Understanding interactions between tectonic faults and a nearby active volcano is often realized by combining seismic and field observations. A good example of such an interaction is the Caviahue caldera. It is located in an intra-arc extensional pull-apart basin, within a transition zone joining the northern part of the right-lateral strike-slip Liquiñe-Ofqui Fault System and the thrust-fault Antiñir-Copahue fault zone. Most of the active volcanoes in South Chile are related to the Liquiñe-Ofqui Fault System. Some faults located inside the Caviahue caldera were described with reverse mechanisms by some studies whereas they were found to be normal by others. In order to discriminate the actual focal mechanisms, two seismic clusters that occurred in 2017 and 2018 inside the Caviahue rectangular caldera, close to the active Copahue volcano, were studied. Earthquakes (520) were located; focal mechanisms (56) were determined from which an average seismic moment tensor was calculated. The locations and focal mechanisms of the earthquakes allow splitting the seismicity into two main regions, one of tectonic origin (with strike-slip faults) and another one of volcanic origin (with normal faults). The first seismic cluster is located close to Caviahue village, with strike-slip focal mechanisms, in an NNE direction as the nearby Liquiñe-Ofqui Fault strikes. The other part of the seismicity is located close to the northeastern structures of Copahue volcano, in the hydrothermal zone of Anfiteatro, Termas de Copahue, and Maquinitas. It is oriented in an NE direction and is composed of earthquakes with normal focal mechanisms, not reverse as postulated in past studies. The active Copahue volcano lies in the SW prolongation of these normal faults, in agreement with the tectonics of the Caviahue caldera. Then, the two nearby seismic clusters reveal both a tectonic origin, with strike-slip focal mechanisms compatible with the Liquiñe-Ofqui Fault System, and a hydrothermal origin with normal focal mechanisms, compatible with the hydrothermal system of the Copahue active volcano.

通常通过结合地震和野外观测来了解构造断层与附近活火山之间的相互作用。这种相互作用的一个很好的例子是Caviahue破火山口。它位于弧内伸展拉脱盆地中，在过渡带的过渡带内，该过渡带连接了右侧走滑利基涅-奥奎断裂系统的北部和逆冲断层的安蒂尼-科帕休断裂带。智利南部的大多数活火山与利基涅-奥基断裂系统有关。一些研究描述了位于Caviahue破火山口内部的某些断层具有相反的机制，而另一些研究则认为它们是正常的。为了区分实际的震源机制，2017年和2018年在Caviahue矩形破火山口内部发生了两个地震群，靠近活跃的Copahue火山，被研究了。发生地震（520次）。确定了震源机制（56），由此计算出平均地震矩张量。地震的位置和震源机制可以将地震活动划分为两个主要区域，一个是构造成因（具有走滑断层），另一个是火山成因（具有正断层）。第一个地震群位于Navi方向附近的Caviahue村庄附近，具有走滑震源机制，这是附近的Liquiñe-Ofqui断层走向所致。地震活动的另一部分位于Anfiteatro，Termas de Copahue和Maquinitas的热液区，靠近Copahue火山的东北结构。它的方向是东北方向，由具有正常震源机制的地震组成，而不像过去的研究中所假定的那样逆转。活跃的Copahue火山位于这些正常断层的西南延长，这与Caviahue破火山口的构造一致。然后，附近的两个地震群既显示出构造起源，其走滑震源机制与Liquiñe-Ofqui断层系统兼容，又揭示了热液成因，具有正常震源机制，与Copahue活火山的水热系统兼容。