Aerial view of Sabancaya, the summit in the left background is Ampato
|Elevation||5,976 metres (19,606 ft)|
|Prominence||~500 m (1,640 ft)|
|Volcanic arc/belt||Central Volcanic Zone|
|Last eruption||November 2016 (ongoing)|
Sabancaya is an active 5,976-metre-high (19,606 ft) stratovolcano in the Andes of southern Peru, about 70 kilometres (43 mi) northwest of Arequipa. It is considered part of the Central Volcanic Zone of the Andes, one of the three distinct volcanic belts of the Andes. The Central Volcanic Zone includes a number of volcanoes, some of which like Huaynaputina have had large eruptions and others such as Sabancaya and Ubinas have been active in historical time. Sabancaya forms a volcanic complex together with Hualca Hualca to the north and Ampato to the south and has erupted andesite and dacite. It is covered by a small ice cap which leads to a risk of lahars during eruptions.
Sabancaya has generated numerous long lava flows especially during the early Holocene, while activity in the later Holocene has been more explosive. Historical reports indicate eruptions during the 18th century. The volcano returned to activity in 1986, culminating in a large eruption in 1990. Since then it has been continuously active with the emission of ash and gas.
The name "Sabancaya" is Quechua and means tongue of fireor spitting volcano, likely a reference to the eruptive activity. The name is attested from 1595, implying that volcanic activity was observed since that date.
Sabancaya lies about 70 km (43 mi) northwest of Arequipa. The Rio Colca valley is located north of the Sabancaya-Hualca Hualca-Ampato volcano complex.
The subduction of the Nazca Plate beneath the South American Plate in the Peru-Chile Trench leads to volcanic activity in the Andes. This volcanic activity presently occurs in three segments, the Northern Volcanic Zone, the Central Volcanic Zone and the Southern Volcanic Zone. There is an additional volcanic belt south of the Southern Volcanic Zone, the Austral Volcanic Zone.Sabancaya is located in the Central Volcanic Zone of the Andes, which extends through southern Peru. Many volcanoes in the Central Volcanic Zone are poorly known, owing to their remote locations and adverse conditions such as high altitude.
Sabancaya is part of a series of volcanoes that line the southwestern coast of Peru at a distance of roughly 100 kilometres (62 mi) from the shore. Of these volcanoes, Sabancaya, El Misti, Ubinas, Huaynaputina, Ticsani and Tutupaca have been active during historical time. Further volcanoes in the area with Pliocene-Quaternary activity are Sara Sara, Solimana, Coropuna, Ampato, Chachani, Yucamane, Casiri and Tacora. All these volcanoes are considered part of the Central Volcanic Zone of the Andes, and lie c.150–200 kilometres (93–124 mi) east of the Peru-Chile Trench. Notable among them are Ampato and Coropuna for exceeding a height of 6,000 metres (20,000 ft), Huaynaputina and El Misti for their large eruptions and Ubinas and Sabancaya for their recent activity.
These volcanoes are found in places where strike-slip faults which delimit the volcanic arc and strike along its length intersect additional faults formed by extensional tectonics.Such faults occur around Sabancaya as well and include the Huambo-Cabanaconde, the Huanca, the Ichupampa, the Pampa Sepina, Sepina, Solarpampa and Trigal faults; the volcanoes Ampato and Sabancaya are aligned on this fault, which may thus be responsible for their existence. These fault systems are still active and experience occasional earthquakes and deformation.
Sabancaya is 5,960 metres (19,554 ft) high and rises 1,500 metres (4,920 ft) above the surrounding terrain. It forms a group of volcanoes with the northern Hualca Hualca and the southern Ampato in the Cordillera Occidental, which tower above the Colca Canyon in the north and the Siguas Valley in the southwest. Ampato and the more heavily eroded Hualca Hualca are the dominant volcanoes of this group, with Sabancaya forming a northeastward extension of the former 4–5 kilometres (2.5–3.1 mi) away from Ampato's summit. There is evidence of age progression from the oldest, Hualca Hualca, over Ampato, to the youngest volcano, Sabancaya.
Sabancaya consists of two separate centres that are formed by neighbouring domes, Sabancaya I North and Sabancaya II South. 20–25 cubic kilometres (4.8–6.0 cu mi).The summit crater of the volcano lies between these two domes, with traces of an additional crater just northeast. Despite the presence of an ice cap, lava flows are recognizable in the summit area. They have a total volume of
A set of over 42 Holocene lava flows emanates from the volcano, 68 square kilometres (26 sq mi), with individual lava flows extending up to 8 km (5.0 mi) east and west from between its two neighbours. The lava flows at larger distances are older than the ones close to the vent. These flows are blocky, have lobe structures and reach thicknesses of 60–170 metres (200–560 ft); the total thickness of this pile of lava flows is about 300–400 metres (980–1,310 ft). Pyroclastic flow deposits are also found, but they might originate from Ampato rather than Sabancaya.and covers a surface area of about
Sabancaya, like its two neighbours, is covered by an ice cap 2.5–3 kilometres (1.6–1.9 mi) from the summit. In 1997, a surface area of 3.4 square kilometres (1.3 sq mi) was reported. Between 1986 and 2016 the mountain lost over three quarters of its ice cap, and the remaining ice field broke up into several ice bodies. Moraines at elevations of 4,450–4,250 metres (14,600–13,940 ft) above sea level testify to the occurrence of more extensive glaciation during the last ice age between 25,000 and 17,000 years before present; these moraines have diverted some lava flows. Younger moraines are found at higher altitudes, 4,400–4,650 metres (14,440–15,260 ft) above sea level, and may have formed between 13,000 and 10,000 years ago, shortly after the beginning of the Holocene.which in 1988 extended to distances of
Earthquake activity has allowed the identification of a candidate magma reservoir beneath Pampa Sepina northeast of Sabancaya about 10 kilometres (6.2 mi) away from the summit. Between 1992 and 1996 this area inflated at a depth of 11–13 km (6.8–8.1 mi) below sea level, indicating that the magma supply system of Sabancaya may not be centered directly below the volcano. Indeed, a phase of ground uplift at Hualca Hualca volcano and earthquake swarms in 1990 could indicate that the magma chamber of Sabancaya is actually under the neighbouring volcano.
The tectonic conditions in the region have not been constant over time; at various times the plates approached each other at higher speed, and this led to a compressional tectonic regimen. In the Western Cordillera however, tensional faulting facilitated the occurrence of voluminous volcanism. This faulting is still underway and produces earthquakes in the area.
The basement of the volcano is formed by Precambrian rocks, which are overlaid by various sediments and volcanic formations of Mesozoic and Cenozoic age. Especially during the Neogene, the supply of volcanic material was high and dominated the region, forming a volcanic "foot"; the present volcanoes are constructed on this volcanic "foot".This "foot" is made out of an ignimbrite plateau that drops down south. The "foot" beneath Ampato, Hualca Hualca and Sabancaya has been dated 2.2 ±0.15 million years ago, while a lava flow beneath the first and the last of these is about 0.8 ±0.04 million years old.
Fresh volcanites of Sabancaya consist of porphyriticandesite and dacite which form a potassium-rich calc-alkaline suite similar to other volcanoes in southern Peru; the andesites occasionally appear as fine-grained enclaves. The rocks are not very vesicular and contain a moderate amount of phenocrysts. Minerals encountered in both phenocrysts and groundmass are amphibole, biotite, hornblende, iron oxide, plagioclase, pyroxene and titanium oxide; degraded olivine is also found.
The magmas formed at temperatures of 920–990 °C (1,688–1,814 °F) with uncertainties of 30–50 °C (54–90 °F); the highest temperatures are associated with the 1992 eruption products. Isotope data indicate that the pre-magmas interacted with the crust at great depths before rising to shallower magma chambers. In these shallower magma chambers, magma genesis involved processes of magma mixing which formed at least part of the andesites and fractional crystallization which gave rise to the dacites. Partial crystallization and flow events within the magma chamber caused the formation of the andesite enclaves. The total magma production rate of Sabancaya without accounting for repose periods is about 0.6–1.7 cubic kilometres per year (0.14–0.41 cu mi/a).
Sabancaya is a source of volcanic gases such as SO
2 and H
2O. The amount of water emitted by Sabancaya is noticeably large for a volcano (about 250,000 tonnes per day or 2.9 tonnes per second); the source of this water might be an evaporating hydrothermal system in the volcano. Together with Ubinas Sabancaya is among the main emitters of CO
2 and H
2O in the Central Volcanic Zone of the Andes and among the top fifteen volcanic emitters on Earth.
Most activity at Sabancaya occurs in the form of lava domes and lava flows, one of which is dated to 5,440 ±40 years before present on the eastern flank. BC, 420–150 BC, 100 BC – 150 AD and between 1200–1400 AD, could have originated either on Sabancaya or Ampato, however. There is evidence that early and middle-Holocene Sabancaya mostly erupted lava, while the late-Holocene volcano was more explosive in its activity. It is possible that the Inca performed human sacrifices in response to eruptions of Sabancaya to calm down the mountain spirits.Additional surface exposure dating has yielded ages of 6,650 ±320 and 6,300 ±310 on various lava flows, indicating that effusive activity started shortly after the beginning of the Holocene although the basal part of the edifice did not exist yet at that time. Pyroclastic eruptions are less common and have a low volume, with one such occurrence dated to 8,500 years before present. This tephra layer, along with layers dated 2500-2100
Spanish chronicles mention probable eruptions in 1752 and 1784, which might have left layers of tephra. 12 kilometres (7.5 mi) from the summit and was accompanied by strong earthquake activity and the formation of eruption columns that reached heights of 7 km (4.3 mi). The eruption and further activity, through 1990, enlarged the summit crater and caused the formation of new rows of fumaroles. Chemical analysis, of the volcanic rocks, suggests that this phase of volcanic activity was started by the injection of mafic magma into the magma chamber. This eruption displaced between 4,000 and 1,500 people in the region.After the 18th century, the volcano went dormant for about two hundred years during which only fumarolic activity was recorded. In late 1986 an increased fumarolic activity heralded the onset of a new eruptive period, and satellite images observed the occurrence of black spots where the ice had melted or boiled away. During this time, the death of animals was observed in the area. This period reached a climax in May 1990, when an eruption with a volcanic explosivity index of 2–3 occurred. This eruption threw ash to distances of
After the large 1990 eruption, the style of activity at Sabancaya changed towards a frequent occurrence of explosive eruptions with however low output, 1 kilometre (0.62 mi) from the summit crater; this pattern of activity is referred to as "Vulcanian eruptions". These explosive eruptions became less common over time (from paroxysms every 20–30 minutes to only 5–6 eruptions per day) and the proportional amount of fresh volcanic material increased at first; since 1997 discontinuous eruptions generate steam columns no higher than 300–500 metres (980–1,640 ft) and ejected material is almost entirely lithic. Satellite imagery has evidenced the occurrence of temperature anomalies on Sabancaya on the scale of 13 K (23 °F), probably owing to fumarolic activity.which threw ballistic blocks to distances of about
In March and April 2013, fumarolic activity and the occurrence of seismic swarms increased SO
2 , which was being emitted at a rate of 1,000 tonnes per day (0.012 t/s) in 2014. Ash was emitted by the volcano multiple times through 2014 and 2015.
A further increase of fumarolic activity was observed in 2016, when new fumaroles appeared and sulfur flux increased to 6,000 tonnes per day (0.069 t/s) sulfur dioxide. Ash eruptions have occurred since 6 November 2016, with an eruption column 3 km (1.9 mi) high five days later. A lava dome began to grow in 2017 within the crater, with unsteady explosive activity and occasional seismic swarms. In early 2020 there were about eight explosions every day. A persistent gas plume lies above the volcano and repeated emissions of ash have happened, resulting in several alerts for the local population.
Sabancaya rises above the valleys of the Colca river and of some tributaries of the Siguas river with about 35,000 people living in them. 30 kilometres (19 mi) from the volcano. The flanks of Sabancaya themselves include roads and a major power line that comes from the Mantaro Power Plant and delivers electricity to southern Peru; all of these could be threatened in an eruption. In the case of a major Plinian eruption, at least 60,000 to 70,000 people would be threatened. Rock fall would affect the area close to the summit domes, as would pyroclastic flows; these would be a further hazard to the valleys draining the volcano.Sabancaya is particularly dangerous for the Colca river valley, a major tourism destination in Peru with the towns Achoma, Cabanaconde, Chivay, Ichupampa, Lari, Maca, Madrigal, Pinchollo, Yanque and others. About 30,000 people live within
The presence of an ice cap is an additional source of danger,as its melting during a volcanic eruption could form hazardous lahars, although the small volume of the ice cap limits their damage potential. The Majes River and Sihuasi River drainages would be threatened by such mudflows in case of an eruption; the former is the site of a major irrigation project. Other dangers from eruptions at Sabancaya are tephra fallout, which can impact the health of people; and lava flows, which however are not much of a threat to humans owing to their slow speed.
The Peruvian Volcanological Observatory SO
2 air pollution in the Colca valley, which can damage plants and cause respiratory distress in animals and humans.
Parinacota, Parina Quta or Parinaquta is a dormant stratovolcano on the border of Chile and Bolivia. Together with Pomerape it forms the Nevados de Payachata volcanic chain. Part of the Central Volcanic Zone of the Andes, its summit reaches an elevation of 6,380 metres (20,930 ft) above sea level. The symmetrical cone is capped by a summit crater with widths of 1 kilometre (0.62 mi) or 500 metres (1,600 ft). Farther down on the southern slopes lie three parasitic centres known as the Ajata cones. These cones have generated lava flows. The volcano overlies a platform formed by lava domes and andesitic lava flows.
Huaynaputina is a stratovolcano in a volcanic upland in southern Peru. Part of the Central Volcanic Zone of the Andean Volcanic Belt, it is the product of the subduction of the oceanic Nazca tectonic plate beneath the continental part of the South American tectonic plate at a rate of 10.3 centimetres per year (4.1 in/year). Huaynaputina is a large volcanic crater, lacking an identifiable mountain profile, with an outer stratovolcano and three younger volcanic vents. The vents of Huaynaputina form a north-northwest–south-southeast trend.
Lascar is a stratovolcano within the Central Volcanic Zone of the Andes, a volcanic arc that spans the countries of Peru, Bolivia, Argentina and Chile. It is the most active volcano in the region, with records of eruptions going back to 1848. It is composed of two separate cones with several summit craters. The westernmost crater of the eastern cone is presently active. Volcanic activity is characterized by constant release of volcanic gas and occasional vulcanian eruptions.
Nevado de Longaví is a volcano in the Andes of central Chile. The 3,242 m (10,636 ft) high volcano lies in the Linares Province, which is part of the Maule Region. It features a summit crater and several parasitic vents. The volcano is constructed principally from lava flows. Two collapses of the edifice have carved collapse scars into the volcano, one on the eastern slope known as Lomas Limpias and another on the southwestern slope known as Los Bueye. The volcano features a glacier and the Achibueno and Blanco rivers originate on the mountain.
Ampato is a dormant 6,288-metre (20,630 ft) stratovolcano in the Andes of southern Peru. It lies about 70–75 kilometres (43–47 mi) northwest of Arequipa and is part of a north-south chain that includes the volcanoes Hualca Hualca and Sabancaya, the last of which has been active in historical time.
Mentolat is an ice-filled, 6 km (4 mi) wide caldera in the central portion of Magdalena Island, Aisén Province, Chilean Patagonia. This caldera sits on top of a stratovolcano which has generated lava flows and pyroclastic flows. The caldera is filled with a glacier.
Taapaca is a Holocene volcanic complex in northern Chile's Arica y Parinacota Region. Located in the Chilean Andes, it is part of the Central Volcanic Zone of the Andean Volcanic Belt, one of four distinct volcanic chains in South America. The town of Putre lies at the southwestern foot of the volcano.
Hualca Hualca is an extinct volcano in Arequipa Region in the Andes of Peru. It has a height of 6,025 metres.
Calabozos is a Holocene caldera in central Chile's Maule Region. Part of the Chilean Andes' volcanic segment, it is considered a member of the Southern Volcanic Zone (SVZ), one of the three distinct volcanic belts of South America. This most active section of the Andes runs along central Chile's western edge, and includes more than 70 of Chile's stratovolcanoes and volcanic fields. Calabozos lies in an extremely remote area of poorly glaciated mountains.
Yucamane, Yucamani or Yucumane is an andesitic stratovolcano in the Tacna Region of southern Peru. It is part of the Peruvian segment of the Central Volcanic Zone, one of the three volcanic belts of the Andes generated by the subduction of the Nazca plate beneath the South America plate. Peru's active volcanoes Ubinas, Sabancaya and El Misti are also part of the Central Volcanic Zone.
Solimana is a volcanic massif in the Andes of Peru, South America, that is approximately 6,093 metres (19,990 ft) high. It is considered an extinct stratovolcano that is part of the Central Volcanic Zone, one of the volcanic belts of the Andes. It features a caldera as well as traces of a sector collapse and subsequent erosion. The volcano is glaciated.
The Andagua volcanic field is a volcanic field in southern Peru which includes a number of cinder cones/scoria cones, lava domes and lava flows which have filled the Andagua valley. The volcanic field is part of a larger province that clusters around the Colca River and is mostly of Pleistocene age, although the Andagua sector also features volcanic cones with historical activity. Volcanic activity in the field has flooded the Andahua valley with lava flows, damming local watersheds. The Andahua valley segment of the larger volcanic province was declared a geopark in 2015.
Coropuna is a dormant compound volcano located in the Andes mountains of southeast-central Peru. The upper reaches of Coropuna consist of several perennially snowbound conical summits, lending it the name Nevado Coropuna in Spanish. The complex extends over an area of 240 square kilometres and its highest summit reaches an altitude of 6,377 metres above sea level. This makes the Coropuna complex the third-highest of Peru. Its thick ice cap is the most extensive in Earth's tropical zone, with several outlet glaciers stretching out to lower altitudes. Below an elevation of 5,000 metres, there are various vegetation belts which include trees, peat bogs, grasses and also agricultural areas and pastures.
Huambo volcanic field is a volcanic field in Peru. Andahua-Orcopampa lies north-northeast and Sabancaya east of Huambo, east of the Rio Colca. The town of Huambo lies between the two fields.
Tata Sabaya is a 5,430-metre (17,810 ft) high volcano in Bolivia. It is part of the Central Volcanic Zone, one of several volcanic belts in the Andes which are separated by gaps without volcanic activity. This section of the Andes was volcanically active since the Jurassic, with an episode of strong ignimbritic volcanism occurring during the Miocene. Tata Sabaya lies in a thinly populated region north of the Salar de Coipasa salt pan.
Tutupaca is a volcano in the region of Tacna in Peru. It is part of the Peruvian segment of the Central Volcanic Zone, one of several volcanic belts in the Andes. Tutupaca consists of three overlapping volcanoes formed by lava flows and lava domes made out of andesite and dacite, which grew on top of older volcanic rocks. The highest of these is usually reported to be 5,815 metres (19,078 ft) tall and was glaciated in the past.
Ticsani is a volcano in Peru. It consists of two volcanoes that form a complex: "old Ticsani", which is a compound volcano that underwent a large collapse in the past and shed 15–30 cubic kilometres (3.6–7.2 cu mi) of mass down the Rio Tambo valley; the other is a complex of three lava domes which were emplaced during the Holocene. The last eruption occurred after the 1600 eruption of neighbouring Huaynaputina.
Sara Sara is a 5,505-metre-high (18,061 ft) volcano lying between Lake Parinacochas and Ocoña River in Peru. It is situated in the Parinacochas Province, Puyusca District, and in the Paucar del Sara Sara Province, in the districts of Pausa and Sara Sara.
Ubinas is a stratovolcano in the Moquegua Region of southern Peru, it is 60 kilometres (37 mi) east of the city of Arequipa. Part of the Central Volcanic Zone of the Andes, it rises 5,672 metres (18,609 ft) above sea level. The volcano's summit is cut by a 1.4-kilometre (0.87 mi) wide and 150-metre (490 ft) deep caldera, which itself contains a smaller crater. Below the summit, Ubinas has the shape of an upwards-steepening cone with a prominent notch on the southern side. The gently sloping lower part of the volcano is also known as Ubinas I and the steeper upper part as Ubinas II; they represent different stages in the geologic history of Ubinas.
Chachani is a volcanic complex 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.