions may give rise to pyroclastics, but there is no evidence of such pyroclastic deposits. Pyroclastic flow - and Plinian eruptions constitute
3294-722: The volcanic complex. Subduction of the Nazca Plate beneath the South America Plate occurs at a rate of 4.6 centimetres per year (1.8 in/year); the subduction process is responsible for the volcanism and earthquake activity of the region. In the Andes, volcanism is distributed between three volcanic belts, the Northern Volcanic Zone , the Central Volcanic Zone and the Southern Volcanic Zone which coincide with segments where
3355-458: The volcanic rocks has varied over the lifespan of Chachani, sometimes rocks of basaltic andesite composition were erupted as well while the younger volcanoes are usually more homogeneous; this was paralleled by a decrease in the eruption rate. Under the influence of the cold Humboldt Current and the subtropical ridge , the region features an arid climate with less than 100 millimetres (3.9 in) annual precipitation in Arequipa. The mountain
3416-564: The volcanoes El Rodado, La Horqueta and Chachani ( c. 130,000 - 131,000 years ago) formed as a west–east alignment, along with the Uyupampa lava field (about 230,000 - 280,000 years ago) far west from Chachani, the Airport Domes south (between 290,000 - 400,000 years ago), the Cabrería lava domes south-southeast and the Volcancillo dome northeast from Chachani. The youngest reported date of 56,500 ± 31,600 years ago has been obtained on
3477-651: The white "sillar" rocks that were used in construction of the famous buildings of colonial-era Arequipa, which is also known as the "white city". Volcanic group Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.226 via cp1108 cp1108, Varnish XID 225297231 Upstream caches: cp1108 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 08:48:28 GMT Caldera A caldera ( / k ɔː l ˈ d ɛr ə , k æ l -/ kawl- DERR -ə, kal- )
3538-653: The world's best-preserved mineralized calderas is the Sturgeon Lake Caldera in northwestern Ontario , Canada, which formed during the Neoarchean era about 2.7 billion years ago. In the San Juan volcanic field , ore veins were emplaced in fractures associated with several calderas, with the greatest mineralization taking place near the youngest and most silicic intrusions associated with each caldera. Explosive caldera eruptions are produced by
3599-674: The world. The oldest volcanic formations linked to Chachani are the so-called " sillars ", which are rhyolitic pyroclastic flows / ignimbrites containing pumice beds. These ignimbrites include the La Joya Ignimbrite of Pliocene age, the Plio-Quaternary Arequipa Airport Ignimbrite and the Quaternary Yura Tuff and Capillune Formation . The 16–24 cubic kilometres (3.8–5.8 cu mi) 4.8 million years old La Joya,
3660-406: Was later destroyed by sulfur mining and plundering to the point that no trace of archeological sites can be found, such as e.g. walls. Nevertheless, evidence of Inka human sacrifice known as capacocha was found during archeological expeditions; a finding from 1896 is the earliest known finding of such a sacrifice. Chachani was reportedly mined for sulfur during the colonial era and for
3721-464: Was the largest known eruption during the ongoing Quaternary period (the last 2.6 million years) and the largest known explosive eruption during the last 25 million years. In the late 1990s, anthropologist Stanley Ambrose proposed that a volcanic winter induced by this eruption reduced the human population to about 2,000–20,000 individuals, resulting in a population bottleneck . More recently, Lynn Jorde and Henry Harpending proposed that
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