A Super-pooping Supervolcano?

Image from Wikimedia commons.

Image from Wikimedia commons.

Though I walk through the valley of the shadow of death, I shall fear no evil

It is said that within great beauty lies grave danger and few places are more beautiful than Lake Atitlán. Poets have filled cheap notebooks with particularly flowery hyperbole in their attempts to catch the beauty of the caldera lake and the encircling volcanoes roaring out of the lake mist, catching fire as the morning sun hits them turning the green into imaginary gold and fiery red. It is truly a place of dreams, and as with every dream there is a spot of darkness hinting at a lack of a sign: Beware! Here be Dragons.

I rarely write about supervolcanoes. To date I have only covered two real supervolcanoes. The first was the perfectly balanced volcanic system of Tondano and the second was the rather comatose Yellowstone. I have though on occasion mentioned that some volcanoes have better PR agents than others. Where Yellowstone in its dying shroud sprouts a scientific volcanic paper a month, the rest of them will be happy to merit one per year for all of the known supervolcanoes.

It is sad that things are like this, but it is in the end hard cold political facts running science. Yellowstone will get you money to write a pointless paper and it is all about the number of papers, not the quality or merit of research that runs academia in the twenty-first century.

In the end it might not matter that much, the main reason I do not write about supervolcanoes is that they are such a boring bunch. After all, they very rarely do anything interesting, and when they do they either suffer a side vent eruption like Tondano, calmly inflate like Uturunku, or do a bradyseism and goes back to sleep. Or they do nothing and get papers written.

So let us get back to the matter at hand, the rather interesting Lake Atitlán.

A brief background

Who put a small roof in the lake? Photograph by Dr Carmen Morataya.

Who put a small roof in the lake? Photograph by Dr Carmen Morataya.

Lake Atitlán as we see it today is the result of activity after the 300 cubic kilometer Atitlán III eruption that happened 84 000 years ago. In the wreckage of the caldera collapse, the volcano started a new cycle towards yet another major explosive event, by the rapid serial construction of 3 major volcanic edifices, one after another and each of them built more rapidly than the previous.

The oldest of the 3 volcanoes born after the Los Chocoyos caldera event is the 3020 meter high Volcán San Pedro. It was built during 44 000 years of eruptive activity ending 40 000 years ago. After that volcanic activity started at the Volcán Tolimán which in the next 30 000 years grow into a 3 158 meter high edifice.

On the flank of Tolimán is the failed volcano of Cerro de Oro that might have erupted 5 000 years ago. Instead the new main volcano was born on the rim of the old caldera instead of within it as Volcán Atitlán started erupting 10 000 years ago. This volcano grew very rapidly and matured into a classic 3 535 meter strato volcano.

In historic times Volcán Atitlán is the only erupting volcano in or near the Atitlán Caldera. The volcano suffers mostly from small to medium sized explosive eruptions. In the 384 years between 1469 and 1853 the volcano suffered 12 eruptions ranging from VEI-2 to VEI-3, but after 1853 the volcano has gone into a dormant state without any obvious signs of a pending eruption.

The area is highly seismic and in 1976 the area was struck by a M7.5 earthquake that killed 26 000 people. The earthquake most likely fractured the bottom of the lake and within a month the lake water level dropped two meters. It though rapidly filled up, most likely due to later seismicity closing the fractures.

The Lake

We all want lifeguards in the water, but lifeguard-towers? Photograph by Dr Carmen Morataya.

We all want lifeguards in the water, but lifeguard-towers? Photograph by Dr Carmen Morataya. Notice that the water level has under-mined the stone wall.

Lake Atitlán is more than 300 meters deep and is covered with a 300 meter deep layer of sediments. The sedimental layer is filled with prodigious amounts of methane that effectively hinder analysis of the actual caldera bottom 600 meters below the surface.

Sedimentation occurs with a normal rate of 0.5 centimeters per year, and that accounts for half of the 20 meter uplift of the water level in the last 2 000 years. We know the rate of uplift from C14-dating of artifacts found in a sunken Mayan village.

The lake is suffering from extensive deep hydrothermal activity releasing large amounts of energy (290mW/h inside the lake and 230mW/h outside), this creates an ideal environment for the silt producing cyanobacteria inhabiting the lower two thirds of the lake (the source of the methane in the sediment).

To compound the problem the lake is endorheic, lacking any outlet of surface water, instead release happens through seepage into two river systems through the caldera rock. This traps the water at depth and makes it very stagnant and a perfect breeding ground for highly toxic cyanobacteria.

The Caldera today

Who pooped in the water? Photograph from Prensa Libre.

Who pooped in the water? Photograph from Prensa Libre.

By now the caldera has filled in with about one third due to the construction of the three volcanoes, and another third has been filled in by silting and resurgent pistoning of the caldera floor due to magmatic intrusions.

Under the caldera floor there is believed to be a large reservoir of magma with an unknown amount of eruptible material. The amount of hydrothermal energy seems to signal that the amount of hot material is either very large, or quite close to the surface. The lack of doming though seems to indicate that the main reservoir is at depth since the resurgence is uniform over the area.

During the last 2 000 years there is evidence of episodes with highly increased silting due to hydrothermal energy increase. This most likely are signals of magma moving upwards into more shallow repositories.

During the last 15 months the surface of the lake has risen uniformly more than 200 centimeters, something that has caused great problems for the local Mayan residents.

The dangers of Atitlán Caldera

There are four principal dangers from the current volcanic system. I will briefly expound upon them in the order of possible risk for anyone nearby.

The largest danger is obviously seismic. Another large earthquake may happen here at any time. The second largest risk is of course that Volcán Atitlán suffers a renewal of volcanic activity and erupts. The eruption would not be that large, but evacuation of nearby population might be problematic.

The second least likely risk is due to the unique sedimental setup and the large amount of deep water cyanobacteria. With time the amount of methane trapped in the sediment will be higher than is possible to contain within the confines of the sediment. As the lake gets closer to the threshold of containment the likelihood of an earthquake setting off a chain reaction increases and as that happens the bottom sediment will explode out of the lake bringing with it a deadly mixture of cyanobacteria, SO2 and methane poisoning everyone within the caldera. For those who are unfamiliar with these phenomena I recommend googling the Lake Nyos disaster.

The least likely risk is that a large fast explosive eruption (VEI-6) will empty out the magma reservoir under the caldera floor at such a speed that the roof of the reservoir collapses and a supereruption occurs.


The rare volcanic water-palm as seen in its natural habitat. Photograph by Dr Carmen Morataya.

The rare volcanic water-palm as seen in its natural habitat. Photograph by Dr Carmen Morataya.

There are many possible ways to explain what is currently happening with the water level in Atitlán Caldera. There are though three that are more likely than the others.

Seismic activity could have pushed together the natural pathways for the seepage out of the lake into the rivers. There is though no evidence that the rivers fed by the seepage have suffered a decrease in water reception.

Then there could be increased upwelling of hydrothermal water into the lake. This would lift the level of the cyanobacteria boundary upwards and there would be cyanobacterial (algae) blooming. We know for a fact that there have been large problems with such blooms during the last 15 months.

The third cause could also be piston-like inflation of the caldera floor due to magmatic intrusion either at depth, or in a shallower reservoir under the lake itself. The most likely thing in the end is a combination of a shallow emplacement causing a dramatic increase in hydrothermal activity.

Locally the belief is that the increase in surface cyanobacteria is due to release of waste water and other nutrients into the lake. This is highly unlikely to be the main cause; the waste water flow into the river has been roughly the same for decades. And in the end this would have caused normal algae bloom of garden variety green algae, not cyanobacteria. Why now? Well, for starters waste water contain too little sulphur to feed the bacteria, also you need something that cooks off the oxygen, and explaining that with sunlight warming the water does just not cut it. It is much more likely that an increase in hydrothermal activity has elevated the temperature of the lake and deposited the necessary sulphur to feed the cyanobacteria.

Most likely this is all caused by a deep intrusion of magma at depth, of which a small part has intruded in a shallow reservoir under the lake. This in turn caused increased turbulence of the water at depth as the levels of hydrothermal activity sky-rocketed. In the end there is an increased risk of eruptions occurring in Volcán Atitlán or from a new vent. I do though not believe that this will cause any large eruption within the foreseeable future. After all supervolcanoes are well known to inflate at prodigious rates and very rapidly without erupting, or erupting through one of the side vents that functions as safety valves.

Sorry all, no supereruption seems to be around the corner even though there is a bit of pause for thought when something on this scale shows signs of unrest.


359 thoughts on “A Super-pooping Supervolcano?

    • I have rarely found that Sigrún pulls anyones leg…
      I could in a way imagine a way of that working for a specific set of Icelandic volcanoes, but it would be wrought in uncertainties.
      I will go and read the paper and get back on it later. I do though think that it will be a sollid paper, Sigrún tends to do sollid work.

      • pulling “the money” leg ?
        It is like you say on Pinatubo, just one data point, and only applicable to them volcanoes about to go Caldera ..

        • I would say that the paper is more likely to have any use than the ones published every week on Yellowstone…

          And what on earth have Sigrún done, taken your parking spot? :mrgreen:

          • As far as Yellowstone is concerned I can see that the issue of buoyancy could be instrumental in causing an explosive eruption, if the body of magma is being held down by a range of mountains. It would suggest that once too much of the surface is under pressure there might be either a build up, where the surface is more elastic, or a sudden release under the weight of the surface rock.

            • Problem is just that there is not enough eruptible magma, and what little there is has been totally depleted of volatiles. Basicall Yellowstone is a huge dud. In theory the hot unmolten magma could float up and create a large hot magma dome, but that would be a rather silly sight.
              Give Yellowstone a million years or two and it will get back to life.

  1. Excellent article. Enjoyed reading it. Now I have bit of an off topic question: Which volcano would be considered as having the highest chance of going caldera?

    • That question is almost totally impossible to answer. One could probably make top 100 candidate list, but not even get close to deciding which will be the next one to go. Most likely one will go caldera within the century and it will most likely be a VEI-6 eruption, not more.
      Currently I would say that we know of no volcano that might go caldera within the next year, or even decade, but then volcanoes tend to do as volcanoes wish… and that is surprise the heck out of us both in positive manner and in negative manner.

      Let us take an example from Iceland. The most likely culprit to go caldera there is Grimsvötn, it is showing signs of getting to the limit of what the system can take before erupting so hard that it collapses into itself. It is probable to happen within the next 1000 years. And still it is more likely that we get surprised by another volcano or that nothing at all of the sort happens.

      After all, we have only wittnessed one puny caldera event in well instrumented times and that was Pinatubo, and heck knows if we really learnt anything from that eruption due to unfortunate circumstances. And one datapoint is just not enough to learn anything really useful from.

      • And with Pinatubo’s nasty nasty show… how much of that was due to the ill temper of the volcano, and how much was due to having the main event happen in the middle of a Tropical storm?

        One things hurricanes and tropical storms do, when healthy, is dump water like there is no tomorrow. Drop that much water and run-off into an erupting crater, and it’s not going to be very peaceable about it.

        • I have had a few thoughts on that, and in the end I ruled it out. After all a hurricane will not dump down the amount of wather that a lake ontop of a volcano does. Grimsvötn for example blasted right through a lake 100 meter or more deep without ever emptying it. And still it did not go caldera, and a hurricane dumps less water than that.
          It probably though worsened the effect of the eruption and made the column go higher but calderawise I believe not.
          Usual caveat: I do not collect podiatrists… 🙂

          That lake is the second reason for me believing that Grimsvötn will go caldera with time.

        • Well, my point is that the presence of the water likely assisted in the very high lofting of material… it added a phreatic component that would not have ordinarily been present. The Hobbit launcher went 6.5 km on water/steam alone.

            • I’ve had thoughts on Oregon’s Crater lake, if it ever goes especially. if it is Wizard Island (which may not ,also.) there is a lot of water….
              Re: Atitlan My wife spent quite some time in Guatemala . Had a friend who ran a bookstore there.
              She was Mestizo lady who said: “We are always a little sad here because we could die tomorrow because of the Volcanoes. ” She lived on the lake…

    • The one that forms a big eruption next :).

      That’s kind of an impossible question to answer if we’re being realistic, since you would need to know which volcanoes are going to erupt next in the first place, which is a tough call with over 600 volcanoes in the world.

      Overall, there are a few things to look for when considering a volcano to potentially be in line for a caldera event.

      1. How tall is the edifice? This doesn’t really apply that much for highly rhyolitic volcanoes, since they can never really form much of an edifice in the first place. But for standard arc-based stratovolcanoes ranging from Basalt to Dacite, looking for tall, steeper edifices is probably a good start. Tall cones are inherently instable, but also have two other issues. The larger the edifice, the more weight is being pushed down on the magma chamber itself. When the chamber empties out during an eruption, there is no longer a large pool of magma pressurizing that internal chamber, and the heavier a volcano means it’s more likely to destabilize and collapse without the pool of magma to hold it up. The other thing a large cone does is blocks the flow of magma out of a system. The larger a volcanic cone, the easier it is for magma to clog up in the conduits on the way to the surface. This leads to an increase in pressure and an increase in the amount of magma that gets held prior to an eruption.

      2. How shallow is the magma chamber? The deeper the primary magma chamber, the more difficult it is for a proper traditional caldera to form. This is fairly simple mechanics – if there is only an extremely thin layer of crust between the volcano & the primary magma chamber, when that chamber empties, the thin crust will have a much more difficult time holding itself up than thick crust associated with a deep pocket of magma.

      3. Has the volcano produced large eruptions in the past? Has it had a caldera forming event previously? These two questions are fairly simple. On the whole, volcanoes that start to see larger and larger eruptions are probably more likely to create a caldera forming eruption than volcanoes that just putter around with VEI-2 and VEI-3 eruptions. Volcanoes do after all start on the small side, and gradually grow larger and larger as the magma chamber is expanded through various eruptions. If the volcano has already formed a caldera from a previous large eruption, it’s important to ask how recent that eruption was. Volcanoes like Krakatoa & Santorini have done their caldera thing multiple times, and they’ll most likely keep doing it in the future so long as fresh magma keeps getting supplied. The trick is in guessing where they are at in that cycle – and for Santorini / Krakatoa, they are still more or less recovering and rebuilding from their previous caldera eruptions.

      4. How much magmatic input is the system receiving? This is fairly simple, but the more magma being pushed into a volcanic system results in an increased likelihood of a caldera event. The problem here, is you really can’t measure this very well, and a volcano that has seemed dormant for 6000 years may have been receiving injections of magma that entire time, but is just very good at not erupting. The only thing you can really go off is inflation & how much is currently being erupted. Typically, for volcanoes that erupt frequently (open system), they have a tougher time creating a caldera event since they alleviate built up pressure with regular small eruptions. With that said, there are volcanoes that erupt frequently and still have caldera events, or still inflate. SakuraJima has been inflating regularly since the early 1900s despite being one of the most active volcanoes in the world. Grimsvotn erupts extremely frequently, but also has had caldera events in the past despite it’s high level of activity. The key is knowing whether the pressure being implaced is greater than the pressure being relieved.

      Overall, there are a few other small factors that some consider relevant from what I know, but aren’t really anything you could use to predict a potential large eruption.

      -Some say side-venting, or a volcano erupting around a ring in it’s base is a sign that the cone is entirely plugged up, and the system could be in the initial stages of forming ring fractures.

      -Volcanic clusters often represent a series of volcanoes that are actually feeding from a much larger, deeper, central magma chamber. This doesn’t necessarily indicate an imminent caldera eruption, but it does signify the potential for something much larger if the large central chamber starts having difficulty alleviating pressure.

      -Obviously, having extremely explosive, volatile rich magma plays a big role. Most of the huge eruptions have been predominantly rhyolitic, but large explosive caldera eruptions have even occurred with basalt before. As a general rule of thumb, I would guess that the more basaltic volcanoes would require a larger edifice & shallower magma chamber to form a caldera from an explosive eruption.

      -Water is a catalyst as can bee seen with Krakatoa and Santorini. If a volcano has water enter it’s magma chamber from even a VEI-5 eruption, the water can then accelerate the rest of the magma that likely would not have erupted out of the chamber, causing a larger eruption. As a result, I personally don’t really count out any volcano that can form decent sized eruptions (likely VEI-5 or higher) from caldera formation if it’s in very close proximity to a decent sized body of water.

      • I have to agree with this…. particularly items #1 and #2, and especially the closing paragraph. It fits quite well with what I have read.

        As a side note, an eruption (normal) occurs when a feeder dike makes it all the way to the surface. This dike is propagated when the chamber pressure exceeds the tensile strength of the chamber walls. (determined by the rocks tensile strength and the lithostatic stress. (confining pressure from the overlying rock) As soon as the chamber pressure drops below the critical hoop stress needed to keep the path open, it closes and the nascent eruption stops.

        One thing that “super volcanoes” tend to have in common, are resurgent cones around the periphery of the old caldera. (Hello Sakurimima.) This is where (roughly) the ring faults occured as the roof collapsed. Some do not have a clearly defined ring system, having collapsed by blocks falling in from the roof. (Whakamaru, the grand pappy of Taupo). With regards to Whakamaru, from what I have read, it showed zonation in it’s eruption. That means that the tepha and magma from it changed chemically as lower and lower levels of the chamber came into play. Taupo, which seems to have formed from the same chamber system thousands of years later, showed almost no zonation (if any) in it’s last eruption. That points to it being well mixed or that the whole chamber went up at once.

        • Whakamaru is in New Zealand, Toba in Sumatra. I think you misread the paper on Timescales of Magma Recharge slightly.

            • True.

              I have gone back in and corrected the issue for clarity of the comment. But I did make the error. I freely (though not gleefully) admit that.

              Now.. think about this. Taupo and Toba are close enough in spelling that I stumbled over them. Both are “supervolcanoes” and these things are common enough to where a couple of names can trip me up. “Supervolcanoes” are not rare items. In fact, they are quite common in the geological record. I even know of three in the southeast part of Spain from a paper on why one of the three is mineralized and not the other ones. (Mineralization concentrates ore and make them viable mining areas)

    • Probably some obscure jungle and lake filled depression that nobody ever bothered to look at closely. “Oh crap, its a volcano!”.

    • As for some popular candidates, it’s hard to pick any, but I would have a tough time picking against Ioto (also known as Iwo Jima).

      It basically fulfills all the requirements in the checklist here. The question is just a matter of how much more it can stretch it’s dome before the bubble bursts, but that’s anybody’s guess at this point. Ioto wouldn’t be such a terrible candidate to erupt since it’s so far in the middle of nowhere as well, although you would possibly worry about small tsunami risks.

      One thing that is interesting is that there is a lot of research done into caldera forming eruptions. While there are some definitive warning signs prior to large eruptions, it seems that the more explosive magma tends to just sit there, and then all the sudden goes kaboom when it’s ready. This doesn’t really apply as much to standard stratovolcanoes (since they aren’t usually predominantly rhyolitic) with a risk of creating a caldera-forming eruptions, but for volcanoes such as those in the Taupo Volcanic Zone, I’m not sure it would be that easy to discern an imminent super-eruption between a run of the mill basaltic injection of magma.

      Comparing mafic magma to volatile rich Rhyolite is like comparing expanding foam to nitroglycerin. When mafic & intermediate magmas reach the threshold required to erupt, they may take a bit of time to punch through and erupt out, which provides some obvious warning signs of an incoming eruption. Rhyolite on the other hand, seems to be more “all or nothing”, which may leave much less warning time prior to a large eruption. Just as a note – Rhyolite doesn’t necessarily = large ridiculous eruptions (there are numerous rhyolitic lava flows around the world that were likely accompanied by not-so-large eruptions), but most large ridiculous eruptions do involve plenty of rhyolite.

      • It is not so in the middle of nowhere as one might think, it is pretty much guarding the center of the worlds most important shippin lane.
        It would also be a major blow to the japanese defense force.

        Iwo Jima would definitely be on my top ten list.

  2. “Do no evil” my ass.

    A man has been arrested after his Google+ account sent an automated invitation to his ex-fiancée.

    A Massachusetts court ruled that the invitation violated the no-contact terms of the restraining order that Tom Gagnon’s fiancée took out against him.

    Gagnon, 32, argued that he never sent the message to his ex, who has not been named, and that it was sent automatically by Google.

    Gagnon’s attorney Neil Hourihan said that his client had no control over the message and did not mean for it to be sent due to the restrictions put in place by the restraining order.

    Salem News reports that Hourihan said Google operates differently than Facebook, where users personally select which friends are extended requests.

    Instead, he said, Google+ sends friend requests to ‘anyone you’ve ever contacted’.

    Read more: http://www.dailymail.co.uk/news/article-2536013/Man-gets-ARRESTED-Google-sent-automatic-invitation-ex-restraining-order-against-him.html

    Ylvis may like Massachusetts, but that’s because they don’t know just how much the entire state blow goats.


  3. Hello all and a “beautiful Monday” to all! 🙂
    Update on Pacaya from yesterday, 12 January 2014
    (excerpt, translation by Google)

    “The eruptive phase of the Pacaya volcano continues through small on top of the main cone explosions and release of gaseous emissions of bluish-white color, which rise to an average height between 75 and 100 m above the crater, according to [..] INSIVUMEH.
    [..] 2 lava flows formed on the flanks east and west, which are joined at the base of Mackenney cone, [..] size to an average between 2,800 to 3,000 m, also continuing the release of gases from the auxiliary craters or vents, through columns of average height between 200 and 300 m above the cone.
    Although the Colossus begins to stabilize and from 23:00 pm yesterday maintained its activity within a normal range, the institutions that make CONRED maintain appropriate monitoring actions since according to the same historical background, the possibility remains of a recovery in the next 36 hours.
    [..] kept in readiness five shelters and resources for immediate reaction [..] The public is advised to stay calm, be alert to information that authorities release based on the changes that the volcano could present not spread rumors, avoid putting their lives at risk and report any incident to the number Dial 1566.

    Full text here: Information Bulletin No. 3462

    • Just to put Pacayas current eruption into perspective, Carmen actually pondered upon spending her sunday hikeing up Pacaya.
      The volcano is having one of the more peaceful eruptions so far.

  4. And completely OT and rather sad. The black western hippopotamus has been declared extinct.
    They where slaughtered and their horns cut off and remade into erectile dysfunction pills that never worked.
    So, one of the mightiest animals on the planet is know gone because moroons wanted a booner.
    May their wankers turn green and fall off.

        • Don’t think so, the four remaining are the ones that was closest to people all the time. These are the Serengeti animals and they have been around people all the time. What is so sad is that these are not gamewardens, these are paras from the regular army. It takes a large proportion of Kenyas army to keep away the poaching assholes.

          • The rhinos came from a zoo in Czech republic – two males and two females. They are in a game reserve that has a breeding population of black rhino

          • We could fix that with a squadron of A-10s and free fire permission against the poachers. Put your spotters out in key locations and if you spot an armed poaching group, vector the A-10 in for a strafing run.

            Not knowing whats going on until your area if barraged with thousands of rounds of tungsten that can cut through almost any armor might act as a deterrent.

            (Yeah, I know it’s unrealistic. But the potential for massive firepower out of nowhere tends to act as a de-motivator)

    • I think you mean rhino!
      The western blacks were actually declared officially extinct in 2011. Last reliable sighting a decade before that.

      Still a tragic example of what humans can do to the planet – it was a thriving animal before hunting began, and the introduction of modern agriculture.
      With China ‘buying up’ most of Africa I don’t hold out much hope for the other species, and the ones in southeast Asia are all but gone.

      • Of course, the loxodonts are still safe since they lack horns.

        Few understand exactly how into horn chinese are, and to what lengths they will go to get it. Spending a billion on a road to get to the horns is just nothing to them.

        My favourite cultural difference crash is the Samí and the Chinese. The Samí refuse to sell the horn of reindeers to the chinese. Not due to them being even remotely near extinction, no they refuse to sell it because they refuse to rip the chinese off. And since only the Samí are allowed to sell or handle reindeer horn… the price of black market reindeer hoarn is sky high since the chinese can’t understand the Samí wanting to protect them from being ripped off, and so on and so forth ad absurdum.
        For the rest, Samí bone work is quite probably the best on the planet and it is entirey legal to buy it. You will though bleed through your nose if you buy some. The best work is often the knifes. There is just nothing like it.

        Image and video hosting by TinyPic

        • For those interested. The blade is real damascener steel made out of meteorite iron that has been hand-steeled, it is layered with lake iron. The layering has been done by hand.
          The knife will set you back the price of a car, and not a cheap car at that. A knife like that is handed down through the generations.
          Mine is simpler and was a gift from my an uncle married to my mothers sister. He was a rather famous knifemaker back in the sixties and seventies. It has been my only knife for 30 years and I have used it in ways a knife was never intended to be used and it has just gotten better and better as the years has gone by. I have even shaved with it a few times.

      • Nothing to worry about, they are still stuck on Yellowstone.
        We do not even get them out of Yellowstone by headlining an article like this one… The doomers are really a narrow-minded group in more than one way. :mrgreen:

        • I always find it funny how the doomers are usually anti-media, thinking there is a media conspiracy going on. Yet they always seem to believe anything media driven about disaster without doing much more research on their own. For the media, it’s not a huge surprise they keep going on about Yellowstone – it’s easy cheap ratings, and they are a business after all.

          • I do not really have an issue with the media, they need to sell newspapers, and Yellowstone is “hot”. And the newsies see a flood of scientific journal articles, so they of course think it is dangerous.
            No, my problem is with all of the useless scientific papers published about Yellowstone.

        • Hopefully they won’t get word out about Aso being ridiculously “overdue”. Going off Yellowstone logic and including only the last three large eruptions, there is an average repose time of approximately 30,000 years, and it’s currently been 90,000 years since it’s last large eruption.

          Of course, we all know this is complete BS, but doomers aren’t the most educated crowd.

          • Well, judging from the “usually anti-media” statement, a moderately wide brush would include me…. though I am not a classic “doomer.” I look at it from a “what is likely” point of view and come to the conclusion “don’t live there.” That’s why I live in a coastal town… but my house is 140+ feet above sea level. This was my town of choice due to the place where I grew up being infested by crime and police with the “I don’t give a shit” attitude. Far more than half of my time in service was spent here in Florida, and I had several station assignments here. In essence, this became my surrogate home town. Is is immune from disaster? Nope. It has a long history of being decimated by hurricanes. (even since founding, just look at the exploits of that idiot Tristan de Luna.) In order for me to get whacked her by natural Black Swan events, It’s gonna take an asteroid or comet plunging into the Gulf of Mexico. Geologically, the area is pretty dead (and boring). But I do have a transform fault that passes within 40 miles of here. (equally dead).

            As for the media, I am at the point where I do not watch very much at all. Their bias is easily seen. And yes, it’s all about selling a product or providing a distraction.

            • I moved here to Skye for peace and safety like you. It’s nice to have my house built on a thick lava flow and with a cracking view of an enormous volcano but the whole lot dead and still for 56 million years 🙂
              The only problem we have is incessant wind and rain but it’s worth it.

  5. Nice post!
    So still people swim in the lake?
    I presume you mean that the methane is produced in the sediment layers of decaying cyanobacteria, because as photosynthetic organisms they should mainly have an aerobic metabolism.

    Are there any GPS stations around (cannot find the information on the Insivumeh website)?

    • Yepp, should have explained better. Methane is indeed produced in the sedimental layer.

      I have found no information either on GPS stations for the caldera, nor for Volcán Atitlán.

      • And no obvious spot for us to put in a station on either.
        We could though get Amatitlán Caldera with Agua, Fuego and Pacaya via webcam combined with a seismo and GPS if we somehow fork up the cash for it.

  6. reposting from late last night
    Okay, this is Icelandic “wind” (North Atlantic superstorm to be more precise) and will last for days, and forecast for next days to come. http://hraun.vedur.is/ja/oroi/god.gif

    This below is something else. Looking at it closely its bursts every 20 to 40 minutes (chugging?) and follows some uplift in November in that general area, Spregisandur / Hágöngulón. But if it will get to surface or abowe is anyones guess. http://hraun.vedur.is/ja/oroi/skr.gif

  7. Thanks Carmen & Carl for your article on Lake Atitlán, I loved it! Wanting to know more about it I got some links to sources of further reading (hint, hint 😉 )

    Lake Atitlán – Guatemala

    Lake Atitlán in Guatemala is Threatened Lake of the Year 2009

    Volcano World – Atitlán

    Although the following 10 min. video is probably meant to lure tourists, it shows the people and landscape around the lake. I liked it, and yes, I did feel a desire creeping up my stomach to go and visit!

    Part 1 (Beautiful) Lake Atitlán Guatemala

    • My wife loved the lake and its people. One of the things was the Roosters that would start a morning chorus around the whole lake.

      • There is one somewhere around here that goes of at 3 am like clockwork.

        We hominids see in three colors. Based on a paper somewhere, birds see in four colors. That 4th color being in the UV, which the birds clue on to wake up in the early morn. Dunno if 3 am is when it shows up… this bird may just be strung out on amphetamines.

  8. Where the heck do the gaps come from? I didn’t put them in. So, the text with the 10 min. video refers to the last link.

  9. There is a new development in Aso Volcano (Japan). While there had been a glowing patch visible in the crater wall for months, probably caused by hot gases venting, there is now a second, more homogenous looking “hot spot” in the center of the crater, with the lake completely dry now.

    It is also visible, if barely so, in one of the far less light sensitive cameras at the crater rim. Worth keeping an eye on, I think.

    • I just saw the image Sherine had posted and realized that Naka-dake is part of Aso complex. I have to find out what crater the cameras are on.

      • Well. of course it is Nakadake, the only crater that has been active in recent times. I had looked at the cams durin daylight but saw nothing than lots of steam… My bad not to have known the name of the crater…

    • Hello DFM!

      I have tried like crazy to get to know what the cyanobacteria on the top is. It could be agricultural, or anything running out of the waste water treatment plant that was destroyed in the 76 earthquake. It could also be one of the deeper anaerobic ones. I think it is a nasty mix of it all.
      But if you want to know for sure you would need to test the water yourself, or someone else who knows what they are doing. If we ask kindly I am certain that Carmen would get us a sample.

      • that was unfortunately just a wild question. I’m no algae specialist alas. One way or the other it shows that the water quality is not good. Each year we have some blue algae phenomena in Brittany, at spring. Because nitrate levels in brittany are too high due to the agro indsutry (pigs, chicken). Some times the shellfish are toxic and cannot be consumed.

  10. Anyone ever want to see a movie about blue lava?

    Kawah Ijen, le mystère des flammes bleues
    Diffusion sur France Ô le 15 mars 2014 à 22 h
    Un film de Olivier Grunewald et Régis Etienne

    And a bit information about Ijen:
    From GVP
    “… the renowned historically active Kawah Ijen volcano, which contains a nearly 1-km-wide, turquoise-colored, acid crater lake. Picturesque Kawah Ijen is the world’s largest highly acidic lake and is the site of a labor-intensive sulfur mining operation in which sulfur-laden baskets are hand-carried from the crater floor. …”

    And from Wikipedia:
    “… Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an east/west-trending zone across the southern side of the caldera. The active crater at Kawah Ijen has an equivalent radius of 361 metres (1,184 ft), a surface of 0.41 square kilometres (0.16 sq mi). It is 200 metres (660 ft) deep and has a volume of 36 cubic hectometres (29,000 acre·ft).

    The lake is recognised as the largest highly acidic crater lake in the world,[2] and since it is also a source for the river Banyupahit, resulting in highly acidic and metal-polluted water, it has a significant detrimental effect on the downstream river ecosystem.[3] In 2008, explorer George Kourounis took a small rubber boat out onto the acid lake to measure its acidity. The pH of the water in the crater was measured to be 0.5 due to sulfuric acid.[4] …

  11. Thanks Sissel, I was just about posting the same, again 🙂 But, there have been many PFs lately, and never anything could be seen on this cam. Do you not think it is lava now?

    • The flow seemed to come from the red spot close to the center of the picture, the same spot Carl saw earlier today (above). It still glows – then more, then less.

        • I definitly saw something that looked like strombolian activity on one image. I think our ever changing Sinabung has gone for more liquid lava now. Question is just how liquid, and how much volatiles is within it.

          • Now that’s probably the thing least likely to happen, that a volcano like Sinabung produces the lava we all know from Hawaii or the Hollywood movies 😉
            We’ve seen this sort of stuff happen in “Dante’s Peak”. In real life, the only case that I know of a generally andesitic or dacitic volcano suddenly emitting fluid, basaltic lava is … Mount St Helens, where some 2500 years ago the character of the eruptions changed from violently explosive with pyroclastic flows and lava domes to Hawaiian-style. That would be a scientific sensation – but I am very skeptical this is happening at Sinabung right now

            • I wrote sloppily as usual… I should have written “what appeared like”… After all, more liquid is a sliding slope from a lava dome collapsing with blocks, and the super-runny lavas of Iceland and Hawai’i.

            • And I guess Tarawera doesn’t count because although basaltic (in a rhyolite province) it wasn’t exaclty what you would call non-explosive (ahem).

  12. Just discovered that volcanodiscovery.com has also the latest timelapse videos for their cams listed. Here is one from Aso volcano:
    [video src="http://archive.volcanodiscovery.com/webcam/videos/459/video.mp4" /]

  13. And Shérines latest find… It is not any longer the same volcano. The behaviour has radically altered and now it is pouring out lava. Wonder what the next stage will be.

    Image and video hosting by TinyPic

  14. simple time exposure 🙂
    Now my turn to explain and educate (seen this in real life) =
    Basically is pyroclastics + lava-scoria (hot scoria), dust and steam ;
    the red colour is lighting up steam and gases abowe its path,
    from red hot scoria rolling down (might not be much lava, more like tumbing stones in a tight row, but one call call this “lava-scoria-falls”)
    but is not “fire” per se, unless the tropical forest is on fire, but that can also be, ingited from scoria.

  15. Well, regrettable sometimes humans as well as laptops have to sleep… Good night all that are still here, sleep well!

  16. I love a volcano that is contantly producing ash that is heavier than air…
    Either the ash is fairly cold, unusually heavy, or very dense. Or a combination of all 3.
    I for one would love an analysis of the ash.

    • complet novice here;
      can gas in the rock also be heavier than air, because (given it explodes into dust) if not, then that column would go straight up (as Eyjo did) cause there is less water content in the magma (water wapour is basically lighter than air, and goes therefore more up at once)

      flying a robust drone (plane) into the edge of the eruption column might answer some of that question

      • OK, my turn to play teacher (let’s see how well I fail):
        PF’s are interesting beasts. So are eruption columns. Basically you’ve got similar ingredients but in different ratios to each other resulting in a wide range of different eruptive patterns:
        1. Hot rock
        2. Released gases
        3. Entrained air
        The range goes something like this:
        Explosive eruptions: Hot magma containing a lot of gas (volatiles – mainly water and CO2) rises in the conduit to a point where the gases come out of solution, expand rapidly and burst the magma apart (fragmentation) resulting in violent expulsion out of the vent. Once it exits the heat and sheer force of the eruption entrains surrounding air, which also expands due to the heat. This is why in a classic Plinian column you get the trunk (consisting mostly of erupted material jetting to a certain height) topped off by the branches (the billowing ash clouds) where convective forces set in and expanding air carries the ash away.
        Lava domes: Hot magma low in gas gets pushed up to the surface where it forms a sticky mound that slowly grows with collapse events occuring as the mound becomes gravitationally instable. The resulting fall of hot blocks break upon impact coupled with the convective forces of suddenly heated entrained air and all the other dust they kick up. The base of the flow consists of blocks rolling down the slope and a “fluid” of heated ash and smaller particles. This is why PF’s fall down the mountain but also create phoenix clouds (which can be huge, see that famous picture of Redoubt). The base of the flow is hot and dense and will gradually fall out, the lighter stuff gets lifted by heated entrained air.

        And… you get everything in between..from the cowpat farts of Shinmoedake (an exploding runny lava dome) to collapsing eruption columns that lose their oomph and suddenly fall due to a lack of buoyancy.

          • PPS: PF’s will also cool as they travel, as Boris once pointed out to us, resulting in cold pyroclastic flows. The colder they are the less convective force (as entrained air no longer expands).

        • Bruce,

          “This is why in a classic Plinian column you get the trunk (consisting mostly of erupted material jetting to a certain height) topped off by the branches (the billowing ash clouds) where convective forces set in and expanding air carries the ash away.”

          Actually that kinda gives the wrong sense; a Plinian column is sustained by convective forces; the hot eruptive products and entrained heated air. The column tops out and spreads into the ‘umbrella’ where the convective forces *stop* – where the column ceases to be buoyant.

          • Well, I guess we are talking about the same thing. For me, the initial smooth base is predominantly powered by the eruptive force of the volatiles expanding in the erupted magma. As it rises more and more surrounding air gets entrained and also expands. I have always understood this to be the part of the column where the ash starts billowing (the branches). Maybe I got that wrong and the entrained air is already a major component of the smooth jetting part of the column. Perhaps Boris can clarify that for us. The top of the cloud is indeed where the column reaches neutral buoyancy and “tops out”.

            • The ‘jetting’ can be a factor at the base, but as I understand it the primary force which lofts the column is the convecting entrained hot air. When that convective force can no longer sustain the column (frequently, in a large Plinian eruption when it hits the much colder air at the boundary of the troposphere) the column spreads.

              Vent size and eruptive energy are important to this process; if the eruption forming the column is from a large open vent, with lower energy, you get a Lamington-style eruption, with very large boil-over PFs from the constant collapse of a column which never really gets going with the energy to form a classic Plinian column.

              Boris correct me if I have anything wrong there?

              Paper with some thoughts on some of this:

              Click to access ClarkeNature.pdf

            • Good paper and also a good illustration of what we are both talking about. These photos show a typical vulcanian eruption, powered mostly by short-lived explosions (the classic bursting magma bubbles that Boris has caught a number of at Etna). Eyjafjallajökull also exhibited this behavior with a series of explosions at the vent and roiling clouds carrying the tephra away. I fully agree. In this type of eruption the clouds are almost entirely powered by convective forces, interspersed with lava bombs getting shot out from exploding bubbles. However, in a classic plinian column you have a gas thrust region, followed by a column of boiling clouds which tops out when it reaches neutral buoyancy. This diagram shows it well:

              Here, in my understanding, the smooth trunk of the column is the gas thrust region. In real life, the branchy stuff normally starts at much lower altitudes, like Pinatubo

            • Interesting you should mention Pinatubo. The photo you show is actually one of the small – relatively – precursory vent-clearing blasts.

              The main eruption, when it came, was actually Lamington-type. Yes it developed a high column because of the sheer scale of the eruption, but it was dominated by huge ignimbrite-forming boil-over PFs.

              Due to the arrival of Typhoon Yunya there are very few images of the main eruption, and those only of the early stages, but this one gives a good idea:

              Never mind the height, feel the *width* of the base of that eruption column! – huge boil-over PFs rolling off in every direction, and it got much bigger than that as it progressed.

              I personally feel ‘Lamingtonian’ should be erected as a distinct eruptive type. Or maybe ‘Taylorian’ after the volcanologist who wrote a classic paper on that eruption, documenting the eruption style.

            • “… in a large Plinian eruption when it hits the much colder air at the boundary of the troposphere”
              Temperature drops in the troposphere going higher. I guess that is a factor that keeps the ash cloud going up (cold air denser than hot air). The tropopause is the boundary between the troposphere and the stratosphere, where temperature actually increases with height. The relatively warm, less dense air is an inversion layer on top of the cold dense air preventing exchange.

            • wow, Mike, cool photo of Pinatubo. I hadn’t seen that before. At a guess there must have been a central explosive vent going to town in the middle, huge vent erosion with associated mega amounts of country rock (breccia) in the cloud making it heavier and denser resulting in this curtain of pfs which in turn are all throwing up phoenix clouds.

            • It’s actually simpler than that Bruce.

              Maybe oversimplified, but think of a classic Plinian eruption as knocking off the top of a bottle of champagne.

              Think of a Lamington-style eruption as pan of water boiling over violently.

              Narrow neck versus wide boiling pan. Both driven by foaming bubbly magma.

              OK there’s more to it than that, but you get the idea 🙂

              This may be my last post for a while; I’m off on a three week lava chasing epic trip tomorrow morning. Details classified but it’s going to be *awesome*. Watch this space!

            • shurely we need “eruptions for dummies” book
              that wiil be standard handout for Nubiruists,
              doomsday priests preayches and Yellowstoners..

            • I wonder if the Hatepe eruption was a ginormous Lamingtoninan eruption rather than ultra-Plinian (probably not as it also managed to scale the top of Mt Ruapehu 60 km away, but still Mike has got me thinking..)

          • perhaps I should have said “where convective forces come to predominate” rather than set in. That would have been more accurate.

            • dummies r us! Mike had a good point. Now I am curious where convective forces come to predominate in an eruption column.

            • If I may ruminate a bit (and to help my general understanding in a purely amateur way): As I’m sure most folks here at VC know, part of the convection process is the latent heat of condensation that is released as super-heated air/water turns to steam when hits the atmosphere. In classical meterological convection, the amount of the latent heat of condensation is what transitions a simple adiabatically rising air parcel (i.e. nimbus) which is an open loop system, into a convective cell (cumulous) or a runaway free-convection cell (cumulonimbus) which is closed loop. As an air parcel rises through adiabatic processes, the air and water cools to the (dew/condenation point) and water is forced to condense out of the atmosphere. The condensation of water in turn, releases the heat that made the water gaseous to begin with (latent heat of condensation). This further warms the air parcel, and it continues to rise and expand, which creates an area of relative low air pressure. Higher pressure in the surrounding air then moves in (inflow) to fill the void, and brings with it more moisture that can then condense; which in turn releases more heat to re-inforce the continuing expansion of the cell. As long as enough incoming air/moisture is condensing fast enough, the cell will continue to grow/expand by “feeding” on it’s own heat. It is at this point that free-convection begins.(i.e. the cell becomes a closed loop system).
              Now, with a volcano as a heat source to provide oodles of adiabatic lift (not to mention the ejection pressure/velocity of the gas/fluid from the volcano itself) and super-saturated air/moisture that is rapidly condensing, I would think the combination would create extraordinarily powerful up (and down) drafts as air enters and leaves the convection zone. Might it be possible that PF’s are in part propelled by these drafts? I can envision where a narrow layer of super heated air/debris is forced to the ground by powerful downward moving convective drafts (convective outflow), then get trapped at the surface by the relatively colder/sinking/higher pressure air immediately above, as gravity pulls the whole mess downhill as a PF.
              Anyway, that’s my general thinking at the moment. Hopefully, this is not too remedial for the more educated readers here at VC.

            • Hey, Craig, if that is what you call remedial, then we are heavily into it here!! 🙂
              Sounds good to me, though watching most eruption columns it is hard to see evidence of strong downdrafts (which if I understand it correctly would make the clouds kind of wispy??). You do see ash fall and collapsing columns (pyroclastic flows) and oodles of associated turbulence. Maybe the downdrafts are simply masked by all the ash thrown up. In the stuff I have read, column collapse generally sets in when the eruptive pressure from below falls off and no longer sustains the column which then falls back, in large cases as an ignimbrite sheet.

              BTW, if Mike is still around, there is a new paper out on Lamington that posits the eruption as an upwards blast of a cryptodome:
              “The eruption sequence (cryptodome intrusion + edifice failure + blast), resulted in PDC deposits and tree (tree) blow-down features that are similar to those of the classic blasts of the Bezymianny in 1956 and the Mount St. Helens in 1980. The A, B, C strata recognized in the St. Helens and Bezymianny blast deposts are not as well developed in the Lamington blast deposit. We attribute this to the fact that, unlike the St. Helens and Bezymianny examples, the Lamington blast cloud first ascended vertically before collapsing and producing a PDC. Consequently the Lamington PDC ingested more air and was more dilute than those at St. Helens and Bezymianny. We speculate that the powerful explosion of Lamington was vertical because the rupture surface of the preceding edifice collapse unloaded the very tip of the intruding cryptodome. ”

              Source: https://gsa.confex.com/gsa/2013AM/webprogram/Paper227351.html

              This abstract describes the same mechanism. Blast powering the column which then collapsed when the power was switched off, and, note, collapsed with enough oomph to blow down the surrounding forest.

            • Thanks Bruce for the continuing dialogue. I would think the highest RELATIVE pressure differential would be at the very base of an eruption column where it is the hottest and therefore expanding at the greatest rate.
              As the surrounding higher pressure air is drawn in from all directions, it would preferentially move downward (downdraft) along the outer edge of the convective column all the way down to the lowest pressure at the base. The speed of the downdraft would depend on the pressure differential, and only the speed of sound could theoretically limit the air’s velocity.
              As with a thunderstorm (or any convective cloud), the side walls of the convective region can be remarkably sharp due to well defined temperature and humidity differentials, hence little “wisping” might be noticed if the ejecta column/zone was in free-convection. I too have watched (with awe) volcanic eruptions, and what I’ve seen is that when the volcano is simply burping/outgassing hot water (steam plumes), the “clouds” are not well defined and look like steam rising from a tea kettle. However, when a higher energy/higher volume eruption occurs (such as plinean), the steam clouds quickly take on much more well defined shapes that look nearly identical to cumulous (boiling) cloud formations…and as you’ve said: convective.

              I understand what you (and others) have said about a collapsing ash column and subsequent lateral displacements when the falling debris hits the ground, however what I don’t understand is that without convective flow/turbulence as an accelerant, the maximum speed of the lateral flow should be limited by the terminal velocity of the falling/collapsing debris column; or as high as ~200 MPH (in the absence of any updrafts that is). However, this is only less than 1/2 of the estimated speeds of some PF’s, which have been documented as high as 450 MPH, so gravity alone cannot explain these speeds?
              Therefore, I think it’s likely there are multiple sources of energy/mechanisms that propel a PF downslope.

              Would love to see a super-high-res Doppler data that documents the direction and speed of the air flow in and around a PF on a micro-scale, as the various air flows conceivably might be only meters thick/wide. At super-high velocity, these air flows could be high enough to easily mobilize large boulders (heck, if a tornado can make a house fly, why can’t a PF make a boulder roll downhill?). I know Doppler has been extensively used to measure the speed of volcanic ejecta on a macro-scale, but getting close enough for micro-level wind and debris analysis of a powerful eruption is something I haven’t found yet. Too bad Indonesia isn’t made of money. Sinabung would be a perfect candidate!!!

              “Today is a good day to learn”.

            • .. or impale a jeep on a stick:

              Wow, Craig, you seem to be onto something here. I had never questioned the speed of some pyroclastic flows as I basically imagined the big ones were like the WTC collapse except that you had several cubic km of rock sitting at heights of 30 km or more. I always thought the speed (up to 700 km/hr or so for Hatepe) be explained by the distance involved and gravitational acceleration? Drag would be negligble as, like the WTC, the column is basically falling on itself. It would indeed be great to get some instrumentation to document these things. Maybe we can excite some of the physics buffs here… hint hint..

            • @Carl,
              I do remember this excellent post. However, I am still not clear on how the base surge velocity could have exceeded terminal velocity? (or maybe it didn’t?) I can easily envision a lateral blast moving at incredible speeds, but an atmospheric rebound effect suggests gravity would be a primary accelerant. Obviously we’re talking about huge amounts of material here, so high volume at relatively low velocity can still transfer the huge amounts of energy that would be needed for a > 50kM travel distance as well as the associated tsunami?
              Pressure = Mass x Velocity

              “today is good day to learn”

            • I think it is in the Wiki entry… but researchers in Kiel dumped superheated volcanic material down a chute in water, simulating a PF. The heavy stuff sank (tsunamigenic) and the light stuff boiled the surface water and carried on at accelerated velocity over the surface of the water.

            • Craig that was a very good question.
              I think there was a lot of things happening at the same time. One thing to remember is that there was an edifice on top and that can have done a dome shaped blast profile, and at the same time we know that even though the blast was gargantuan the column rebounded at 25km height due to atmospheric conditions. What is interesting is that the pyroclastic base surge that happened went out equal in all directions even though we know that the windspeed should have moved it in a northerly direction (from the ash spread pattern).
              In the end I think that we have to conclude that above a certain size an eruption will have different dynamics than the ones we have seen and wittnesed.
              In any way it means that there is 0 chance of surviving a 100 cubic kilometer blast if you are within the fifty kilometer distance zone due to pyroclastic base surges. And I think that the shear weight of all that rock dust within a confined aerial space will always create a base surge. Remember that there will be far more rock in the air than at a normal eruption, and as such it creates an area of air that is superheavy, and as such it will just slam back down. Ontop of that you will have assortment of weird vacuum effects occuring.

            • Ah, the slam dunk theory. The vacuum left by the sudden descent of n cubic kilometers of pulverised rock must create a shock wave when the incoming air all meets in the middle to fill the void. Maybe this explains the incredible noise of Krakatoa.

            • @Bruce/Carl
              Thanks to you both for entertaining my question. My last comment is that PF’s are relatively common, so there must be an underlying mechanism(s) in place that could explain super-fast moving PF’s over a wide range of eruptions and volcano topographies. I’ve been contemplating simple pressure waves originating from the explosiveness of an eruption as an PF accelerant, but I believe such a pressure wave would induce more of a circular/bubble pattern (or at least somewhat homogenous) once the wave crested the crater rim…which is not what “typical” PF visual evidence indicates (usually localized near the ground and somewhat directional)? In the case of Aniakchak though, based on CarI’s educated analysis, I would guess a lateral (and circular) pressure wave(s) may be exactly what occurred from such a huge collapsing column of debris that then blew/rebounded outwards up to 50km away,,.but again I am dubious that this phenomenon is present in all PF’s that exceed terminal velocity as it descends a volcano’s flanks.
              Other than the possibility of high speed drafts from local convection, The only other thing I can think of would be a “water nozzle” effect, where a collapsing debris column forces a high speed PF out of some type of a restricting orifice such as a gap in the crater rim, thus reducing the mass of the flow, but at a higher velocity…just like a water pistol. (slow moving trigger finger = fast moving water out the nozzle).

              Hmm, I smell some more research coming on, but it’s time to get back to work.
              Thanks again guys.

              “tomorrow is an even better day to learn than today”

  17. Oh wow, thank you for a really good post. Love to learn something new like that. Also think that the blog post title is the best I’ve ever seen so far.

    It’s also quite interesting to follow the changes in Sinabung. Will try to catch some views as I while away tonight’s shift.

    • I suffer from a rather childish sense of humour so I am happy you liked the title.
      And… to be honest it is hillarious with a supervolcano that basically is producing a shitload of poop.
      Here we go waiting for one of the “supers” to do something out of sorts, and when it finally happens we get brown products. :mrgreen:

  18. it was warm today 36 deg, tomorrow it will be hot 39, 38, 38,35 or so it says, it might give the all time record a nudge (40.8 in 2013) hope not, had 8 in the morning, so I managed to keep the house ok, all doors and windows are open now, a invitation for mozzies but that is life, there where easterlies from the sea earlier, but not much good until now around 20, I better get a few things done

    • Most likely not untill the mountain starts to behave in such a way that there is risk for explosive activity. They might extend for a village or to downrange of the PFs, but they seem to go the same way every time since the dome has moved downslope.

      • Seems so, but they seem far from sure. The Jakarta Post, 8 days ago:
        “The National Disaster Mitigation Agency (BNPB) has instructed all relevant ministries, government institutions, local disaster mitigation agencies and the Karo regency administration in North Sumatra to prepare for a worst-case scenario following an increase in Mount Sinabung’s volcanic activity during the past week.

        The worst-case scenario would be applied if the evacuation zone reaches between 7.5 kilometers and 10 km from the crater.”

        • There seems to be a bit of confusion of what the evacuation zone is. It is currently at 7km according to BNPB, so let us not spread any other info.
          Thy have prepaired to new evacuation zones at 10 and 15 km. The reason for them not increasing is obvious if one take into account that this is the heaviest populated country on the planet. 15km is considered to be the maximum possible evacuation zone possible to create and even that is doubtfull.

        • Someone once said to always plan for and expect the worst Then when it doesn’t happen, you are elated. But if it does happen, you were prepared.

          In other words, it is always good to be hyper cautious.

          But just because an agency that is responsible for thousands of lives is acting this way, that doesn’t mean it will happen.

          • Especially when it is an agency with a rather excellent track record. One should remember that most often the deaths from Indonesian volcanoes occur when people do not head the warnings and evacuations.

            They have a hell of a job really. To little and people die, to much and nobody will listen the next time around. And ultimately, if a really bad one happens there is not a lot they can do since it is impossible to move everyone away.

  19. Hi guys. I’m sitting here reading up about the earthquake swarm that happened in Yellowstone in January 2010. I am wondering if anyone here has above average interests when it comes to Yellowstone?! And if anyone was following this in the weeks and months before it happened?! And also the weeks and months after it happened?! And if you did, was there anything that happened then that made you look twice?


    • Lurking followed that one pretty extensively if I remember correctly.
      There was a paper published on it stating that it most likely was a rather normal event containing either a less likely lateral movement of a small patch of magma, or more likely hydrothermal fluids.
      Anyway it was a very small event for being in a very large old volcano.
      If one compares to what is going on in other volcanoes of equal (or smaller size) one will notice how minimal this event was. Even the smaller Campi Flegrei can throw events rising or lowering the ground with several meters…
      Same goes for Atitlán, two meter of caldera bottom uplift in 15 months and still no signs of an eruption coming.

      Over to Lurking… 🙂

    • Dear Christina, all relevant information on Yellowstone (including its recent earthquake swarms, such as in 2009 and again in 2010) is available on the website of the USGS Yellowstone Volcano Observatory


      On the title page, there is an important note on the recent findings that the magmatic system below Yellowstone is more extensive than previously thought. It says: “Although fascinating, the new findings do not imply increased geologic hazards at Yellowstone, and certainly do not increase the chances of a “supereruption” in the near future. Contrary to some media reports, Yellowstone is not “overdue” for a supereruption. Indeed, it is quite possible that such an eruption will never again occur from the Yellowstone region. Scientist agree that smaller eruptions are likely in the future, but the probability of ANY sort of eruption at Yellowstone still remains very low over the next 10 to 100 years.”

      In the specific case of the 2010 swarm, there is a dedicated page here:


      As always, I recommend all you volcanophiles visiting (and discussing on) this site to first look at the first-hand information provided by the institutions and people charged with studying and monitoring volcanoes, because that’s in most cases where the most accurate information is.

      Hope this is helpful!

    • I have to defer to the actual Geologist. (Boris) He is into volcano activity a hell of a lot more than I am, and he holds degrees in the subject area and has published papers on the subject. I’m just an audience member. A data tourist. I mainly plot quakes that are interesting to me.

      I’ve read some of the papers about that, and they fit the quake swarm data as I saw it progress. The only difference is that I somewhat expected a phreatic event, where the YVO did not. Guess who was correct. → YVO. And like Boris with Etna… Yellowstone is their critter. They are in the best position to see what it is up to. Unlike Boris and Etna… YVO has to beat back all the (typically erroneous) doom mongering that the hyper-excitable are spewing every time they turn around or make a statement. That’s a long row to hoe.

      Here, at VC, we ruminate on real possibilities so that we can catch a good cam show. From that motivation, we at least we try to be realistic in what we expect. We are far from experts (except for a few posters) but we don’t get some perverse pleasure by scaring people like the doom mongers try to do. Other than that, we try to impart a working knowledge of how they work to each other. In some cases, we can be quite wrong. That’s where the actual professionals who post here come into play. They keep us on an even keel with regards to the science.

  20. A couple of big ones under Etna today –

    2014-01-14 04:35:00.011hr 05min ago 38.36 N 14.94 E 11 4.0 SICILY, ITALY
    2014-01-14 03:43:43.011hr 56min ago 38.17 N 15.03 E 10 4.2 SICILY, ITALY
    2014-01-13 20:16:46.0 38.41 N 15.31 E 133 2.4 SICILY, ITALY
    2014-01-13 18:25:45.0 37.76 N 14.43 E 34 2.0 SICILY, ITALY
    2014-01-13 18:01:14.0 37.78 N 14.41 E 36 3.1 SICILY, ITALY

    • The two magnitude 4 and 4.2 quakes were not under Etna, but … very close to the island of Vulcano, which is a dormant but potentially highly dangerous volcano located 75 km north of Etna. It is unlikely that these earthquakes have anything to do with a reawakening of Vulcano, there have been others (and even stronger ones) in the past years and decades, but you never know so this is being watched with attention. Etna herself is granting us some peace; it is very likely that the latest spate of eruptive episodes has come to an end and we’ll have to wait for new magma supply from depth to see some new action.

        • That would be a good reason to visit Etna and Stromboli but not Vulcano 😀

          Anyway, Vulcano is certainly one of our main objects of concern here in Italy, next to Vesuvius and Campi Flegrei. The problem at Vulcano is that there is a village at just a few hundred meters of distance from the active crater (which last erupted in 1888-1890), which has about 500 residents during the winter season, but in the tourist season, especially in August, there are up to 10,000-12,000 people crammed into that tiny place and we wouldn’t want to have a phreatic explosion sending a hot, vapor-rich pyroclastic flow (formerly known as base surge) right over that village. Problem with phreatic explosions is that they are all but unpredictable.

          Currently, though, Vulcano has been rather quiet, with some minor fluctuations in gas emission and fumarole temperatures.

          Bulletins (in Italian language) about the gas and temperature monitoring at Vulcano are posted more or less monthly at the INGV-Palermo web site (among with monthly bulletins on Etna and weekly bulletins on Stromboli)


          • What a nightmare…
            Remind me to not be to jelous about your job, this is a good reason for not being jelous. I would not want to be in the hot seat when Vulcano comes back to life.

            Edit: I will though remain jelous of your view of Etna, the cheezes and so on 🙂

          • 500 people on Vulcan volcano… so few… that is something I’ll never understand. Would it not have been so much easier to disallow new houses on the island so that the number of inhabitants would eventually shrink until nobody lives there anymore? wouldn’t that have saved Millions of expenses for volcano monitoring, equipment and disaster prevention, and the worries before, and the sorrows after a possible eruption?

            • Problem is that those people do not want to go, and they do vote… So, any politician making that rather sensible suggestion would find himself in the unemployment line, and the people would still be there.

              Mitigation of volcanoes sadly has to be done with the consent of the locals. And on top of that the Italians have a tendency to not follow bans on building houses where they are not supposed to. I have been enjoying an afternoon up the slopes of Mount Vesuvius in a honking huge Villa owned by Italys car mogul. He laughed his arse off when I suggested that it was not a good idea of building a house illegaly on a volcano. He claimed it to be a political protest against Burlusconi (whom he contributed money to at the same time).

              Italy is a rather ununderstandable place for us more “law-abiding” northern or german types who normally do as our politicians decide. I do not know how Boris stays sane really 😉

  21. And since there will be nobody of the Icelandic Persuasion here for a couple of hours…
    Wouldn’t it be a hilarious moment for Hekla to erupt right now?
    For those who do not understand this, Iceland is a major power in Handball. It is the Icelandic National Sport and entire Iceland is right now sitting infront of TVs watching them (hopefully) giving Hungaria a thorough belting.

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