Puyehue-Cordón Caulle

The June 2011 VEI 5 eruption sent ash around the entire Southern Hemisphere, disrupting air travel across South America, Australia, and New Zealand for weeks.

The 2011 eruption produced a rare rhyolitic lava flow — one of only a handful of directly observed rhyolitic flows in modern volcanology.

The 1960 eruption was almost certainly triggered by the magnitude 9.5 Great Chilean Earthquake — the most powerful earthquake ever recorded — occurring just 38 hours after the quake.

Cordón Caulle hosts the largest active geothermal area in the southern Andes, a 6 × 13 km volcano-tectonic depression of steaming fumaroles and hot springs.

Historical eruptions originally attributed to Puyehue — including the major 1921–22 and 1960 events — are now known to have originated from the Cordón Caulle fissure system.

The PCCVC has produced three VEI 5 eruptions in the Holocene (~5080 BCE, ~860 CE, 2011 CE) — a frequency that makes it one of the most explosively powerful volcanic systems in the southern Andes.

The complex's magma composition ranges from basalt to rhyolite — the widest geochemical diversity of any volcanic system in Chile's Southern Volcanic Zone.

Total erupted volume from the 2011 eruption was estimated at approximately 1 km³ dense-rock equivalent (DRE).

The eruption column on June 4, 2011, rose to approximately 12–14 km altitude, injecting fine rhyolitic ash particles that remained suspended in the atmosphere for weeks.

Puyehue National Park, established in 1941, is one of Chile's oldest protected areas and surrounds the volcanic complex.

The complex erupted seven times between 1893 and 1934 — a 41-year cluster of activity from the Cordón Caulle fissure system.

Ashfall from the 2011 eruption crossed into Argentina and deposited measurable tephra on towns in the Lake District, including Villa La Angostura and San Carlos de Bariloche.