The Liquiñe-Ofqui Fault is major

geological fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

that runs a length of roughly in a NNE-SSW orientation and exhibits current seismicity. It is located in the

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

an Northern Patagonian

Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...

. It is a

dextral Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use different ...

intra-arc

strike-slip fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

. Most large

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and per ...

es of the

Southern Volcanic Zone The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American ...

of the Andes are aligned by the fault which allows for the movement of

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

and hydrothermal fluids. The fault crosses several transverse faults including the Mocha-Villarrica Fault Zone (MVFZ) and the Biobío-Aluminé Fault Zone. The fault have had periods of ductile deformation associated to

pluton emplacement The methods of pluton emplacement are the ways magma is accommodated in a host rock where the final result is a pluton. The methods of pluton emplacement are not yet fully understood, but there are many different proposed pluton emplacement mechan ...

be it either at great depths or by shallow intrusions. The forces that move the fault are derivative of the oblique subduction offshore Chile's coast. This leads to partition of deformation between the subduction zone, the

fore-arc Forearc is a plate tectonic term referring to a region between an oceanic trench, also known as a subduction zone, and the associated volcanic arc. Forearc regions are present along a convergent margins and eponymously form 'in front of' the vo ...

and the intra-arc region where the fault lies.There is evidence that the fault broke as a 9.07 subevent in the 1960 Valdivia earthquake. A portion of the fault in

Aysén Region The Aysén del General Carlos Ibáñez del Campo Region ( es, Región de Aysén, , '), often shortened to Aysén Region or Aisén,Examples of name usage1, official regional government site refers to the region as "Región de Aysén"., Chile's of ...

likely slipped (moved) in an aftershock a few weeks after the

1960 Valdivia earthquake The 1960 Valdivia earthquake and tsunami ( es, link=no, Terremoto de Valdivia) or the Great Chilean earthquake (''Gran terremoto de Chile'') on 22 May 1960 was the most powerful earthquake ever recorded. Various studies have placed it at 9.4– ...

. This same portion slipped again in April 2007 causing earthquakes in Aysén Fjord, triggering

landslide Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated grade (slope), slope failures, mudflows, and debris flows. Landslides occur in a variety of ...

s and a local

tsunami A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explo ...

. The fault name was coined by

Francisco Hervé Francisco Hervé Allamand (born 1942) is a Chilean geologist known for his contributions to the paleogeography and tectonics of Chile and Antarctica. Together with I. Fuenzalida, E. Araya and A. Solano he named the Liquiñe-Ofqui Fault in 1979.Ha ...

, I. Fuenzalida, E. Araya and A. Solano in 1979. The fault itself was first inferred by Chilean government agent

Hans Steffen 250px, Picture of Dr. Hans Steffen in 1916 Hans Steffen Hoffman (20 July 1865, in Fürstenwerder, Prussia – 7 April 1936, in Davos, Switzerland) was a German geographer and explorer of the Aysén Region in western Patagonia. Steffen also w ...

around 1900 who referred to it as a "tectonic furrow" (Spanish: ''surco tectónico'').

References

Seismic faults of Chile Strike-slip faults Geology of Patagonia Geology of Araucanía Region Geology of Los Ríos Region Geology of Los Lagos Region Geology of Aysén Region Taitao Peninsula Mapuche language {{Chile-geo-stub