In 2008, as seen here, Chile’s Chaitén volcano erupted after being dormant for more than 9,000 years. The eruption was the most powerful to occur on the planet in the last decade.
November 22, 2013 – CHILE – Increased seismic activity has been detected under the volcano, Chilean scientists reported. The devastating Plinian eruption of Chaitén in May 2008 forced the evacuation of the entire population of the small coastal town of Chaitén, located only a few kilometers south of the volcano. After the initial explosive phase, several lava domes have been growing slowly by extrusion of degassed, viscous magma. This phase ended in 2011 and since then, the volcano has only produced degassing. On 20 Nov at 08:07 (local time), a volcano-tectonic magnitude 2.4 earthquake occurred at 6 km depth north-east of the volcano. It was followed by a swarm of more than 80 quakes of mostly long-period type, characteristic for movements of fluids (gasses, water, and possibly magma) inside cracks inside the volcanic edifice. They are considered potential precursors to eruptive activity. In addition, pulses of volcanic tremor and a second volcanic-tectonic quakes of magnitude 2.7 at 11:39 local time, this time at shallow 4.4 km depth were recorded. –Volcano Discovery