| Liquiñe-Ofqui Fault | |
| Other Name: | Falla de Liquiñe-Ofqui |
| Namedfor: | Liquiñe, Ofqui |
| Namedby: | Hervé et al. |
| Yeardef: | 1979 |
| Pushpin Relief: | 1 |
| Range: | Andes |
| Length: | 1200km (700miles) |
| Plate: | South American |
| Status: | Active |
| Earthquakes: | 1960 Valdivia earthquake aftershock, 2007 Aysén Fjord earthquakes |
| Type: | Intra-arc strike-slip fault |
| Movement: | Dextral |
| Orogeny: | Andean |
| Volcanic Arc/Belt: | Southern Volcanic Zone |
The Liquiñe-Ofqui Fault is major geological fault that runs a length of roughly 1200km (700miles) in a NNE-SSW orientation and exhibits current seismicity.[1] [2] It is located in the Chilean Northern Patagonian Andes. It is a dextral intra-arc strike-slip fault.[2] Most large stratovolcanoes of the Southern Volcanic Zone of the Andes are aligned by the fault which allows for the movement of magma and hydrothermal fluids.[2]
The fault crosses several transverse faults including the Mocha-Villarrica Fault Zone (MVFZ) and the Biobío-Aluminé Fault Zone.[2] The fault have had periods of ductile deformation associated to pluton emplacement be it either at great depths or by shallow intrusions.[3]
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 and the intra-arc region where the fault lies.[2] There is evidence that the fault broke as a 9.07 subevent in the 1960 Valdivia earthquake.[4] A portion of the fault in Aysén Region likely slipped (moved) in an aftershock a few weeks after the 1960 Valdivia earthquake.[5] This same portion slipped again in April 2007 causing earthquakes in Aysén Fjord, triggering landslides and a local tsunami.[5]
The fault name was coined by Francisco Hervé, I. Fuenzalida, E. Araya and A. Solano in 1979.[6] The fault itself was first inferred by Chilean government agent Hans Steffen around 1900 who referred to it as a "tectonic furrow" (Spanish: surco tectónico).[6]