The Reykjanes update

It is now three days after the start of the Reykjanes eruption. What is the state?

The flow field is slowly expanding, and is thickening. It remains a touristy eruption, but tourism is up and down. Initially it was discouraged as events were still unfolding. On Sunday they came in large groups; our local correspondent commented that half of Reykjavik wanted to come. That caused some problems. The ridge next to the cones were popular, but evacuated around mid-day. In hindsight just in time as a little later a significant collapse of the cone pushed a lava surge in that direction. A video of the event shows it nicely. The ridge is now close to being surrounded by the lava.

Some people got in trouble last night when the weather deteriorated and they got lost and cold on the 2-hour cross-country walk back. Today the weather was atrocious, and measurements indicated that gas concentrations close up to the lava reached dangerous levels – presumably that was true the previous day as well.

Lisabet, our local correspondent, send some very impressive photos and made many commenters feeling very envious. Click on the image for the full resolution.

The eruption is now concentrated in three cones. The dominant one had the collapse (and may have more to come). The smaller, middle one showed a mystery last night: in addition to the spatter, flames came from the top. They moved in the air exactly like real flames. But it is very unclear what caused it. Apparently this has also been seen in Kilauea. The most plausible combustant would be carbon, picked up from peat on the surface underneath the cone. But this is speculation.

Here is a video showing the f=mysterious flames at Kilauea.

The story about the groups of archeologist doing emergency excavation was overstated. There was only one, trying to do a very quick site survey before it was overrun by lava.

There are now some reports coming out on magma composition, as mentioned in the comments. The magma is a bit less gaseous than Holuhraun was. It originated from a magma chamber 17-20 kilometers below the surface. It may have spend considerable time there (one may guess centuries). This would explain why the lava is a bit blocky, as it will have become more viscous during long-term storage.

We estimated that over the first 24 hour, the eruption rate was roughly 15 m3/s. Today, numbers of 5-10 m3/s were reported. The eruption may have decreased a bit since the initial flush. But it is still going strong, without any indication that it would end soon.

The eruption rate can tell us a bit about how wide the feeder pipe of the eruption is. The magma is pushed up by two effects: buoyancy, and overpressure. The buoyance comes from the fact that the liquid magma is slightly less dense than the solid basalt of the crust. If we assume that this is the only effect, there is a simple equation which sets the flow rate. For a cylindrical conduit, it depends on the radius R, the viscosity, and the difference in density. Putting in the numbers, and assuming a difference in density of 100 kg/m3 and a viscosity of 104 Pa s, gives that a flow rate of 10 m3/s corresponds to a conduit radius of about 3 meters.

If it is overpressure, the numbers change. A rift suggest a dike rather than a spherical conduit. The picture shows the model: a magma chamber at 5 km depth, a flattened conduit going to 1 km depth, and a cylindric conduit for the final kilometer. For a magma overpressure of 20 Mpa, the dike could have a cross section of 500 m2 ( for instance 500 meter long, 1 meter wide), and the conduit t the surface a radius of 15 meters. This also gives a flow rate of 10 m3/s. This model is rather plausible. It allows for several conduits, each feeding a cone. Models of such a situation suggest the possibility of varying eruption rates over a period of weeks to months. (Costa et al.,

We do not expect a sudden end to the eruption in the next day or two (although this can never be excluded!). We are looking forward to days of envious staring at the camera. Reports that a shield may build should be taken with caution. That hasn’t happened here since the early holocene, and a more typical, smaller eruption is more likely. Whatever happens, like Holuhraun, we will learn a lot about how volcanoes work.

And a final point. Today our current VC site reached 4 million views, something the VC team is quite proud of. We try to provide a forum where volcano science and volcano experience can meet. We are glad that VC is appreciated.

The average website has a carbon footprint of 1.8 gm of CO2 per view. That means that VC is responsible for 7200 kg of CO2. How does that compare with the volcanoes that we study? Read

(and its precursor post )

There is one volcano that produced less net CO2 than VC: Eyjafjallajokull, now exactly 10 years ago. It managed to offset all its CO2 by causing the flight ban. Icelandic volcanoes never cease to amaze.

336 thoughts on “The Reykjanes update

  1. Are the Icelandic vents working on merging into one vent?

  2. I know some of it is from the low resolution but it looks like the vents are actually fountaining now, even if not the main cone is unchanged while the lower vent is now much more visibly active. To me the eruption rate has definitely gone up to some extent, if there is also earthquakes along other parts of the dike then this could be a precursor to more vents opening.

  3. “Journey to the Center of the Earth”
    Maybe J.Verne was right.
    Tunel between …… two eruptions at once.

  4. The lower vent really has grown up into a proper cone now – going to be interesting when we get some better views during the day

  5. Hú sceoldon we séo útberstung þæs fyrbeorges on Geldingadale nemnan? Geldingadalurhraun?

  6. now most of the lava seems to be going in the direction where the overflow will eventually happen

    • It seems to me that part of the hill side was covered overnight?

  7. From the ruv camerea, someone was fiddling with it a moment ago, zoomed inn and out etc, now it is out off focus…

  8. Quality seems to have dropped markedly on the main ruv cam. The framerate is significantly reduced. Watch the clouds in the sky near the top — patches of them lurch to new positions, then other patches, then all of them at once, etc. instead of smooth movement like we saw yesterday. That different parts of the image have separate framerates is quite odd. I’ve never seen that done before. The framerate where the cones are is better, but still only a few per second. The resolution also seems lower than yesterday.

    • Framerate is better in the smoke above the lava field, but bad again at the bottom (the clock is jumping up in intervals of 3 or 4 seconds, rather than once a second, when it’s even legible).

      Curiouser and curiouser: the “Keilir í beinni” stream is distinctly superior, with a continuous motion of the lava spattering in the cones instead of the lower framerate at RUV’s own stream. The resolution is no better but I would have thought the quality couldn’t possibly be better in any way than the “horse’s mouth” feed, yet the framerate is better, on par with yesterday.

      That stream has also been significantly less stable though …

        • The first camera used be from Ruv direct and was top quality, then it switched to a YouTube feed and quality dropped. I wonder if the ruv direct feed is still around?

      • Compression. It is updating only pixels where something changes. Zoom does the same.

      • Worth checking youtube settings for the stream and select 1080p if not already selected. Youtube can drop you back to 360p with no warning (other than poor image).

  9. There are quite a few shallow quakes again overnight. Looking at the quakes less than 1km deep, there is a cluster just over 1km NE of Meradalir, around Meradalahlithar (I can’t type it in Icelandic). Conicidentally, if the current lavaflow escapes, it will then flow north towards Meradalir.

      • Looks to be a bit out of place for the location of the dike though, unless im mistaken on where that is. If there is a spot where the dike erupted though then there would most likely be quite a few places that magma got close to the surface without erupting, this spot at geldingadalir was maybe just the spot that was slightly closer to the surface, or maybe the closest point to the deep origin that was within that upper km.

        Really though I guess we have no really good comparison to go off of here as to what might happen next. Krafla seemed a good fit but that took years to get going, and when it did the eruptions were fast and voluminous, not a slow but stable vent like this. Descriptions of the eruptions in the middle ages sound a lot like Krafla, so perhaps this really will be a different sort of eruption, like a shield. Thing is we have observed shields form in Hawaii and they have always started with a hig hfountaining stage, which is obviously not what we have here. Perhaps that is the long term destination though, that this currently small vent will indeed be episodic but not as a fissure but as a 500 meter lava geyser, which might then evolve into a lava lake and a shield.

        Well I guess all of these options and everything we know about eruptions here say this will last years regardless, will be a good show 🙂

        • This has been going on for less than a week. It is a bit early to say that it will last years. Kilaueau is not a good comparison because that was fed from a higher position, through a magma reservoir. Krafla was perhaps more similar but that also was fed though dikes from a central point and it was very intermittent. Here there is no major reservoir. It depends on getting its magma from 17 km down (apparently).

          I think that the dike is currently providing the pressure. Actually the pressure is provided by the sides of the dike pushing it in. That is why the rate is fairly constant (apart from the daily fluctuations). Once the dike is empty or solidified (whichever comes first) it will depend on the 17-km deep feeder channel and that will be fragile. The closest analogy I see is actually the Indonesian mud volcano. That lasted for years because the eruption rate was low compared to the available mud, and the mud never solidified underground. This eruption uses up 1% of the dike volume per day (which is high) and magma does solidify.

          Even Laki was intermittent and erupted in different locations at different times

          • There is always some magma reservoir, this time the reservoir that the eruption is feeding from would be in the mantle. I guess it would depend in how big the magma reservoir is or in the characteristics of the conduit, and we don’t really now much about these two aspects.

            Krafla had a lot of dyke intrusions, a total of 21, each propagated from the shallow magma chamber (2-5 km deep below the caldera) and many of them breached the surface and erupted. The Skaftar Fires were similar but much faster.

        • It’s probably alongside the dyke. If you draw a SW-NE line from Geldingadalir, it is about 2 km from the centre of where the dyke is assumed to be to the outermost point in the cluster. Logically, if it was going to produce another fissure in that area, then it would probably be a bit west of that point. The nearest point in the obvious cluster is 1.5 km and if you include the three slightly further away, they are probably around 0.5 km from the centre.

        • Just to mention, there is inbuilt error, as I can no longer work out how to put GPS coordinates into Google Earth, like I used to, so I estimated where Fagradalsfjall was. All of the quakes coud be a couple of kilometres to the west, which would put them right on top of the dyke. I will have more of a play to work out the GPS coordinates, as they will be more accurate (and less fiddly probably).

  10. Anybody know how high is cone from bottom of the valley to the top?

    • From figures I’ve seen, the cone is currently 22 metres tall. The top of the ridge it’s on is 218 metres above sea level and the base of the valley in the region of 180 metres, so the ridge plus cone is probably close to 60 metres.

  11. Geldingsbrother seems to be trying to catch up with the larger one. Wonder if they will eventually merge into one large cone.

    • I wonder if they really have measured the chemistry of every lava erupted in the last 7000 years, probably not.

  12. What an utterly breathtaking show from Etna last night! It was very, very late (or better: early in the morning) when I forced myself to bed, with Etna still going strong, collapse of the crater and the start of a lava flow. Etna truly showed who’s currently boss in the volcanic company, lol.
    Attached to the tweet below an infrared video of a pyroclastic flow in that 16th paroxysm:

    Sergio scornavacche@Sergio_etna 2 Std.
    Buongiorno, ecco una colata piroclastica prodotta stanotte dal cratere di Sud Est #Etna. Vista da 17km di distanza da #mascalucia. Video girato nell’infrarosso

  13. I was looking at the rear webcam yesterday and assumed what I saw was a grass fire – two small smoke plumes on the hill.
    I looked today and was surprised to see the smoking is still there. Perhaps new openings may be slowly occurring?
    Here’s what I am looking at:
    These two small smoke plumes have now been going for 24 hours.

    • This is a crack which has been present right from the start. When people were allowed onto the fissure hill, a few photos were snapped showing it steaming. I’m not sure if anyone has already posted here, maybe under one of the older articles.

    • this is steam coming out of a crack in the ground, it has been doing this since day 1 of the eruption

    • If you go to the time lapses on the left hand side of the RUV image, you’ll see that steaming/smoking crevasse has been there since day 1 Clive. There are some close ups of it around the web. I think the word was that it was steam rather than smoke. It hasn’t developed into anything else over the last 4 days.

    • Ah – thank you. I never noticed it. It’s probably because I sat on my glasses a few weeks back. Must get them fixed.

  14. The seasons in Iceland are baffling. It seems that since the eruption started, the eruption site has experienced the onset of winter … which I would not have expected from a northern hemisphere site. It was grassy and snow-free but has been accumulating snow in the last few days, and the weather is getting snowier, as if autumn is just ending there, when as far as I know the opposite should be happening and spring arriving.

    Moreover, the weather itself is odd. Storms often seem to circle around and hit the same location 2 or 3 times, a few tens of minutes apart, rather than traveling in a roughly straight line so that they come and then go and then stay gone like they do elsewhere in the world.

    Anyone know what’s going on in that regard?

    The relevance to the volcano is that these peculiar phenomena are making visibility at the eruption site get steadily worse day by day on average, on top of which there are repeated bouts of especially bad visibility when a storm shows up, rather than just one.

    • The answer to your inquiry is:

      Welcome to Iceland. 😉

      Seriously, our weather is crazy unpredictable.

        • For a more technical explanation: we have an extreme oceanic climate, with little difference between summer and winter temperatures (only ~14°C or so). So periodic fluctuations in weather conditions on the scale of a couple weeks can swamp seasonal weather changes.

          As for wind directions, we’re in the shooting gallery of extratropical cyclones, so wind can come from any direction, depending on how a low is passing; it’s not some broad steady fronts. The unpredictability is compounded by the complex mountainous terrain.

          So in short:

          Our weather be crazy 😉

          • Do low-topped supercells (storms with a persistent rotating updraft) also often occur in Iceland? In our country the Netherlands they often occur in situations with showers in polar air masses behind a cold front when there is a strong upper wind. Strong wind shear is necessary to develop rotating updrafts.

      • Expect the coldest temperatures to be at about 6 AM Iceland time on Saturday. It’s predicted to be -10°C at Grindavík, less up at Geldingadalir. If you prefer winds, try Friday morning from 6AM to noon and Sunday from 3AM to 6PM (peaking at 9AM) (Iceland time).

    • I don’t think it is the “same” storm circling around. Think of it more as bands of rain/sleet/snow that move with the wind. The wind direction has been remarkably stable for many days now (might be changing tomorrow).

      It’s not entirely unusual to see snowstorms well into April.

        • And in the Highlands, snow is not out of the question even in mid summer, in my experience.

    • Visibility has improved dramatically now, enough to see in the ruv cam that there are dozens of little red and white dots near the right flank of the lava field. They move. It looks like someone kicked over an anthill there, except the scale has to be a lot larger …

    • I’ve visited Iceland a couple of times in March, both times I had serious blizzards. One occasion was on arrival, it was fine when I left Keflavik, but when I got to Selfoss, heading north, it hit. Very poor visibility to a few kilometres north of Reykholt, trying to find a turn-off to our cabin, that was difficult to see in good conditions and having never been there before (although I’d driven along the road previously).
      Second time, staying in the same place, while driving back from Jokulsarlon, the other driver decided he couldn’t drive in the dark, so I took over at Skraftarhreppur. Not long after leaving, another blizzard, all the way back to Selfoss, before easing off on the road north. The inevitable rear end slide happened on the upland road between Vik and Skeithflotur, heading downhill on the twisty bit, but I was ready for it. In the end, I was glad I was driving, as we found out the other driver had also never driven in snow before on the outward journey, so it would have been hairy if he had a slide. Then there was another blizzard heading to Reykjavik, on the way back to Keflavik. There were a few occasions, where one minute it was bright and sunny, then sudden blizzards for five minutes, then back to sunny again.

      • had some hairy experiences like that… it seems sunny skies and whiteout conditions are actually worse than night whiteouts… both terrible. Up here in the winter i like to get behind a semi truck and just let them plow thu the mountain passes. But even they can jackknife. sorry OT… volcanoes are interesting… (just to belay the dragons)

    • And why it’s dangerous to walk on the crust! Good video. I saw a video clip a couple of days back of someone retrieving a drone from crust. He was a good six feet from the edge.

      • Amazing video! Because the lava is pouring into a valley it is collecting into a sort of rootless lava lake so it doesn’t solidify, it can suddenly overturn at any time.

  15. Hey, anyone know where to get *cheap* heat resistant / reflective gear? I have an itch to collect fresh molten samples, but also don’t want to burn myself like an idiot. Already have gas protection, but I’m seriously lacking in the heat protection department.

    • The one word you don’t want to use is ‘cheap’. Life is not cheap. A thermal camera seems essential, so you know which is the hot stuff.

      Here is the list of essentials for volcano tourism that we were given by Mike Ross. It is his ‘gear list’ for fieldwork – may be added to or subtracted from depending on the volcano, locality, and rationale:

      – Hard hat. Should go without saying! When to wear it at all times and when to merely carry it ready for instant use in case things go pear-shaped is left to the judgement of the individual.

      – Satellite phone. Bit pricey but no excuse for not having one if you’re serious about this.

      – Radio receiver/scanner. Can be useful to tune in to emergency service broadcasts etc. as well as normal broadcast news and weather.

      – Gas meter. Doesn’t need to be precisely calibrated at vast expense so long as you’re sure it work. I recommend MultiRAE meters; they can be found on eBay and are good reliable instruments – we used them in hazmat work at the fire department. The ideal sensor combination for volcanology would be H2S, SO2, and O2. CO is not a significant volcanic hazard. CO2 is – but your alarm sensor for that gas is the O2 sensor as CO2 is an O2-displacing asphyxiant. The meter should always be worn on the waist belt in case you blunder into a CO2 pocket; it’s heavier than air!

      – Thermal Imager of some kind. It’s good to know when something is hot! It can be hard to tell fresh and still very hot lava flows from old cold ones – until you get uncomfortably close! These days I would suggest the CAT S60 phone which has a built in TIC. It’s also a very rugged phone; important on volcanoes!

      – Gas masks (plural). You need a range – different masks for different conditions. If there’s just a little ash blowing around a nuisance dust mask may suffice. If there’s significant SO2 around you may want to break out the proper respirator style make fitted with the correct ‘acid gas’ filters. And if things get really nasty you may need a firefighter-style full-face mask equipped with the same filters; it covers your eyes too – there’s no point in being able to breath if your eyes are so irritated you can’t *see*!

      These are the more volcano-specific add-ons to the general outdoors/mountain gear you’ll need anyway.

      • PS CO2 is acid and seriously affects breathing rate. Its NOT just an asphyxiant but had significant physiological effects. Anyone who has thoughtlessly put their head into a fermentation vat finds out pretty quickly that there is a reflex action too.

        • This property of CO2 is a *good thing*. 🙂 You cannot be silently poisoned by CO2; hypercapnia is painful. Hypoxia, however, can be a silent killer.

      • “The one word you don’t want to use is ‘cheap’ ”

        If you spend a fortune on things that rarely see usage, you’re wasting money (and resources). Durability is not a key element. I’m not going to be visiting lava flows daily. I don’t need something well made. Just looking for something a step up from chicken wire and alumium foil. 😉

        “A thermal camera seems essential, so you know which is the hot stuff.”

        Already own one, even though I know people who’ve been walking fresh lava fields in Hawaii without one for decades.

        “Satellite phone”

        There’s cell reception – and tons of visitors – there.

        “Gas meter”

        They close the site if CO2/SO2/H2S levels rise too high (let alone if O2 levels get too low), and that’s based on a standard of people without any gas protection, which as mentioned, I do have.

        “a CO2 pocket”

        This is Iceland. Still air is like a unicorn here. 😉 Air mixes. Still, if you know of a place that sells affordable meters, by all means make recommendations alongside what I actually asked about, thermal protection.

        “If there’s just a little ash blowing around a nuisance dust mask may suffice”

        In the COVID era, we all have these.

        “the proper respirator style make fitted with the correct ‘acid gas’ filters”

        As mentioned, already have it. Got it during Bárðarbunga.

        “And if things get really nasty you may need a firefighter-style full-face mask”

        I’m literally here asking about heat-protective gear.

        • Without commenting in any way on your experience, this blog is read by many people who may be less experienced than you. Getting close to lava is a risky endeavour and the public should be aware how risky it is. We would prefer not to be seen as recommending the public to collect some lava! It is a job for trained geologists.

          The list came from a professional volcano photographer. The local conditions may be different (cell phone reception was limited in the area, at least a few days ago). I am glad to hear you have gas meters! IMO is warning about gas levels well in excess of legal values.

  16. Has anyone got details of the original ridge prior to the eruption, photos, surveys, etc? I’m curious as to how old it may be?

    It is noticeably barren when compared to it’s surroundings, both on google Earth and the live footage. That may be a coincidental aspect of how Icelandic flora comes and goes with the seasons or erosion, but it does seem as if it might be a bit of an anomaly?

  17. Hello all. Timelapse from yesterday 0630 am to 0250 am the next night. Both cams are included,. It’s abit long but one big advertisement for Iceland.
    1 second=1 minute, a few cuts were made.

    • The timelapse shows the movement of the lava, even when it looks like activity has slowed down, so it overcomes the dark/light variance in appearance and shows it isn’t slowing down during daylight hours.

    • Thanks!
      Great timelaps showing the activating second cone at about 14.50 and several lava lobes turn around suddenly in the foreground about 15.00 to 16.00.

  18. It’s so easy to trust the theory of how a a lava tube was built…

    …but so hard to imagine how the last drop of lava past through it without solidification…

    Are there tubes where the lava flow back into the earth, back to be magma again?

    • I love this guy and the pragmatic attitude of Icelanders. Explains all the dangers of volcanoes and treacherous route – then tells you how to get there and how to be prepared. Totally different attitude to health and safety obsessed UK where in these present times you can get arrested for sutting on a park bench.

  19. The past two nights, ca 2 to 5 am saw eruptive activity that was much more intense thn during the day. Looking at the peninsula quakes there is a hint of correspondence, intensity raised at night. Since the quakes are distributed along the fault, what does this tell us about the forces driving the eruptive activity?

  20. To me it looks like the smaller cone is becoming the more active of the two. Quite big outpour of lava from that cone right now. Either it will become the more dominant or the two will merge.

  21. It looks like two parts of the second vent have collapsed allowing two separate streams of lava to form.

      • I almost suspect that there is a secondary drain from the upper vent into the lower one, because the amount of visible outflow from the bigger vent doesnt seem to match the activity within the crater, or what has been seen previously. There has often been multiple drains, not always visible.

  22. Lot of ppl watching again. Also a lot of smoke, is because it’s colder due to the snowfall?

    • I’d say it’s the additional moisture from the snowfall throughout the day (so more steam mixed in with the regular gases).

    As can be clearly seen, a second prominent vent has now formed adjacent to the previous central vent at #Geldingadalir. This vent has been there since the eruption began but has grown in size to form a spatter cone. This is typical of effusive fissure eruptions of basaltic lava.

  24. Crater about 20 meters tall

    Height maps have been processed based on the imagery and compared to older maps have obtained information about the thickness and volume of the lava, as well as lava flows.

    The latest images were taken at 13.20am yesterday and show that the height of the crater is about 20 metres, the highest thickness of the lava is 22 meters and its average thickness of 9.5 metres.

    5.7 cubic meters per second and the flow does not change

    The volume of the lava is 1.8 million cubic meters corresponding to a lava flow of approximately 5.7 cubic meters per second, from the beginning of the eruption.

    The same average lava flow is available for the period from March 22 at 13.15 to 23 March at 13.20.

  25. It’s like a rock concert up there tonight! (Er, pun intended!)

  26. More of the hill side is now covered in lava. That may make things a bit more safe! People can’t get quite as close

  27. Pingback: Viewing Volcanic Eruptions – Dr. Roseanne Chambers

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