Battle of the Giants: Etna VS Tondano

Photograph by Marco Tomasello. The new pit-crater at Bocca Nuova. Renewed activity at the craters, or even formation of a new crater, at Etna often starts with the formation of a pit-crater.

Photograph by Marco Tomasello. The new pit-crater at Bocca Nuova. Renewed activity at the craters, or even formation of a new crater, at Etna often starts with the formation of a pit-crater.

The big talkie during the weekend has without a shadow of a doubt been Etnas comeback. And to top it off one of Tondanos subsidiary volcanoes had an eruption almost exactly a year after the last time I wrote about the volcano.

Etna

The Sicilian giant is one of those volcanoes I rarely write about since it is so complex that I find the task rather daunting. So, to get things straight I went and asked Dr Boris Behncke from INGV a few questions and made sure to read up on the INGV bulletins, any mistakes are completely mine.

Etna came back to life on the 3rd of September when it ejected cold rock and ash as it cleared the throat of the New Southeast Crater (NSEC). On the 7th weak strombolian activity started with the typical fiery cascades reaching about 40 meters above the crater of the NSEC. At the same time eruptive activity occurred at the Bocca Nuova. When that crater later was examined it became apparent that a part of the crater floor had fallen in on itself. It is unclear if this happened due to magma withdrawal or due to clearing of the vent for possible future eruptive behavior.

The strombolian action has diminished from onset of the eruption, and is today greatly diminished. According to Dr Behncke the current eruption is not out of the ordinary and is not a cause for any alarm.

Tondano

Photography by Dr. Richard Roscoe and duly borrowed from his fantastic site Photovolcanica. This picture is from an eruptive phase in june 2012. Please notice the location of the Tompaluan vent between the volcanoes of Lokon and Empung.

Photography by Dr. Richard Roscoe and duly borrowed from his fantastic site Photovolcanica. This picture is from an eruptive phase in june 2012. Please notice the location of the Tompaluan vent between the volcanoes of Lokon and Empung.

As I have written before Tondano is one of those volcanoes in need of a better PR-agent. It is one of the few active volcanoes that have suffered a VEI-8 eruption, and to boot it is one of the world’s oldest volcanoes with about 2.5 million years of activity.

This time it is a subsidiary volcano named Lokon-Empung that is erupting. It is a twin volcano separated by a mere 2.5 kilometers. And to be quite honest it is hard to say which of them is actually erupting since the erupting vent, Tompaluan is situated perfectly centered in the saddle in between Lokon and Empung.

The current eruptive phase started in February 2011 and the eruption has since then been more or less continuous with frequent ash pillars reaching heights up towards 5000 meters.

During the weekend an eruptive column rose to the height of 4 000 meters. Often Tompaluan erupts together with another volcano named Soputan, and as late as in June a prolonged seismic event occurred at Soputan, but without any eruption having started as of now.

If anyone wants a deeper understanding of this highly fascinating volcano I recommend my former post on the subject:

https://volcanocafe.wordpress.com/2012/09/27/did-you-notice-the-erupting-supervolcano/

Conclusion

Both Etna and Tondano are old and very imposing volcanoes. Tondano is even in the rather hyperbolically named category of supervolcanoes. The important lesson here is that even these true giants in the world of volcanoes are still doing what giants most often do, namely having small eruptions. In the hunt for the; “Oh my God! We are all going to die” sensationalism we lose track of the fact that these volcanoes have mainly small unassuming eruptions.

Yes it is true that Tondano had a VEI-8 eruption 2 million years ago, and that has had one VEI-7 eruption and quite a few VEI-6 eruptions, but still the mind-boggling majority of the eruptions have been small and unassuming. Since Tondano seems to have been very prolific in its number of eruptions there has most likely been somewhere around 100 000 eruptions that is not worth writing home about from this volcano. Imagine, a few thousand small eruptions per every large one (VEI-6 and upwards).

CARL

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149 thoughts on “Battle of the Giants: Etna VS Tondano

  1. Hopefully Etna will give us something new and entertaining to watch and follow along to that doesn’t cause any harm or damage to nearby residents!

    • Hopefully. While the February-May paroxysms were very powerful and impressive, they did well at disrupting the area. I still doubt that one will occur soon.

          • Yepp, complete with tremor spikes at the same time.
            Thing with Etna is that she seems to be able to go without any warning since the conduits is very dilated pretty much all the time.

            • Which is a guarantee of multiple small eruptions as soon as any magma enters the system. No chance of a build-up, at present anyway.

            • Well Hernik…

              With such a complicated magmatic system I guess it could mix up something nasty and go big anyhow. Etna is good at pulling pranks.

        • The signal that was visible yesterday, first at EBCN and half an hour later at ETFI, with a slow buildup, a big peak and then a slow decline, was caused by Gino the caterpillar driver. No kidding. The guy was carrying out work on the dirt road leading around the summit on the western side, and which had been in a very bad shape lately (the drive in 4WD cars had become a sort of a rodeo). The road passes quite close to the said stations. In contrast, all eruptive activity has come to an end after midnight on 9 September.

          • Hah! Tremor we know thy name! “Gino!”

            I had a guy that used to work for me named “Jeano” who always had this really hot girl hanging out with him when we were all out partying.

            He turned around and married her. It put a damper on the group since many used to make passes at her. It’s bad form to come on to someone’s wife.

            Last I heard they were still quite happy with each other and getting along fine. Jeano never had to go to loggerheads with anyone, so I guess everyone minded their manners.

            Note: The Link attached to “Loggerheads” is the origin of the term. When you were at loggerheads with some one, the fight had devolved to trying to bash each others brains out… with a loggerhead.

  2. Was an entry on our Nine O’clock News here in Sweden where scientists at Uppsala Volcanological Institute (virtually identical to NordVulk of Iceland) said that while there will be at least a thousand years before the next big eruption at Krakatoa, Mexico’s Popocatetepl will have a large one much sooner. Since we’ve recently had a debate about water, it was interesting to hear them explain that their research proves that the reason for the very explosive behaviour of Krakatoa is that small amounts of water-rich sediments get mixed into the magma and that the amounts of carbon dioxide are elevated too.

    • Krakatau is fairly ruined and it will taking some time before it has healed enough to blow, but Popo on the other hand has been going for quite some time.

    • Popo will go big at some time or another. The question is whether it’s in a few years, or a few millenia.

      With that said, there are two things Popo currently has going for it that may imply that a larger eruption may be coming sooner than later, and by sooner, I mean within the next 100-200 years.

      The first can be seen here with the video link below. The edifice trembles due to the shockwave of the explosion, which causes all the loose ash to stir up dust. But if you look carefully around the base of the volcano during this eruption, it’s pretty clear that vents opened up releasing gas of their own. This isn’t the result of tephra bombs starting localized wildfires as there isn’t enough tephra landing during the initial explosion to cause this. It’s also clear that the continued emission isn’t a result of more ash unsettling via shockwave, as you would continue to see more ash further up the slope creating even larger dust clouds as it’s closer to the source of the eruption.

      In other words, it looks like a ring fracture is forming on Popo, which as Carl explained in his post on Mayon, isn’t particularly “good” news when trying to avoid a large eruption. See the video below for reference.

      http://www.wired.com/wiredscience/2013/06/watch-the-shockwave-of-an-explosion-at-mexicos-popocatepetl/

      The other problem Popo faces is also somewhat similar to Mayon – it’s very tall and large, which makes it much more vulnerable to flank collapse and structural failure. The size of the edifice also is better for bottling up large amounts of pressure, which could explain the potential ring fracture formation. Worse than Mayon, Popo has a known history of flank collapses, and another collapse event would lead to a very large eruption that would likely be larger than what was seen during St. Helen’s flank collapse eruption. When st. Helens collapsed, it was a decent sized volcano, but in the grand scheme of things, it wasn’t “huge” in any sense. Popo on the other hand is the second tallest mountain in Mexico, which would presumably increase the size of any collapse event by a very significant magnitude. Even independent of an eruption, a 5000 meter high mountain losing half it’s slope is a really big deal.

      For whatever it’s worth – take a look at this picture from Mexico City of the edifice (see below). Mexico city really isn’t all THAT close to popo, but in the rare chance that a flank collapse were to occur in the direction of either Puebla or Mexico City, I know I would not want to be living in either of those cities. The issue with flank collapses is that they can send pyroclastic flows and debris avalanches really far, since they’re directional in nature. I wouldn’t want to find out how far a debris avalanche from an eruption 5000 meter high volcano could travel.

      • Just to show that the possible ring fracture wasn’t a one-time thing caused by some tephra bombs stirring up a wildfire, here is another lower quality video from a separate date that shows similar activity at the same area on the mountain. You have to scroll to the end to see the potential fracture emitting gas.

        • I don’t mean this to sound disrespectful, but I distrust geology by Youtube video 🙂

          Where are the reports? The papers? Presumably volcanologists have been out and all over these alleged ring fracture cracks by now and will have a good picture of what’s up?

            • Care to enlarge on that?

              I’ve watched the video a couple of times, there’s a total of about half a second of footage of what looks like some kind of plumes in a forested area. No particular alignment, just… patches with some kind of vapor. Steam, smoke, gas… dunno.

        • I have a feeling those might be fires.. wonder if any Mexicans ever come in here.. we could ask them to go and have a look!

          • Fires from what? Summit eruptions don’t randomly cause fires at the base of the edifice. And when they do, it’s because there is plentiful lavabombs and tephra being slung out of the crater, which doesn’t seem to be the case here.

            Also, if you look at the dust shooting up out of the base, if you look close, it’s pretty apparent that the plume isn’t behaving like an ordinary smoke plume caused by fire. Smoke from a fire slowly drifts up without much velocity. In this example, it’s pretty clear there is some velocity and pressure directing the plume at the base of the edifice. This wouldn’t be possible simply from a quick fire forming.

            • There’s another meteorological phenomenon that had us all excited during the Eyjafjallajökull eruptions, the term for wich I cannot of course recall. Clouds would suddenly appear out of nowhere which gave the false impression that an eruption had started. Could that be the explanation here as well or do you have positive news that it’s volcanic in nature?

            • Let us give CBUS time to put together his post. And then we can discuss the finnished form. More fun that way I think.

            • I won’t be able to put anything together soon – I’m at work right now and I’ll be busy most of tonight. Maybe wednesday evening.

              I know there is a zone southeast of the volcano that has a high concentration of earthquakes and a fault, but i’m not sure if that’s related to this at all.

              If anybody wants to help out with this post – making sense of this document would help quite a bit. Or rather, interpreting anything about the faults / microseismicity would help as i’m not great in this area. This was the only non-paywalled document I found that had anything related to faults & microseismicity. If other people have access to paywall stuff they could likely find out more.

              http://www.scielo.org.mx/pdf/geoint/v50n3/v50n3a6.pdf

      • Cbus, I’d love to see an article from you on this as you obviously is the one who has read most on the destructive potential of Popocatetepl! Especially the ring fractures if you could have any sort of official confirmation of it!

        Go for it!

        • DOG PILE!!!

          Me to. I think it would be a most informative post. Especially if you happen to run across a map of the fault structures in the area.

          … and that makes me wonder if a list of low magnitude quakes are available for central Mexico… that might go far in looking for lineaments…

          • First off – the ring fracture theory IS speculative, and… based off a few youtube vidoes. I know, it’s not science, but for the purpose of speculation, it’s what we have to go off, and sometimes the advantage of a blog or forum for open discussion is you don’t need 100% hard evidence proven by rigorous testing to have conversation about something – it’s just important to understand the difference between theory and fact.

            Even if the fractures do exist, they’re likely new, and won’t have any discussion about them for a while (and what does exist is likely behind a paywall and in spanish).

            As for popo overall – I can’t say I’ve read a ton, but perhaps enough to have a rudimentary understanding. Maybe I could enlist some hep with looking for faults and low magnitude quakes as I’m not the best person for finding stuff like that.

            • Yes!
              I am so much looking forward to reading it, and I agree. A blog is a perfect spot to sometimes bring forth a theory. As long as one is clear with it being a theory it will bring many peoples attention to the idea, and with their help it can either be furthered along, or shot down. Kind of crowd-science with built in peer-review.

    • Nahh, not a chance for myself. Up 38hrs now. Loved the post Carl. However, damm you for spreading that Fox video from Norway the other day, Its on CNN now and the world.
      The defeat in the Soccer is down to you too. 😀

      Just the sleep thing, I can not post it on you. 🙂 so many jokes.

      • The Fox video has some of my gaming clan mates questioning my sanity. They have cursed me for the same reason. (tune stuck in their heads)

        On the other hand, I thought that the mouse was very cute.

    • No, didn’t put me to sleep. I have developed an idea about what’s going on, it’s probably wrong, but it’s pretty neat waiting to see what happens.

      As a treat, the company that I sub for, sent me on a call for the company that they spun off from. The site was still way the hell out in the middle of no where. Did the 135 mile drive out, and Google Earth promptly points me at a house. Being fairly certain that the Bank was not in the house, I called them up. Sure enough, they were two blocks back down the road. Finished up, drove the 135 miles home, only to encounter a FREEKING MORON passing an oncoming vehicle going up hill. Head to head aspect with me. Highbeams and Horn as they dart over to the shoulder on my right side and pass me over there.

      I wish this upon them

      Dunno what movie this is from, but Gorgonopsid is part of the group that were precursors to mammals. “They were among the largest carnivores of the late Permian.” So… not only did mammals make it past the K-T extinction event, our predecessors made it across the Permian-Triassic event. One of their mammalian characteristics were that they were heterodonts. “Having different tooth shapes.”

      Elsewhere in the Wikipedia article on them (I looked them up to compare the enormous canine teeth with the skeletal representation) “The early gorgonopsians were small, being no larger than a dog.” They went on to become the dominant predator of the late Permian.

      • Believe it or not, the closest living relative to those monsters are the sheep. If you get hold of a more arcane race of sheep then you can see that the large teeth have been pushed into a forward position.
        The issue with them becoming vegeterians? Their prefered pray got tired of bleeting sheep munching on the and decided that land was a baaaad idea and returned to the ocean to become dolphins.
        How can dolphins be considered bright when the meat eating sheeps could drive ’em off?

        Picture of sheep with vestigial forward teeth holders:
        Image and video hosting by TinyPic

        In the end the joke was on the sheep. The distant relatives of the Dolphin got ontop of the bleeting pests and the wolf was born. The sheep is actually the only species I can think of that have evoluted backwards. It still is the only animal that drowns if it stands in water even though the head is aboved the surface. The water goes the rear way into the lungs after a while.

        • When I was first married to my present wife she almost got a sheep ranch (Port Orford, Oregon) via her divorce from her Psycho ex. The fact that sheep are still around-are a mystery to me. The fact her ex is still around is also a great mystery..
          What happened is that the Ex lost all 255 head of sheep in a flash flood (Except one who was that:”most dangerous of creatures- smart sheep”)that was the only one to make for high ground…
          So he backed off on letting her have that ranch…
          I would be there to this day because of knowing too much about sheep to fail…

    • Well Carl, unlike El Hierro, Etna is not an exciting volcano to this community. A couple of small earthquakes, 1/1000th the intensity both energy-wise and numericallay of the period of unrest and most likely the result of magma cooling in the conduits, will see El Hierro get a topic of its own with several hundreds of replies. Funny-peculiar, but there it is.

      • I appreciated very much the post on Etna. The thing is, (imhpov) Etna is really something terribly complex which should require many many posts to begin getting some overview of the whole thing. The concise explanations of Boris Behncke below bring some light.
        On the other hand, El Hierro seems “simple” (even if it’s a false feeling) and as some people here (including myself) followed from the start of the activity, it became sort of a “pet volcano”.

          • Yes Etna would need many posts. However I’m doing a plot for quakes on Etna since 2012-02. I did one a few months ago, but I’m updating the data. If all goes well it should be ready tonight.

  3. On a US Carrier, Yellow Shirts are worn by aircraft handlers. This is part of the color scheme used to denote various positions of the deck crew. At a glance, you can tell what a person is involved with. Green shirts are (for example) Catapult and arresting gear crews and Air wing maintenance personnel, Purple shirts are Aviation fuel handlers. Other Nations may have different protocols.

    This is just a sample. As a side note, Purple also denotes fuel piping and valves on ships. Some of these have counterparts on non-ship airfields. Aircraft handlers essentially direct traffic when aircraft are pulling out to go to the taxi way. {via hand signals} (at which point the tower tells them when and where they can go)

    Caveat: I have never been stationed on a carrier, and never was involved in the aviation community.

    But I found this video quite funny.

    • And that was how Libya was won…

      Personally I wonder about the need for them on land. No wonder they grow bonkers and start doing dance routines.

      The Spec Ops are also good at dancing…

    • What video?
      The flight deck at least in the late 60’s to early 70’s was the easiest place it the navy to expire unexpectedly working on flying bricks (F4) was downright dangerous made a really good excuse to get into the P3 flying community

  4. Let’s have some (intellectual) fun with Etna! There are two ways to explain Etna’s eruptions, the first being the classical picture with a build-up of magma and pressure, released by something giving way. I now give you a second possibility:

    When a pulse of magma arrives in the Etna upper magmatic pathways, this causes the mountain, little more than a pile of clastic rubble, to inflate. Then there is intense degassing on a scale of days to weeks – this has been observed on numerous occasions, the phenomenon is real. The result is that the mountain no longer can stay inflated once the equilibrium point has been reached. It obeys the old m x g x h, a release of potential energy as it falls back which is what squirts magma out in short, sharp fountains.

    This model neatly explains why Etna has these short, sharp, visually appealing and relatively non-violent paroxysms. It explains the long periods of outgassing observed prior to the paroxysms of the past years, outgassings which common wisdom would demand interpreted as a lessening of the chance of any eruption whatsoever, not the reliable indicator of an upcoming paroxysm they have proven to be. Anyone recall Dr Boris Behncke’s opinion on the 2001-2 eruptions? Very nasty and unpleasant iIrc. That is how Etna would erupt if it erupted in the classical manner.

    Over to you!

    • Now suppose that this “pile of rubble” suddenly looses the magma from it’s chambers either through a conduit through a rift zone or withdrawal back into the lower chambers?

      What would happen if a significant quake caused additional space at depth and drew that magma back down? Would the overlying lid feel a vacuum and undergo collapse?

      Would any one notice?

      • And then you have the fact that often when you have a large eruption from Etna a goodly portion of the mountain starts sliding towards the sea from the inflation.
        If memory serves, during the last eruption a part of the mountain moved more than a meter downhill. Boris wrote about the motion over at Eriks quite some time ago when he was the summer temporary.

      • I do not know if this is what you’re after, but there is the Valle del Bove flank collapse of about 9,000 years ago and the summit collapse that accompanied the large 1669 flank eruption and lava flow, a part of the unusually high levels of activity of the first seven or eight decades of the 17th century with frequent summit activity and no less than ten flank eruptions.

        • And to make things even more interesting, during the last 100 years there have been 20 flank eruptions and a Valle del Bove sized are moving about without dropping away.

        • I think it was after the 2002 eruption that roads on the east flank of Etna began to suffer damage from this movement. Luckily, any flank collapse there is not only well away but also directed at 90 degrees from Catania. That’s not to say that Mascali (pop 12,498) and Giarre (population 27,785), who are in the direct path of any such collapse, would not be a horrific disaster.

          • If I understand it correctly they constantly map the area and have GPSes to keep track of any movement. I have also seen a good computer model of how the crack runs through the mountain.
            But, it is the scariest part of Etna. I do not think I would care to get a tenth of a mountain ontop of me.

          • “Luckily, any flank collapse there is not only well away but also directed at 90 degrees from Catania”

            I don’t know if you would call that direction luckily, it is the seaside of the volcano. If their would be an collapse big enough, not only Mascali and Giarre (between the Mediterranean sea and Etna) would be overwhelmed, also a big part slide into the sea. And than you’ve a deadly Tsunami. I read somewhere (have to look it up) that the landslide, that created Valle di Bove, formed 40m high waves near Etna. The Tsunami lacross the whole Mediterranean Sea and 4m high waves hit the coast of Israel after a few hours. This scenario today would be catastrophic. Catania would get unscathed through the collapse to get hit by an even destructive Tsunami that is possibly 30-40m high. And than you also have the south coast of Italy, Malta, Greece, Egypt etc. that will get a direct hit

            • It all hinges on how BIG such a collapse is and whether or not it hits the sea. I’ll grant you that worst-case scenario however. IF there is a repeat of the 9 kA Valle di Bove collapse, then that’s a very likely outcome. But since this collapse has already happened, and geologically recently at that, the chances of a repeat worst-case scenario are very slim indeed. Just because no one can give a 100% guarantee that something will not happen, that does not constitute a 100% guarantee that it will and in the immediate future too. Such reasoning is much too black-and-white and Nibiruistic for my liking. You might as well argue that because Campi Flegrei is situated mostly beneath the Gulf of Pozzuoli or that the giant volcano Campi Flegrei del Mar which lies south of Sicily (Ferdinandea) is subaquatic too, this leads to a guaranteed 50m tsunami across the Mediterranean and it’s as likely to happen tomorrow as in 10,000 years’ time.

            • No, Etna lies at the East-side of Sicilia, at the Ionan Sea. Any Tsunami will be directed to the East, thus towards South Italy, Greece, Egypt etc. To hit Spain the Tsunami would have to go through the Island. Even Malta is protected by the Island of Sicilia, but is to close I think.

              Image and video hosting by TinyPic

            • Ah, now I understand Sake, I was actually thinking about if it went upwards since we talked about a landslide going towards the sea missing Catania.

              Now I just wished that Boris swings by and reminds us of where that loose piece is pointing.

            • @Milord P
              It is indeed worst case scenario and the odds are low, but I think I think you’re missing one thing, the Pernicana Fault. The Pernicana Fault is already sliding away towards the sea. IF (big if) that would give away suddenly, you’ve a Valle del Bove event. But to have such event I think you will need a big eruption at the right place.

            • But Sake, you have already had the Valle del Bove event and as a result a) There is far less mountain to start sliding, and b) What has already slid down now lies in the way, blocking or impeding what may come after. Taken together this means, as far as I can tell, that even if the Pernicana Fault gave way today you would not have anywhere near the same amount of material and also, far less of what actually slid away would reach the sea. That’s not to say you could not have a 5 – 10 m tsunami around the Strait of Messina, which is bad enough locally, even if it does not have the potential to cause widespread destruction across the Mediterranean Basin.

              I wish there were good photographs to show you the terrain in question, but at least you can have a look at Valle del Bove and see just how much has already slid away, how far it would have to travel in order to reach the sea and, as a consequence, how much less devastating a new landslide would be.

              DragonEdit: Fixed link. One can not do imagelinks like that.

            • I went there in 2003. The volcano is quite removed from the coast. I was camping near Acireale and yes, the volcano looms above you, but it is quite far. If you compare to (let’s say) Teide, the distance and the slope are very different.

            • Henrik really invented brand spanking new word here…
              There is not a single instant of “Nibiruistic” before today on the entire internet.

              And here is the best part, it is still completely understandable. Nibiru = the fabled non-existing planet of the 2012ers. “Nibiruistic = something non-existing or that is not going to happen but exist in the world of the tin-foilers”. Simply brilliant word!

    • I like alternative views on things. This has some merit. The things that intrigue me about Etna:
      1) how steady is the magma influx from depth
      2) how does the mountain manage to degas almost constantly yet still produce high-gas fountaining?
      3) why is the fountaining so periodic

      .. among a whole host of other questions 😉 I already conjectured that the periodicity in the fountaining at the SE crater is due to some geyser-like chamber structure under the SE crater which is filled from below with fairly gas rich magma that, upon reaching the cavity, suddenly foams from the pressure drop, fills the cavity and whizzo, it pops a valve, fountains, rinse and repeat. Maybe your idea has more merit. We should then see deflation prior to each paroxysm. Is this the case?

      What I am also not sure about is the rest of the system. Is it filled with degassed magma? Is it possibly topped up with the degassed magma left over after each paroxysm? If so, this could fuel a non-explosive flank eruption further down the track. Or is the rest of the system also getting enriched with injections of similarly gas-rich magma like the SE crater? How rapidly does gas migrate through a fairly fluid magmatic system?
      The pathways seem to be fairly unobstructued for both gas and magma to leave the system if the pressure got high enough. Maybe Etna is just a huge sponge structure filled to the brim with degassed magma and the SE crater is a bit of an anomaly with a direct feed from depth.

      • The amazing thing is that magma flux at Etna is not really all that regular. It comes in batches, sometimes small, sometimes more voluminous. When a rather voluminous batch starts to make its way from about 20-25 km depth into the shallower portions of the system, we see peculiar earthquake sequences at different depths and below different sectors of the volcano, starting deep below the west flank and then more shallow below the southwest and south flanks. There seem to be a few passages where magma does not get through all that easily, putting the surrounding rocks under stress and this leads to the earthquakes. Such sequences have been well documented before the major eruptions of 2001, 2002-2003, and 2008-2009. Each time there was also significant swelling (inflation) of the volcano. We haven’t seen similar events since 2008, and it seems pretty certain that in these past few years there has been rather a series of small magma batches coming up to feed the summit activity since early 2011.

        The degassing of Etna is one of the most intriguing facets of its activity and – along with many other factors – renders it rather unique among the volcanoes on Earth. Although degassing is continuous, the flux of the various species of interest – CO2, SO2, H2O and halogens – shows significant fluctuations, it’s not at all linear. And this tells us a lot about where the magma is and how much it is. When a new batch of magma comes up, it will bring still more gas with it, and CO2 is released already quite deep, about 15 to 18 km, SO2 is released at 3 km or less below the surface, H2O and halogens come still later. So if H2O, which is essentially the one gas that makes eruptions explosive (CO2, which has the same effect, is usually lost long before the magma gets close to the surface), stays with the magma until it’s just about 1 km below the surface, then it will cause the famous “champagne bottle effect”, which in basaltic volcanism we call a lava fountain.

        The feeder system of Etna is currently largely restricted to the central conduit system, with several storage areas of more or less limited extent at various depths. The uppermost storage area (often also called “magma chamber”, which renders a false impression of what it really is) seems to be rather cylindrical in geometry, and it’s there that water vapor exsolves, forms bubbles that grow and coalesce, demanding more and more volume in rather short time intervals, and thus transforming the surrounding magma into foam. Once this process really gets going, then a lava fountain, or paroxysm, starts. Once the foam is gone, the dense, gas-depleted residual magma will sink back into the conduit and form a sort of “lid” on top of the magma column, which for a time will keep the magma underneath under growing pressure. Eventually, H2O will start to make bubbles in the magma underneath that “lid”, the volume of the magma will grow, and this will lead to its upward expansion within the conduit, pushing the “lid” before it. The “lid” is eventually released in the form of small explosions or non-explosive lava emission (we saw this every time before each of the 66 paroxysms – except the first – in the year 2000 and again during 15 similar events in the spring of 2001), while the gas-rich magma below is subjected again to the foaming process, and once most of the “lid” is gone, the next fountain lets loose. Only once the available magma is exhausted, because supply of new magma has slowed down or temporarily stopped, the series of paroxysms will come to an end.

        Amazingly, we have seen that even in the absence of new magma supply, the system is capable of auto-stimulating itself to make paroxysms as long as there is gas-rich magma where H2O exsolution and bubble growth can lead to foaming and fountaining. This happened in the spring of 2013 – the last paroxysm, on 27 April, seems to have ejected the last little bit of magma still capable of bringing itself to foaming. A few days after that, a few gas bubbles still formed in the remaining few droplets of magma and small explosions occurred at the New Southeast Crater, seemingly starting the prelude to yet another paroxysm, which never came. Since then, magma supply into the system seems to have been rather slow, and only a very tiny quantity of magma has arrived in the past couple of days near the surface, bringing the mild Strombolian activity at the New Southeast Crater, which in the meantime has again stopped.

        • Awesome to hear from the source itself!

          Etna is such a mysterious volcano. Does it have a legitimate magma chamber at depth? From reading what you and others have mentioned, it seems to be fed directly by what seems to be a feeder tube almost right to the summit itself. If it doesn’t have a magma chamber, what would have prevented a magma chamber from forming when compared to other volcanoes in the region?

          • I think that with magma “storage area” Boris means the same thing, but that he prefers not to use the word chamber since the magma rarely stores in chamber-like structures.
            Storage area is vastly better since it does not imply a specific shape of the volume of magma.

        • I am so stealing the phrase magma “storage area”. Have been struggling for a while to come up with something better than the word chamber.

          And thank you for the explanation. So clear and so easy to understand. 🙂

        • Great post! The last paragraph confirmed an observation I had before. After the episodes of lava fountaining earlier this year, Etna ran out of gas pressure and magma.

        • way cool coming home from a hard day’s work and finding this… great. Thanks Boris, I think I owe you yet another drink (we must be up to a dozen bottles of Nero d’Avolo by now!! oh weia, that’s going to be some headache) …degassed magma as the lid. Of course! Mind you, the system must be pretty finely balanced with just enough gas rich magma frothing up under just enough degassed magma to hold it in place until it pops.

      • Yes, that is the most likely scenario at current moment that it will not have a larger than normal eruption. But, as Boris wrote up above, the magma arrival rate varies and in theory an unusually large magmatic blob could move up from depth, but it is unlikely.

        • A large blob of magma could rise up, but it is unlikely as you said. It seems like Etna has quieted down for now, like I expected. Better not be too sure of myself…

      • Being a decade volcano doesn’t really imply much towards how large of eruptions it can produce. kilauea is also a decade volcano.

        Most of the decade volcanoes are actually relatively benign in their likelihood towards producing larger eruptions (most, not all). That doesn’t mean they shouldn’t be on the list, but the list was made mostly due to proximity to highly active volcanoes.

      • Etna is on the Decade Volcano list because she meets (at least) two of the criteria for inclusion – lava flows and volcanic edifice instability.

        • I have always had a nagging suspicion that the decade volcanoes was selected purely from the amount of scenery, and how good parties you could have there while having volcanologist conferences.
          One should remember that the concept came into fruition when one such conference came to a very tragic end.

        • Some caldera development there (albeit a few thousand or so years ago) has produced Plinian eruptions and pyroclastic flows there.

  5. OT Today the first (weak) autumnal storm is hitting the coast of the low countries, So we’ve real autumn weather, very wet, windy and cold (max 15°C). Last Thursday it was the first day in September in more than 50 years that was above 30°C. So we went from Summer to Autumn over the weekend.
    Because it’s bad weather and it is the silly animal season, when all rare species pop up everywhere (hunting sea eagle, wolf or fox at a bad trail-cam photo, escaped black panther a few years ago etc.) a song to cheer things up:

            • It will be possible to use wet ethanol – a few percent water – that has not gone though enrgy-expensive drying that is required for mixing it with gasoline. A bit greener.
              The ethanol I’m using is really dry! But I shall try adding water as an experiment, but it might ice up the butterlfy- could be exciting.

          • Nice project ! You could of course have used a toyota supercharger SC12/14, they have a magnetic clutch so you can switch it off when boost is not needed 😉 unless you want to use timely parts..

            • Those Toyota blowers didnt make it to UK, pity. We have lots of Eaton blowers off Mercs, which take up a third of the space and dont heat the mixtue up so much. But I fitted the old Wade 15 years ago,and I’ve got used to it. And as you say its ‘in period’.
              De-clutching a blower has disadvantages. The rotors smash up the fuel to vapour improving distribution – worth sacrificng the perhaps 1 -2 HP saving.

      • Whoa…. at first I thought there was massive bruising from the bit, but that is a tattoo.

        If they do not capture the snake, and if the Met predicts a mild winter again, that snake is a goner. As good as already frozen stiff. Lest it finds it’s way into the sewers.

        • Haven’t you seen the documentary “Anaconda – The Movie”, in it they prove that any large constricting snake left to it’s own devices is A) Indestructible, B) Will grow to a length of 20 meters, C) Be able to fly by rotating the tail quickly.

      • That is complete and utter nonsense.

        A 3 meter Python has 4 cm between the fangs, and there is just no possibility for a bite having this effect: “My right leg went black and I was shaking and couldn’t get warm. My face started to swell up. I was put on three different drips and my face started swelling up – the blood wouldn’t stop coming from my right leg.”

        It is not even likely that it was a constricting python at all. If it had been a constricting snake that struck here there would have been bruising from the force of the bite-impact (they strike harder then poisonous snakes to “stun” the prey a bit. Then there would have been tearing in the wound as the snake ripped the head back. Problem here… Constricting snakes do not take the head back, they encoil the pray.

        In reallity the snake would have made a coil around the leg, after a while even a thick-headed python would have let go about 3 to 5 minutes later since she was to fat and large to swallow. There would have been fairly little blood.

        With an 8cm bite mark? Well, than it would have been a snake about 5.5 to 6 meters and she would have been found dead, or even eaten depending on her size.

        I grew up with Lurkings new favourite pests, the burmese python, used to bread them. I’ve been bitten several times by snakes that size so I know very well what I am talking about. You get bit, look at the stupid ball hanging from your arm (trying to not move) and wait for the little rascal to let go, then you calmly put the snake back in the cage and go wash the wound. End of story.

        She was bit by her own dog and got gangrenous.

        • Exactly, you get four rows of bites.
          She is lying through the her snake teeth…

          Okay, to get a bit scientific here. Python Molurus Bivittatus (commonly known as the Burmese or Tiger Python) is a constricting snake. A Viperous snake strike, inject venom and then release to avoid being hurt or damaged by its pray. Only Viperous snakes leave a telltale 2 puncture mark since they have injection fangs. Every other type of poisonous snake ejects the venom as it bites and then grinds the venom in, it still takes a short time, but it leaves a different type of bite mark then a viper.
          A constricting snake is not poisonous at all so it strikes and bite down to keep the hold on its pray and then quickly coils itself around the pray. The teeth are therefore directed backwards and a python even have a bit of problem to get a pray loose from its mouth after biting. The teeth are sheated as you see in the image below, inside those sheets sits the teeth. And a bite tear if you struggle, a python bite has as much with her bite wound as a Horse cart has to do with a London Double-decker bus.

          What that woman described sounds more like a viper-bite (both the puncture wounds and the effect), problem is just that there is not poisonous snake on the planet large enough to cause that bite width.
          I say her own dog bit her and she for some reason did not want to tell someone, probably to not have the dog put down.

          Image and video hosting by TinyPic

        • I agree with Carl. The reported story is full of crap.

          Coral Snakes are the only indigenous non pit-vipers here in the SE US that are poisonous. They clamp down and grind. All the vipers hit and back-off, preparing for the next strike. King Snakes just wonder why they are getting the shit beat out of them again… people tend to spook around all snakes. (better safe than sorry). In my minds eye, I have actually managed to go into a full hover due to a coral snake that I discovered between my feet. Logic says it didn’t actually happen, but that is how I perceived my reaction after pushing the rock off the side of the tiny cliff. (it was a lime pit where we used to look for sharks teeth).

          I never was successful at getting the sharks teeth, my cousins were. All I ever got were what appeared to be petrified sponges.

  6. North Korean volcano
    http://www.bbc.co.uk/news/science-environment-23981001
    “” Surprisingly, the volcano is relatively unknown in the West, not helped by the fact that it takes a confusing array of names. In China it is known variously as Tianchi or Changbaishan, but its Korean name is Baegdu-san or Mount Paektu, while the Japanese call it Hakuto-san.
    …… In 940 AD, the volcano exploded in a huge eruption, known as the “millennium eruption” that threw ash vast distances. Measurements of ash deposits from that eruption measured in Japan indicate that this was one of the two largest known volcanic eruptions on Earth since that period, matched only by the Tambora eruption in Indonesia, in 1815 AD “”.

    • Never Fear, they’ve got a Time Lord on it.

      Dr James Hammond from Imperial College London, and Prof Clive Oppenheimer from the University of Cambridge have begun a collaborative study with North Korean scientists,

      At least that was the first thing that came up when people over at Eruptions first saw his visage.

      I’m pretty sure that with Prof. Oppenheimer in the mix, some really good science is going to come out of the endeavor.

      … as long as the Daleks don’t show up.

      • Eh… Are the North Koreans really the ones we want to have time travel? Imagine King Jong-Un travelling backwards in time to make the history into his likeing? Oh, wait a minute, forgot what family I was talking about… He would just do his grandmother and go back and brag about it.

        • Logically time travel would explain a lot regarding Kim Jong-Un.
          Being severely inbread would make someone rather on, especially if it was done on a time-loop. Than he would be his own grandfather infinitely much.

  7. How honoured I feel to get home and read such an illuminating post + comments!
    Great discussion and the man-To-answer-all-questions right there among us.
    So worth missing my few hours of sleep!
    Thanks Carl, Boris, Henrick et al!!!
    BTW: a second “volcanetto” spewing mud at Fiumucino. Too late to find the link right now, but worth taking a look.
    BBGN!

  8. And yet a last comment: Sakurajima has not ceasing erupting for days and it seems that not only Showa crater is involved. I am statring to get concerned about that one!

      • Not in the last four years – I check every day and night. I am not talking about esporadic single explosions; I mean one long non-stop eruption, spewing black ash continuously. That is new to me!

        • Horrible misspelling on my part… Should have sad “unusual”…
          The point my sleep derived mind tried to put forward is that I have never heard of a such a long eruption for many a good year.

  9. Peter talked about cars up above, and I found a car that I would actualy like to own. I am at best dubious towards cars, regardless of my one attempt at owning a cool one previously.

    But this one would fit my personality perfectly.
    Image and video hosting by TinyPic

  10. Messing with Carl…

    Since Carl is a Floyd fan, why not? (This is from the soundtrack of “La Vallée,” a movie that I have never seen, but from what I have read, is a pretty convoluted story itself.)

  11. I have seen a lot of discussion above about the Valle del Bove collapse at Etna – an event that many scientists assume took place some 8000-9000 years ago, though others still doubt it and still more so the giant tsunami it should have unleashed. The whole eastern to southern part of Etna – a good third of its entire surface – is known to be unstable and moving episodically, with a large slip between 2002 and 2010 (it has considerably slowed since), but it looks rather like before there will be any massive, catastrophic collapse, there will be many, many more episodes like this. It seems that basaltic volcanoes are capable of accomodating numerous smaller slip events without catastrophically failing like andesitic or dacitic stratovolcanoes, with great collapse events happening only every few tens to hundreds of thousands of years. Currently we do not expect a large-scale collapse to happen, at least for the next few thousands of years.

    For some more background information, I can lead you to a three-part piece that I wrote for the Eruptions blog three years ago: “Brief Anatomy of an Exceptional Volcano”, and which is still valid though it obviously lacks information on the three-years spate of paroxysms that started a few months later.

    Part 1: http://bigthink.com/eruptions/etna-week-part-1-brief-anatomy-of-an-exceptional-volcano

    Part 2: http://www.wired.com/wiredscience/2010/08/etna-week-part-2-the-current-dynamics-and-activity-of-etna/ (this part contains a discussion of flank instability and the Valle del Bove)

    Part 3: http://www.wired.com/wiredscience/2010/08/etna-week-part-3-etnas-volcanic-hazards/

    This should keep you busy for some time 😀

    • Oh, that one! The slab-roll-back stuff. It keeps me busy whenever I decide to improve my knowledge on Etna – this spectacular volcano. But then the firework show begins and it all becomes art and awe!
      But I am sure the guys here will like to debate the whole thing in depth. I t is a must read.
      Thanks, Dr. Behnke for your everlasting love for Mamma!

      • I would also recommend a visit to your Etnaboris Flicker site. Great images with detailed explanation written in plain, yet accurate, language. It’s been always fun to drop by and pick some gems that are available there. Still don’t know why it hasn’t become a book!

    • Those articles by Boris is often read by me. And as Renato says, the Flickr account is wonderfull, a must on a rainy day for a true Volcanoholic. 🙂

  12. Hi

    Here is the Etna animation from February 2012 to september 3rd 2013.

    It looks pretty complex (understatement of the day !)

    The most striking figure is the earthquake swarm of 22/11 and 23/11/2012 on the NW of the volcano.

    The quite recent seismicity in the region of Zafferana is also shown.

    Data from INGV and NOAA, made with Gnu Octave

    There are several sequences (day to day from the south, then from top view), rotation, vertical rotation and finally zoom.

    The title bar shows the date span.

    The color bar has 2 scales terrain elevation (on the right) and date (on the left)
    Earthquake size is proportional to magnitude (see scale on one side with the size in magenta).

    • Brilliant animation! I’d say that you have tectonic earthquakes to the S and E along the known fault lines together with two rapid magmatic pulses, the first at ~25 km depth, the second at ~10. But then I’m a rank layman! 😀

  13. Thank you to Dr Behncke , Carl and Shteve. I have been a sporadic visitor for the last few days but I have found time this morning to read this and the last Posts.
    I really appreciate that busy professionals like Dr Benhncke find time to write a comment. These put everything into perspective and set us back on the right course for ruminations. 😀
    I never cease to be impressed though by the time, trouble and resulting animations produced by the amateurs here. Thanks dfm for your latest work of art. Most interesting and those latest ones of El Hierro are rather disturbing.
    Another thanks to another friend of this Blog, Armand Vervaeck .he and his colleages do a Stirling job with their Blog Earthquake report.
    http://earthquake-report.com/about-2/
    here is a clip of Lokon Empung erupting back in July

    >>>>>and as this is beginning to sound like an Oscar Award rumination, a special thank you to The Sheep….Our original source of inspiration for ruminations great and small.

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