Puyehue-Cordon Caulle

Geography & Climate

Puyehue-Cordon Caulle is located in Chile, within the Southern Andean Volcanic Arc of the broader South America Volcanic Regions. Situated at 40.59° S, 72.12° W in the Southern Hemisphere, the volcano lies within a temperate climate zone. At 2,236 meters above sea level, Puyehue-Cordon Caulle rises above the surrounding terrain into montane or subalpine conditions. The elevation creates distinct ecological zones along its flanks, from forested lower slopes to exposed rocky terrain near the summit. The volcanic landform is characterized as a composite, which describes the physical shape and structure of the volcanic edifice as observed from the surface.

Geological Context

Puyehue-Cordon Caulle sits in a subduction zone, where one tectonic plate dives beneath another, creating intense heat and pressure that generates magma. Subduction zones are responsible for many of the world's most explosive volcanoes and deadliest eruptions. For communities in Chile near Puyehue-Cordon Caulle, this tectonic setting means the volcano is capable of producing powerful explosive eruptions, pyroclastic flows, and lahars that can threaten populated areas within tens of kilometers of the summit. The dominant rock type is andesite / basaltic andesite, a dark, fine-grained volcanic rock that forms from rapidly cooling, low-viscosity lava. Basaltic eruptions tend to be less explosive and produce fluid lava flows that can travel long distances. While less immediately dangerous than explosive eruptions, basaltic lava flows can destroy structures and infrastructure in their path, and volcanic gases released during these eruptions can affect air quality over a wide area.

Eruption History Summary

Puyehue-Cordon Caulle has 20 recorded eruptions in the geological database, spanning from 1490 BCE to 2011 CE. The most powerful recorded event was a paroxysmal eruption with devastating regional consequences in 2011 CE, reaching VEI 5 on the Volcanic Explosivity Index. Notable eruptions include 2011 CE (VEI 5), 1960 CE (VEI 3), 1921 CE (VEI 3). With an average interval of roughly 175 years between eruptions over a span of 3,501 years, this is one of the more frequently active volcanoes in the database. This persistent activity suggests a robust and well-supplied magma system beneath the volcano. With eruptive activity as recently as 2011 CE, Puyehue-Cordon Caulle remains an actively monitored volcano.

Significance

With a maximum recorded VEI of 5, Puyehue-Cordon Caulle has demonstrated the capacity for paroxysmal eruptions comparable to the 1980 eruption of Mount St. Helens. Eruptions of this scale can devastate areas within 20-30 kilometers and produce ash fall that disrupts aviation and agriculture across hundreds of kilometers. Its 20 recorded eruptions make it one of the most prolific volcanoes in our database, reflecting a persistent and well-documented eruptive history that has provided volcanologists with extensive data for understanding eruption patterns and forecasting future activity. Given its recent activity, Puyehue-Cordon Caulle is closely monitored by geological survey organizations to provide early warning of future unrest.

GVP Reference Summary

The Puyehue-Cordón Caulle volcanic complex (PCCVC) is a large NW-SE-trending late-Pleistocene to Holocene basaltic-to-rhyolitic transverse volcanic chain SE of Lago Ranco. The 1799-m-high Pleistocene Cordillera Nevada caldera lies at the NW end, separated from Puyehue stratovolcano at the SE end by the Cordón Caulle fissure complex. The Pleistocene Mencheca volcano with Holocene flank cones lies NE of Puyehue. The basaltic-to-rhyolitic Puyehue volcano is the most geochemically diverse of the PCCVC. The flat-topped, 2236-m-high volcano was constructed above a 5-km-wide caldera and is capped by a 2.4-km-wide Holocene summit caldera. Lava flows and domes of mostly rhyolitic composition are found on the E flank. Historical eruptions originally attributed to Puyehue, including major eruptions in 1921-22 and 1960, are now known to be from the Cordón Caulle rift zone. The Cordón Caulle geothermal area, occupying a 6 x 13 km wide volcano-tectonic depression, is the largest active geothermal area of the southern Andes volcanic zone.

— Smithsonian Institution, Global Volcanism Program