This week has yet another anniversary to mention - the one year anniversary of the eruption from Puyehue-Cordón Caulle along the Chilean-Argentine border (the 2011 Pliny winner). Over much of the spring of 2011, it appeared that an eruption might be brewing, but on June 4, that suspicion was proved to be true as the volcano erupted in impressive fashion. Some of the images, videos and descriptions of the ash and pumice near the volcano are amazing, with entire lakes seemingly consumed by pumice over their entire surface and roads buried in centimeters of volcanic tephra. Over the course of the next months, the volcano produced a significant ash plumes that disrupted air travel across much of southern South America into the fall and as far away as New Zealand and Australia, with the ash wrapping its way around the globe. One of the other impressive results of the eruption was a blocky lava flow from the Cordon Caulle vent. The flow had all the hallmarks of a dacite lava flow, with a steep flow front, well-developed pressure ridges and levees. The BBC has an article for the post on the recovery of the area since the eruption, including the estimate 250,000 truck trips it took to clear Villa La Angostura of ash.
Now, the volcano is currently under a "yellow alert" status according to the latest update from SERNAGEOMIN. The eruption has become much more subdued, with little to no activity at Puyehue-Cordon Caulle besides the occasional small steam-and-ash plumes (<1200 meters) from the previously active vent, although seismicity is still elevated, with hundreds of small earthquakes each week - however, the latest update says that this activity is a "low level of activity and energy compared to previous months".
To mark the occasion, I've compiled a little slide show from images from the NASA Earth Observatory of the Puyehue-Cordón Caulle eruption. Some of these we've seen before, but it is still fascinating to see an eruption of this magnitude unfold.
Image: The initial ash plume from Puyehue-Cordón Caulle seen on June 4, 2011 punching through low level clouds and topping out at ~13.5 km / 45,000 feet. Image courtesy of the NASA Earth Observatory.
June 6, 2011
Image: The Puyehue-Cordón Caulle stretching across southern South America on June 6, 2011, when the ash plume was still reaching over 12 km / 40,000 feet. Image courtesy of the NASA Earth Observatory.
June 11, 2011Image: A close-up, false color image of the Puyehue-Cordón Caulle vent on June 11, 2011 showing the ash plume and some of the prominent pumice deposits of lakes near the volcano. Image courtesy of the NASA Earth Observatory.
June 13, 2011
Image: Ash from Puyehue-Cordón Caulle stretched across the southern hemisphere within 10 days of the eruption, prompting airspace closures in places like New Zealand and Australia. This image is from June 13, 2011, courtesy of the NASA Earth Observatory.
July 2, 2011
Image: The ash plume from Puyehue-Cordón Caulle heading off over the Pacific Ocean in July 2, 2011. Image courtesy of the NASA Earth Observatory.
Image: The ash plume from Puyehue-Cordón Caulle on July 8, 2011 heading in the opposite direction as it had been only 6 days ago. Image courtesy of the NASA Earth Observatory.
Image: A close-up view of the lava flow from P-CC seen on October 9, 2011, when the main ash plume had begun to subside. Image courtesy of the NASA Earth Observatory.
March 7, 2012
Image: Very subdued activity from the P-CC eruption seen on March 7, 2012, showing clearly the extend of the area fully affected by the ash and tephra from the volcano. Image courtesy of the NASA Earth Observatory.