I meant to mention this last week, but Dr. Boris Behncke had a brief post on the rumbling at the Northeast Crater of Etna. Over the past year, much of the action has been at the New Southeast Crater, but that is a recent phenomenon. Although the Northeast Crater has taken a back seat lately, minus some ash emissions, apparently there is some speculation that this could change based on its current state of degassing.
Sometimes it takes as many days as the meeting to catch back up afterwards — which is clearly the case for me after GSA this year. Finally getting almost on track as we hurtle into November.
So, like clockwork, right as I leave for Denver and the GSA meeting, a volcano decides to put on a show. This time it was Etna. After six months of relative quiet, the Sicilian volcano put on quite an impressive show (see above), with eruptions from two craters simultaneously: the New Southeast Crater and the Northeast Crater (see above). Both of these eruptions were explosive, producing plumes that reached a few kilometers over the volcano and spread ash across the area of eastern Sicily. At the same time, a lava flow issued from the saddle between the two crater, meaning that Etna has erupting from at least three different vents simultaneously during the October 26 eruption. Dr. Boris Behncke of the Osservatorio Etneo posted an excellent video of the action during the 10/26 paroxysm that shows the lava fountaining that occurred from the New Southeast Crater. Towards the end of the video, you can see some great examples of strombolian activity during the waning stages of the eruption from the New Southeast Crater as giant bubbles pop in the conduit of the erupting vent. Each “pop” of that bubble would send out thousands of lava bombs, and created the booming sound you can hear on the video. Dr. Behncke also posted a great sequence of images and a story behind the remnants of a former volcano observatory on Etna. Right now, only the antenna of the former building sticks out above many years of volcanic debris, but the October 26 paroxysm lava flow came with 1 meter(!) of knocking down even that last vestige of the structure. Things have settled down at Etna after this eruption, but as we all know, the volcano can ramp up quickly to a new paroxysm.
Across the world in Indonesia, Sinabung continues to produce explosive eruptions. Right now, these discrete event have been producing ash plumes that reach up to 7 km (23,000 feet) over the volcano. All of this activity at Sinabung prompted the PVMBG to raise the alert status at the volcano to its second highest setting (siaga – alert). This move increased the exclusion zone around the volcano to 3 km and ~1,300 more people have evacuated the slopes of the restless volcano. Elsewhere in Indonesia, looks like people want to add some fearmongering to the menu (as if actively erupting volcanoes weren’t enough). The IB Times has an article proclaiming “Lake Toba’s Volcanic Underbelly ‘Could Erupt at Any Time’“, snatching a poor choice of words by the president of the Indonesia Geological Experts Association, Rovicky Dwi Putrohari. The article itself sounds like an attempt by the IGEA to promote its annual conference that occurred this week — nothing like capitalizing on fear of the next eruption from a caldera to grab the media’s attention.
The submarine eruption at El Hierro continued into 2011. Image: INVOLCAN
2012, for all the hype about apocalypse, was a volcanically-quiet year. No Eyjafjallajökulls, no Puyehue-Cordon Caulles, no Pinatubos. Sure, we had some notable eruptions, but most were small-to-moderate events that, many times, won’t even end up getting preserved in the geologic record. However, that didn’t stop me from posting way too much! No, really, it was still a great year for Eruptions, with decidedly more posts about the science of volcanoes when the actual volcanic events were low. Here is the 2012 Volcanic Year in Review!
I also tackled a topic that came up repeatedly during the year – the missing eruptions in the ice cap record. Namely, the ice cores suggest a large eruption in 1258 AD, but no source has been definitively identified (although inroads have been made). Another mysterious caldera eruption, the Kuwae caldera eruption in the 1450s, was also examined about whether it actually occurred.
So, there you have it. The Volcanic Year in Review … and hopefully 2013 will bring us more volcanic excitement.
Erik Klemetti is an assistant professor of Geosciences at Denison University. His passion in geology is volcanoes, and he has studied them all over the world. You can follow Erik on Twitter, where you’ll get volcano news and the occasional baseball comment.