The ballad of Ballareldar: twister in the snow

Volcanoes are nature at its most impressive – and most damaging. The fire and the lava are a deadly alluring combination. Once the flow gets going, it is unstoppable. It may be deflectable: people are currently trying hard to save their road by building a wall. We were wondering, will the wall work? It would be the first time that people have managed to change a lava flow by 180 degrees. We are doubtfully cheering them on.

Tornadoes too are nature at its most impressive – and most damaging. They come in many different forms and sizes, from small dust devils to the massively destructive ones in tornado alley. No wall will help there. And the damage can last: in the city of Utrecht, the cathedral is some distance away from its tower. In 1674, it was hit by a tornado which destroyed the church but left the tower standing. The church was rebuild, but an open square was left between church and tower, a lasting reminder of the power of nature. And not even Iceland is immune. In August 2018, a farm in South Iceland was damaged by a tornado. This was deemed so unusual that it made international news.

A combination of a volcano and a tornado must but the ultimate scare, one step above even sharknado. What are the chances of that happening?

It turns out, that depends on what you mean with tornado. A combination of a volcano and a true tornado is rare. But if you think ‘spout’ or ‘devil’ then the chance is rather high. Luckily they tend to hit where lava has gone before, with nothing left worth damaging apart from an occasional careless tourist.

On Thursday, the still camera covering the Geldingadalir eruption caught an amazing view – amazing, that is, for Iceland in spring. First there was the snow, proving to the world that Iceland never really left the ice age. It is waiting in the wings, and here ragnarok is always just around the corner. But this snow shower had more. It was only seen on one frame, a 1-second snap every 10 minutes. A beautiful spout showed, left of the cone that just at that moment wasn’t spouting anything. The image showed the funnel, the sharp thin edges and the horizontal striping that delineate the rotating winds. Towards the bottom it became fuzzy, clearly showing that it touched the ground and was picking debris – dust, presumably.

Once this was found, the twister was quickly located on other webcams. The still was taken at 11:50am, just as a heavy shower moved in. The Meradalir webcam was in snow, but this was only on its hill. The closer langihryggurNV webcam was in the clear, and showed no snow at the tornado itself. It had formed just after the storm passed through. If you like the full frames, click on these pictures.

The tornado was also seen in the life webcams. This is shown in the video extract below. The tornado forms on the left, over the lava field. Initially it is hard to see. It quickly rotated up the side of the hill, and now it became clear, forming a funnel of cloud. Once it reached halfway up the hill, it fragmented and disappeared. The still frame had, by pure accident, caught it at its best.

How did this form? Why was it in a snowstorm? And why did it end so suddenly?

Before addressing these questions, what are tornadoes anyway? Think hurricane – but with the action packed into one funnel. They are amazingly easy to make: all it needs is some upward movement of air, and something that gives it a bit of spin. And just let it go. We have a tornado chamber at work. It is about 2 meters tall, and creates a vortex of air inside. Add a bit of oil vapour, and you see a beautiful tornado. I lend it once to a science show for primary school children. The teacher was talking about different kinds of clouds while behind her the chamber was being powered up. After a minute or so the tornado-in-a-box suddenly appeared and all the children went wide-eyed.

A tornado forms within a thunderstorm. The storm can contain a rotating vortex, powered by the different winds around it. This is especially if the storm is fast moving. The downdraft around the thunderstorm can take this vortex below the cloud base. Now we have a funnel cloud. If the funnel cloud touches the ground (most don’t) it is called a tornado. Let mayhem begin.

A devil develops differently. They start on the ground, as a bit of excessively warm air begins to rise. The rising bubble can pick up rotation from variations of the wind, either with height or on the ground. A devil starts on the ground and moves up, while a tornado begins in the storm and comes down.

But there is a grey zone: a devil may connect to a cloud above, and it that case it is both a devil and a tornado. This only happens if it touches the cloud base and that is rare: if that happens it probably used both the updraft and the downdraft, a true mix. I’ll leave it up to you whether to call this tornado devil or a devil of a tornado. Strictly speaking, if the devil does not get its spin from the cloud but from the wind lower down it is not a tornado, but this is hard to tell from the ground! So in practice, if it connects ground and cloud it is called a tornado even when strictly speaking it isn’t.

Warm air rises and cool air descends. This is a crucial part of the formation of tornadoes and devils. But the rising and falling is not automatic. To get a column of rising air, you need a fast change of temperature with height. Rising air cools – by about about 1C per 100 meters (less for humid air). The air only continues rising if the temperature of the surrounding air drops with height at least that fast. This works best if either the ground is very warm, or the upper air is very cold (or both). The temperature gradient can be very large near the ground when the ground is heated by the sun, but may be be much less a few meters up. So the devil may grow only to a few meters. At other times the temperature continues to drop fast with height and the air is called unstable: now the column continues to rise. The rising column can pick up rotation if the winds change with altitude, and becomes a funnel cloud reaching for the clouds above. The same can happen with the descending air coming from the cloud above and taking its rotation with it. The direction is different but the physics is the same.

The speed of rotation of tornadoes is enormous. Devils are a bit less vigorous. There is a lot of meteorology in here, but the principle is easy to understand. is something is rotating and it suddenly becomes smaller, the speed of rotation increases. The standard experiment is a victim siting on one those rotating office chairs, holding out their arms and given some spin. Now the victim pulls in the arms – and the chair spins up enough to make the person seasick. Dancers use this: in a pirouette, if you pull in your arms you go faster. It is called ‘conservation of angular momentum’ and it is a basic law of physics. As incoming wind is focussed on a small devil, the rotation it brings speeds up in the same way. In a devil, the wind may come in from 100 meters or so, and is focussed on something a meter across. The rotation increases by this factor of 100, so even an insignificant rotating movement of 10 centimeter per second can become a strong wind of 10 meters per second. In clouds, the circulation is faster. It also extends further: the circulation may measure kilometers across. So the amplification is higher and it gives much stronger winds. Tornadoes really are scary. Even Icelanders would not flock to watch a tornado. Tornado chasers are like rock climbers: admired, followed, but best not copied.

Water spouts form (the clue is in the name) over water. They can develop when the water is warm but the upper air cold, something that is most common in late summer. These are conditions that give rise to thunderstorms, and so water spouts may be true tornados: starting from the storm above and coming down to the water, connecting cloud and surface. Water spouts can also form from the water up, in which case they are water devils. True tornadoes are not that common over water: most water spouts come from rising convection and get their rotation from wind, not the storm above. Tornado may be strong enough to suck up water (and a few fish or frogs), but water spouts don’t normally do this. Forget about shark-infested tornadoes: this is one of the many things sharknado got wrong. However, a water spout can move over land and drop some of its animal load there. The song ‘raindrops keep falling on my head’ would not be the same if the rain included an occasional fish.

On land you may get dust devils forming above heated ground. They are land spouts, and they do not normally become tornadoes. The reason is that clouds stop the ground from heating, so dust devils do not easily form underneath thunderstorms. But they can grow large: on Mars they can become kilometers tall. And they can be dangerous. I know of one person who died when the driver of the car decided to drive through one.

But any ground heat will do. Forest fires are well known for forming ‘firenadoes’. The air over the fire rises, and the forest fire pulls in colder air from all around. This incoming air brings with it a bit of rotation, and the vortex, filled with burning fragments of the forest, rises up. It is not a tornado, though. They should be called fire devils.

Source: wikipedia

Volcanoes also do it. Volcanic eruptions are much smaller than forest fires and their devils may not be as impressive. But air above a hot lava field will rise and if the wind over the lava field brings some rotation with it, it will form a rising vortex. It may even be strong enough to even pull up lava fragments from below. Again, they are not tornadoes as all their energy and rotation comes from below. These volcanadoes are really lava devils.

There have been several reports of such lava devils on the fields of Geldingadalir. They were most common on the hottest part of the lava. Here is nice video of one that tries to make its way to the centre of eruption. The air above the cone is rising, and this pulls in the air around it. The lava devil moves with this flow towards the cone, and probably picks up rotation from it as well.

The vortex can also form around the edges of the lava field, fed by the heat. The air flow can take it off the lava field and up the slopes of the hill (warm air, after all, rises). Now it becomes a real dust devil. There was one visible on Thursday, shortly after the tornado. In true Icelandic fashion it decided to take a good look at the local camera and show off for the world while obliterating the view of the lava fountain behind it.

As an aside, what makes a tornado or devil visible? In the videos you can see that they can sometimes move invisibly. There are two main possibilities. The low air pressure inside the vortex, combined with humid air, leads to condensation. The funnel cloud really is a funnel cloud: it forms a cloud. The other way to become visible is by what it picks up from the ground. This can be dust, or it can be larger debris. Sometimes dust devils have no dust, and become invisible. I once was sailing in a narrow canal, when a dust-less dust devil came of the fields, unnoticed and invisible. The boat suddenly was flat on the water. In a forest fire, the fire is what makes the fire devil visible. And above lava, tephra does the trick. In the video above, the lava devil becomes visible when it hits open lava but is difficult to see otherwise.

But let’s go back to our original tornado. Can we understand what happened?

It started just like the lava dust devil of the previous video. It formed on the lava field, moved to the side and up the hill. But the conditions were unusual. The upper air was very cold and a snow shower was rolling in. There was even a bit of rotation in the cloud: this is visible in one of Virtual’s beautiful time lapses. If you look at, towards the end around 11:40 you can see rotation in the cloud. The snow brought the cold with it, setting up a very large temperature gradient. The rising lava devil, aided by the very cold air above, met the downdraft from the cloud and took off. The rising bubble of low pressure in the cold air caused condensation and formed a cloud, which made it visible at heights where the dust could not reach. It went high enough (150 meters, perhaps) to touch the base of the cloud. And so it became a tornado. This is actually pretty rare for volcanic vortices. On the images you can distinguish both the funnel cloud above and the dust devil below.

But it did not last. The wind took the vortex up the slope of the hill, away from the lava. It lost its source of hot air on the ground. The updraft lost power as the temperature gradient was now much less steep than before. It quickly lost the connection with the downdraft from the cloud above, it survived for a few seconds more after its downgrade to a dust devil, but then disintegrated. But by then it had already become immortalized by the webcam.

The tornado (let’s call it that, even though this name is disputable) happened on the tail end of a snow storm. Snow tornadoes (really, snow devils) are known, but they are very rare. They have been seen mainly during snow storms over warm(ish) water. Wikipedia claims that only 6 snow devils have been photographed, all in Canada. I am not aware of any having been seen during a volcanic eruption. However, do correct me on this!

So this was a very unusual development in what was otherwise a fairly common event. Lava devils do not normally become tornadoes. They don’t normally form during a snow storm. This was, as seems typical for this eruption, exceptional.

The current eruption may be exceptional, it is also a small one. You would expect that anything this adorable toddler volcano can do, grown-up volcanoes can do better. And indeed, larger eruptions can have larger lava devils. There were some very impressive examples seen during the 2014 Holuhraun eruption. Here is one which was caught on infrared camera. It reached a kilometer high. There was a bit of cloud on the infrared camera, but not the kind that would have given any downdraft. And so this was a superb lava devil, but not a tornado. And though it had fire, it lacked snow. But it was a very good try.

And Hawai’i can do it too. How do you feel about a volcanic water spout? Sounds scary? One was seen in Hawai’i in 2008, formed in the cloud of steam where lava entered the ocean. It does connect to a cloud but this is the steam cloud of the lava ocean entry itself, so it does not qualify as a tornado. Our Gedlingadalir tornado remains unique.

Photo is by Stephen & Donna O’Meara

Eruptions are both scary and beautiful. And it is not just the lava. It is also the atmosphere.

What are your stories of volcanic weather phenomena? Please us the comment box to share your knowledge and experience!

Albert, May 2021

And for a bit of volcanic atmosphere, I can strongly recommend the Meradalir camera.

741 thoughts on “The ballad of Ballareldar: twister in the snow

  1. A large break-out has appeared behind the theatre hill, out of view of any of the cameras until it went too far.

    • Albert. I have look and even more think alot.. i cant really get this 6-8 min flooding to keep up with the expending lava. Is it a another source under lava beds somewhere.? Sorry if this have been asked before and answer, i dont read everything. because i am away time to time.

      • The answer is that we don’t know! There is only one eruption site. But whether some lava makes it out underneath the cone is not clear

  2. Would it buy some time for building the wall if the edge of that sharp right turn of the lavaflow cold be somehow broken? The lava might then flow north and that east to west ridge made by the flow would act as a natural barrier for some time. Explosives, artillery, whatever.

    • I wouldn’t do it that location but above Meradalir. but yes, it is something to think about. It has not worked in the past but explosives have improved since then.

    • Weaken up north side of lava river probleby could work.. But must be in a spot that effect the flow the right way.. Also with explosivs you get a shock wave. So if other side of lava river is little weak it can go very wrong. Not easy in any way..

    • That rock doesn’t look like it’s been there very long. Must have come rolling down the slope during one of the earthquakes.

      • Seems a good explanation! I don’t know how to find out when the google earth imagery dates from.

    • Gutn Tog walks across the face of the desert, trailed by Icelandic security services….
      Not…far…now….got to get…to…the bunker……

  3. Merlot I am watching that crack too, It seemed to widen after that last fountain. The diggers are busy lower left of the Flo cam and that lava flow middle far left beyond the diggers seems wider and more fiery.

  4. The lava seems to be getting pretty close to both walls, now, as seen on the Langihryggur camera. Let’s hope they get all staff, equipment and vehicles off the area between the dams.
    If the dams don’t stand up to the pressure, that could quickly become an island, and while staff can be airlifted out, it would be a lot trickier to do that with the bulldozer and excavator.

    That’s not to say it would not be fun to see an Mi-26 drafted in to carry some heavy metal…

    • i suspect the heavy metals will run for the hills… they would still have some time to beat it.

  5. Just got here for a catch-up on today’s doings, it looks like replaying Lateralus 3 times in succession has been a good preparation… Wow, just… wow.

      • Get so excited that i puch most buttons twice it look. 🙂 And spell. I blame auto correction.. Have a nice day out there..


    Viscous spiney toothpaste pahoehoe VS plastic bottle …. I woud like to Incenirate my old playstation 2 that none wants to buy.. thrown it in there … still No real pahoehoe yet… eruptive rates are simply too high for that

    Enviromental pollution Gutn Tog

    • Yes, the gods only know what toxic chemistry is going on with that.
      I’d not recommend it as a disposal mechanism for plastics. Environment Minister Rebecca Pow was excoriatd on BBC Radio 4vthis morning about single use plastic and how a large proportion of plastic ends up in Turkey since many other countries banned their import for disposal. We desperately need circular pathways for these materials to ensure total reuse.

  7. Seems that the only reason the fountains dont look as big now is that everything else has grown, the cone is something like 100 meters tall and the lava flow is probably several tens of meters thick at the channel, while fountains still reach 200-300 meters high they only get about twice as high as the cone now.

    If it stops for a whole day the scale of the eruption is going to change completely, 15 m3/s is 1.3 million m3 of lava per day, and assuming the effusion rate during the fountain itself is about 100 m3/s (based on Pu’u O’o 1980s values) then to erupt 1.3 million m3 will take 13000 seconds, 217 minutes, or a bit over 3.5 hours. That isnt a lot in the grand scheme of things but having the fountain go at full power non stop for 3 hours is really going to shake things up, a wall isnt going to stop that…

    Just to add, if it stops for a whole month and then erupts at the same vent again (probably a bold assumption) it could erupt at current full fountain force for a week. 300 m3/s could be sustained in this situation for a day and a half, and that is as powerful an eruption as we saw at Kilauea in 2018, or at Holuhraun. That is the situation we see a lava flood racing to the ocean faster than you can run. Knowing how repetative this eruptio nhas been so far, and that Pu’u O’o did exactly this in the 1980s, it is quite a plausble evolution.

    I think though the conduit will continue to get bigger and more efficient, the effusion rate getting ever bigger, until the magma body feeding the eruption is drained and the eruption shuts off suddenly and transitions to a shield fed by direct decompression, effectively a vertical dam burst, where the initial tiny chanel keeps eroding and accelerating the process. This is a bit different to the hell machine, it is a crustal effect, but similar. Maybe unlike the hell machine it is also a proven phenomenon, not least as we already observe it… 🙂

    • I hopes the conduits enlarge themselves.. for now its behaving like a lava geyser .. a shallow chamber at 150 m depth acts like a rocket combustion chamber with the magmatic gas pressure. As it is now.. it will form a big Aa plateau mess.
      The lava appears to be just somewhat above Puu Oo s viscosity near the vent

      I hopes the conduit gets wider
      I wants something like Kupainaha Shield .. a constantly overflowing pahoehoe lava llake shield .. and pahoehoe lava flows invading Grindavik becomming Icelands own buried Kalapana – Royal Gardens.
      Still not giving up hope for my pahoehoe shield to materialize…

      • I dont think that will happen, its too narrow to do that right now and it is also goign to be too high effusion rate. Like I proposed above the eruption will probably just keep getting stronger until the magma body feeding it right now is gone, then it wil lsuddenly stop and that is where we see if decompression melting can keep it going. I dont really see it likely though, maybe for a few months but unless

      • Also on the viscosity, dont forget the lava is also getting churned around a lot right away. The lava lake is all fountain fallout and it is also degassed lava, the fountain itself doesnt generate a lava flow the surge is from the degassed lake getting ejected from the crater by the fountain.

        I dont think it would be any less viscous than the stuff in Hawaii, think about the vents in 2018 erupting the same lava as Pu’u O’o but it also looked a bit more viscous, even with Ahu’aila’au having a magmatic component that was more primitive than anything erupted at Kilauea since 1959. Same for Mauna Loa, its flows are turned to a’a almost immediately, but erupt just as hot as Kilauea eruptions outside Halemaumau, 1140-1170 C.

        I think really it is the colder climate of Iceland that is to blame, Hawaii is around 25 C, where Iceland is maybe more often around 0-5 C. That isnt a lot but it is also the difference in temperature often observed…

        • Puu Oo flows even at lower temperatures 1160 C where amazingly smooth fluid and liquid aluminium like perhaps because they only had very little and very small crystals. Hawaii is smooth and glassy cools into a glassy crust skinn.

          Even when Etna reached 1140 C in 1960 s there was not as fluid as Hawaii despite lower sillica.. and thats kind of strange. Not even Nyiragongo as as shiney as Hawaii But perhaps because much lower sillica

          Fagradalshrauns Ragnar Vent Displayed fluid Hawaiian smoothness a few days ago close to the vent watch here

        • Ahu’aila’au 2018 was amazing with its eruption rates and even at 1144 C
          Fissure 8 was much smoother and liquid looking than Holuhraun that was 1180 C

          Holuhraun was very fluid close to the vent.. but even near vent overflows had a rough texture
          IMO says that Holuhraun was jam packed with olivine microlite crystals explaning the Aa crusts close to Baugur vent. Perhaps Holuhraun too should be classifyed as a Picrite Basalt? it had a high olivine content

      • I don’t mind the shield part, but the Grindavik situation worries me, and I think the good people of Grindavik would certainly have something to say about that.

        • Yes, In view of southern highway/Grindavik situation, my heart would not be broken if the eruption ceased soon ..

      • Hawaii can be really hot at sealevel.. even in december! Hawaii Island may have
        10 climate zones, amazing diversity. But at sealevel its always really warm. In 2017
        I was in Hawaii last time watching the kamokuna firehose flow. I was there for a month in december.

        We had 30 degrees C in the shadow everyday! and in the direct Sun its Impossible to be in. Really oven hot everyday with high humidity. Promenades where limited to evenings and mornings, days noon where simply unbearable, days where like an oven there, But its because Im not used to that.. I live in the Polar Arctic at current. Kailua Kona is really oven warm even in winter.

        Hawaii is quite a distance north from the Equator its latitude 20 N Kailua Side. Yet I was very supprised indeed How hot it was at sealevel even in december. Despite Not being at equator it haves an Equatorial climate.
        Perhaps its the High Pressure at Lat 20 that really warms Hawaii up?

        As you gets towards the
        Lat 30 s the weather suddenly turns very mild and pleasant all year around ( Azores )

        Basaltic Lava is over 1100 C hotter than sourrounding air so – 5 C and +30 C does not make very much diffrence
        I think. Even Antartica can display beautyful old pahoehoes in pleistocene outcrops. Neither air or sea chills lava flows very much interior .. rock have low thermal conductivity.. submarine sea lava flows can flow many many kilometers by developing a insulating crust.

    • You can see on the map that the lava is just about to enter the next small valley south of Geldingadalir. Sadly no camera

      • On the 3d map it’s difficult to figure out the slope. If one turns the map and looks from below the surface it seems that the area just south of the Geldingadalir lava stream is more or less level. So some pressure is needed to go there, the lava is not flowing downhill.

        • Judging from contour lines on topographic maps, the exit here is about 10 meters above that of the location of the cone. But the topography has changed a lot with all the lava. If the cone has build up the location by more than 10 meters, then the exit is available. The main extension of the lava flow in the past week has been in this area, and this suggests it is not longer uphill

          The wall is being raise to 8 meters. That brings the height to only a little below the level of this new exit

          • A south westerly exit means that lava would first fall towards a saddle and then perhaps split: one stream east to Natthagi, the other west to Natthagakriki (where Kriki lives). The latter might be visible from the good old Mila cam at Thorbjörn.

          • I was seeing the same thing a couple of days ago. If it overflows into Natthagakriki, then it can access the coast road as it turns inland.

  8. Haven’t seen this camera mentioned yet, but it’s just up the hill from the camera that got eaten recently, very nice close up of the volcano, probably not as well known because it’s not on youtube:

    • Why not calling the cone ‘Snow White’? Then we would have obvious denominations for the small cones…

    • Looks like it has already breached the wall in two places. Hard to make out with the resolution though.

      • Shame the camera is so far away. I was watching another eruption just now, and the distant view really shows the huge volume of lava pouring out of the cone! The close-up cameras don’t show it so well.
        I think they may struggle with containing it. Good luck to them.
        Hopefully Gutn Tog will update us today.

    • I think it may be time to start a second line of defence, half way down Natthagi. In Meradalir a slight reduction in the valley width seems to have slowed the lava front.

        • The cables might survive being covered by lava. As the ground freezes in winter, the cables need to be buried at least 1 metre deep and surrounded by sand to prevent damage from the ground moving. If the cable insulation survives constant heat from above the glass fibre should be unaffected. I doubt heat will affect the transmission of data; but who knows? I don’t think anyone has tested their download speed under a few metres of hot lava yet.

          • The fibre should not be heated too much or it affects the glass. You want to avoid large changes so the fibre does not develop cracks. It should still work with a bit of crackling but the signal will arrive much weaker. Obviously fixing it much present a problem.

    • It also shows far more about the older lava field where the first lava pond was/is (seeing as it drained a couple of times). This area, and the lower Meradalir valley, has been woefully neglected in volcano coverage by the big companies. Just think, if they co-ordinated better and the two cameras had been relocated before destruction, how much better the coverage could have been…

  9. From

    Efforts are being made to raise the defense walls at the lava field in the southern part of Merardalir from four meters up to eight meters. contacted Bogi Adolfsson, chairman of the rescue team Þorbjörn, who says that the work is progressing well and that it looks like the increase will be completed in the next ten days. It should be emphasized, however, that the gardens are not designed to stop the flow of lava.

    “A bulldozer has been added and they are in full swing today. Two bulldozers and one crawler excavator are in the area now. This will not take them long on these machines they have. Now that another bulldozer has arrived, the working speed doubles “, says Bogi.

    Asked if it looks like the defense walls will be able to control the lava flow, Bogi reaffirms that they are not designed to control it:”This is designed to slow it down. It’s about buying time, trying out and planning for the future. This way we get good information on how we can use this if it comes close to settlements. Then an underground cable was placed under it to see how the heat passes through the earth and whether it affects the underground cable. There is a lot of good information coming out of this. This may never stop, but let’s say that there is a need to evacuate a municipality, that there is a possibility of setting up such a fortification and it would then buy us time for evacuation “.
    According to Bogi, there are still no plans to raise the walls further or launch other measures if it turns out that the current measures will not work.

    “There is little that can be done. There may be defense walls built below. That’s a decision that just comes from above. “

    • Regarding that last sentence, I can’t decide if the speaker is being bureaucratic, or is being religious. Kind of fun.

      Perhaps it’s just the translation.

      • Nah, it is not the translation. The Icelandic line is just as ambiguous, although from context an Icelander would be much more likely to interpret it the bureaucratic way – even if the religious way would have been said just the same… lol

      • I also read it as a little bit of from a higher authority, be that spiritual or beaurocratic, but also from the lava; as it flows from higher to lower.
        As Albert has mentioned higher up (another usage!), if the cone’s fountaining results in an elevation of the lava lake inside, then that brings other spaces into play for lava storage and escape.

    • The point of the wall is that it tries to make the lava want to go somewhere else.. but it seems more persuasion was needed. When closing a door, it is best to open another one

      • I know that the engineers that have been interviewed while patting their own backs, have mentioned “similar” efforts in Heimaey, Sicily, and at Kilauea. It seems that they forget that a) the successful ones where diversion walls not damns, and b) if you want to divert lava try not to pick a route that is uphill from where you are diverting it from.

        I may be a little harsh on this but here we are..

        • The lava hasn’t breach the actual walls, only the smaller mounds they made in the beginning to protect themselves while working on the real ones. So far, so good…

        • Yes, as Hildur says, this is only breaching the b uttressing, which was only there to protrect the workers and their engines whilst they threw up the first fortification. The lava will still need to spread sideways and fill up that protective portion before it can then bring its force to bear on the main berms.

      • I am now inclined to believe the professor, I think that the lava ( with the current volume rate of eruption) will have a hard time making it to the road..

    • Love the Giggle translate from the article:
      “a floating lava elf came from the solidified lava and began to run along the eastern edge of the lava..”
      Damned Elves, get into everything! What next, Faeries? Bogles?

      • I was just about to post that too…it’s making me laugh out loud while my wife is in a meeting…oops!

      • I am really worried now as next door has gnomes and fairies in her garden. I am not sure if icelandic elf is the same as a gnome however as the lava is heading into the garden I shall have to check on my marrows and Courgettes. I suppose I could harness the geothermal heat to help evrything grow as Spring hasn’t happened here yet and growth rate of everything is rather static.

    • If a Grimsvötn eruption last long enough you gets a tephra hill in the meltwater lake and later effusive lava fountains

      • A Grimsvoten eruption would put paid to any post pandemic holidaying for Europeans & Brits. At least it would solve the problem of whether one should fly to amber countries. Non of us would be flying anywhere!

  10. It seems very probable now that Kilauea has stopped erupting. No more DI events, background SO2, no liquid lava lake surface. Since the 16th the tilt has shown only an upward signal right as a DI would have been expected to stsrt, I think that is the point it actually stopped with the last lava being passive overturning. Kilauea Iki had lava lake foundering for a week after the eruption so that seems to be a common process.

    GPS looks to be accelerating, the volcano is quickly inflating again. We will have to see how long this signal lasts but it looks likely to continue.

    • HVO hasn’t yet called its end although they do prepare for a ‘pause’. They also warn that the danger remains, which I guess is based on a possibility of gas explosions underneath the crust. The cessation of DI events may be related to the fact that the lava lake is almost entirely crusted now, which effectively has blocked the expansion vessel. If the eruption ends now the DI events may cease entirely (for now) but it is also possible that we will get another one once the pressure inside grows high enough. There is no significant inflation but there is significant expansion of the caldera. That suggest magma that is less deep than the caldera is wide!

      • Yes, Its hard to call the end like this anyway, if it resumes within 3 months at the same location it will be called a pause but it it takes longer than that or opens at a new location any time it is a new eruption…

        Magma under Halemaumau is 1-2 km deep, which is less than the distance across the caldera from HVO to Keanakako’i,

  11. As not a lot of change is happening and comments are becoming somewhat random in nature. I would like to add my bit to the mix.
    Now here is a volcano that is totally unpredictable. No earthquake swarms to give an alert. It just erupts with about 30 minutes warning and gives off very toxic elements . if you are unlucky enough to be hiking on the mountain you don’t get much chance of getting off in time! As it produces large amounts of ash it’s not a good volcano for tourist visits and causes a real problem for anyone living in range of the ash fall.
    Katla is another unpleasant volcano and would be problematic for Europe.

    • Not sure it deserves all of its bad rep. The half hour warning is common at many volcanoes, and is usually a result of inadequate aequpment for the job. Some volcanoes far exceed Hekla in the lack of warning, Kilauea is my pick for a place that really deserves the title of unpredictable when it erupted in 10 minutes from nothing right under the noses of the biggest monitoring network of any volcano and one of the best teams of volcanologists, and for doing this in the 21st century and the pandemic that has billions stuck indoors. Lack of early warnings at Hekla seem to be only for its eruptions 1970 and onwards, eruptions before that do have often cases advanced warning, and today would at least be known long enough to mitigate the risk, 1845 was making tremors strong enough to feel a day before. Quite on the opposite trend the eruptions of former centuries were far apart and big and dangerous, with evolved magma, while today it is basaltic andesite and mostly effusive from the start, its like a big version of an Etna paroxysm. It seems to me Hekla has evolved from an infrequent big hitter into a less explosive and more active volcano.

      Next eruption though I think could be quite big, not plinian but of a much larger volume than 2000 or 1991. I guess we will get to see eventually 🙂

    • I sure wish the MBL wide-angle camera was still working. Are you watching the RUV wide-angle?

    • Again from the other crater, the saddle crater as Boris has called it, not the NSEC crater that was erupting earlier this year.

    • To be so big Etna very shy. Alot of night erouptions 🙂 but spectacular look at it never the less

  12. Umm, are we just going to ignore the 2 km steam plume at Taal?

    • I am intrigued. Do you have a link?

      I am not a runny lava person.

      I like volcanoes that chuck things into the air, so I can say “whoooeee! look at that!

    • That is probably a normal thing for a volcano that has a massive hot lake and is in a humid climate, steam plume is basically the same as a cloud. What is probably more important is that there is a lot of SO2, Taal is going to erupt soon I think but it is probably not going to be massive.

      If I was to guess, based on eruptions after 1962 most or all of them will be largely effusive, but on a volcano like Taal which has viscous basalt that still means some pretty massive fountains and probably a plinian eruption column, as well as a thick lava flow filling in the crater.

      I would like to know about the faults of this area though, as Hector pointed out Taal is a rifting volcano that is prone to hydrothermal eruptions of a scale comparable to a magmatic eruption or even more so, but it seems the magma system is not big enough to actually collapse that much, there are no eruptions at all on the fissure swarm, but a collapse big enough to make the caldera would be something like Laki or Eldgja, way too big to fit entirely underground. There are also no eruptions on the ring fault, only at Volcano Island, which is in the center of the caldera. The ignimbrites around the caldera also point at a more violent origin, not a passive collapse, but still only basalt no silicics as expected for an eruption like that.

      Is the caldera actually an explosion crater, a VEI 7 maar…

  13. The 04:23 am 21-May-2021 burst seems like a one huge gusher lasting about 10-15 secs or so. This seems like a gradual change in the length of the gusher, as it appears to be less time, but increased rate of flow during that time. Has anyone else noticed this? Or was this unique to this burst?

    • Have notice a slightly change in behavior time to time. Not any kind of expert in this. But i am looking with 2-3 days off. It growing 🙂 . Build up material on the outside and inside it collaps so the gushing have much more space so a wider fontain. (bigger nozzel) Also the level on the lava pool higher and higher. If there is a change in temp or that the tube system get wider or a combo. I thought that the bursts should calm down more and get a more steady flow should be if it wide up. But still it have some power and gas traps. Interesting times.

      • So it is a slightly down in flow rate.. At least at that time. Also if the fontaining get little lower can be that when lava pump up in the crater just before it fontaining it is much more volym of lava in the “lake” now so the harder press up a fontain.

    • Cucumbers are mostly water and water has a high heat capacity. It takes a while to boil. Are you suggesting an ice wall?

    • We British can build the wall for them! Using tea, and cucumber sandwiches. The odd muffin and scone with jam could be added for variety. Strawberry jam, of course.

  14. I wonder what Grimsvötn will do next time… will be intresting

    • Seen in Hawaii too, its the way the sun looks through acid clouds 🙂

  15. I get the feeling there’s a low chance of the lava reaching the coast -it could ofcourse, but at the going rate of output its going be a while yet! To put it in perspective the 1950 Mauna Loa eruption the lava flow traveled 24 km(15 miles) and reached the Ocean in less than 3 hours.But ofcourse that’s a extreme example- back in Iceland as things stand they have time to divert the lava -or atleast attempt too.

    • Reaching the coast or even the coastal road would require a step change. If the wall hadn’t been build the lava would now just begin the flow into Natthagi. It is a steep downhill so the initial flow would be fast. The wall may buy a week. In the longer term, the backroad behind Theatre hill may be a concern? If the lava river blocks, the flow may all go there and that would overrun the next small valley very fast

  16. Yes, not as fast as 1950! It’s all the unknown lies ahead-thats the thrill of watching and second guessing volcanic activity! None of US are experts!

  17. I wonder if there is a workable design for an earth and concrete structure that might protect the main south road, in the event that lava eventually reaches the coast? If the lava flow could be confined to a fairly narrow area; perhaps with earth dams to guide the flow; it might be possible to create a tunnel under the lava with a concrete bridging structure, supported on both sides by a gentle earth slope, over which the lava could flow. I imagine at least one difficulty would be preventing the lava spreading to either side before it climbed the approach slope. Another difficulty might be reducing the width of an already wide lava front. Perhaps a wide lava front could be split into several more narrow fronts; say about 100 metres each; to be guided over bridging structures. Would it be worth the expense in a perhaps futile attempt to avoid the disruption of losing a significant main road? It is probably smarter to accept the loss and reroute traffic along more northern roads until the lava cools enough to carve a new road through it.

    • Guiding the Lava over the road is potentially the best solution if a long disruption has to be organised.
      Build gentile slopes over a concrete structure, potentially taking out a sudden step in the terrain and keep the lava high.
      Some meters of soil over concrete must be sufficient to keep the road usable.
      The inverse will be difficult: the height you need to prevent heat of the lava to pose issues for the structure and users would be substantial.
      Soil is insulating and you can add channels to cool using sea water.
      You can see that it is impossible to predict the exact route lava will follow, Meradalir is in theory the easy route bus still decent amounts of Lava prefer the south direction.
      One idea could be to transform one of the valleys into a lava collector, to enable the heat to be harvested.

      • Over the road? After what I’ve read so far on VC I wouldn’t drive under a lava stream. Above might be a bit hot too. If that goes on they have no other choice than to go for a new road.

        This volcano is like the new CV. It seems to have come to stay. It might relax for a while and then break out again. After what I’ve read about volcanoes the road is lost. There are worse things, thinking of Naples, Managua or Guatemala City. It’s only a road. Looks like Much Ado About Nothing.

        I spent numerous times on the Island of Ischia. The first thing I had to do was to forget about Epomeo. Epomeo looks completely innocent, so it was easy.

      • This is a golden opportunity for the construction engineers and industry to carry out experiments to see if they can protect infrastructure and delay lava flows by diversionary tactics, for the future eruptions that will inevitably come.
        The scientists have privately admitted that the lava cannot be stopped, so the efforts are to discover as many ways as possible to protect escape and evacuation routes, and plan infrastructure mitigation for the future.

        They’ve buried cables to see what happens and are getting results already. I’m sure that there’s a lot more going on that we’re not being told about. One of the paramount objects will to be keeping anyone from panicking about the capacity that this type of eruption could have in the much longer term.

        • Actually this is a good idea. I was thinking about steel heatpipes. These can extract huge amount of heat. Maybe even enough to let the lava crystalize. It requires some engineering.

        • the base is the most important. There is a rock wall several meters tall pushing against the wall. You have to deflect the force so the lava moves up rather than just pushes the wall out of the way. The base has to be as wide as possible with a shallow slope. If the wal crumbles, ghye got it wrong. If the lava goes over it, it worked. Basically.

    • Iceland is good at building bridges. A bridge over an active lava flow might be a bridge too far, though.

  18. Another stupendous video from yesterday from Gutn Tog, the collapse of the boulder at the vent mouth and subsequent lava flood; views of the Channel and overflows near the vent, and of the new pond up against the western side of Geldingadalir valley. I’ve not seen this before, except a brief view through the v-shaped gap,south of the viewing hill.

    • Somebody should buy that man a beer! Another great video with some closeups of the lava at the wall

      • I’m seeing small piles of sand or earth on top of the lava; that makes me think that the bulldozers were shoring this up as the lava was right there… Astonishingly brave if that was what they were doing; this eastern rampart is out of view of any camera or oversight.

        As regards the vent, the lava level during the fountaining seems to be several metres, possibly ten to twenty metres, above the normal level of the channel. Can anyone work out how high it is? Does this bring the SW approach to the Geldingadalir valley back into play as another escape route for the lava?

        • You can rewind back to about 14:25 to see them starting to do it.

        • From the videos, the lava river and its mini shield sits some ten meters above the lava in the valley with no name. If that goes south, the wall has no chance. But with such a high flow, any break down could send a lot of lava in another direction. Which direction is unpredictable. At the moment there are three flows. If all the lava were to go southwest, it will be in Nattahi in no time. But if it all goes into Meradalir, there is plenty of space there to fill.

          • This is two days ago. It shows the two initial walls which are now overrun and the lava is now against the high walls. The lava river is visible which feeds lava in all directions. Any failure of the river is most likely to lead to a flow into Meradalir (steepest descent), with as second likelihood from the first bend southwest into the narrow valley. Failure towards the wall is least likely. But very much possible.


    • Gutn Tog really has contributed a lot to seeing this volcano. HIs videos and descriptions of events have been superb.
      I see he was originally from Ukraine, which explains his accent.
      Perhaps we ought to offer him “Honorary Dragonship” of VC? 🙂

      • That would be Ewesome. I bet he’d get bought quite a few beers at the Bar.

    • The wall is working! At the far end, the lava flow is away from the wall.

      • For now! The dozer operator appears to have finished for now. The height extention is just uncompacted dirt though…to quote the Borg Queen: “Finding your weakness is just a matter of time” 🙂

  19. Poor dozer operator has to work with lava tourists walking on the top of the damn they are working on.

    • No problem. Just added bulk to the dam wall. No-one will notice… 🙂

  20. They are just starting to increase the height of the west wall.

    Serious question – if the map

    is correct, the hill that this camera

    is on, is surrounded by lava front and rear – how is the camera now powered? Generator and big fuel tank? How are the cameras generally powered, running 24/7?

    • Solar panels, and in the case of the equipment on Tech Hill, at least some of it also has access to a wind generator.

      • The first flow into Meradalir has cooled enough that they tried to walk across it. Presumably successful

        • The camera has moved right to show work on the East wall, and on the hill (far side of the eruption) you can see people, so presumably the lava behind that hill has cooled.

          Must say it’s hard to recognise the landscape from the early days.

  21. From RUV streaming page

    Contractors are working on the western defensive wall. Later today, they plan to move back to the eastern wall. Lava is still flowing there but seems to be starting to solidify, but there is still lava flow to the wall, according to what journalist Hólmfríður Dagný Friðjónsdóttir described in the lunch news. Contractors had to retreat quickly yesterday after a lava pond ruptured just above the eastern defensive wall. Mila dug a fiber optic cable in the edge of the fortification for experimental purposes. Daði Sigurðsson directed the work.

    “We were laying a fiber optic cable right in front of this new eastern defensive wall that Verkís took care of and we have connected with measuring equipment and we are now monitoring the condition of the cable, we are interested to know what happens if lava flows over a fiber optic cable. We are operating a fiber optic cable just north of Suðurstrandavegur, which is in danger if lava flows over Nátthagi. And the lava flowed over the string this Wednesday night and the string is still fine and we are interested to know how long it lasts and if it gives in when that will happen, “says Daði Sigurðarson.

    I was wondering where they had laid that experimental fiber optic cable, it will be interesting to see how long it will last before they will start seeing distortions or data loss in it

  22. This is the Amirani basalt pahoehoe flow on IO ( the largest active lava flow on IO in year 1999 ) this lava flow is almost 400 kilometers long and is supplyed by lava tubes glowing skylights can be spotted from orbit. Lava breaks out on the surface very much like hawaiian flows. IO erupts high temperature basaltic magmas
    1300 C, thats rich in sulfur gas, the sulfur escapes the lava lakes and snows out as sulfur snow. Tube feed flows like Amirani can last for many decades. The largest pahoehoe field on IO is called Lei Kung Fluctus thats big as Nicaragua

    Another style of IO basalt flows are the Pillanian style, that involves huge lava fountains and fast flood basalts ( Pillian Patera 1997 erupted 56 km3 of basaltic lava in a week and filling a 70 km wide pit crater with a lava lake.

  23. Pahoehoe flows from another Ionian volcano

    ”1999 during its 24th orbit. The lava flow is 100 kilometers (60 miles) long. The dark flows have intricate fractal margins that are characteristic of a type of lava flow seen seen on Earth called pahoehoe. The source of the lava flows is a 25-kilometer (16-mile) long fissure that extends to the east of the central vent off the mosaic to the upper left = Nasa

    • Hi Albert! as you can see.. liquid lava absoultely flow and churn over IO s surface it Absoutley does that and it cannot be denied…

      in 1997 Pillan Patera 70 km wide and 3 km deep was filled by flood basalt huge lava falls crashing down

      Do you know How lava can flow in the vaccum of space? .. but I also knows that liquid rock is not water either
      Looks like the sillicate lava itself is affected very little by the vaccum of space

      Here you can see the shiney skinn of IO s lava lakes reflecting in the sunlight .. shiney spots are lava lakes

  24. This is a thermal photo of Pele volcano on IO. This is IO s most active open lava lake with the most constant thermal emissions. Ionian lava lakes are huge compared to earths counterparts. Halemaumau was 300 m wide, but Pele lava lake on IO coud be 60 kilometers long and 25 kilometers wide! The bright spots are lava fountains where sulfur gases escapes and the black crust breaks up. Up to 1500 C been estimated for Pele lava fountains on IO. Galileo probe spotted many fountains and crust founderings in Pele lava lake. This lava lake must be a spectacular sight, sitting in a massive ”canyon” with fountains and waves roiling over the black crust. There is a constant tephra plume from Pele too suggesting tall lava fountains. Smaller emissions are spattering.
    Splashing are common among the pits walls of this lava lake.

    I woud like to stand on the edge of this massive lava lake pit.. in my spacesuit looking down on the spectacle below 🙂

    • As spectacular as standing on the edge of that lava lake sounds, there’s one little problem – Jupiter’s radiation belts.

      I’d think it’s better to watch this virtually via some heavily shielded surface probe/rover. Even better if that footage could viewed via fully immersive VR!

    • Pele Patera is indeed a huge lava lake for soure! As large as Teneriffe Island
      Earths lava lakes are miniscule in comparsion.. perhaps these lava seas are open windows into IO s astenospheric magma ocean ..

      I hopes Juno gets closeup Photos soon

    • Fountaining bubbling areras are many kilometers wide! in these Galileo data Probaly lots of runny dome fountains and lava lake upwellings.. upwelling zones the size of Holuhraun field .. large waves rolls under the black crust

      IO s sillicate lava lakes are a competely diffrent scale from terestrial lakes.. the lava is also 1500 C
      Most of Pele Patera is Probaly a huge black skinned plain.. that what it woud look like I think from closeup. Its a lava lake so Big that you cannot see any pit walls IF you where in its middle!

  25. From the static time-lapse photos, it looks as if the lava waited for lunch time before breaking out and making a run for the wall… Just lacking a motorcycle…

  26. Novise question; lot of smoke on the last “eruption” a few minutes ago, It also was very short-lived.
    Are we in for a big change in behavour?

  27. I’m surprised by how few diggers they have building the walls up. I would have thought the government could have co-opted a lot more to speed things up.

    • They’re not really serious about stopping the flow because that’s not possible. This has been a research exercise for future flows that threaten areas with far more infrastructure and people to protect.

  28. oh boy. big EQ in China. Last time they got this size of shaking it tested hard their building “quality”.

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