UPDATE: Eruption at Puyehue-Cordón Caulle in Chile

UPDATE 8:00 PM (Eastern): It looks like Bariloche is being heaviest hit by the ash from the eruption – looks like a lot of ash on the ground in the resort town. You can see more of the ash fall images here as well. The Chilean government is evacuating over 3,500 people from the region near the volcano and also closed a border crossing between Chile and Argentina. Some incandescence was spotted at the summit of the volcano as well. Eruptions reader Miguel posted this great animated GIF showing the ash plume from Puyehue-Cordón Caulle spreading to the east. Eruptions reader Raving posted a great clipped version of the NASA Aqua satellite image the eruption (see below), showing the tan plume towering over the lower white clouds.

NASA Aqua image of the Puyehue-Cordón Caulle plume on June 4, 2011.

UPDATE 4:30 PM (Eastern): It looks like a significant eruption has started at Puyehue-Cordón Caulle. The Volcanism Blog has a great image of the thick, grey plume seen today from the volcano. There is also a VAAC warning for ash up to 10 km / 35,000 feet (pdf). Check out some of the early video and images of how dark it has become in towns near the volcano. You can even see the plume on the weather satellite images of southern South America (see below). {Special thanks to all who provided links/info for the update.}

Weather satellite image superimposed on a map of southern South America showing the plume from Puyehue-Cordón Caulle.

Here is an official announcement from ONEMI about evacuations and emergency information regarding the eruption.

I’ll add more information as it comes in – feel free to do the same!

Original Post

I’ve seen a few reports today about a potential sharp increase in activity at Chile’s Puyehue-Cordón Caulle, some of which suggests that a new eruption might be in the cards soon at the volcano. Now, since around midnight (local time) there have been 20 earthquakes (spanish), that were strong enough to be felt (spanish) in the towns around the volcano (~M3-4). The volcano has been at Yellow 2 Alert Status for the past few months after the SERNAGEOMIN reported an increase in earthquakes from 2-5 km depth under the volcano – but on Friday, the SERNAGEOMIN reported (pdf) over 60 earthquakes per hour at the volcano, the alert has been elevated to Yellow 4 Status, meaning 24 hour observation will begin at the volcano and the potential for an eruption in days to weeks. The towns around the volcano were put an Red Alert status by ONEMI (the emergency management office) so as to be prepared for a potential eruption (yes, it is a little confusing that the towns and the volcano get different alert scales – one volcanic, one civil). A recent flight over the volcano also showed signs of new vents at the summit (spanish) as well.

The last eruption of Puyehue-Cordón Caulle was in 1990 and was relatively small. The last VEI 3 or greater eruption was in 1960 (possibly triggered by the great Chilean earthquake of 1960). You can check out the seismicity (if large enough) for all of Chile here.

Top left: An undated image of Puyehue-Cordón Caulle in Chile.