Posted on by Jón Frímann

Bárðarbunga volcano update at 20:49 UTC

This information is going to get outdated quickly. Minor spelling note. It appears that dike is spelled with a simple “i” not a “y”. Information on what volcano dyke is can be found here on USGS website. Added: That is in U.S English, UK English uses Dyke so I am going to use UK English. Thanks to Squonk to pointing me to this information.

Special note on Askja volcano

There are many people speculating that the dyke might reach into Askja volcano. I find that to be unlikely outcome. That does not appear to have happen in the past and I don’t think the geology setting allows for it. The area is full of old dykes that have cooled into granite type of rock (and other hard types of rock) in the crust (this is a volcano area and I find this to be likely). Given the density and how hard granite is I find it unlikely that this magma is going to break it. It has been crossing softer rock in the crust for the past week. What I can’t rule out is that Bárðarbunga volcano might start an eruption in Askja volcano by some other mechanism that might or might not be well understood. Askja volcano did start to prepare for eruption cycle in the year 2010 (earthquake swarm at 20 km depth was the clue), but the process appears to be slow, at least the volcano doesn’t appear to be ready for an eruption as things look now.

Special note on Tungnafellsjökull volcano

Yesterday (24-August-2014) an magnitude 3,0 earthquake took place in Tungafellsjökull volcano, a small volcano west of Bárðarbunga volcano. There had been few other earthquakes also yesterday, just smaller. Currently there is nothing suggesting that Tungafellsjökull volcano is about to erupt. There has been earthquake activity taking place in Tungafellsjökull volcano during the past year, suggesting that the volcano is experiencing flow of new magma at depth (more then 15 km depth), but there isn’t anything to suggest that an eruption is imminent in it. There is also a good chance that current earthquake activity in Tungafellsjökull volcano is due to stress changes in the crust that are taking place due to the caldera of Bárðarbunga volcano is getting lower (more on that later in this article). I don’t think Bárðarbunga volcano is able to start an eruption in Tungnafellsjökull volcano, but this is also an volcano that has never erupted during historical times and current data suggest it might not have erupted at all during the last 10.000 years (or more). Tungafellsjökull volcano is located west of Bárðarbunga volcano, it has a green star on it currently (as of this writing) on Icelandic Met Office earthquake maps.

Bárðarbunga volcano update

Earthquake activity remains strong in Bárðarbunga volcano. Medium sized (magnitude 5,0 – 5,9) earthquakes (more information here)) have been taking place as the caldera gives away due to outflow of magma from the magma chamber in Bárðarbunga volcano. This appears to be happening due to less inflow of magma from depth (the mantle). The crust in this part of Iceland is up to 46 km thick due the mantle plume beneath it (more information in details here, warning a large pdf file). The lowering of the caldera is creating stress changes in the area. What the end result of that is going to be I don’t know, since the crust is slower to respond, but as more stress is build up in the area this way stronger earthquakes can be expected at later time.

Currently the dyke is now at location that last erupted in the year 1797, it has remained bit unclear if it was Bárðarbunga or Askja that started that eruption. Chemical analyse says the lava is from Bárðarbunga volcano, not Askja volcano. This is according to the news I did hear today. Currently the dike north end is now 20 km east of Trölladyngja. Earthquake activity has been picking up and increasing in that area for the past 24 hours. It however doesn’t appear to be as high as it is on the main area of the dyke (about 20 km ENE of Kistufell, north of Dyngjujökull glacier, just check the earthquake map if you are confused by this).

140825_2015
The earthquake activity for the past 48 hours in Bárðarbunga volcano. Green stars show earthquakes with higher magnitudes then 3,0. Copyright of this image belongs to Icelandic Met Office.

140825_2015_trace
The earthquake activity during the past 48 hours in Bárðarbunga volcano has been dense. Copyright of this image belongs to Icelandic Met Office.

dyn.svd.25.08.2014.at.20.25.utc
Harmonic tremor remains high on Dyngjuháls SIL station. It goes up and down in accordance with the magma inflow into the dike. Copyright of this image belongs to Icelandic Met Office.

ask.svd.25.08.2014.at.20.32.utc
Harmonic tremor is also high on Askja SIL station. Same movement can be seen as on Dyngjuháls SIL station. Copyright of this image belongs to Icelandic Met Office.

DYNC_3mrap.svd.25.08.2014.at.17.39.utc
GPS data shows that more magma has flowed into the dyke during the past 24 hour. More GPS stations can be found here. Copyright of this image belongs to University of Iceland.

In the news today in Iceland I have seen that there is now some discussion that this dyke might not erupt at all. Since it appears both to be getting deeper in some areas and there are currently no signs of it going upwards. The problem with this is the idea is in my view based on wrong parameters so I don’t agree with it. This dyke is going to erupt in my view, it is just a matter of time now. It might not erupt, that is always a possibility. I just think it is highly unlikely to be the outcome of all of this. This dyke is going to continue making a path for it self until it hits a resistance in the crust it cannot break after that it is going to go up, since its easier path for it, rather then to go down into the crust where its path has more resistance. When that might happen is something that I do not know.

Article updated at 21:03 UTC.
Article updated at 21:26 UTC.
Article updated at 00:13 UTC on 26-August-2014.
Article updated at 10:35 UTC on 26-August-2014.

71 Replies to “Bárðarbunga volcano update at 20:49 UTC”

      1. Oxford Dictionary:

        Definition of dike in English:
        dike
        Syllabification: dike
        Pronunciation: /dīk/

        Entry from US English dictionary
        noun
        Variant spelling of dyke.

        —

        Americans are always right about English words, its a product of certitude. I just speak Ostraylyan, which is another language altogether.

        (‘A’, not ‘O’)

      2. I think when they were naming it they didnt have additional meanings in English. I mean REALLY, they could have called it an umpty ump… just as easily.

    2. Dyke (or Dike) is also an ancient English surname.
      Named for – The Dy(i)ke men – Builders and defenders of dyke fortifications.
      The Dykemen were a Celt(Norse)origin border tribe who inhabited the lands in the West of England below Scotland and beside Wales.

      A fortification was normally a wall with a ditch (dyke) in front of it. The wall might be only six foot (2metres) high but the ditch in front was also 6foot (2metres) deep. So an attacker could be standing in the bottom of the dyke and be looking up at the defenders on top of the wall 12 foot(4 meters) up.

      During sieges the ditches(dykes) were often filled with water forming “a moat”
      The defenders would then fill the wet ditch with offal and sewage.
      Attackers would be loathe to stand in a smelly ditch trying to attack a wall partly because any wound or cut would become infected from the poisonous concoction in the dyke.

      The Normans didn’t like the Dykemen – they were loathe to enter the smelly defenses. Instead the lords of the Dykemen were given titles – it was easier to make friends with them .
      Later on the Dykemen sided with the King against Cromwell. When Cromwell was dispensed with and the monarchy reinstated, the Dyke Lords were given a Baronetcy. This Baronetcy exists until today. The Dyke-Acland Baronetcy.
      (A few hundred years ago the Celt dynasty mixed with the Normans – hence Celt Dyke, Norman Acland.).

      Over the years the term dyke also became a military term for a ditch used for the latrine. Hence a military office would order some crew to build a dyke. This was a long ditch dug to be used by the ordinary soldiers to be used as a latrine.

      anthropology/

  2. Excellent job, Jón. I agree it’s less likely that the dike reaches Askja but not impossible that a decent seize earthquake could trigger something there.

  3. Thank you for the update!
    Can’t wait to see some ash soon :p

    Good night and keep the flow :o)

  5. “There are many people speculating that the dyke might reach into Askja volcano. I find that to be unlikely outcome. That does not appear to have happen in the past and I don’t think the geology setting allows for it.”

    This is exactly what is thought to have triggered the 1875 plinian eruption in Askja:
    Sparks, R.S.J., H. Sigurdsson and L. Wilson, l977. Magma mixing: a mechanism for triggering acid explosive eruptions. Nature 267, 3l5-3l8

  7. What’s going in at katla?

    There have been a fee quakes over the past week but most have been shallow, I figured maybe they where just icequakes.

    Tonight though I see a mag 4 and it’s been checked.

    1. This are not ice-quakes, they appear on my geophone in Heklubyggð. They are low frequency earthquakes. I am not sure yet if this is something to worry about just yet.

      1. Perhaps then they are maybe connected to what is going over the vatnajokull region?

        But why would they be so shallow?

  8. People say that the volcanoes on Iceland are not connected wich is somewhat true, but if we look at the bigger picture Iceland is planted on top of a enormous hotspot, that lies deep under the island.All the magma/lava comes from that single large hotspot.So if its unrest in one part it will somehow affect the rest of the volcanoes placed on the top op it.Its like stirring a fish bowl of water. Now magma/lava will always seek the easiest way up and out, and will try to find the weakest point to erupt from. its like water in a river, if it meets and obstacle it takes the easiest way around or changes direction and goes around. Now if the dyke tries to go toward Askja, it might not be able to break through the granite , but it might cause such a stirr under Askja volcanic field, that might trigger Askja to start something. We also see some quakes at Myrdalsjøkull, but that i reckon is because the whole hotspot is in some unrest because all the quakes happening at Bårdarbunga.it just makes all the volcanoes “nearby” to become affected by it slightly, it does not necessary have to lead to anything, but it has happen before . What will happen the next few days is in the hands of nature it self, we can only speculate but I am not surpriced if it ends with an eruption somewhere at the dyke. When it comes to Katla, my guess we only will get some unrest, small quakes, maybe we even get a small swarm, but I think it will calm down again. Im more worried about Askja, as she has had movement and unrest for a while and there have been some movement of magma under there for some time, there has even been a large landslide, not so long ago, so something is stirring underneat that lake. if she goes of,it wont be pretty. When it comes to Tungafjellsjøkull, its the same as with Katla, its only unrest because the whole hotspot is affected by the large swarm under Bårdarbunga,I dont think she is going to blow at this moment, but if she does , something dramatically,will happen as that volcano has not erupted for the last 10000 years or so and Volcanoes that has had looong resting period usually wakes up with a big bang. what is certain is, if this keep going on it will lead to something, Now some friends of mine have asked me if there is something going on at Laki, but i belive that fraction is still quite calm, there is sporadic quakes there , but being located between Vatnajøkull and Myrdalsjøkull, it lies on another branch so to speak,and hopefully its not much affected by Bårdabunga. Now this is only speculations I have, but it somewhat seem logical to me. If we get an eruption it will happen somewhere between or around Bårdarbunga and Askja. what does you people think?

    2. Nicely said, btw, take a look at the vertical CGPS for Grimsvotn.

      Curious for your thoughts on why that’s happening?

      —

      Personally, I think the site of eruption is almost irrelevant if we were talking a potential tensional decompression melt. Anywhere that magma comes out will be bad. In the end the style of the eruption will be trumped by its overwhelming substance no matter what orifice or combination of them that it uses. Cumulatively, similar effects come either way.

      If it is tensional spreading that leads to rift fissure extension than anything it disturbs in the preparatory phase up to that (say Askja) still would not much change the unfolding, because tensional spreading volcanism will not be altered by a pressure release at Askja, or even at Bardarbunga. It will only desist once the tension in the crust is lowered, and volcanism will only stop when the solids manage to cover the rift fissures and bury them again.

      So it comes down to how much tension has to be released, and where it will do so. It could be this side of Askja, or the other side of it. It could be incremental tension adjustment or it could be one of the big protracted episodes. If it is big tensional release the locus in crustal tension vector is then transferred next door to another volcanic fissure complex, so it rends open next.

      Hence the nature of the sympathetic connections and the ‘communication’ across the terrain, and tendency for them to connect at some level. If you are all being periodically pulled apart then the mutual wounds will always sort of connect or actually connect to the neighbours. The mantle drives, while the crust is just forced to get back into step with the mantle’s movements when the crust has been a-seismic and stretching too slowly for too long.

      As all crust is affected the same it will all resonate with the need to readjust to the mantle’s movements. If it happens in one place first, then it mus occur next door next. And any stiff resistance to tension release will result in the most forceful magma rise, tension pull apart fracturing, earthquakes, surface rends, and then the long battle to close it over and slowly settle it down again, for the next 150 years and remnant magma squirts out menacingly from time to time.

      So how much tensional dilation needs to be accommodated, determines if an eruption occurs.

      So I’d want to know, since 1477 say, how much the mantle moved, and also how much the crust moved to catch up to it. If the difference is large then a large rift fissure can and definitely will open (sans decollement). If the difference is small, then smaller eruptions will prevail, for a century or three, until the tension is too high again, so more rifting.

      It’s been 537 years since 1477. There has been plenty of volcanism but has there been enough catching up to the mantle yet?

      1. Yes, I think you are on to something here,. The Mid Atlantic Ridge ,pushes the continental mass, in 2 spearate directions(If we look at it in a big picture, there are some movements that goes in other directions also so its not just in one way,as the ridge it self has small branches that reach out and goes in other directions), westward and eastward, where the island of Iceland lies, there is a big Hotspot, that is stationary. Now as Iceland moves along with the ridge movement, some of icelands landmass will always be over the Hotspot area, and it will keep pushing magma upward toward the main crack of the ridge, so even if Iceland keeps moving in 2 directions the hotspot will continue to feed the active areas with magma, so it will keep on bulding the land as fast as it can manage.as an example, make a pancake. drip your batter on one place ,it solidifyes due to the hot pan, now continue to drip more and more batter at the same spot, and the cake will grov, solidfy and grov,as more batter is poured on. now take and split the cake in the pan while dripping batter on the same spot,the crak will soon be covered with new batter from that same area you split the cake, but its changed shape. this is how Iceland is formed sort of,. exept dont do this inside and the fryingpan must not be to hot as you might get an fire due to way to muc frying hehe,. anyways I think you are on to something, the Volcanoes and movement of the continental plates is of course conected under iceland, and When one volcano is in unrest and shows sign of eruption, others will be affected by the movement and eartquakes, it is as I said stirring water in a fishbowl ,Now when it comes to Askja, the magma is trying as hard as it can to move in that direction, But the granite, will be a tough nut to crak, unless there is some weaknesses and hidden pathways for the magma to travel under there scientists dont know about, there is probably more ways than we can count to make an eruption happen. “Nature finds a way” and sometimes it will do things that baffles even the most educated. Erik Klemmeti, has written some interesting things about what the possibilites are and how likely it is and what might happen if the magma finds a way to Askja. If it manages to do so and mix with the “slush” as he calls it, it might get very very interesting. But who knows what this event will become, it can easilly stop and become notting or it might erupt slowly and gently or it might become something we are going to write down into our history books, as I wrote earlier ,my guess is that it will lead to something,if its goint to erupt it will be somewhere between Bårdarbunga and Askja. It just need to find the easiest way up and out.

    1. Icelandic Met Office has confirmed this magnitude. This is the largest earthquake in Iceland since 2008. When a magnitude 6,3 took place on SISZ.

  10. Reply

    shane says:
    August 25, 2014 at 17:09

    If someone has pic’s of the lake from 3 days or so ago i think the lake ice is melting off,,,

    I think..
    Reply
    Lorride says:
    August 25, 2014 at 17:38

    So the lake is covered with ice all year? If not, why should there be ice now since its still summer?
    Reply
    Mafl says:
    August 25, 2014 at 18:04

    He meant another Lake in the Kverkfjöll-Mountains.
    Askja had no ice. There was a Landslide in July:
    http://en.vedur.is/about-imo/news/nr/2919
    Mafl says:
    August 25, 2014 at 18:08

    …but at the Askja Lake could be rest of ice in summer, because it’s also in the mountains.

    I was talking about : http://vedur2.mogt.is/kverkfjoll/webcam/index.php

    Is this not ASKJA, The one on the left..

    1. Yes,but I guess the hotspot under Iceland are the main deliverer to all the volcanic activity on iceland. the Ridge it self just helps the continental landmass that Iceland rest on to move, in eastward and westward direction, slowly twisting and splitting the islandmass in two.But I guess the hotspot will stay put on its center where it is now, as it really dont move much, and because of the ridge movement it leaves enough space for the hotspot to do its magic to create more land to the island. It would be coool if there was a simulation that showed how Iceland would become and how much it would change the next million years.

  13. Interesting!!!!

    Thanks so both ways are correct. And it sounds as [dík]

    Ostralian Ossies surfing the Ocean

      1. To make Things worse. A Dutchmen will definitely pronounce Van Dyke as ‘Ven Daik’. No matter what.

  15. You should definitely use “English” English, rather than that weird pidgin dialect called “American” English.

    2. The magma in the dyke is fed by the magma chamber in Bárðarbunga volcano. I don’t think the mantle is in contact with the crust at this depth. Since the crust in this part of Iceland is around 46 km thick.

  17. It appears that activity is slowly dying away. Is it likely that it will pick up again, or is it going to end with a whimper?

  18. Less than 8h ago a Eq 5’7 happened…the biggest from the series so far….
    We learn how to be patient with tremors and moves, but the chef is still at work I’d say…preparing what we can’t predict. Humans!!!!!

    1. possibly reached Askja’s granite and cant progress, but more movements around the edge heading for Herðubreið.

  20. Quakes seem to be on a downward trend but remember that the quake activity isn’t linear – Premature to say this is over by any means.

    Look at the tremor, for instance:

    http://hraun.vedur.is/ja/oroi/dyn.gif

    Harmonic tremor still high. It’s not at one of the peaks but the “typical” tremor we’ve had (at the time of writing) since this started has all been much higher than the prior background levels.

  22. And ust as I write that the tremor has jumped up, and seemingly earthquake activity too…

  25. A long line of almost simultaneous earthquakes up the valley east of Askja. Does anyone know if Herðubreið is the same composition as Bardabunga and whether it is as impervious as Askja’s seems to be?.

  26. Notice VONC has turned from SE to SW and sinking, so it also is now picking up the increasing tension and area subsidence.

  28. Saw a 3.3 over 30km deep under the main caldera chamber area. I would look for the main caldera to start to inflate again to signal fresh magma coming in from below.

    It would seem that right now the main chamber area quakes are being caused by settling of the ground, not inflation.

  29. If quakes are dying would it not be possible that it could be waiting on pressure building up again as it gets so far ahead of itself ?

    1. I wouldn’t be so dismissive at this point of life in Iceland changing dramatically. For me, its a wait and see to see what the effect of tectonic forces is on multiple volcano’s becoming active again. Perhaps a holy virgin or 2 would be prudent at this point.

  31. I’m curious about something. We saw the 5.7 come through on your Heklubyggð, Iceland webicorder last night, I saw when I got up that the magnitude had been upgraded.

    There’s a second quake on there, though, that looks even bigger, but IMO is saying it was a 4.6. Why would it look so much larger on your webicorder?

    1. The earthquake east of Trölladyngja was more tectonic in nature. The earthquake that take place in Bárðarbunga caldera are for some reason more volcanic in nature. That means they are lower in frequency then normal tectonic earthquakes.

      The earthquake east of Trölladyngja also did travel trough more solid crust then earthquakes in Bárðarbunga, that seems to be passing trough more magma then I would expect.

      I am still thinking about. I am working on ideas that I am going to write about in next update.

  33. A question and a bit of speculation on my part here…

    In the [unlikely] scenario that the dyke extends as far as Askja and triggers an eruption there, what effect would this have on Bardarbunga, assuming the source of this intrusion is from the magma chamber beneath Bardarbunga?

    Would the resulting eruption and continued pressure gradient draw yet more magma out of the chamber below the caldera, and contribute to a heightened risk of the caldera collapsing? If not collapsing, then at least “cracking” and allowing part of the glacier above to fall down, presumably resulting in a violent explosion.

    So, a lot of speculation here of course, but I’m just interested to think of what may happen under these circumstances – any thoughts?

  35. Excellent site Jon good effort. One question – has there ever been a recorded incident of this much seismic activity without a significant eruption occurring?

  41. This volcano watching is pretty enthralling. I have to admit that I may just have caught the bug.

    I’m a pretty fast reader so I’ve already been through “Eruptions that shook the world”, “Tambora, the eruption that shook world” and “Island on Fire”, since this thing started.

    I would really appreciate some further reading recommendations to get me up to speed on Volcanoes.

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