The column of ash measured seven miles high when it erupted. The natural disaster has displaced 5,000 people living near the volcano, who had to leave the area not only because of the eruption itself, but also because of other natural disasters that the eruption could trigger such as landslides, floods, and avalanches (especially avalanches since it is approaching winter time in the southern hemisphere) — volcanic eruptions are not standalone events.
“Local officials say people are very, very frightened. The immediate concern is the volcano’s eruption could trigger snow melts and cause flooding,” said NPR’s Lourdes Garcia-Navarro.
Calbuco’s eruption history makes it especially dangerous for local citizens — it has erupted at least 10 times since 1837, an average of once every 18 years.
Related: A GoPro gave its life so you could watch this way-too-close volcano footage
The cloud of ash caused by the volcano is also spilling into neighboring Argentina. It even caught some observers by surprise. “For us it was a surprise,” said Alejandro Verges, the emergency director of the Los Lagos region where the volcano was located. He added that the volcano itself wasn’t under any special observation. Many major active volcanos are monitored by scientists — a volcano is considered “active” if it has erupted in the past 10,000 years. According to Sernageomin, Chile’s geological agency, the Calbuco volcano erupts every 34 years on average, placing it well within the definition of an active volcano.
There are around 90 active volcanoes in Chile because it is located on the Pacific Ring of Fire, which spans the west coasts of North America and South America, and the eastern coasts of Japan and New Zealand.