Villarrica (volcano)
Overview
Villarrica is one of Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

's most active volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

es, rising above the lake
Lake Villarrica
Lake Villarrica, also known as Mallolafquén , is located about 700 kilometers south of Santiago in Chile’s Lake District in the southeast area of the Province of Cautín...

 and town
Villarrica, Chile
Villarrica is a city and commune in southern Chile located on the western shore of Villarrica Lake in the Province of Cautín, Araucanía Region south of Santiago and close to the Villarrica Volcano ski center to the south east. Residents of Villarrica are known as Villarriquences.Tourism, grain and...

 of the same name. The volcano is also known as Rucapillán, a Mapuche
Mapudungun
The Mapuche language, Mapudungun is a language isolate spoken in south-central Chile and west central Argentina by the Mapuche people. It is also spelled Mapuzugun and sometimes called Mapudungu or Araucanian...

 word meaning "House of the Pillán
Pillan
The Pillan is a powerful and respected male spirit in Mapuche mythology....

". It is the westernmost of three large stratovolcano
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

es that trend perpendicular to the Andean
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

 chain along the Gastre Fault
Gastre Fault Zone
The Gastre Fault Zone is a NW-SE trending fault responsible for the alignment of Villarrica, Quetrupillán and Lanín volcanoes. The fault is believed to be a continuation of Lanalhue Fault which was active in late Paleozoic Era....

. Villarrica, along with Quetrupillán
Quetrupillán
Quetrupillán Volcano is a stratovolcano located in the Araucanía Region of Chile. It is situated between Villarrica and Lanín volcanoes, within Villarrica National Park. Geologically, Quetrupillán is located in a tectonic basement block between the main traces of Liquiñe-Ofqui Fault and...

 and the Chilean portion of Lanín
Lanín
Lanín is an ice-clad, cone-shaped stratovolcano on the border of Argentina and Chile. It forms part of two national parks: Lanín in Argentina and Villarrica in Chile. It is a symbol of the Argentine province of Neuquén, being part of its flag and its anthem. Although the date of its last eruption...

, are protected within Villarrica National Park
Villarrica National Park
Villarrica National Park is located in the Andes, in the Araucanía and Los Ríos regions of Chile, near Pucón. The centerpiece of the park is a line of three volcanoes stretching transversely to the Andean range: Villarrica, Quetrupillán, and Lanín....

. Ascents of the volcano are popular with several guided ascents reaching the top during summer.

Villarrica, with its lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

 of basaltic-andesitic composition, is one of only five volcanoes worldwide known to have an active lava lake
Lava lake
Lava lakes are large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression. The term is used to describe both lava lakes that are wholly or partly molten and those that are solidified...

 within its crater
Volcanic crater
A volcanic crater is a circular depression in the ground caused by volcanic activity. It is typically a basin, circular in form within which occurs a vent from which magma erupts as gases, lava, and ejecta. A crater can be of large dimensions, and sometimes of great depth...

.
Encyclopedia
Villarrica is one of Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

's most active volcano
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

es, rising above the lake
Lake Villarrica
Lake Villarrica, also known as Mallolafquén , is located about 700 kilometers south of Santiago in Chile’s Lake District in the southeast area of the Province of Cautín...

 and town
Villarrica, Chile
Villarrica is a city and commune in southern Chile located on the western shore of Villarrica Lake in the Province of Cautín, Araucanía Region south of Santiago and close to the Villarrica Volcano ski center to the south east. Residents of Villarrica are known as Villarriquences.Tourism, grain and...

 of the same name. The volcano is also known as Rucapillán, a Mapuche
Mapudungun
The Mapuche language, Mapudungun is a language isolate spoken in south-central Chile and west central Argentina by the Mapuche people. It is also spelled Mapuzugun and sometimes called Mapudungu or Araucanian...

 word meaning "House of the Pillán
Pillan
The Pillan is a powerful and respected male spirit in Mapuche mythology....

". It is the westernmost of three large stratovolcano
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

es that trend perpendicular to the Andean
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...

 chain along the Gastre Fault
Gastre Fault Zone
The Gastre Fault Zone is a NW-SE trending fault responsible for the alignment of Villarrica, Quetrupillán and Lanín volcanoes. The fault is believed to be a continuation of Lanalhue Fault which was active in late Paleozoic Era....

. Villarrica, along with Quetrupillán
Quetrupillán
Quetrupillán Volcano is a stratovolcano located in the Araucanía Region of Chile. It is situated between Villarrica and Lanín volcanoes, within Villarrica National Park. Geologically, Quetrupillán is located in a tectonic basement block between the main traces of Liquiñe-Ofqui Fault and...

 and the Chilean portion of Lanín
Lanín
Lanín is an ice-clad, cone-shaped stratovolcano on the border of Argentina and Chile. It forms part of two national parks: Lanín in Argentina and Villarrica in Chile. It is a symbol of the Argentine province of Neuquén, being part of its flag and its anthem. Although the date of its last eruption...

, are protected within Villarrica National Park
Villarrica National Park
Villarrica National Park is located in the Andes, in the Araucanía and Los Ríos regions of Chile, near Pucón. The centerpiece of the park is a line of three volcanoes stretching transversely to the Andean range: Villarrica, Quetrupillán, and Lanín....

. Ascents of the volcano are popular with several guided ascents reaching the top during summer.

Villarrica, with its lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

 of basaltic-andesitic composition, is one of only five volcanoes worldwide known to have an active lava lake
Lava lake
Lava lakes are large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression. The term is used to describe both lava lakes that are wholly or partly molten and those that are solidified...

 within its crater
Volcanic crater
A volcanic crater is a circular depression in the ground caused by volcanic activity. It is typically a basin, circular in form within which occurs a vent from which magma erupts as gases, lava, and ejecta. A crater can be of large dimensions, and sometimes of great depth...

. The volcano usually generates strombolian eruption
Strombolian eruption
Strombolian eruptions are relatively low-level volcanic eruptions, named after the Italian volcano Stromboli, where such eruptions consist of ejection of incandescent cinder, lapilli and lava bombs to altitudes of tens to hundreds of meters...

s, with ejection of incandescent pyroclasts and lava flows. Melting of snow and glacier ice
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

 as well as rainfalls often cause massive lahar
Lahar
A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley. The term is a shortened version of "berlahar" which originated in the Javanese language of...

s (mud and debris flows), such as during the eruptions of 1964 and 1971.

Geography and Geology

Villarica's symmetrical edifice stands in the Chilean Central Valley
Chilean Central Valley
The Central Valley , Intermediate Depression or Longitudinal Valley is the depression between the Chilean Costal Range and the Andes Mountains. The central valley should not be confused with Central Chile that encompasses part of the valley...

 as the westernmost of an alignment of three large stratovolcano
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

es. The alignment is attributed to the existence of an old fracture in the crust, the North West-West trending sinistral
Sinistral
Sinistral and dextral are scientific terms that describe chirality or relative direction in a number of disciplines.The terms are derived from the Latin words for “left” and “right” ....

 Gastre Fault Zone
Gastre Fault Zone
The Gastre Fault Zone is a NW-SE trending fault responsible for the alignment of Villarrica, Quetrupillán and Lanín volcanoes. The fault is believed to be a continuation of Lanalhue Fault which was active in late Paleozoic Era....

, the other volcanoes in the chain Quetrupillán
Quetrupillán
Quetrupillán Volcano is a stratovolcano located in the Araucanía Region of Chile. It is situated between Villarrica and Lanín volcanoes, within Villarrica National Park. Geologically, Quetrupillán is located in a tectonic basement block between the main traces of Liquiñe-Ofqui Fault and...

 and Lanín
Lanín
Lanín is an ice-clad, cone-shaped stratovolcano on the border of Argentina and Chile. It forms part of two national parks: Lanín in Argentina and Villarrica in Chile. It is a symbol of the Argentine province of Neuquén, being part of its flag and its anthem. Although the date of its last eruption...

 are far less active. This alignment is unusual as it crosses the N-S running Liquiñe-Ofqui Fault
Liquiñe-Ofqui Fault
The Liquiñe-Ofqui Fault is major geological fault that runs a length of roughly 1000 km in a north-south direction and exhibits current seismicity . It is located in the Chilean northern patagonean Andes. It is a dextral intra-arc transform fault...

, around which most currently active volcanoes are aligned. Currently the volcano covers up an area of 400 km2 and has a volume 250 km3 according to estimates.

About 25 scoria cones dot Villarica's flanks. It also has volcanic caves. The constant degassing at the lava lake turns Villarrica's otherwise quite effusive lava more viscous, heightening its explosive potential. Two large ignimbrite
Ignimbrite
An ignimbrite is the deposit of a pyroclastic density current, or pyroclastic flow, a hot suspension of particles and gases that flows rapidly from a volcano, driven by a greater density than the surrounding atmosphere....

 layers are visible around the volcano; the Licán Ignimbrite and later the Pucón Ignimbrite.

Villarrica emerged as a volcano during the Middle Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 and grew forming a large stratocone of similar dimensions to the current edifice. 100 thousand years ago during the Valdivia Interglacial the ancestral Villarrica collapsed following an eruption and formed a large elliptical caldera
Caldera
A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

 of 6.5 and 4.2 km in diameter. During the Llanquihue Glaciation (Last Glaciation) Villarrica produced pyroclastic flow
Pyroclastic flow
A pyroclastic flow is a fast-moving current of superheated gas and rock , which reaches speeds moving away from a volcano of up to 700 km/h . The flows normally hug the ground and travel downhill, or spread laterally under gravity...

 deposits, subglacial andesite
Andesite
Andesite is an extrusive igneous, volcanic rock, of intermediate composition, with aphanitic to porphyritic texture. In a general sense, it is the intermediate type between basalt and dacite. The mineral assemblage is typically dominated by plagioclase plus pyroxene and/or hornblende. Magnetite,...

 lavas and dacite
Dacite
Dacite is an igneous, volcanic rock. It has an aphanitic to porphyritic texture and is intermediate in composition between andesite and rhyolite. The relative proportions of feldspars and quartz in dacite, and in many other volcanic rocks, are illustrated in the QAPF diagram...

 dykes. The volcano collapsed once again 13,700 years ago forming a new smaller caldera, among other pyroclastic flows the Licán Ignimbrite has been related to this event. Beginning with the Licán Ignimbrite, generated just after the last deglaciation, activity continued in similar fashion. The Pucón Ignimbrite was ejected during a minor collapse the uppermost stratocone 3,700 years ago.

Glaciers

The upper part of Villarrica is permanently covered by snow and has some 40 km2 of glacier
Glacier
A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s. The largest glacier of Villarrica is the Pichillancahue-Turbio Glacier situated on its southeastern flank, which has the most favorable environment for glacier formation. Ashfalls from the frequent eruptions of the volcano do sometimes enhance ablation
Ablation
Ablation is removal of material from the surface of an object by vaporization, chipping, or other erosive processes. This occurs in spaceflight during ascent and atmospheric reentry, glaciology, medicine, and passive fire protection.-Spaceflight:...

 due to increased absorption of solar radiation. Some ash coverings around Villarrica are thicker than 5 cm
Centimetre
A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...

 and insulates
Thermal insulation
Thermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...

 the glacier decreasing ablation instead of enhancing it. Between 1961 and 2003, Villarrica lost 25% of its glaciated surface. During the same period glaciers shrunk at an average rate of -0.4 km2 each year.

Tourism

Villarrica is one of the world's most climbed stratovolcanoes. Guided hikes to the crater are offered from the town of Pucón by several enterprises, but may ascent might be suspended due to cloudiness and in periods of seismic or increased volcanic activity. Helicopter sightseeing services offer flights over the crater as well. In the winter (July-September) a ski resort operates on the northern slopes.

Eruptive history

Villarrica is one of Chile's most active volcanoes and has had recorded eruptions even since the time of the conquest of Chile
Conquest of Chile
The Conquest of Chile is a period in Chilean historiography that starts with the arrival of Pedro de Valdivia to Chile in 1541 and ends with the death of Martín García Óñez de Loyola, in the Battle of Curalaba in 1598 or alternatively with the Destruction of the Seven Cities. This was the period...

 and the founding of the city of Villarrica
Villarrica, Chile
Villarrica is a city and commune in southern Chile located on the western shore of Villarrica Lake in the Province of Cautín, Araucanía Region south of Santiago and close to the Villarrica Volcano ski center to the south east. Residents of Villarrica are known as Villarriquences.Tourism, grain and...

 at its foothills in 1552. As in the case of other volcanoes in southern Chile
Zona Sur
The Zona Sur is one of the five natural regions on which CORFO divided continental Chile in 1950. Its northern border is formed by the Bío-Bío River, the limit with the Central Chile Zone. By west with the Pacific Ocean, by the east with the Andean mountains and Argentina. Its southern border is...

 eruptive record uncertainties exists in the first half of the 17th century due to the surrender or abandonment of Spanish settlements during the destruction of the Seven Cities. The earliest registered eruption was recorded in 1558. Since then, there have been at least 65 eruptions with assumed Volcanic Explosivity Indexes
Volcanic Explosivity Index
The Volcanic Explosivity Index was devised by Chris Newhall of the U.S. Geological Survey and Stephen Self at the University of Hawaii in 1982 to provide a relative measure of the explosiveness of volcanic eruptions....

 of magnitude 1 or 3.

1964 eruption

The two last weeks of February in 1964 the volcano showed signs of unrest, such as small but still violent lava effusions followed by temblors. On March 1 at 2:45 am the volcano begun a strombolian eruption
Strombolian eruption
Strombolian eruptions are relatively low-level volcanic eruptions, named after the Italian volcano Stromboli, where such eruptions consist of ejection of incandescent cinder, lapilli and lava bombs to altitudes of tens to hundreds of meters...

. Dwellers at Coñaripe
Coñaripe
Coñaripe is a Chilean town and resort area, located on the shore of Calafquén Lake. Administratively it belongs to Panguipulli commune in Valdivia Province of Los Ríos Region....

, a wood-logger town, woke up in the night and fled to the surroundings hills while it was raining after hearing strong noises and temblors. As the volcano was capped by an early autumn snowfall to its foothills the melting for snow and ice from Pichillancahue-Turbio Glacier produced together with the heavy rainfalls several lahar
Lahar
A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley. The term is a shortened version of "berlahar" which originated in the Javanese language of...

s. Coñaripe, then located on the northwestern shores of Calafquén Lake
Calafquén Lake
Calafquén Lake is a lake of Chile, which straddles the border between the Araucanía Region and Los Ríos Region. It is one of the Seven Lakes and forms part of the drainage basin of the Valdivia River....

, had about half of its buildings destroyed and was later reconstructed further east.

1971 eruption

On October 29, 1971, at 4:00 am, several explosions were heard from the crater, according to skiers and staff working at the Villarrica ski resort on the slope of the volcano. The same day a small column of white smoke was seen at the top of the volcano and later the same day the white column alternated with black smoke. One month later on December 29, quarter to midnight, Villarrica begun a new eruptive cycle. Pyroclasts were ejected and the snow surrounding the crater
Volcanic crater
A volcanic crater is a circular depression in the ground caused by volcanic activity. It is typically a basin, circular in form within which occurs a vent from which magma erupts as gases, lava, and ejecta. A crater can be of large dimensions, and sometimes of great depth...

 and on some parts of the slopes melted due to the heat. This was followed by a brief halt in activity followed by the opening of a new vent in the northeast flank through which lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

 went out. The lava flows melted considerable amounts of water, causing several lahar
Lahar
A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley. The term is a shortened version of "berlahar" which originated in the Javanese language of...

s that went down through the troughs and valleys of the volcanic edifice. The lahars affected the localities of Pichaye, El Turbio, Collentañe, Minetué, Molco, Voipir and Curarrehue
Curarrehue
Curarrehue is a town and commune in Cautín Province of Araucanía Region, Chile. The origin of Curarrehue dates back to the occupation of Araucanía and the Conquest of the Desert by the Chilean and Argentine army respectively in the 1870s and 1880s when Mapuches were pushed by the Argentine Army...

, all of them in the Trancura River
Trancura River
Trancura River is a river located in the Araucanía Region of Chile. Its headwaters drain the southeasternmost portion of Villarrica National Park, including the northwestern slope of Lanín volcano...

's basin. In the larger settlements of Villarrica
Villarrica, Chile
Villarrica is a city and commune in southern Chile located on the western shore of Villarrica Lake in the Province of Cautín, Araucanía Region south of Santiago and close to the Villarrica Volcano ski center to the south east. Residents of Villarrica are known as Villarriquences.Tourism, grain and...

 and Pucón
Pucón
Pucón is a Chilean city and commune administered by the municipality of Pucón located in the Province of Cautín, Araucanía Region, 100 km to the southeast of Temuco and 780 km to the south of Santiago....

, toxic sulphurous gases
Volcanic gas
|250px|thumb|right|Image of the [[rhyolitic]] [[lava dome]] of [[Chaitén Volcano]] during its 2008-2010 eruption.Volcanic gases include a variety of substances given off by active volcanoes...

from the volcano turned the air unbreathable for moments. At least 15 people are reported to have died because of the eruption.

External links

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