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. So much smoke in the midle of lava field… why this is happening?

    • Good question.

      Wild guess: Steam from fairly shallow sub-surface water that has come to a boil now that it’s under a lava lake.

    • Or, the soil seems to burn in this area. Maybe it’s a thick deposit of peat that is smoldering under the lava?

    • Depends one which one you mean. The one at the lava river is where the lave becomes stationary and presumably sinks into the liquid reservoir below. This is degassing at a bit lower temperature. The one close to the wall seems to be related to pushed up soil below the lava, from a close-up on one video

  2. I have been looking at the seismic tremor charts and thought I perceived a ‘pulse’ to our eruption on them. I took a chart a little further away from the Grindavik area. The Vogar chart shows the pulse clearly:

    Does anyone know why this increase/decrease pulse may be happening? If the date markers mark midnight, why would the eruption be more ‘noisy’ at night?


    • I could understand it being traffic / footfall if the date marker times were midday.

    • If the markers show midnight the dates should be in between the markers, not centred on them; slightly confusing. I’m leaning more towards Clive’s interpretation; the markers are 12 noon, making it noisier in the day, going down as 2300hrs and the closing of the site approaches. Is the noise greater/more intense at weekends? Looks like Saturday/Sunday is different…

    • Has anyone tried to correlate the position of the sun/moon/tidal effects on the pulsing? If this is truly a deeply connected source could those factors play a role?

    • It repeats perfectly from day to day including the onset at 7am and the narrow feature at noon which is present every day – except for 15 and 16 May which are Saturday and Sunday. We can call this a work pattern!

    • The tremor is high when there is a fountaining event, then it goes down to background levels. The width of the tremor plot shows the difference between max tremor and background level. At night the background level is lower, so the difference is larger. The eruption is just as noisy at night as during the day, but the background level is less noisy.

    • Whoohooo! My comments don’t seem to end up in the dungeon any more, whoop whoop!

    • This happened to me and my daughter at Niagara Falls. As we approacxhed the falls, so the static and negative ions built up. Daughter had 4 foot long hair that she could sit on… It radiated out like a Van der Graaf generator!

    • I chose to look at 12:10am UK time and someone was standing right in front of the camera taking a photo of the same scene.
      Please can the MBL and RUV networks fit a very loud air horn onto each camera and place an on-screen button for viewers to press?

  3. Dedicated to all of you and Bob
    Have a peaceful night everyone.

  4. So…regarding those efforts to prevent lava from reaching Nátthagi. The chatter here in Iceland is that the main issue isn’t the road, but protecting that fibre optic cable just north of it. It’s dubbed a “NATO cable”.

    The US army layed cables around Iceland to connect NATO observation stations when they had a base here.

  5. Quick Ingenuity update

    Flight 6 coming up but..

    “Ginny” went silent during a downlink session causing extreme anxiety to the team as you can imagine but they did have an idea why. Next day the helicopter woke up at the expected time apparently healthy. Diagnostics indicated that a firmware timeout had expired during a checksum operation – the firmware assumed the linux system had crashed and entered “safe” sleep mode. Apparently the offending routine has been replaced with the shell “ls” command as a temporary fix!

    Plans Underway for Ingenuity’s Sixth Flight

    Ingenuity’s flight plan begins with the helicopter ascending to 33 feet (10 meters), then heading southwest for about 492 feet (150 meters). When it achieves that distance, the rotorcraft will begin acquiring color imagery of an area of interest as it translates to the south about 50-66 feet (15-20 meters). Stereo imagery of the sand ripples and outcrops of bright rocks at the site will help demonstrate the value of an aerial perspective for future missions. After completing its image collection, Ingenuity will fly about 164 feet (50 meters) northeast where it will touch down at its new base of operations (known as “Field C”).

    Ingenuity is planning to continue to expand its performance envelope during Flight Six. The top groundspeed Ingenuity is expected to achieve on this flight is 9 mph (4 meters per second) and the time aloft will be around 140 seconds. It is also the first time the helicopter will land at an airfield which it did not survey from the air during a previous mission. Instead, the Ingenuity team is relying on imagery collected by the HiRISE camera aboard NASA’s Mars Reconnaissance Orbiter that suggests this new base of operations is relatively flat and has few surface obstructions.

    • The wall hasn’t been overtopped yet, but lava has crept up left, right, and centre. Just a matter of time now…

      Will the engineer count that as a partial win (e.g. successful delay) or a failure (only a short delay despite a lot of effort)?

      Thanks for the webcam operators for zooming in on the action!

  6. Looks like some small fountaining at around 01:27, but may just be some energetic degassing.

  7. Whatever it is, it’s been going pretty consistently in the same spot for over an hour.

    • i ran it down and it is an excellent catch!! Best one i’ve ever seen! Higher than the cone; almost 2x’s higher. Beautiful!

      • Here it is in full glory. Note that the lava devil remains in the same place. Once the cone erupts it is pushed away and disintegrates

        • i might slightly disagree…. altho i don’t have the shot; i observed the lavaler (as in ‘duster) to last through at least one eruption. But i don’t often disagree with You… You may have caught the last of it. Best!mots

  8. Been preoccupied with work for a while … looks like I’ve missed a whole lot of bulldozing!l

  9. And it looks like Kilauea is in fact not done yet… Still small breakouts of lava near the vent on the lake surface, and while the tilt is still trending up there was a DI event too, which suggests the vent is still open. I do wonder though if the vent has been flooded and now lava flows directly into the lake rather than flowing through tubes, and which might be why the eruption has slowed down – the vent gets clogged and acts as a drain for the denser erupted lava, which is the D in DI according to HVO and their best research.

    I guess now though if the vent is entirely covered and the lake is surfaced, if a significant flow breaks out through the middle of the lake in a few weeks or months does it count as a new eruption or a continuation of this one…


    I would like to see someone forge a knife in the lava, forging temperature is a bit hotter than lava but it could work. It would certainly be possible to heat treat in the lava, its above 700 C. Could also make a spoon so you can take it home 🙂

    • Viscous pahoehoe .. due to stress and cooling in the lava channels as well as the fountains

      The cucumber was fun .. slowly that green turd simply vanished into steamy water vapour and some cO2.
      A watermelon woud perhaps do the same .. or explode with boil pressure

      At extremely high temperatures
      1200 C in a furnace or lava lake pretty much anything organic burn No matter how wet it is. An unlucky person burns on its own if thrown submerged Into a lava lake..

      Still the watermelon woud be fun to test outside will burn If submerged and inside boils .. dry.

      Burned watermelon and grapefruits tastes horrible If the wet fruit tissues been exposed to a few 100 s of C its the sweet sugars that breaks down .. leaving a wet and very disgusting tasting mess … 🙂

    • The houses and cars and concrete that was swallowed in Leilani eruptions .. will be will protected inside the lava flows .. protected against erosion.. they coud be there for millions of years! long after humans are gone .. well packed in in Kilaūeas giant bigger than Mauna Loa future lava pile..

      But these remains will likley end up in future East Rift Zone magma chambers .. as they are buried kilometers deep by overriding lava flows. Still locking away it in rock will protect them for a very long time at least the concrete I think

      • But travel back in time and build a huge iron concrete structure .. and let Deccan Traps bury it deeply

        Very likley it woud still be there today .. 66 million years later .. protected inside the basalt rock layers

        Exposed structures dissapear instantly as example New York woud be mostly gone in only 400 years IF humans vanished

  11. Is a fascinating look at the active crater and drives home the fact that we have very gaseous lava erupting, almost like fizzing soda or whipped cream in consistency. Video by Robert Runarrson

  12. Leucitite – Melilitite lava can also be found in Nyiragongo.. another insanely rare magma produced by the very smallest ammounts of partial melting. Leucitite – Melilitite is the older products from Nyiragongo. Lavas like these are produced in their most minior ammounts by the mantle… so its extremely rare these ultrabasic foiditic extrusives. Nyiragongo is the rarest pure sillicate stratovolcano on the planet! its incredible that there is even enough partial melting to maintain large long lived lava lakes and big stoorage areras deeper.. in Nyiragongo.

    Modern Nyiragongo lavas are ultrabasic Nephelinites. Melilitite lava and Nephelinite are insanely rare on Earths surface .. and is a great must have in my rock collection. .. Nephelinites can be found in the dying stages of Rejuvenation of old Hawaiian Islands .. so its time to go to Oahu to grab a Nephelinite from young holocene tuff cones there 🙂

    • Chad is there any superalkaline magmas in Australia? I haves a complex of Ijolite intrusive complex nearby me .. Thats the plutonic form of Nephelinite.. we also haves a few superalkaline Melilititic dykes here.
      Lecucite-Melilitilite is another crazy rare magma related to Nephelinite series

      While some of these old dykes haves sillica contents as low as 30% or even below .. the magmatic liquid that was intruded Probaly was a cool viscous crystaline mush .. only somewhat above 1000 C. .. Extrusive flows are indeed insanely rare … because its produced in souch small ammounts

  13. RUV Langihryggur camera just panned over to the eastern wall, and lava is now spilling over it.

    • Was only a matter of time, maybe earlier in the eruption it would have worked longer but once that lava lake was built up in the valley there was no chance, it is downhill and the walls are just in the way now.

      I think the idea was that the walls would be indirect diversions to keep the flow into Meradalir, but now they are just dams, and as we know from Kapoho dams dont work… I think the idea was right but the effectiveness is pretty much non existent. Trying to control any of the eruptions on Reykjanes is going to be a failed effort, the eruptions are way too big, as I always say it is intensity that matters not volume and the intensity of eruptions here is almost unparalleled among basalt volcanoes.

      It is probably easy to forget Heimey was really the most ideal situation to try this diversion, viscous lava that is slow, and the direction of the town was also not necessarily preferred over the alternatives so the flow was not directed, as well as endless water and a declining eruption, even then it was a close call. If the eruption was a more fluid lava or in a different location there would be no such story to tell, or rather a very different and much more tragic one. It is that exact risk that fall on Grindavik.

      • The walls are pointless If this turns to a real fluid pahoehoe eruption.. it will just keep inflating until the pahoehoe spills over the barriers .. like in Kalapana in 1990

        If fagradalshraun areras goes off like Wolf .. then you haves a Hell of a Aa flood comming down to Grindavik and Valley becomes a rootless lava lake

        • It is pointless in any situation that sees the eruption last longer than 1 day at anything over a very low rate. The trend of the eruption in general is that of it increasing over time, it is kind of reminiscent of Nishinoshima, which went full on fire fountain from hell mode in its grand finale…

        • Would it get to Grindavik, itself, or the coastal road and then the sea? Although there may be some farms / houses on that route, too.

        • They’re not pointless as the object was to delay the lava flowing straight into Nátthagi. As far as I can see, the western berm is holding and that’s the critical one. On the eastern side there’s a small holding area before the main dive down the slope.

          • And it’s amazing how comments get out-dated in minutes… 😉

    • The construction supervisor just made a quick visit to check both walls and inspect the damage. I wonder if they’ll bother to try shoring it up any further. It seems futile at this point.

  14. The fiberoptic cable they dug in for testing purposes should be thoroughly warmed up by now…

    • I hope they publish the results of their tests, otherwise my curiosity could lead me to take a blowtorch to the telecom pit in front of my premises.

      • I trust that is not in the UK? Trying to get British Telecom to repair is could lead to a nervous breakdown and years of exclusion from the Internet! 🙂

  15. The lava river next to the dams appears to have stopped flowing and is unlikely to reach greater heights for now. The lava does not seem to be moving down the gully any distance.. It may have the effect of adding extra bulk to the dams if it cools without further significant spills,

    • Moss fires seem to indicate that lava has flowed a bit down the gully; it went quite quickly after the overspill on the right. But there is more hotter lava coming over the earthworks now.


      What are the chances of the lava making a path through the earthworks? Think if it manages that the volume going into the gully would be a lot higher.

      • More construction personnel have arrive to inspect the spill. I guess they’ll be wondering the same thing and assessing whether bulldozers can make a difference at this point.

      • If the dams stay intact, will they slow down the flow even if after the lava has buried them, or does the lava only flow near the surface anyway?

        • The lava can stay mobile at depth; but it will only flow over the top if the dams remain intact. Even with the walls in place, their positions are still the lowest points at the southern end of the valley and unless the flow from the lava plateau in the center of the field changes direction to the east and then north, the flow will continue unobstructed down the valley toward the coast.

  16. A big increase in spill at 10:20 am with lots of smoke. Lava is now obvious in the lower part of the visible gully, moving very slowly. Thinks will probably speed up quickly with the new spill. It appears to have some volume.

  17. Lava now spilling over eastern wall at 4 points. I’d say that definitely spells the end for further efforts to divert the flow from a clear run down to the coast,

    • At least 4 points; think there is another that you can’t see because the rocks on the right of the image are obscuring it.

      • Smoke from moss fires seems to indicate that the lava has now gone a long way down the gully. How far is it to Náutthagi from there?

  18. Does anyone have the link to hand for the Náutthagi webcam?

  19. It’s probably time for Iceland’s government to put in a call to Tracy Island and International Rescue…

    More seriously, why is there so much steam/gas coming out the centre of the lava field? Is there a water interaction below there? Or a deep pool of lava collecting there?
    I don’t think it can be another fissure because it is well off the fissure line.
    Answers on one side of lined A4 paper please.

    • I have been looking at that for 5 days or so – must be steam from a water source because at night there is no orange glow from that area so it is not lava or a new fissure

    • Lava is degassing. IMO and/or one of the volcanologists said a few days ago that not all the lava is coming out in the jets; most is fed by lava channels below the visible crater(s).

  20. I’m off to the supermarket to buy a large tub of popcorn.

    • You might want to get back quickly. It’s looking more like the earthworks are springing leaks.

      • Well on the way to Náutthagi now, judging by the smoke and dust on the left. Source as above.

    • Love this comment… but the stars are not working for me today… 🙂

  21. 8 minutes apart… The lava is running pretty fast down into Nátthagi

    • Looking at the webcam, I think the other dam will not last much longer.
      Oh dear.

      • I think so much is flowing down the eastern breach, it may take the pressure off.

    • Not far off the bottom of the valley in what, less than 30 minutes?

  22. Those lava falls will be reminiscent of the falls during the Fimmvörðuháls eruption.

  23. The camera whizzed around to look at the sea. It’s not that far to the road.
    With the other (intact) dam looking threated, I really wonder at the sense of the folks wandering around the ground between. I have an urge to shout: “move!” If the other dam goes, they will have to be airlifted out.

  24. If the other earth dam fails, the minions wandering about the hill between the dams may need the coastguard to lift them out of the area.

  25. Looking at the Meradalir time lapse camera sequence for this morning, the good flows peter out into one narrow surface flow, which may be itself getting less supply. It is possible that the whole lake may drain this way now. Time will tell.
    12.04 pm.

  26. The overflow is down the bottom of the slope and into the valley proper now.

  27. If you scan quickly up and down the Langihryggur N camera shots, you can see the lava level increase rapidly between the walls. I cannot see any shift – yet – in the massive lava field, so it looks to just be fresh pahoehoe flowing at present.
    But if the whole lot starts shifting, that will be a sight to behold. Lavabergs whizzing down the slope…

    Has anyone got an asbestos surfboard!? *cue Beach Boys music of your choice*

  28. Do I spy another Mildly Moist Boggy Bit, or does that dew pond have a name?

    • You mean the bit of dried clay with wheel tracks right through it? Not boggy at all, Iceland has been too dry recently for that bit of exposed clay to remain wet. But clay surrounded by gravely topsoil sure looks like wet patch though

      • I’m just amazed how fluid the lava still is this far from the vent.

        • Me too, specially considering how low the output is. I bet that the majority of it is flowing in tubes under the surface, which will then insulate it and keep it more fluid for longer

          • There was quite a buildup behind the dams. It seems the surface level there has dropped noticeably after the dams overflowed. A bit like a punctured blister.

          • Looking at the Geldingadalir webcam the lava level seems to have dropped as the overflow happened. Also videos being posted online are showing it starting to crust over.

        • Lava tubes are great insulators .. Natural furnaces
          It can flow many 100 s of km If insulated by deeply buried lava tubes

          The tube feed Rahjamundry Traps Pahoehoe flow in India is 1500 km long ..

      • Here in Sussex on the top of the South Downs, we have chalk grassland, which is traditionally used for livestock grazing as much of the landscape is too steep, or with too thin soils for arable agriculture. Dew ponds are clay-lined saucer-shaped dips in the landscape which fill up with rain or dew moisture, some man-made or improved, used for watering the livestock centuries before the advent of piped water troughs. Often in dry weather the water disappears.
        So your description is great confirmation.

        • Where sealed by puddled clay, unless livestock are on there when it rains, the drying cracks are not sealed, weeds creep in and the dew pond is no more. A lot were lost in ’76.

          • I was on local TV in 1995 restoring a dew pond that disappeared in 1976.
            My only 15 seconds of fame…up to now.
            The puddling bit is best done when the livestock themselves are used to trample all over the gradually filling pond. We used tankers to fill it and sheep to puddle.
            I have made about a dozen of them, only one failed, the dreaded running sand beat me. The sheep mixed through the clay and away the water goes every time.

  29. The lava flow into Natthagi valley may not be so disastrous. The valley is wide and flat with a depression in the middle, much like Meradalir, where the flow has been stuck in the same spot for weeks. The initial flow is fast where it is steeply downhill. When it flattens out, the flow spreads out into a wide front that moves slowly and allows the lava to cool. The cool lava at the front then acts as a dam for the new lava behind it. The lava front at Meradalir is stuck right in the area where it has to start moving uphill, and the new lava has been going into building up its depth at the start of the flat section. I expect that the lava in Natthagi will react the same way; and it will be months to years before it can get to the road, unless the lava flow rate increases significantly.

    • That is a good video.
      I wonder how long it will take to get to the NATO(!) cable?
      I expect they will bury it in a deep insulated trench. The road will be cut through, that is unavoidable now I presume.

    Nephelinite!! Nephelinite!!! Nephelinite!!! Nephelinite Nephelinite Nephelinite 😍😍😍😍
    ULTRABASIC ssshhhhhhhhh lol

    • Er……”Adventures with Crows and a Magpie”.
      Odd-looking wall!

      • Was there a Jackdaw too? I adore any corvids, so this was an unexpected pleasure to watch.

        • No just 2 crows, the one that gets closest suddenly started to approach me closer than usual about 1 month ago and now doesn’t mind sitting at 1 meter distance, but taking a peanut out of my hand is still too much. But he or she (and partner) is finally getting used to my camera, I’m making progress.

          A lot of jackdaws recognize me as well and fly along with me when walking or on the bicycle (I always carry some shelled peanuts). All the corvids in the neigbourhood recognize me by now. It’s my ‘pet’ project.

  31. I hope the people of Goma stay safe. That looks like a really big explosive eruption, and so many living near by. I hope no pyroclastic flows (or whatever the new name for them is.)
    Please watch this link it gives food for thought when compared with Iceland.

    That lava puts our Icelandic flow to shame.
    The breach happened of course, when I was busy away from my PC.
    I shall be back later after evening chores finished.

    • Lava with only 36% sillica
      The Nephelinite is let loose

  32. Nyiragongo. How interesting it may be.. If this go wrong. Many can die. So i hope that it get ok. Fingers crossed.

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