Magma sponge

There is one question that has been bugging me lately. Why are there two types of eruptions in the Reykjanes Peninsula? Slow and fast. I have talked about this before, in here. Basically eruptions can be classified into two broad categories depending on how fast the maximum eruption rate is, which clusters into two end-members, 10 m3/s and 1000 m3/s. A very significant difference!

The fissure swarms of Brennisteinsfjöll and Tindaskagi produce slow fissure eruptions, which I have also called “wandering eruptions”, because of how I think a certain vent was active for periods of days/months and then the eruption shifted somewhere else, in a way resembling the eruption of Surtsey. The characteristics of these eruptions indicate that the eruption rate was around the boundary of tube-fed and channel-fed eruptions, about 5-10 m3/s. The current Fagradalsfjall/Geldingadalir eruption is of this type.

Reykjanes also has shield volcanoes. Dyngja. This type of eruptions are very voluminous, lasting years, decades, and maybe even centuries. The rate is probably around 5 m3/s or less. They are related to the slow fissures, possibly being just a scaled up version of typical slow fissures or simply a second stage that some of them develop. Some of the dyngja eruptions had multiple vents that each was active for a lengthy period of time, so that they may have been fissures. For example, Hallmundarhraun, the youngest shield, had 4 long-lived vents. Dyngja eruptions also seem more abundant near Brennisteinsfjöll and Tindaskagi. But they show up everywhere too though.

Sandfellshæð, a lava shield of the Reykjanes Peninsula, formed 14,000 years ago. From Google Earth.

The other style is like a flood. A  ~1000 m3/s effusion I’d say, by comparing with the similar eruptions of Krafla Volcano.  Reykjanes, Krýsuvík, and Hengill fissure swarms practice this particular style. Intense but short. The area around the fissures is briefly submerged into a giant pool of silvery lava, and a long wall of fire shoots 50-200 meters into the sky. The 1000 m3/s peak doesn’t last long though, this could be over in a few hours. It slowly wanes afterwards.

The opposing end members are as different as the day and the night, as different as basalt lava flow eruptions can get. But why?

A matter of structure

I initially thought it could have to do with the primitiveness of the magma, how deep it comes from, and how pristine it is. I started checking magnesium/iron ratios. But no. There was no strong correlation between primitiveness and eruption type. It is true that primitiveness increases towards the west, towards Langjökull, but this seems to be due to the increase in crustal thickness. Eruptions in this whole area come from the MOHO, base of the crust, and the MOHO is deepest at Langjökull. This could give the wrong impression that shields are more primitive because the greatest concentration in the whole of Iceland is in Langjökull. This I saw later. Initially I checked only the area around Hengill and the different eruptions span the same range of primitiveness.

The clue was somewhere else however. It was crystals. Apparently shields may have higher crystal contents. One of them, Lambahraun, has a crystal content of 25-75%, really high. Some of the shields even erupt picrite basalts, like Vatnsheiði, a shield next to Fagradalsfjall. Pricrite is a term used for the highest olivine crystal contents. As far as I know picrite doesn’t happen in the fast fissure eruptions of Reykjanes. It turns out however that there is not too much data on crystal content so I couldn’t really find whether this correlation was really strong or not.

What could crystals mean? A mush. A mixture of molten rock and solid crystals, where the crystals form the greater percentage, is called a crystal mush. And this could explain A LOT. And when things really make sense that is good.

Wikimedia, by Julien.leuthold.

Imagine a wet sponge with water slowly dripping from it. Now imagine the sponge is a crystal mush, the water is the magma, and it is dripping upward because it is driven by buoyancy. You get an slow eruption. Normally this wouldn’t happen because the mush is trapped under the crust, but if a leak has formed, a dike, then you can drip all you haven’t done in hundreds, or thousands of years. The slow fissure eruptions and shields would be feeding from the mush. Magma would need to be slowly extracted from the pores between the crystals.

Fast fissure eruptions would follow the classical model. Magma comes from a magma chamber. This time it is more like popping a water balloon. A chamber is ready to unleash hell because its magma is all placed within the same space that can drain out rapidly when the leak happens. It doesn’t drain entirely, just until pressure drops low enough.

The geochemistry between the two types would not be too different because it is really the same magma. What changes is whether this magma is gathered in one place, or distributed over the sponge,

What are the implications of this idea? It means the magma from the Fagradallsfjall eruption is coming straight from the source. The decompression melt itself. Not stored. Melted and erupted right away. Mid-ocean ridges are underlain by areas of decompression melting. The mantle rises up to form new crust, and because the solidus point is lower at lower pressures, you will get partial melting, and therefore the mush or magma sponge.

The Mid-Ocean Ridge

Why should we favour this idea? An idea based on incomplete data due to the lack of it. First because as much as I’ve tried to look for all possible answers, you do need the magma sponge. The nature of the magma sponge could be many, it could be a mush, or perhaps it could also be a group of thin sill intrusions. But you do need something that releases the magma “drop by drop”, or otherwise you would get the lava flood.

It does match however with the distribution of dyngja eruptions in Iceland. They are found under the mature mid-ocean ridge segments, from Reykjanes to Langjökull, and from Vatnajökull to Tjörnes. They are lacking in the off-rift volcanism like the Snaefellsnes Peninsula. The Eastern Volcanic Zone also lacks them. It is a very young rift, the very powerful volcanoes Hekla, Katla, Torfajökull, Grimsvotn and Bárðarbunga are cutting through the crust like they were slicing through a cake, producing massive, fast fissure eruptions, and creating new Mid-Ocean Ridge, but which it isn’t ripe just yet.

Trölladyngja, a shield volcano formed in one huge eruption. From Wikimedia, Heidi Soosalu.

Shield eruptions are known to have peaked during deglaciation, This makes sense. The deglaciation would have augmented decompression melting in the mantle magma sponge. And who would have been affected? Feeding from the magma sponge the shields would be the first to be benefited from these changes.

The size of an eruption has a reason. For example Holuhraun was so big because the summit of Bardarbunga underwent caldera collapse. The large calderas can feed large eruptions. Fast fissure eruptions of Reykjanes could be limited by the small size of the magma pockets from which they feed and the great depths that makes it impossible for them to collapse. But the magma sponge is almost limitless, so big that each segment runs through half of Iceland and beyond, continuously producing new melt. Shield eruptions can be in fact the largest ones in Iceland, even when they do not come from caldera collapses, they reach up to 50 km3, outperforming even the giant fissure eruptions of the Dead Zone.

Future of the Fagradallsfjall eruption

I still think we are going to see new vents open, even if it takes time. But I have already said this before. So instead. What does it mean to come from a magma sponge? The sponge is big, yes. But Fagradallsfjall still can only tap a certain portion of it, and melt production isn’t as big as it was during deglaciation times. Some say we will get a shield. I’d say a 1 km3 shield would be a realistic possibility. A really big shield like 9 km3 Hallmundarhraun, 25 km3 Skjaldbreiður, or 48 km3 Eríksjokull, seems too much for Reykjanes. This is something that can still happen in Langjökull. But a large shield hasn’t erupted in Reykjanes in over 5000 years, since Brennisteinsfjöll’s Leitahraun. Deglaciation was a while ago.

Skjaldbreidur shield volcano. Wikimedia, from Ingeborg Breitfeld.

A cubic kilometre is also a common size for slow fissure eruptions, probably. The last eruptions of Brennisteinsfjöll and Tindaskagi were about this size. In that case the eruption could last a few years. Good for tourism! Bad for optical fibre cables, I guess.

A magma chamber that can be visited on Iceland, from the Brennisteinsfjöll eruptions 1000 years ago. The image looks up from inside the open volcanic conduit of Thrihnukagigur. A lift use to move people up and down the 120-meter drop is visible in the image. Wikimedia by Dave Bunnell.

We are watching the creation of new ocean crust. Something hard to find anywhere that is not submerged under a few kilometres of water!

549 thoughts on “Magma sponge

  1. A very timely and interesting article. Many thanks for taking the time to research this, Héctor!

  2. Héctor, thank you for that article. I appreciate how you layout your thinking process.

    • I have to echo this sentiment. I have been out of state to see relatives that I haven’t seen in 20+ years. While I enjoyed that quite a bit… I missed out on the hot VolcanoCafe action.

      Thank you for the article! 😀

      Additionally…. one of my accelerometers has a croaked Li-Ion battery, so I wasn’t able to take any soundings of a geologic formation that I wanted to look at. I did spend most of my outdoor time fighting a horse fly that ultimately lost the battle. 😀

      One oddity of the trip is that my typical sleeping problems seemed to have completely disappeared while I was there. I attribute that to being in the area where I spent much of my youth in the summers. It was “home.” The downside? We only cooked half of the 10 pounds of 26 count shrimp that I took up there. (my other cousin didn’t make it down.) But I did meet a large quantity of seeming strangers that turned out to actually be distantly related to me.

  3. Interesting article, particularly the explanation of why shields form where they do in Iceland.

    1km^3 seems to be the failure point for the rifts in the Reykjanes eruption. However, since Fagradalsfjall has not erupted in thousands of years, the rock will be colder and more solid to a greater depth. Doubt it would have erupted at all, unless there was more eruptible volume than that. With the number of cycles missed it could be up to 5 km^2 or so, but it might have gotten sealed because it took longer than neighboring systems to recharge and the roof meanwhile solidified, plus some of the excess might have escaped sideways to Eldvorp and Krysuvik. Conversely, since it is coming directly from depth through a comparatively narrow channel, a larger % might erupt rather than fill the rift underground.

    A 5 km^3 eruption would be large enough if my math is correct for an shield 6X8 km (longer toward the sea, because lower elevation) with a ~5° slope and a summit 500 meters above sea level. About a third of its apparent volume would actually be the buried Fagradalsfjall high plateau and the ridges. That would be the absolute max though, don’t see how there could be more supply than that. Definitely not the volume of the shields listed.

    • Thanks Reykvolc. There are a many unknown factors. It would seem the long dormancy of Fagradalsfjall could make the eruption bigger if more melt has built up underneath, as long as it hasn’t leaked too much to the neighbouring volcanoes.

    • Thanks for the timelapses, it looks as if the volcano was breathing.

  4. I found a clip of the video where the person is climbing on the slope of the volcano and has to make a run for it. Crazy stuff.

    • The fool’s a little hard to see – look in the upper left quadrant. Amazing how fast the lava’s flowing, but that’s because this is on a steep slope.

      During at least one of the Krafla Fires eruptions from 1975-84, some of those flows were so fast that scientists had to use snowmobiles – the lava was coming down too fast to outrun them on foot.

      • There was a story of something like that on Kilauea, could have been in one of the 1974 eruptions, or maybe at Pu’u O’o in its early days, again very fast lava suddenly flowing in their direction.

        I did find a video from 1983 that was of an eruption at early Pu’u O’o where a collapse blocked the crater outlet for a minute and it all broke out towards the observers, with a clip of their tripod stuck on an island surrounded by fast moving a’a when they got to a further distance. It is on youtube I believe.

        • I remember that video well. It was a lateral view of the flow and it was moving as fast as we see exiting the rim of the cone here. I thought of it when watching the video of the ‘wackjob; on the slope. It wasn’t a day to die.

          • I couldn’t spot the fool on the hill in the video. Is this comparable to what mark twain did during his sojourn to hawaii?

          • Yes, perhaps it is not so fair to consider this recent individual a fool if we do not also consider the early explorers to be fools too. They gave us invaluble knowledge but one must have thought Mark Twain and Titus Coan were crazy, Coan in fact did walk on a lava lake at Kilauea, if you tried that today a personal observation report no matter how good is not going to cover your actions from the title of fool… 🙂

  5. Cool article on the melts and mushes and fractionating crystals and phenocrysts. Gut’n Tog shows some really nice colour changes, creamy yellowish to green and reddish ground matrix, and a piece of bubbly lava with green olivine crystals, but also with white patches which he doesn’t identify. Would they be plagioclase? Too opaquely white for quartz, and I wouldn’t expect to see that in a basalt anyway.

    It looks as if a flow is about to go over the saddle between Theatre Hill and the new Viewing Hill.
    Really pleased that Vedur have begun to put the webcam photos up on their main site. The Meradalir shots aren’t nearly as panoramic though, so we still cannot see what’s going on in the Eastern Meradalir valley.

    • Gutn Tog’s an amazing guy. He’s working so hard through this eruption. Has anyone from VC contacted him? He could write an awesome article on his experiences there.

      And I think we all owe a big thanks to Iceland’s authorities for giving access to the webcams for the eruption!
      Three cheers to them all!

  6. Great article Albert! Magma sponge sounds like a cake! By the way seems a new flow will go over the saddle.

    • Yup, as I suspected; I’ve been watching the outgasssing from behind the hill all day and it’s now over the top and descending in several streams.

    • There’s also something weird going on to the east of the cone, but it’s hard to see on any camera clearly.

      • Overview camera,, at 23.38 a glow appears and gradually grows.

    • Hector, not Albert.. Hector actually understands how magma works.

  7. There seems to be no pause in erupting lava presently, or is the gas and smoke playing tricks and its just just light reflection?

  8. Could someone who’s in Iceland maybe drop by the mbl close-up camera and give the lens a wipe? It’s been horribly smudged and grimy for three days now. Can barely see a thing through it.

    And while you’re at it, could you maybe give the IMO a ring and ask them for a different wind direction? For a similar amount of time it has been blowing the vog from the vent straight at the camera. That’s also been hurting the view. 🙂

  9. I have been seeing multiple reports that the effusion rate is now 30 m3/s, it is double the rate of a month ago. I dont know if this is true but if it is that is a massive deal. I would expect if there is a major cone collapse that drains out the lava lake inside it will result in some pretty impressive fountaining.

    The hell machine is working 🙂

    • That number seems to come from an overactive tourist group and was put on youtube as clickbait. The same group also mention lava fountains hundreds of meters so clearly had their wires crossed. Neither did they seem to carry any instrumentation with which the lava flow could be measured – just the cameras they advertised. The official channels states that the flow has been constant at 12-13 m3/s since early May. I think this group just heard ’13’ as ’30’.

      • Ok, Albert take that info as a give.It looks greater the exit flow, but viewing the cams on my mobile is a limited science tool.But damn it I do enjoy watching this new kid on the block!

      • Yes, I think you are right, though it would seem maybe the outflow is a bit higher than it was last week.

        • It is not easy to measure, especially with the many bursts. It is measured from the change in volume of the lava fields. That needs quite a bit of time: you need at least several days for the lava field to have grown enough that the difference can be accurately measured. The larger the lava field, the more time time is needed between measurements. This is why we only get measurements every week or two weeks (the cost of the overflight may also be a reason). In the past 6 weeks, it has been remarkably constant. The earthquake activity a few days ago may however indicate a change (or not) so it is worth keeping an eye on it. I was a bit negative about the tourists. Their main fault was their excitement. In science, data should always be correctly reported. Interpretation can change, but wrong data can cause problems for decades. So I am a bit allergic to these kind of mistakes!

  10. Chad your right! Seems there are large cracks of the Cone to the right of the hell spillway.

  11. Always within view, hereabouts, are craters dominating the volcanic plain they have created. There are four in a close row which must have been templates for these Icelandic Johnny-come-latelys. One even has a large dimple in its side from which would have issued similar spectaculars. All about 200-300m elevation. So, I come to this site and it reveals the history of the local hills. The volcanic soils are now agricultural gold; but under the basalt lie the ancient buried rivers from whence the real stuff came out by the tonne. Tried to post a pic but am hamstrung by ignorance in such matters. (Ballarat Region, Victoria, Australia)

  12. There is a raging lava river flowing from the crater continuously now, total laminar flow and then disappearing into a tube or some other hole, it is not really in focus but must be flowing very fast.

    • Looks from the camera angle as if the new flow has met the main flow. It shows you just how thick the main lava flow has become!

      Zoom in:

      Source as above.

  13. That has now cut off the 2nd viewing hill by the looks of that flow

    • Also it looks as if quite a few people are cut off from their return path .
      Camera Just zoomed in on them.

      • And so a helicopter rescue will be needed…

        Which camera, and when?

          • To be honest, bearing in mind the running man allowed us to see scale, this is very many tens of m^3/sec. I am not watching constantly but it seems to be continuous to me now.
            I take Albert’s comments to heart, but equally without any proper measurements I feel that the flow is significantly higher than a week or ten days ago. By how much is another question.

          • I’ll keep an open mind. A lot of the flow is invisibly below the surface. That makes it hard to compare the output to say last week, and impossible to put a number on it. It can be frustrating that new numbers only come one or two weeks after the fact. An approximate way to judge output is to see how much the outer edges of the flows expand. A constant flow gives slow expansion, slowing down over time, a decreasing flow stops expansion, and increasing flow gives faster expansion. There has been little expansion in Natthagi for some time. Meradalir has shown more activity.

          • Here is a Sentinel image a few days ago which shows the expansion to the north

            Note the light/dark stripes towards the top left. They look to me like diffraction patterns formed as the sunlight travels through the hot air above the eruption

      • I counted at least 7, maybe 9 people visible on the skyline, there may be more on the path lower down behind the hill.

      • No. Replay the zoom and look more closely. They don’t appear to be on that hill; they look like they’re on another hill, behind that one, on the other side of the lava filling that valley.

  14. So that must be coming from the southern end of Geldingadalir? Wow… busy little volcano. Or maybe not so little, now.

  15. The question now is, is the lava also flowing into the other valley behind the hill ?

    • From the screenshot I did in the last post, from the latest 3D model, it has potential to flow either way from that location. The visible flow was the one I labelled as most likely, as the slope out of the SW exit of Geldingadalur slopes quite steeply left, heading east, but it wouldn’t take much to flow the other way into Natthagakriki. There is also a second exit from that area that isn’t much higher and would flow directly into Natthagakriki.

    • 67doug ..

      We need to help finance a 2nd Iceland trip for you and your drone to find out !!

  16. Langihryggur cam now has a clear view on it.

    Indeed this comes from the south end of Geldingadalur, but from here it’s very possible to fork into the valley just west of Natthagi (Borgarhraun/Natthhagkriki), if it’s not already doing it right now. GutnTog pointed that out last week.

    Looking at the map, it may even overflow the highway there sooner than from Natthagi

    • I’d say it would much better for the road if the lava flowed into the west, there’s a much larger area with nothing in it, that the lava can spread out into, and considering how long the defensive walls held earlier it should be possible to contain the lava in that huge area for quite some time.

      As so artfully demonstrated here

      • Not sure if they have enough time to throw up a barrier there, unless that has been planned for in advance.
        The saddle overflow I watched early this morning wasn’t enough to take the pressure off the southernmost lobe.
        I looked at this possible direction at the start of the eruption, but it looked improbable at best then. This eruption continues to throw curve-balls.

        • Its because the lava isn’t really a liquid. It has a very marked slope and further tends to quickly build levees each side where cold solid fragments as pushed to the side. As a consequence it tends to go the same way for quite a while, getting ever higher, until it breaks out and goes down the slope that it made in the first place.

      • Yeah, that would be a good option, but that’s a wall of over 1000M. And considering a slope in the lavafield, it needs to be at least 50m high on the east side just to close it off. Probably a few 10s higher just to be sure.

        They better start digging then…

  17. I counted at least 7 people on the skyline.
    MBL have reported the cut-off, but not that people are stranded.

  18. Looks like no one is trapped so far. Everyone I saw during the last pan was on the other side of the flow and they can go back down using trail A. The area probably got evacuated in time.

    • They’re not on the othe side. The new viewing point and hill is cut off.

      • I thought the same at first. But look more closely at the zoom, and the contours of the hill. They’re on a hill on the other side of the valley, beyond the area filled with lava.

    • May be two people stuck. But as they haven’t moved in a while, could be signposts or told to stay where they are so they are visible?

  19. And another fresh load arriving at Natthagi (RUV-cam now directed towards Natthagi).

    Impressive continuous action of the volcano today.

  20. I’m late to the party as usual. So, we have Theatre Hill cut off and a filthy camera (disgusting…), and “Balcony Hill” (the more distant cheaper seats) cut off by a new flow? Wow. I hope no folks are caught on the hill – they’ll need a helicopter ride.
    The vent appears to have switched to continuous flow (more like raging)?

  21. Any rescue of the trapped people yet?

    I can’t find any rescue on the video streams…

  22. It looks like a slow breakdown of the cascade area, started by erosion of the overflow to a point where the sides can be undermined and weakened. Compare the Langihryggur stream where it’s dividing its attention between the col area and the vent itself.

    • Hmm. Looking at a side by side comparison, I don’t think theres a collapse. I blame the camera wobble. That’s my story and I’m sticking to it.

    • Thank you for that. Of course, the Icelanders have everything under control. It’s what they do. 🙂

      • The amount of magma in the new fall is still small. It seems last night some of the lava began to go south from the cone. It came over the saddle but not enough to reach the wall, but apparently added the 1-2 meter needed to go over the edge at the end of the flow. Now it depends on whether the southward flow grows or stops again. Either can happen. The main flow is still into Meradalir, I think, although this is said without having seen what is going on there!


    Webcam Fagrdalshraun have now entered constant lava effusion! with lava pouring into a lava tube at high speeds
    This is now becomming a tube feed lava shield and IMO experts think it coud last perhaps 5 years or more.
    The effusion rates are still much bigger than Puu Oo

  24. Hi there Albert, Carl, Héctor and the VC team. Thanks very much for your great posts.
    I think it’s time you came to Iceland to inspect this thing first hand.
    Icelandair has some pretty cheap offers and if I’m not mistaken the quarantine hotel is free for the duration.
    I can pick you up at the airport (if that is allowed) and then take you to the eruption site (after quarantine) and put you in contact with some of our local geologists.
    You can contact me through the e-mail address I used for this comment.

    • Can I hitch a ride, too? (unfortunately my offspring would frown on me for even asking; I can’t even go to the local shop unnecessarily atm, until they both have their second jabs)
      Unutterably frustrated and desperate to get to Iceland right now… Or even leave the house…

      • This is what comes of having highly intelligent scientific offspring who counter every argument with the latest medical research and local/regional covid-19 numbers. All that nurturing comes back and bites me!
        But that’s only half of the reasons why I’m stuck at home, and I won’t jeopardise anyone’s health for a volcano jaunt. Cultivating patience, a seed that takes time to grow well.

    • That is a generous and tempting offer! Manchester though is back on non-official travel restrictions

      • What ?

        Iceland is on the UK’s green list ….. small list that I think only Iceland is on ! lol

        I might have to go back …..

      • Iceland may be on the green list. Manchester isn’t. We are asked not to travel.

    • Booked my flight to Iceland yesterday. Will go mid August and plan to go hiking around the eruption site. Hope the eruption is still active. Will stay with Icelandic friends but any advises from VC-friends are wellcome!

      • Eruption will still be active then dont worry 🙂

        At this rate though it will be very hard to actually go somewhere you can see the vent though by August, unless a trail is made that goes directly up the far side of Fagradalsfjall which should be lava free for at least some months time yet.

    • Wow! Just wow! What a time to be alive when we can see a volcano up close and personal like in this drone footage.

  25. OK, going to try posting an image link again. If this works, you should see a map of the eruption locale with the areas of the various basins and some interesting distances. (Warning, it’s a 4K image, here’s hoping WordPress will create a thumbnail :-)).

    • And again, maybe it’s too large… If this doesn’t work I give up

        • Please explain the magic – did you add the anchor tag yourself? perhaps a screenshot of your comment before you posted it 🙂

          • That posted before I intended, sorry.

            I right-clicked > Copy image link > pasted the link as below, but with spaces removed. I didn’t need to alter it at all, but het link I copied ended .jpg, not .jpeg like yours did.

   HtVKdhD. jpg

        • Thanks. But I don’t understand … imgur seems to change from jpeg to jpg depending on when or where you get to my pics. How hard can they make things? Sigh…

    • WP does not make thumbnails in comments, we have found, and so very large images are best avoided. It will display image either directly or as a link. It is hit-and-miss which one happens. It depends on which site the image is on. For an image this size, a link is probably best!

    • Best not respond … it just encourages a repeat or (worse) copy-cat.

      • Makes one look at some 20th century footage in a new light eh?
        Bet the romans are laughing at our boldness, or rather lack of it.
        Nothing worse than being not correct on the Internet, history repeats, etc. LOL’s

    • Not to recomend anyone do it but I was hoping for a video of this 🙂

      I remember seeing a very similar close up view of the lava in Hawaii in 2018 just like this, someone who climbed Ahu’aila’au while it was erupting, no you didnt read that wrong…

        • Yes, there was a video taken from the edge of that lava pond just near the breach in the cone, it was called ‘mini 8’ by many. This was also back in June when there was still a fountain, and that area was flooded repeatedly in July when the highest effusion rates were reached, nearly 1000 m3/s during surges.

        • Ah, I may vaguely recall that incident. I used to call mini8 the bath-tub. Those octopus-resembling braided channels remain etched in my memory.

          • ad3-05af-4a9e-bb66-7e58cf71f3a4

            Mini 8 overflowing. This was when the greater caldera began to collapse, not just Halemaumau, so the effusion rate was probably way higher than the accepted average of 250 m3/s. That and the volume is a lot more than expected, 1.3 km3 DRE, turns out there was way more that went into the ocean than the original measurements accounted for… 🙂

            Not sure, but I think that would also make it bigger than Holuhraun, or very comparable, and it was erupted in half the time too.

          • well it wont show, but it is ‘July 15 2018 Lava surge and New Island’

  26. Geldingadalir looks like its skipped the breaks, just lava on tap now…
    Flooding out without end.
    Is this real or has the close up cam gone into a loop LOL’s

    • Camera blurry with rain at times, but lava appears to have been flowing continuously and almost directly into tubes all day. About two hours ago, volume increased and surface flows spread. Hopefully we will get tomorrow the new flow rates based on Friday’s flyover.

  27. Small blobs of lava have been found 3km away from the eruption site, most probably from earlier in the eruption when the huge fountaining was going on. From the Fb group “Jarðsöguvinir – Friends of Historical Geology”

  28. It is interesting to see the transition from pulsing to continuous flow reflected in the seismogram.
    It looks like the flow will be continuous now.

    • I’d like to see a few more days with no pulsing before I’d think that that episode is truly over.

    • The faf highpass 2.0 seismogram is not showing up in my original post, the transition is obvious.

  29. It will be interesting to see how much longer the south part of the active cone stands up. More leaks have developed as of this writing, 23:51 pm. It seems like the hot lava wants to etch away several channels at once now.

  30. Flow rate is very high now, it looks as high as it was back in the fountaining days only it is now a continuous river. It is evidently too big for the existing tubes because the ponds are filling again and overflowing, as well as a leak appearing in the side…

    • Hard to tell too but it looks like the lava lake level is lower, like the lava is cutting down into the cone. There is a lot more vigorous bubbling in the lake too, could be because of increased flow rate or because there is less lava over the vent, probably a bit of both, but it looks like it is trying to fountain again.

      Would very much like to see an overview of the area, particularly of north meradalur, if that really is where most of this lava is going.

      • The vent has grown massively, sideways as well as up. Presumably melting of the interior was compensated by splatter/overflow on the outer edge allowing the vent to grow seamlessly. Since fountaining reduced and overflow became concentrated its not unlikely the sidewalls (not structurally great) are being eroded/melted from inside. So its not impossible that sidewalls are getting thin.
        In which case they may start to fail in places,

    • Yes the channel is definitely lower, it is cutting down into the cone. Fountaining is also starting up again, still more like violent lava lake overturning but it is continuous now, as is the flow from the crater. But it looks way higher than 10 m3/s, just on my observation.

  31. Lots of long period earthquakes on Kilaueas east rift, near Mauna Ulu. Not so much at the summit but the tilt is still inflating, that last DI event was tiny and the trend is holding for an upward rise on the order of 6 microradians this week and 17 for this month. GPS has shown cross caldera distance increase of about 6 cm in the last 2 weeks. CRIM station has moved 1.5 cm east in the last week too.

    • 12-13 microradians last month. Counting from the bottom of a DI event wouldn’t be right. Still though it is very rapid inflation. This doesn’t mean the eruption is imminent though, it will depend on how much more pressure is required to erupt than last time, probably how much it takes to overcome the added weight of the lava lake.

      • The typical rate of inflation was 6-8 microradians per month in 2019, while in 2020 it was lower, sometimes none at all.

        • I guess if it is about the weight of the lava lake then it will take an extra 40 million m3 on top of whatever set off the December eruption. There is high supply right now so that might be around 2 months off. Probably it isbt that simple though, if the rift conduit can reach the Heiheiahulu magma chamber, or even Pu’u O’o, then it will have potential access to an area at lower elevation than the floor of Halemaumau, be that the bottom of Makaopuhi or Pu’u O’o, or the area around highway 130. At present though only the segment to Kanenuiohamo is open and that is all 900 meters elevation ir more, much above Halemaumau.

          Course this is all a guess, if the lake fills up to the rim of the 2018 caldera we have a Nyiragongo situation of the highest calibre, I dont know what will happen then but being on a rift zone isnt recomended.

  32. This thing looks like it is about to fountain big time, like the only thing stopping it is the lava lake above the vent, which is slowly draining as the channel erodes, and more leaks appear.

    • However, as the lake level in the cone drops, there will be more wall collapses as the relatively weak walls lose the support of the lake.
      It is not easy to say what impact such collapses will have on the eruptive behaviour, as we have seen pretty much everything from near immediate fountains all the way to a whole lot of nothing, so the results of the lake draining will be quite unpredictable.

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