Posted on by Jón Frímann

Grímsfjall/Grímsvötn volcano eruption update at 16:02 UTC

Here is the second update today of the Grímsfjall volcano. But it is also known as Grímsvötn.

Process of the eruption: The eruption has not changed a lot since this morning. But its power has dropped a little bit since it started yesterday. But there also seems to be the case that this eruption increases on regular basis. But it is impossible to know for how long that eruption pattern is going to continue in Grímsfjall volcano. Early estimates of this eruption (reported by the news in Iceland) is that this eruption is about 10 times bigger then the eruption in Eyjafjallajökull volcano. But that is a early estimate and is a subject to a change. But in general there is nothing to suggest that this eruption is slowing down, even if it does not have the same power as it did in the first few hours of eruption.

Ash cloud: The ash cloud has dropped a little from it’s high of 20 km. Current measurements place the hight of the ash cloud around 15 to 18 km high up. Reports say that the lowest point was around 10 km, before the ash cloud did get higher again. Update 1: There have been recorded over 15,000 lightnings in this eruption alone. But they where recording 2198 lightning in 1 hour since the eruption started. News about it can be found here (Icelandic, picture). Update 2: The ash cloud is now from 10 to 20 km high. But it depends on the power of the eruption. But that seems to change over time and does not remain a constant.

Earthquakes: So far, most of earthquake activity in Grímsfjall volcano has stopped. But that suggest that the magma now has a clear path to the surface. There has been some earthquake activity in Hamarinn volcano. But it is unclear if that is connected to the eruption in Grímsfjall volcano.

Other: It is dangerous to go into the ash cloud. The government has closed off part of road one due the ash cloud. People how find them self in the ash cloud should find a shelter soon as possible, or of they are inside a house they should remain there. Reports are of communication problems where the ash clouds goes over due to static charge in it. This interferes with GSM, 3G phones, radios and tv receptions. In worst cases people can not expect a reception of any radio signal where the ash cloud is most dense.

Sorry for lack of links. I do not have the time to post them into this blog post.

Please note that information here might get outdated really fast and with no warning at all!

Updated at 16:17 UTC.
Updated at 16:26 UTC

71 Replies to “Grímsfjall/Grímsvötn volcano eruption update at 16:02 UTC”

  1. The 2010 Eyjafjallajökull eruption has been classified as VEI4. Since Grímsvötn’s is apparently 10 times bigger than that, does this means it could be a VEI5 eruption?

    1. No, bear in mind that the 2010 eruption was hardly a VEI4, rather a VEI3. For a VEI 5 an ash cloud has to exceed the 25km height and the emitted amount of ejecta has to be at least 1 km³.

  2. An intial EQ was picked up yesterday as a 4.0
    GFZ Potsdam – Earthquake Bulletin
    F-E Region: Iceland
    Time: 2011-05-21 18:53:22.4 UTC
    Magnitude: 4.0 (mb)
    Epicenter: 17.76°W at 10KM depth.
    But the depth, 10KM is used for various shallow depths, may not be relevant
    None since. So is this the initial eruption?

  4. The reason the Eyjafjallajökull eruption was classed on Wiki as being VEI 4 is that the DRE (Dense Rock Equivalent) ejected was over 100 million cu m, or 0.1 cu km. However, at no stage was the eruption powerful enough to be classed as a VEI 4. Most of the time, the explosivity was in the VEI 2 range, occasionally reaching VEI 3. I guess professional vulcanologists would only class it higher than VEI 2 because of the amount of DRE ejected. Using the Eyjafjallajökull eruption as a measure – if this goes on as long, the DRE *might* approach 1 cu km BUT the explosivity would place it no higher than VEI 4, being VEI 3 most of the time.

    Once the Norvol starts issuing bulletins, we shall know more about how many tonnes are being ejected every second, get their estimates of how much DRE is involved etc. My guess is that this eruption would rate a VEI 4, not more, unless of course there are significant developments over the next few days and weeks.

    1. An enterprising vulcanologist needs to come up with a new scale for the instantaneous power of an eruption. VEI tries to address both instantaneous and cumulative, and thus isn’t so useful during an eruption.

    2. Using the Sparks equation and a 12 km plume height, a rough guess is about 2026.8 cubic meters per second. The Mastin et al refinement of that equation would put it at about 1693.7 cubic meters per second.

      In both cases, the accuracy is a “factor of four”. In other words, it could be four times greater, or smaller, than the equation.

      http://www.geo.mtu.edu/~raman/papers/MastinetalJVGR09.pdf

  5. Was the Eyjafjallajökull ash cloud also dangerous to peoples’ health or was the ash too fine to be dangerous?

    Do you guys think the government will close the road when Katla goes off too? When I took a trip to Iceland last year an Icealandic tour guide told me about his experience in Eyjafjallajökull’s ash cloud when it was at it’s darkest and I made it my mission to drop everything and try and come back and experience that if a similar volcano erupted.

    1. Good luck getting to the island 🙂

      I´d love to see this one, too.. unfortunately there´s no time and space for me to witness this. Waiting and hoping for another one soon!!

      1. Thanks AlexBavaria. 🙂 That’s why I make donations to this site, so I can choose the right time to use up my airfare money on the real thing and not blow it.

    2. Eyjafjallajökull’s ash cloud was dangerous beacause the ash was very fine and the particles was very sharp. Small particles are harder to stop from geting in the lungs than larger particles. Correct me if I’m wrong, I am no expert at this.

  6. I wish there was a web cam. I also hope everyone is safe and well even though this is very interesting

  7. Really impressed with your diagnosis Jon. Been watching for over a year now and you are spot on, not slept either with all the excitement last night and its not over yet!

    So why isnt this a priority world wide. In the UK this news was only mentioned as the last highlight and only aired for a minute. If I blinked I’d have missed it. Did they want us to listen to all the rubbish first to keep us on the channel…As you all say if this happened in California…….?

    Henrik you said “When will we begin to read articles about impending Doomsday because of this eruption?

    Well its happening now Twitter is inundated with it and it will only be a matter of time until this event is related to “Rapture” and twinned with the 6.1 EQ in NZ yesterday (which wasnt even felt by anyone)
    Whatever happens keep up the blogs they are brilliant. Thank you

  8. Volcanic “ash” is always dangerous to your health. It’s minute, microscopic particles of roch, akin to glass, with very sharp edges. If it gets into your lungs, it will cut the microscopic blood vessels and cause haemorrhaging (bleeding). If you inhale large amounts, and I do mean LARGE amounts, the blood and ash will mix to a cement-like substance and you’ll slowly suffocate.

    The ash is also coated in and contains trace omounts of substances such as fluorine, which can play havoc with the digestive systems of herbivores such as sheep. Not a big problem for humans except indirectly if their cattle, sheep, horses and goats die.

  11. When I went to Iceland I heard that Iceland’s media reported that breathing in the ash of Eyjafjallajökull was comparable to breathing in Los Angeles, the size of the particles are the same. Now that I think about it that sounds a little hard to believe. But I certainly hope, for the people close by, that ashy air is only linked to higher disease risk and doesn’t cause disease a large % of the time.

    But I was just wondering about if this is a new policy by the government or if the road is only closed because it’s a different kind of ash, because last year I don’t think they closed roads.

    1. I think that is the normal color, Google Blue Lagoon Iceland and look at the pictures.

  13. Rob James on May 22, 2011, 1:07 PM
    Any official confirmation that Hamarinn has also erupted now in unison with Grimsvotn? Hamarinn being located to the west of the Vatnajokull glacier.

  14. I just woke up, local 7pm, the sky is all overcast in a yellowish grey fog, here north of Selfoss. There is already a fine ash layer outside. This is unbelievable how the cloud got already this far!!!! I cannot believe!

    We are about 1hour east from Reykjavik, so probably the cloud already reached there as well. This never happened with Eyjafjallajokull. Its crazy. The size of the ash cloud is now huge, because ash falls all the way from Vatnajokull to Selfoss.

  15. As there has been a (theoretic) connection between Grim, Hamarinn and bardarbunga how big of a risk is there that this eruption will affect these two volcanoes? As far as I know Bardarbunga is the central volcano right?

    Lurking has made alot of plots in the past (thanks for all of them Lurking) and there seems to be a clear connection between the three of them.

    And deep earthquakes has been occuring beneath both Hamarinn and bardarbunga now since the eruption of Grimsfjall. Tremorwise it has been a similar increase as Grim also but that might just be Grim roaring.

    1. Bárðarbunga is the central volcano for it’s swarm. Hamarinn is it’s little sister. Grímsvötn is also a central volcano with it’s own fissure swarm, Tordarhyrna is it’s little sister. There has been some indication that the Bárðarbunga and Grímsvötn swarms may overlap or mingle, specifically in the events leading to 1996 Gjálp eruption. It was preceded by a Mw 5.6 under Bárdarbunga. (“The Puzzle of the 1996 Bárdarbunga, Iceland, Earthquake: No Volumetric
      Component in the Source Mechanism” Bulletin of the Seismological Society of America, Vol. 99, No. 5, pp. 3077–3085, October 2009)

      http://www.rses.anu.edu.au/~hrvoje/Tkalcic_etal_BSSA2009.pdf

      For more on Gjálp:

      http://astrogeology.usgs.gov/Projects/VolcanoIceWorkshop/website_archives/Vatnajokull.pdf

      The relationship of the different calderas and fissure swarms can be see in the Bouguer anomaly map from M.T. Gudmundsson, T. H¨ognad´ottir / Journal of Geodynamics 43 (2007) 153–169

      http://i51.tinypic.com/2d799vb.png

      Source Document:

      http://notendur.hi.is/~heidi/Data/Article-richard/GudmundssonHognadottir07.pdf

      1. @Lurking (and Daniel_swe for the hint). Phew… Thanks for that, great bedtime read (for the next few nights and more). I do get the impression that it may be more than one eruption site.
        captcha quote: “dsAllin gigantic”… Relevant?

      1. This is basalt eruption. So there might be lava fountains at the eruption site by now. If the water does not get into the crater any more. But it is impossible to know that for now due to ash cloud cover over Vatnajökull glacier.

  18. I want to see some news. From here home, north of Selfoss, 200 km west of Grimsvotn, I report an overcast sky with the ash cloud, really really smoky above. And some fine ash fall. I don’t like it.

    I am curious to hear more news about the volcano. Looks like to hear that eruption has taken a break. Its scary. This morning we drove 4 hour east, and it was pitch dark about 70km away from the volcano. When we were there, the police was almost closing the road from Vík eastwards to stop people getting into the ash cloud. Its getting darker here (cannot see the sun anymore) and we are so further away the volcano!

  19. Does anyone know if Hamarinn is erupting? The earthquake map looks like it might be.

      1. It is the mass of eartquakes just west of Grimvotn on the Icelandic Met office chart

      2. Bouguer anomaly map (gravity variation) from Gudmundsson et al. Full document linked in a previous post.

        http://i51.tinypic.com/2d799vb.png

        This shows the relationship of the calderas and fissure swarms for the the central volcanoes and their siblings.

  20. There is speculation about Hamarin.
    Yesterday we saw, at least 2 ash plumes. This was confirmed in many reports.

    Right now the ash cloud covers the entire glacier, so it is not possible to know about the site of eruption.

    Bardarbunga/Hamarin would explain the size of this eruption, the biggest in Vatnajokull since 1873. The ash released was very very heavy.

  21. With this I want to tell: only Grimsvotn is confirmed to be erupting. There is no visual confirmation of any activity in Bardarbunga or Hamarin, at least when flights went there yesterday. Today the ash cloud hides the entire glacier.

    1. Thanks. It really looks like Hamarinn is having a rather strong earthquake swarm, like it is erupting or about to. Does anyone know how big Hamarinn’s previous eruptions have been? Could it be having an under ice eruption, like that which forms table mountains?

      1. The earthquake map doesn’t seem to be updating for me. The last earthquake on the map near Grimsvotn was a few hours ago.

      3. This cluster of eq is not at Hamarinn, it’s more in the center of a triangle formed by Grimsvötn, Barðarbunga and Hamarinn. Iirc, we saw eq-swarms in that area before on one of Lurking’s plots.

      4. There has been EQ activity there ( ie ca 20-30 km NW of the plume) for past couple of years, as well as recently. Monthly EQ maps here:
        http://hraun.vedur.is/ja/viku/all/skj2010m.png

        But Bordabunga proper has had more action, though its quiet at present. Nothing I see from past two years’ accumulated EQs marks the ‘Hamarinn’ spot as special. But if it does erupt its under several hundres metres of ice, and the outflow might not run south. If it ran out north westerly down Sprengisandur it could reach Thorisvatn putting a large part of Iceland’s hydropower is at risk.

      6. I seem to remember that Gjalp has erupted before relatively recently. Can anyone confirm that for me please?

      10. Thanks Peter…Extremely informative find. A lot of great explanations re: volcanic formation and the local geo. I guess what ought to be considered in reference to the present is how thick the ice is.

  22. Jon
    Thank you very much for this blog and your great information search

  23. @treacleminer

    you can find more about Hamarinn volcano here:
    http://icelandgeology.net/?p=32

    Does anybody else noticed this eq at Katla caldera:
    Saturday
    21.05.2011 07:45:12 63.638 -19.068 22.6 km 0.6 99.0 6.6 km NNE of Hábunga

    Is it usual that Katla have that deep eartquakes (over 20km), i don’t remember i seen any eq that deep?

    1. Yes, but then we all wrongly predicted Grimsvotn would be a weaker eruption than it has been, so the truth is, no-one is ever sure how big eruptions will be or how long they will last. Far all we know there could now be a magma channel broken through from Bardarbunga to fuel Grimsvotn, we simply do not know, and unfortunately, nor do Nordic Volcanological Centre Institute of Sciences. Time will tell, but until then, everyone is guessing.

      1. Exactly my thoughts. Remember Eyja had a rather small eruption in March before the big one opened up in a different place. With all the quakes in this triangle, no one can say with any degree of certainty what is going on under there.

        What I wonder about is whether the mainstream news out of the west is cherry picking quotes from geologists out of the current context in order to minimize this eruption. Remember, the mainstream media always has some hidden agenda in their reporting these days. Its funny how in their subtle editing, how there is an underlying theme of conclusion with no mention at all that these assumptions could be entirely wrong or out of date given how fast things change. I dont even listen to what comes out of the media anymore.

      2. @RonF :A case of ssshhhh… “Don’t make them panic” ! One other reason could be that, not many scientists have much knowledge about what goes on under several hundred meters of ice, let alone the main”scream” press, and to keep us all guessing is great for the drip feed business.

    1. Luis:
      I have been grabbing snapshots from Jökullsárlón webcam regularly, and what you see now seems to be a slow moving (ash) cloud that was not there some time ago. Winds are slow at this spot. But I might be wrong.
      BTW Thanks for the link to article in Portuguese. I didn’t see any other reference for the ash plume reaching Canadian skies elsewhere.

    2. Surface wind is from north so ash can be blown southward of the glacier.

  28. It looks way better now in Jokulsarlon! The sun is shining there now!!! It was heavy overcast with ash this morning.

    But where I live, 200km west, we have now a heavy ash cloud above us, rather dark, and some ash has fallen during the afternoon. But only a fine layer. Cars blow the dust when they pass. Its going to be a darker nighttime for the first time in weeks.

    Any news on the eruption and earthquakes?

  29. In satellite we can see the wind entering from the southeast in Iceland, and a weather front coming. This is good news, it will clear the ash in the South Iceland, and stir the ash further north, away from Europe. The ash is going to fall mostly north of Vatnajokull where no one lives. I don’t know how is the eruption right now.

  35. I’ve been checking water/river flow rates at http://vmkerfi.vedur.is/vatn/vdv_gmap.php
    many have shown an increase prior to the eruption (view 3 day graphs) or was it raining? I hope most of the melt, went up with the plume and trust no jökulhlaups. Could it be possible that water is released prior to an eruption , or that Grimsfjall lake is that land locked?
    Thanks Jón… et al for all your dedication, and interest.

    1. Hard to say what is going on. But this eruption is setting it’s own rules. It did just throw out the rulebook that Icelanders had gone used to over the past 50 years or so in regards to eruptions.

    2. I think it already melted the ice close to the rock in the jökulhlaups last October.

  36. I am in Hella. Cannot sleep, I am a bit worried as I have a strange sore throat. Wonder if it’s because of the ash? We only drove to Vik and I did not go outside. Thoughts?

  37. Hi, I live in Dublin, Ireland and my car was covered by ash left after the rain poured on it late afternoon today. So the ash got to Ireland, I even felt it in my mouth after the rain. I was shocked by my discovery.

  38. Sulphurous smelly air just reached us in Torbay, Devon, UK. Not sure if it is from Grimvotn as it smells not ony of hydrogen sulphide, but also sulphur dioxide and thiols so might be of industrial origin. It’s a bit of a coincidence though as I have never smelled it here before. I have not noticed any ash, but have put out black and white shiny papers to see if I can collect any.

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