Posted on by Jón Frímann

Bárðarbunga volcano continues to deflate

The eruption in Holuhraun is over and nothing has been happening the crater for the past three weeks. This does not mean the deflation is over in Bárðarbunga volcano. Currently Bárðarbunga volcano continues to deflate at the rate of 2cm/day, total deflation since 31-August-2014 is around 60 meters. All this deflation has started to move the glacier inside the caldera, creating what appears to be inflation, that change in the glacier, that inflation is 1,5cm/day. That inflation should be 3-4cm/day according to Icelandic Met Office, so the difference is the deflation taking place. Currently the GPS sensor inside Bárðarbunga volcano caldera is not working so the only way to monitor this deflation is to continue to fly over the glacier and measure it that way. Next scheduled flight for Bárðarbunga volcano is going to take place after Easter.

News in Icelandic

Bárðarbunga hefur sigið um 60 metra (Rúv.is)

25 Replies to “Bárðarbunga volcano continues to deflate”

  5. Scots John, What do you think this means in relation to the present situation at or around Big B. Also, does this mean the the rifting is continuing, and if so are things moving faster or slower? I have so many question that I would like answered! Sometimes, I think I am just too curious!

    1. You can never be too curious!

      I am puzzled by the lack of movement on other stations. I’m sure the IMO would have the data corrected for variables by now, the tremor in the region is still very high, and I am also noting heightened wave form activity on Hellas borehole strain data.

      http://hraun.vedur.is/ja/strain/1sec/index.html

      I am reading this as indication that the event is far from over, rifting is continuing yes, it always will to varying degrees, but its what is happening with pressure and magma flow deep down that is the concern. There may not be major warnings of any eruptive cycle since the magma has already established channels in which it is now confined.

      It does not have to be bardarunga that goes, it could be any of the vatnajokull volcanoes, and potentially others. I’m not forecasting impending doom, it may be less impressive than holuhraun, but I suspect it will start subglacial. Timescale is impossible to determine from the available data, but it will happen.

  6. I’ve been backtracking GPS data and there seems to be an error, I’ll come back on this at a later date when I’ve checked this out fully.

    1. Yes, seeing this continued activity in the dike is interesting. Is this due to lava still trying to find a new path or is lava retreat and cooling causing the small quakes.

  8. Scots John, Thank you for your helpful ideas and information. There is little information for me, a complete novice, that I can understand. I just have to ask and keep wondering. I miss all the chatter and discussion that was so interesting during the eruption at Bardarbunga. I wonder now if lava is on the move or if it is in retreat. When I have looked at some of the data, I think I am still seeing tremors, but I really do not have the knowledge to trust my interpretation. It is interesting to get the information that the rifting event is still probably continuing as was predicted. I am hoping you and John will continue to keep posting about all that is going on in Iceland and in particular the EVZ. Thanks again and please keep posting! 🙂

    1. Just back from Iceland, and I wondered whilst I was there (with only v limited internet access) about the same dramatic movement of GFUM that Scots John reported. However, it seems now to have disappeared from the velocity charts.

      As to how long the event will go on: I bought Thor Thordarson and Armann Hoskuldasson’s excellent Iceland book in the Classic Geology in Europe series and leafing through it, I was reminded that the Krafla Fires lasted from 1975 to 1984, in a system that was 100 kms long. T and H also record that during that period there were 21 rifting events as the caldera gradually inflated and then suddenly deflated. Many of these deflations were accompanied by eruptions, one of which – in July 1980 – I was fortunate to witness. Also, the largest volumes of lava were erupted during the second half of the episode.

      So, as Scots John and others have pointed out, it is unlikely that this episode in Bb is over.

      2. Wind wasn’t too bad, except last night when it turned northerly, but everyone was talking about how stormy the winter has been.

        I got very excited by the (erroneous) GFUM reading and carefully explained it all to my wife. Thought we might have a show from Grimsvotn while we were there. Ah well!

        Not quite sure what you’re seeing on Mila 1: to me, it doesn’t look much different to what we had when Baugur was erupting. I haven’t been checking M1 much since Baugur shut down, but I’d have thought it was lava cooling on contact with water and/or steam/gas coming off the lava that is already there.

  10. A bit of gas or steam (seems to be lasting too long for steam), coming from front edge of Holuhraun on Mila 1 at the moment.

  12. Yes. What can one make of the recent continual quakes under Öræfajökull..? It’s also mentioned in the comments to the latest blog update, and I’ve noticed it myself over just the last few days, especially because the quakes have been relatively close to each other. (A red dot covering an orange dot, covering a couple of yellow, and so on 🙂 ). But depth-wise they span from roughly 3 to 12 km.

    Since there’s relatively low activity currently, both under Vatnjajökull and here on Jon’s blog, (Plus a blank signal from caldera GPS) I might as well come up with atleast something more to add:

    Von stations show a lot of small activity going on now (22:40 and has been doing so for some hours), I reckon? IMO has not picked it up yet, so might it be other factors? Or is it in deed a minor swarm?

    http://hraun.vedur.is/ja/drumplot/von.png
    http://hraun.vedur.is/ja/oroi/von.gif

    1. *Err. Maybe swarm was too dramatic a term to use here, but a rise in activity at least..?

  13. Jon and others here have said that things will continue to happen. We do not know where, when, or how explosive the next event will be. I am thinking vigilance could be important, since precursors of the next event could start small and may be over looked. I for one would like to get acquainted with the next event at it’s beginning. So, I will continue to lurk about IMO, Jon’s, and other sites to keep up with the latest news. Expectations and new ideas about what will be next could be fun.

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