Two glacier-covered volcanoes in Chile are at yellow alert, the second phase on a four-color scale. At yellow alert, Nevados de Chillán and Villarrica volcanoes are under advisory, meaning they are exhibiting signs of instability. While they are currently on the lower end of the warning spectrum, the two are still among the highest-risk volcanoes in the country, with long histories of activity and eruptions. Shown in the images below, smoke can be seen drifting from the mouth of the snow-capped Villarrica volcano, a clear indicator of volcanic activity.
According to Chile’s National Geology and Mining Service, the two volcanoes became active approximately 650,000 years ago. However, their surfaces are marked by formations from postglacial (the period after the most recent glaciation) eruptions that have occurred over the last 10,000 years. Interactions between lava and ice have drastically altered the topographic features of the Nevados de Chillán and Villarrica volcanoes. Evidence shows glaciers and ice sheets slowed or halted the flow of lava from these volcanoes. The lava melted holes into glacial ice and rapidly cooled after encountering ice sheets. In the 20th century, more recent activity has resulted in 100 fatalities related to mudflows, or lahars, on the slopes of the Villarrica Volcano.
The Nevados de Chillán and Villarrica volcanoes pose imminent threats to the populations living in their shadows. At the base of both volcanoes are cities where tourism from summer vacation facilities and winter sports complexes has been successful. The communities living under the threat of active volcanoes constantly risk destruction from lahars, falling ash, and lava flows. Images of Nevados de Chillán from April 1, 2020 show the volcano puffing out smoke, a stark contrast to the serene images of the volcano on April 2. The difference in appearance of Nevados de Chillán in just this two-day period shows the variability of the volcanic activity.
GlacierHub has previously reported on Nevados de Chillán, posting about a change in alert level in October 2019. That article highlighted that the volcano had been upgraded to orange alert, which indicates a significant risk of eruption. This month’s yellow alert is an obvious de-escalation since GlacierHub’s last report on Nevados de Chillán. Continue to check GlacierHub for updates on this and other glacier-covered volcanoes.