The ballad of Ballareldar: the boom and the bust

The eruption continues. There is so much hiding behind such an easy sentence. It continues – but always changes. It is not life as we know or understand it is the second most memorable phrase (at least in the paraphrased version) from Star Trek. This eruption is like that. You forget that this is actually a very small eruption, because you never know what to expect; it never does ‘more of the same’. You’ll love it, you’ll hate it, but you’ll never get bored.

At first there was the fissure which became the twin cone, slowly eradicating the valley of Geldingadalir. The fissure followed (approximately) the line of what I believe is a small pressure ridge, and ran along its peak. Just when we thought the lava would manage to escape the valley, it erupted a fissure in a much better location and the lava went straight into the valley of Meradalir, the next target on the list. The lava river was spectacular. But it turns out this was just a diversion. The fissure build a series of cones, but eventually the one closest to the original valley won the competition and exterminated the others. Now the lava was undecided, flowing in random directions, but soon found its way into the original valley – and now our favourite camera was the first real casualty of the eruption, sneakily destroyed from behind. The lava sneaked behind the original cones and continued (out of our sight) the onslaught on the escape route. This time it succeeded, and it entered a flattish area with a swampy pond, a rocky outcrop, and two exits – one north into Meradalir, and one south towards Nátthagi. It was a close call. The swamp became a lake of liquid rock, the rocky outcrop became swamped, and (perhaps hours before escaping south) a lava river developed into the Meradalir – absolutely spectacular but out of sight for all of our public cameras. We did wonder where all the Icelandic antics had gone, where were all the people who had been making a fool out of themselves in front of the lava and camera, but it turned out they were at the action we could not see, and no longer had any need to be the action themselves. And so we thought the action would repeat itself, with a new valley to fill and hopefully a new fissure to form. And so we became the fools.

What happened instead was that the victorious cone shape-shifted into a mini-Pinatubo. The change happened just after midnight on May 2nd. The tremor suddenly went through the roof, and the eruption went out – and then boomed. And went out – and again went boom. It became a ‘boom and bust’ volcano exploding into action five times or more per hour. The booms were very impressive and our Reykjavik commentators saw one particular lava geyser from their apartments and gardens. What a view it was. The boom and bust culminated two days ago when after a particular vicious boom the geyser reached 400 meters. We were quite concerned for the people watching from a nearby hill who on camera seemed to be overtaken by the flaming cloud. In reality they were well away, in front of the eruption, but they looked very small compared to the spectacle they were watching! The falling debris set fires in many places. Iceland has had a very dry spring, and the moss was defenceless against the heat of the bombs that were raining down. I am amazed that no one was hurt. After this, the eruption went back to stable effusion, though with some huge lava boats blocking the outflow channel, the lava flooded the lava flood plain and almost found its way back south. After half a day, the cone went dark again and soon the boom and bust cycle restarted.

The evolution is beautifully captured in the time lapses made by Virtual.

The big fountaining is seen here.

The lava field in Meradalir is captured by a webcam accessible at Note that it is fairly slow to load and requires a 4k screen to do it justice. On the right is a menu where you can look through the most recent set of frames. It is the kind of view that makes you want to take the next flight to Iceland.

While the volcano boomed, the lava flow seemed to remain fairly constant. There were spurts following a boom, and there were moments when the river ran a bit dry, but it did not seem that the new behaviour affected the overall lava output very much. That remains true. The lava still reached Meradalir and the edges of the flow are still expanding, but there are no major new developments down there. It suggests that te lava flow rate is still in the range 5 to 7 m3/s. It is a small but remarkably stable eruption. The effusion rate is the only thing that is stable about it.

What caused the recent change in behaviour to boom and bust? There are two clues. One is that this is in fact normal behaviour for eruptions, just normally on a time scale of months to years (or longer) rather than hours. You do have to understand this volcano. It has been bottled up for the past 800 years, and now it is like a hyperactive child in the morning wanting to pack in all the playtime it has been missing into this one eruption, and needing to get rid of a lot of energy. This is the Calvin eruption. The second clue is that change in activity was picked up in the tremor plots. They became very noisy just before the boom started, and in the day when it went back to normal behaviour, the tremor charts also calmed down, before resuming its noisy trend.

What makes a tremor chart noisy? There are two main reasons. (Actually four, but I will ignore the third one, windy weather, and the fourth, human activity.) The first is a swarm of small earthquakes, as happens when magma breaks through rock. Such tremor can precede an eruption. The second one is turbulence. Magma flowing through a conduit is actually remarkably silent. The flow is laminar (like honey) and it flows fast in the middle but very slow at the edges. So there is not much friction with the rock, and it is that friction which can generate noise. Just before an eruption, tremor charts can go quiet. This happens when the conduit is ready and fully filled, and all that remains is cracking open the surface. It is the silence before the lava storm. A full conduit is silent.

But what if the conduit is only partly filled? In that cases it is interacting not with rock but with gas, and that can be noisy. Think intestines after a good lunch, with lots of gurgling showing the gas-rich passage of the much appreciated food. Lava is in effect digested rock (life – but not as we know it), and it too produces gas. Magma can become frothy, filled with small gas bubbles. As the magma rises and the pressure decreases, more gas comes out of the liquid and the bubbles can multiply. Tremor charts pick this up as a continuous background.

In most eruptions, the lava is exposed to the open air, and this allows the gas to escape. This is the sulfur smell of volcanoes. If nothing else convinces you, the smell is the final warning of a volcano that says ‘danger – stay away’. (Current evidence suggest this doesn’t work on Icelandic people who seem to be attracted to the heat of lava as moths are to light.)

But sometimes the gas can’t get out. In that case, the pressure on the gas can rise and rise until finally not even thick rock can contain it. Once the lid breaks, the gas comes out and the pressure inside drops instantly, This forces the remaining volatiles in the magma to turn to gas, they expand their volume 1000 times and what started as a break-out attempt turns into a full-blown explosion. The mountain goes boom, and a Pinatubo is born. From Vesuvius to Tambora, this is one of the main ways volcanoes explode (the second way is flank collapse).

Eruptions can enter a late phase where this kind of behaviour becomes repetitive. Agung did this a few years ago. It erupted explosively, then the lava began to flow but only in the crater. A lava lake developed. As the eruption tapered down, the lava lake developed a crust and this became eventually too thick for the magma below to break through. Kilauea’s lava lake should soon enter this phase. But there is still gas below, and it can no longer get out. So it builds up underneath the crust. Eventually it breaks the crust and blows, and the volcano has a late eruption, which may be months (or more) after the main event had ended. Agung did this after its recent activity, and it had done the same (but more powerfully) after the 1963 eruption. It is also a risk at Kilauea, when the current eruption ends. Even though an explosion down its 200 meter deep hole may be well contained, rocks can fly far. You have been warned.

Let’s go back to the Reykjanes eruption. For now we can make a guess on why it went boom and bust, and why it temporarily went back to steady growth.

The tremor shows that there was gas underground which could not get out. At the same time, the lava glow in the cone had gone dark. Where had it gone?

It seems that the lava had retreated below a lid. A crust had solidified, and the magma was suddenly caught below it. Iceland had tried to put the Reykjanes genie back in the bottle. Calvin did not take kindly to this. The internal pressure build up, as gas collected below the lid. After a while (10 minutes or so) it overcame the lid and the kid exploded back on the scene. The exploding gas took the lava with it, in a tall red geyser. After the geyser, the remaining gas bubbled out causing a phase of turbulent lava flow in the cone. But the lava itself lacked sufficient pressure to make this permanent, and once all the gas had gone the lava retreated, waiting for the next cycle.

Why did it change after the massive explosion? That explosion happened after a collapse of the walls of the cone. Two things may have happened. First, the rubble may have blocked the exit even more than it already was, and in consequence the gas pressure build up higher before it could overcome the weight. Second, the collapse cracked the lid and provided a hole which triggered the eruption, but the hole it made was very narrow. In either case, it made quite an entrance. The geyser went hundreds of meters tall, aided by the narrow nozzle (we know the opening was narrow for this eruption because the lava geyser was well focussed: the width of a jet is closely related to the size of the exit hole).

But this explosion was big enough to do real damage to the plumbing of the volcano. The back pressure wave moved through the magma conduit, and was big enough to even force out a bit of magma from the original cone – which had been dead for weeks. The zombie apocalypse produced a small lava flow. The fact that one cone could damage another shows that the fissure is fed by a single conduit, by the way. If each cone had its own conduits to the dike, then the pressure wave could not easily find its way to the other cones.

Now two things may have happened which changed the shape of the eruption to strong and stable. (The UK does not like stability, by the way. The last prime minister going to the polls on a record of ‘strong and stable’ lost her job. The current incumbent is about as unstable as they come, and has two clear election victories as reward. Life in the UK is an adventure. But back to Iceland.) The pressure wave may have pushed open the feeder channel and increased the magma flow to the cone: the flow rate increased enough for the magma to stay above the obstructing lid in the cone. Or perhaps somewhere, perhaps through the zombie cone or through the side of the active cone, a crack was formed in the rock which allowed the gas to escape.

The phase of stable eruption did not last long. Either the crack closed again (a 5-cm wide crack filled with lava could solidify in half a day), or the feeder conduit narrowed again and the magma flow went back to the old level. Gas began to collect again below the lid, and boom and bust restarted. Volcanoes will not be denied.

So this is my guess on what happened. It is speculation!

What will happen next? I can safely predict that something will happen. The tremor charts show that the tremor has steadily (linear, in fact) increased since May 2nd. The current phase of instability is itself unstable. It is heading for another change. The only uncertainty is what change it will go for.

Perhaps the cone will collapse (it is looking pretty unstable already). Perhaps a new fissure will open. Perhaps the eruption will end. Perhaps it will pretend to end while in fact preparing for bigger boom. Or perhaps it will fool me and the current phase will last weeks, with fountains visible from Reykjavik. Or perhaps Hekla will blow. Predictions are best made in hindsight.

But this volcano has become much more dangerous to sight seeers. The warning signs are clear.

Albert, May 2021

357 thoughts on “The ballad of Ballareldar: the boom and the bust

  1. We all know that a normal basalt can with time evolve into a ryholite
    For normal non alkaline melts

    The Extremely most alkaline version of Ryholites and Dacites are a Phonolitic Melt
    Is Tephrites, Basanites and Nephelinites “the parent” of a Phonolite melt?
    What woud happen if you let an ultrabasic nephelinite evolve over a long time? woud it turn into a Phonolitic Melt?

    Mount Erebus is saied to have basanite as parent melt of its hot Phonolite

    • If it takes really small levels of melting to make nephelinite it might not be possible to have an evolved magma starting there. A lot of rhyolite provinces are underlain by very hot basaltic systems that have massive levels of partial melting, both Yellowstone and TVZ are bimodal rhyolite and tholeiite basalt. Rhyolite has a very high heat capacity, it can be eruptible at 700 C but still requires the massive heat source at all times. Its quite strange that most sources try to separate basalt abd rhyolite, in real life they are closely related.

      • You can see that as you drive up the Snake River Plain to Yellowstone. Right before you start to climb into the Island Park caldera (Mesa Falls caldera) you can see row after row of basaltic cinder cones off to the west interspersed with basaltic shield volcanoes. I once saw a drill core record from the area, and it shows hundreds of meters of rhyolite and basalt flows layering over each other.

        Side note, one of those cinder cones has gem quality feldspar phenocrysts as well as granitic xenoliths in the basalt scoria. The biggest feldspar I found was about 4 cm by 2 cm. Shows you something interesting was going on down in the crust.

    • Yes Nephelinite is a product of the most minimal of mantle melting much less then 1% melting of the mantle pedriotite!

      Nephelinites are generated in way too small ammounts to give rise to large evolved chambers of its evolved equalent And too small ammounts to heat larger chambers of stale magma.

      Its also why Nephelinitic volcanism is extraodinary rare and its volcanoes are limited to monogenetic scoria cones and maars. Limited to mostly monogenetic Rift volcanism and on Some oceanic Islands. Nephelinite is a rare rock

      Chad= But Nyiragongo is exceptional!
      For being a Nephelinite volcano.
      Nyiragongo must be the largest Nephelinite system on the planet! Its incredible despite the insanely low melt supply that Nyiragongo often hosts large lava lakes. The size of the deep Nephelinite resovair 50 km under Nyiragongo is estimated to be over 50 km3 .. Thats then supplys a small edifice magma chamber and a smaller crustal. Magma supply rising rates must be quite fast to account for little cooling in Nyiragongo and 2003 lava lake being crystal free

      The Subtropical Island of Bermuda haves also insanely Sillica undersaturated magmatic rocks, Some with sillica contents as low as 30% termed them “Bermudites” Nephelinites are also found there. Bermuda started off with
      thoelite basalt .. But as the Hotspot Died it started to produce nephelinites

  2. While it is fascinating to see a new volcano’s birth I tend to do some excursions from that barren landscape up there not too far from the pole and read equatorial stuff on VC. So I had to come across this fine piece by Carl at some point:

    Completely undermonitored until today. So I wouldn’t be surprized if some missing volcanic boom and bust for the time before the Portuguese decided to look what’s beyond the disk’s border, mainly before Diogo Cao, hides here.

    • It was certainly tephra yesterday on the MBL cam. Today the temp is around 7C so unlikely to be snow.
      These bits don’t look very snow-shaped to me:

  3. Pretty pictures. Katla has some snow and will have most on Friday. One forecast predicts also snow for Reykjanes, but for Friday. I will read about Bali next. Cold spring altogether.

  4. Outbursts are more frequent today: about every five minutes, lasting for two minutes. The fountains look a little lower: more lava and less gas perhaps?

  5. Wednesday
    12.05.2021 15:47:32 64.622 -17.459 5.5 km 3.5 99.0 3.8 km ESE of Bárðarbunga
    12.05.2021 15:45:32 64.621 -17.428 4.5 km 2.8 99.0 5.2 km ESE of Bárðarbunga

    • It’s been quite a long time since the last large quake there. Expect something like an M4.8 or larger to happen there soon.

    • “Slaughterhouse for drones” hahahahaaaa
      Every time these icelanders crush the tephra I’m thinking noooo please send it to me wrapped in cotton wool!

      And that last drone sequence of views, full screen, are extraordinary. Great angles, seeing the lava sloshing and pushing the darker skinning lava downstream, the surges out of the vent, the fountaining spatter turning into a full spraypaint coating on the side of the cone. Looking downriver, there are several narrower parts; difficult to see what the gradient is for these bits in the dark. But it’s quite spectacular, and mesmerising.

    • Thanks for pointing this out. The Þorbjörn cam didn’t deliver useful images during all that snow storms, but is finally back with interesting pictures:

      I admit that I changed the contrast.

    • Yep. it’s also visible in the Slaga Natthagi webcam too.

    • Second night in a row that it’s picked up just before midnight. We’ll await the morning with interest.

  6. Another aspect that interests me: how much longer until Northi and Southi (aka Smeagol and Gollum, or Bob) are completely buried under the ejecta?

    Going back to the old videos from March it is amazing to see how much they were towering over the people that thronged around them. Now they nearly disappeared among the ejecta and lava flows that are coming their way. A clear example that being first doesn’t mean you’ll be the winner in the end…

    • Probably not long, maybe a month before the neighboring cones are buried enough to be unrecognisable. I do expect the lava flow to change directions at some point though as the cone grows, all it would take is a piece of it to land in the narrow channel near the vent and the flows could go anywhere.

  7. On the RUV Langihryggur camera, there is bright glow at what appears to be the western edge of the Geldingadalir flow field. Most likely just a breakout, as I can see numerous other breakouts in the eastbound flow as well and flow volume looks like it might be up a bit.

    There doesn’t appear to be any other camera pointed more directly at it at the moment.

    • Do you mean where the original path to the eruption went? There seem to be a lot of breakouts, helping the idea that there are lava tubes supplying frresh magma to the periphery. The million dollar question is, are they all from Fissure 5s, or are there active tubes still supplying lava from other vents?

      • Heat maps show no sign of any of the other cones. Heat is all channeled through the capital cone.

  8. Well, tonight we may see another of the webcams get incinerated:

    The main channel has sprung a leak close to the cone. At the moment the flow is slowly advancing towards the webcam. If the supply remains steady and doesn’t solidify, it’ll get hot around the webcam soon…

    • Hmmm…. Yeah… They may run into some problems with their warranty from Samsung by now 🙂

      • I bet the warranty includes a statement like “do not leave camera in the path of an advancing lava flow or the warranty will be null and void”.

        Also, often the company wants to analyze the broken camera to figure out what went wrong / what broke. Good luck recovering the semi molten camera from underneath the flow…

        • But what marketing value there is for them in these streams, though…

          “The camera that goes where you can’t.”

    • I have been wondering when that would happen, there was/is a tall “riverbank” right where the outflow took a sharp turn, which kept getting splashed. It was only a matter of time before that little damn broke

  9. Aww! I thought I had lost my little puffy fumerole… but NO! It is glowing and has a pulse! (Check just above the )—volcano/

    It’s 3.06 here in the UK and thanks to dog wanting an out (She’s got a sore paw with claw missing so is confined to barracks) Lack of long walkies and runs , her sleep patterns have gone askew rather like our volcano, so here I am with an early Coffee # 1 and time to read, watch and inwardly digest.
    Thank you Albert for the entertaining resume of the Saga so far. I go with your explanations for changes in behaviour and agree that the area is not a place to take your kids for a Sunday picnic , It could turn out to be a BBQ in Valhalla for some poor souls.
    This early morning there are still the miniscule , white moving lights of humanity on the nearby hills. These should be from official and scientific watchers and potential rescuers but I fear some may not be.
    Like the pandemic , this eruption is certainly showing how human behaviours change in the face of changes to their normal habitat.
    Yes! it is a small eruption, but it certainly is proving to be a thought provoking experience for us long distance watchers . Thankfully we are, so far, not experiencing that awful knowledge that others are in serious danger. I sincerely hope this is not a change we will will have to watch. My admiration goes to the Icelandic officers who are on continuous watch to keep lives as safe as possible.
    To quote Mr Pepys, a past (1633 – 1703) , unusually stable and balanced, member of Parliament in the UK. after writing his daily observations……….”And so to bed”
    Thank you Albert . I am looking forward to the next verse of The Ballad.

    • YES! Your’s is the little fumerol that could! We don’t know how long this will last but it’s beginning to be “interesting”. And to tell the truth: watching from a distance gives us the advantage of the big picture without breathing all that stuff in… 🙂 and we can skip all around the volcano without having to actually trek all the way . Sure enjoying watching this “mostly harmless” past time. Sorry for Your dog…. Hugs, Best!mots

      • Thanks Mots. No need to be sorry for Poppy…She’s a born survivor. She’s the most expensive rescued Mutt ever! Two incidents involving Roe deer antlers (She was bred to hunt deer. Greyhound x Bullmastiff) and countless other injuries to her anatomy as she tends to barge through any obstacle between her and “the quarry” (Mostly Squirrels)The only thing she is afraid of is warm soapy water! She is , despite her huge size , one of the most gentle, obedient and patient dogs we have had, but being a sandwich short of a picnic she doesn’t learn by her mistakes and like any sight hound….if it moves… it! Good job we don’t have bears here and that she has been well trained on and off the leash. The deer incidents happened at night so we now take huge care before letting her run,..even got collars with flashing LED lights so we and the deer can see her ! No animals have been injured (apart from Poppy) in the walking of this dog. Keep well and safe Mots

  10. Looks like that little lava outbreak has run its course and is cooling / solidifying now.

    Maybe that little webcam will be spared and can serve us a bit longer…

    • The camera is apparently about half a kilometer back away from the vent. So not in immediate danger, although it looks to be so because of the zoom.

    • Yup! It says it’s a real hot piece of real estate! I wonder what the insurance of this property would cost in terms of Public liability!

      • Hopefully the Icelanders will let their own make a little profit instead of any megacorporations.

  11. Not sure how many VC viewers are in Iceland but I made this to give a rough idea of what a full scale fissure eruption would look like. View from Hafnarfjordur, based on location of the Kapelluhraun (1152?) eruption, which was the closest historical eruption to Reykjavik itself during the Reykjanes fires.

    Basically if this happens there will be no mistaking the eruption for anything else, it will look like a portal to hell has opened…

      • Well. It looks pretty real. And this is certainly a thought I’ve had for the past weeks. What if… and how will til look from my home (Álftanes). I remember laughing out loud when the possibility of Reykjaneseldar was mentioned, that it was time for a new eruption period. It seemed so far away. And I am not the only one saying that we are looking at the mountain view every morning with a different feeling. The “what if’s” are quite many. And the quakes around Eiturhóll are not making us feel better. I even drive by Hengill and over Hellisheiði with a suspicious feeling.

        Although we Icelanders are used to nature giving us surprises, we are not used to volcanoes erupting in our backyard, at least not us living here in the Capital region.

  12. The main expansion of the lava fields in the last three days has been in the valley named ‘valley-without-name’, and in Geldingadalir. The lava still gets into Meradalir but the lava there is not expanding. I would interpret this as the lava not getting as far as before and staying close to the eruption site. If true, there are many possible explanations. The effusion rate may be less (less lava means faster cooling). The lava may be erupting with a lower temperature or more viscosity. Or the channel that goes into Meradalir is becoming obstructed. My favourite explanation is that much of the erupted lava ends up in a lake well below the surface of the older lava. But that also is guess work.

    • That would explain the existence of my little, pulsing fumarole (and probably many others). I too wondered if there was a mass of lava below the surface. The pooling of lava below would also explain the breakout of lava at the South end of the Upper Natthagi valley.

    • I got the impression that the nameless valley isn’t actually nameless. One of the land owners said in an interview that it is part of Meradalir. Meradalir is in plural form, so it makes sense that it’s made up of several connected valleys. But I guess the name Nameless valley has stuck by now.

    • Would lean towards a combination of the last two, the channel is frequently obstructed by lava boats and lava is still flowing in Geldingadalir even though theres no active vents in it on the surface. If it decreased there would be decrease in SO2 and probably also a noticeable effect on the eruption itself, like less frequent and smaller fountains, but that isnt observed. Not sure how to safely measure the lava temperature and viscosity in the crater itself, it looks pretty much the same to me as it has all week though.

    • AS the old lava degasses and shrinks, I’ve seen many cracks and voids open up. I think the next lot of lava has to fill up all these spaces before it can make any more progress at the edges. If there are intact tube systems within the lava fields, then the lava can get to the edge much faster and more efficiently.

      I watched this play out in the early days of the eruption; periods of super-fast spreading of lava over new land, then days or weeks of slow filling up/inflation of the existing field before new areas are reached.

    • Gutn Tog new video is focused on the lava flow towards the ocean
      along the Natthagi trail to the RagNar overlook ..
      Lots of close ups of the lava flow and general terrain ..

      • Crazy how the chunks of tephra disintegrate when he picks them up. Must be really gassy stuff.

  13. This is part of one fo the Meraldalir frames this morning (webcam_meradalahnukurSSV_20210513_1150.jpeg). Question: what is it? Waterspout? (ok – no water involved) Lavadevil? snownado?

      • You can see similar in the smoke from moss fires to the right of the crater in the background at around 12:31:50.

        Same YouTube link as above

    • Cold air funnel. kinda like a weak tornado, only caused by cold air descending, not warm air rising.

        • you are correct, I’m guilty of a little oversimplification. My point was, something similar to a weak tornado could form in a colder environment (with some warm air from the eruption), and not need massive, warm updrafts like in a tornado-producing super cell.

          • Was a low-toppped supercell situated over the eruption site?

      • Here in California, we are all too familiar with surface-driven tornadoes….and they are not to be underestimated.
        During the infamous CARR fire in 2018, the long-lived firenado reached F4 in intensity (>140mph windspeed) as it triggered a convective cell that topped out near 50,000′ over the Redding area….certainly not a simple “swirl” as with a dust devil (actually an “eddy” that forms in response to a horizontal airflow over a hot surface).
        The firenado as well as these in Iceland are being caused by an ascending plume of heat….which in turn sets up downdrafts away from the core.

    • A dust devil or landspout. Dust devils can be very tall and rise all the way to the clouds, but if they connect I guess they would be termed a landspout, a weak one. It is certainly not a tornado though, no supercell.

      • It is possible though, that under the right conditions a rotating updraft like this can indeed form towering supercells/pyrocumulus (technically cumulonimbus flammagenitus).
        Here’s a link showing the PyroCB that was part of the F4 firenado that ravaged west Redding. Nothing weak or insignifiant here….this storm produced a full-blown twister…and it was caused by a blob of ascending air not unlike what happening in Iceland.

    • i’m glad this was finally caught… i’ve observed this many times at just that point… happens frequently but hard to see.

    • This connects very nicely with the glowing balls and transforming into columns that I saw issuing from the lava stream next to the hill. The lava tornadoes come in different sizes. The ones I saw were small, but moved upward as a column very quickly.

  14. Given the encroachment of the lava fields, I wonder how long before Theatre Hill is off limits

    • From GutnTog:

      “Second eruption after the volcano wall collapsed 10 minutes earlier. It had been very chaotic with massive outflow as you see. Volcano wall crashed just before. It broke off and slided I to the crater. This happened around 2 pm in the afternoon.”

  15. Well, well, well. Apparently the webcam was relocated to a safer distance from the eruption. Looks like the operators didn’t like last nights nail-biter if the advancing lava front would swallow up another of their webcams (which I fully understand).

    • Hooray for it being moved, but we seem to have a plethora of webcams at this location. I make it 3?

      Wouldn’t a better location be in the main Meradalir valley? They missed a trick there.

    • Indeed, the view has switched back to the area close to the eruption. Must have been a short term diversion of the signal only and not a physical move of the camera.

      I like this close up view better for sure, even if it means more risk for the ‘life’ of the webcam.

  16. The flows at the southeast corner of the Mildly Moist Boggy Bit have been a great watch today.
    The chat on Tokolosh’s stream says that the heavy engineering mob are ready to go as soon as the word is given, to attempt an earthwork to keep the flow going to Meradalir, not Natthagi.

    Whatever happens, it will be a fascinating show. Pretty please could we have a nice timelapse?

    • I can’t stop watching today’s sequence on this webcam.

      It’s as if the fluid lava is undermining the existing flow in a similar fashion to meltwater within a glacier. As the blocky lava gives way and is carried forward onto the fluid flow, more space is created behind and yet more fluid lava spreads out into the gaps. From about 4.30pm the effect ripples backwards a huge distance into the lavafield. Which process is the driver, is it the pulling or pushing first? Or a combination of the two? Or is it just weight and gravity?

      • Don’t knowm but if you scroll back on the RUV Langrihryggur camera, there is a sudden surge/breakout.

      • The first outbreak on the sequence seems to occur at the same time as one of the fountains, but it could be coincidence.

      • Yup, that’s the camera photos I linked in the top post.
        The fluid lava beaks out of the middle, spreads like a fan in all possible directions, and sets off collapses in sequence around the corner at the front of the flow. At a point in the middle of the snowstorm, the whole front starts collapsing outwards almost pulling the lava bocks behind, and more lava flows into the space made. It reminds me so much of the glaciers calving in the film Breaking Ice.

    • Judging by the rate the MMBB is filling I doubt that they have that much time left to erect any earthworks. In the last couple of hours it has been epic to watch. Also I would suggest that the average height in that area has dropped following all the movement of the existing lava and as a result this would naturally cause a natural change in the direction of flow of the main lava river from the crater to the lower void to take it’s place. It might happen quickly than expected.

      • I would agree. The change today is massive. At the current rate, it may go into the valley within one or two days. Of course, the lava may find an easy way into Meradalir again and stop feeding this area. Nothing is guaranteed. but things are moving fast

      • Shows you how much of the lava flow is still liquid inside, under the crust. Makes it easier for the new lava from the crater to supply the advance at the front of flow.

        If the engineers don’t get the ‘go ahead’ soon, it’ll be too late to prevent the escape into Natthagi valley.

      • Yep, and they probably need 2 earthworks, judging by the topo map

    • Albert have you seen these?
      Silver smooth splashing lava rivers are reserved for the most fluid of all basaltic lavas on the planet.
      Chad coud be correct with close to 1300 C when its as smooth as this.. smooth shiney means little cooling as well as little crystals and very low viscosity

  17. 3 timelapses from yesterday and today:

    The close up camera by from about midnight to noon:
    (pretty clear now that the tilted horizon is actually just the fisheye of the lens)

    The overview camera from about 20h to 6h30 (lovely as always)

    And the Langihryggur view from RUV between 21h30 and 7h20:

    All of them 1 second = 3 minutes.

    And now I have a question for people who undersatnd Icelandic.
    On the mbl website this is written:”. from the eruption in Geldingadalur in Reykjanes”.”
    Next sentence: “from the eruption in Geldingadalir…..”

    What is it? Geldingadlir or Geldingadalur?

    By the way, I tried to capture the RUV Geldingadalir camera yesterday but that turned out to be close to impossible with so many partial dropouts that I gave up trying to make something decent from it.

    Also I am really tired (burnt out) of keeping up and though my own curiosity and friendly comments keeps me going on, I will get less regular with this.
    I do have mixed feelings about it, because I also think it is a tremendous archive so far and I’d like to have it complete, but obviously I can’t doing this for years.

    • The timelapses are beautiful but a lot of work. We will happily encourage you but don’t want anyone to get burned out! Take care of yourself. Volcanoes can take over your life.

      I can only guess at Icelandic! (In fact it is also written as Geldingdalur.) I believe that dalur is singular and dalir is plural: Meradalir and Geldingadalir are both several connected valleys. But please correct me. I have used both names..

    • “Geldingadalir” is plural of “Geldingadalur”. I think the former is the correct name, in the plural form, “the valleys of geldings”. But people keep mixing it up all the time.

      • Here is a map from before the eruption started, marking both Geldingadalir and Meradalir in plural.

        • That’s a great map; it shows the drainage patterns in finer detail than I’ve seen elsewhere. I presume most of the small streams are ephemeral seasonal streams that only flow at certain times of the year? We have those in Sussex, usually called bournes; for example, the Winterbourne in Lewes.

    • Thank you for all your wonderful videos Virtual. They are a fantastic effort and much appreciated. But you must look after yourself. Please stop if it is too much, and please don’t feel there is any pressure from us for you to continue. We don’t want your health to suffer, physical or mental or both. Take care of yourself.

  18. I don’t think this video has been posted here before. If it has I apologize for re-posting. Anyway, it’s a daytime drone giving a great overview.

  19. Amazing and beautiful video of ongoing eruption. No doubt Gutn Tog is doing important work that illuminates what we can’t be there to see for ourselves, right? But the instability of his videos (read: shaky and sometimes nauseating) makes me want to ask, should we take up donations to help him afford a stabilized rig?

    If enough are interested, I would be willing to contact him and find out the cost and press forward with an appropriate funding mechanism (GoFundMe ?).

    • A muffler for the wind noise on his mike would be good for the ears too… I’d happily donate.

    • Sadly, I can usually only watch a minute or less of these videos – too bad, as the pictures themselves are amazing!

    • It could be a matter of carrying weight. He mentioned in one that he was using his wife’s phone and had left his camera at home. While stabilisers would be good, it would add to the amount of weigtht being carried. I know from experience, carrying camera gear can be tiring.

  20. It looks like the lava river has disintegrated and retreated closer to the vent, transforming the entire lava field into a massive rootless lava lake, its reminiscent of the one that formed early in the eruption in Geldingadalir but way bigger. I say the chance of lava flowing into Natthagi is very high now, but maybe not for it to flow all the way down it into the ocean, not yet anyway.

    Its really incredible how big the new cone is now, Bob is tiny next to it, actually you could probably fit all of the other cones within the crater or Ragnar.

    • I notice that Bob twins are getting spatter. It won’t be long until they start getting buried.

    • Wolf 2015 was probaly just as fast near the vent .. crazy it was .. 2015 only Mauna Loa 1950 was a more Impressive effusive eruption in speed.

      But yes 2020 – 2021 halemaumau flowed quick indeed

      • Only real difference is that this fountain was just a single vent really, where Wolf was a fissure about 1 km long with this sort of rate, the fountains were tall because of higher gas content I think. Mauna Loa at least in I would say is a lot bigger definitively, the entire fissure was actually open at the same time, all 20 km of it, fountaining to 150-200 meters. On that first day it was probably just as intense and voluminous as Laki, which in reality was a lot more like the eruption at Kilauea in 2018 scaled up than it was a proper curtain of fire.
        I expect most of the really big Icelandic eruptions are a lot more prolonged and less visually intense than the popular view, where it is the duration of the eruption that gives the volume rather than an extreme intensity. That being said Laki did have two vents that had 700 meter fountains. I think the fabled 1500 meter fountain though was an illuminated eruption column, or an early plinian stage where the water table was involved, not an effusive fountain.

    • They started working on building an obstruction during the night. The people of Grindavík were getting anxious. Anyway, it’s still under construction, we´ll see how it goes.

      • So the light on the camera was the building work. It is an interesting experiment

        • RUV Langi-cam has panned left so you can see the drop into Natthagi, the lava is very close. There are some vehicles there, if they are constructing something they are very casual about it…

          • Zooming now, one digger has made a small earth berm.

          • exercise in futility…. Movie material for sure. Or a padded cell. i don’t mean to be unkind but do they have a clue? nuts …. just nuts.

          • Might slow it down for half an hour. Lava goes where it pleases, we get out of way.

          • At least two pieces of equipment currently at work ..
            Looks like a dozer and a backhoe ..
            At the extreme left edge of the lava flow in this view ..

  21. The Icelandic “Tommy Lee Jones” has started building his berm. Will it be as effective as concrete blocks?
    From the pictures on the Slaga cam in the early hours they almost missed their chance!

  22. I don’t think they brought any elfandsafety. One guy appears to be climbing on the flow!

  23. 10.05 MBL’s close-up cam, there’s a small but continuous leak of what looks like fresh lava to the left of the main vent exit. I watched it right up to the next fountaining episode & it was still visible afterwards. Something new? Or just something we couldn’t see before?

    • I’ve been watching that small flow as well. I think there is lava pooling somewhere behind the left part of the cone and it slowly flows back to the vent after fountaining.

    • I’ve had a good lookat this, the flow is persisting after each fountaining episode,right up through lunchtime. I had a look at the Gewldingadalir webcam from the other side, and it looks as if the fountaining is reaching through the collapsed flank gap, and has built up a bit of a hump there, before the lava flows away to the southwest in front of the old Fissure 1/Bob twins/Gollum-Smeagol vent.
      So I think that persistent flow is some drain-back from the shallower slope of the flank opening, back into the main vent.

      Or I could be totally wrong and it’s a little tube leaking lava!

    • Let’s see. It was tried in Heimaey but the lava pushed the wall out of the way. (Later, water cooling of the lava did work but that was when the eruption was already ending.) In Paoha, Hawai’i, one or two house owners managed to divert lava from their property towards the neighbours (with all kinds of liability issues, I expect), but again the lava was already reaching the end of its flow. This may work if over the next day or two the lava decides to go somewhere else where it is more welcome. But yesterday the onslaught seemed pretty unstoppable.

      • The people who live in harms way will try, it is worth a try.
        I hope they can do it.
        Failure is loss of everything that can not be carted away after all.
        If lava was threatening my village I would expect effort from the authority’s.
        If lava was threatening where I was born, Wythenshawe I would hope the authority’s leave it to cover the place…start afresh!
        I take it you know the place I refer to Albert.

      • I think it is wrong to think that you can stop a lava flow.

        The best you can do is to give it an option to take another route.
        Lava will have to go somewhere, due the high viscosity the easiest route might not he the preferred route.

        Given the location they are digging I tought they would create a channel to guide the flow the shortest route to the sea.

        What I would study is how to stock it to harvest the heat, could be an interesting source of energy.
        If they want me to pull such a study, contact me.

        • They don’t want the flow to reach the sea. It would cut off the road and you can’t build a bridge over lava flows so the whole idea is to build a 4 meter high obstruction, hoping it’s high enough. It’s based on the idea that lava never flows uphill.

          • “It’s based on the idea that lava never flows uphill.”

            Yeah. Minor, tiny problem with that idea. Lava does NOT flow uphill per se. However what it DOES do is fill in the previous downhill bits so that previous uphill bits become downhill!

            Those who propose berms and other such “obstacles” don’t seem to comprehend this issue. The berms they would have to build to be effective would be so big as to be the size of natural hills. They simply cannot move that much material around fast enough to do any good.

        • To reach the sea We needs a lava tube .. to insulate better.. and we wont form and tubes with episodic high fountaining..

          Eruption needs to change caracther to form tubes .. we needs something like Kupainaha 1986 – 1992 or Erta Ale 2017 – 2019 for the lava to reach the ocean

          • Actually it can probably reach the sea the way it is, maybe not right now but if the fountains become more intermitent the effusion rate will get higher. The overall effusion rate also seems to be getting higher over time in general as the conduit gets bigger and more efficient, there is probably an upper limit and its not going to be enormous but probably the limit is still higher than it is at present. Lanzarote was 30 m3/s on average, which is about twice the value we see, and that lasted 6 years at that rate.

            If a total of 5 km3 is erupted and the effusion rate doubles every 2 months more or less the eruption will last around 15 months and be blasting like nothing we have ever seen before, doing fully half of that total, 3 km3, in that final month before suddenly stopping, like an Etna eruption that lasts a month non stop 🙂
            In that very unlikely but exiting situation though the vent will be so wide it stays open as a portal to the mantle, slowly leaking lava maybe for years as a shield until it freezes up or clogs with crystals.

            In reality I dont think this eruption will ever go above 50 m3/s sustained, but that is still enough to send lava a long way, certainly all the way to the ocean, or into Grindavik if the lava manages to overtop Fagradalsfjall down the line.

      • In Kapoho it didnt work at all, i guess the situation here is different as the lava already has a viable exit but lava also creates its own terrain so possibly the once lower outlet to north has been elevated and is higher than the outlet to natthagi now. Its going to be inevitable the lava will flow this way unless the eruption stops I think. Really Grindavik is at risk too, 10 km away, flows from Pu’u O’o often went that far and in only hours at times…

        I guess in all fairness though Kapoho was a much bigger flow, at times comparable to Holuhraun, and the area probably had been flooded by lava at least twice in the last 1000 years. It must be an important location in pre-contact times as most places at high risk of destruction by eruption were uninhabited for obvious reasons, building houses on rift zones is a last 100 years thing…

    • I have tried to see the berm works on the Slagi NNA webcam photos, but cannot distinguish anything even at full zoom on my new computer’s snipping tool. It appears that the level of the lava behind is obscuring anything in front. I’m surprised not to see even a hint of paler pixels to indicate the machinery, unless there is another slight rise obscuring it from view.

      • Seems to be one vehicle visible on the 13:47 photo.
        I think the clouds of steam rising during the snow indicate how fresh the lava next to the berm is.
        How soon will it push through? 12 hours?

  24. So here we go….THE WALL…but I think there is actualy a basin…they dig with an excavator. If I were to choose I rather use a bulldozer. Digging is hazardous…lava is near and could pass over new pool instead of cooling. If is to work with bulldozer is faster and could make a good dam easy.

    • A roller or other compactor would be beneficial as it would increase the density of the wall material, thus reducing the likelyhood that lava will just go beneath and lift it up.

      The bulldozer is also quite heavy, but the best way would be to let the bulldozer keep piling up the material and have a roller compact it down.

      • That’s the idea…anyway I saw last week maybe..somehow natural buldozing efect of lava …just working against..

    • Given the scale and the forces involved ..
      It sure looks like a case of too little and too late ..
      Any attempt at constructing a diversionary earthworks should have begun weeks ago ..
      Wasn’t this tried with some success on the slopes of Mt. Etna ??

      • So the emergency way: explosives on the saddle betwen this valley and former meradalir exit. Like in winter emergencies when over big river the ice build up natural dams. Now, the Meradalir exit is clogged somehow because is at lower lever that nathangy exit but didnt darin properly…

  25. And on a secong thought maybe was better just to throw some explosive and open up this way the meradalir exit chanel, lava will tend to go on easiest path right?

  26. Soon Gollum / Smeagol vent complex will be gone buried by tephra Spatter

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