Posted on by Jón Frímann

Possible minor eruption in Bárðarbunga volcano caldera

It appears that at 21:22 UTC (on 29-January-2015) a possible minor eruption might have taken place somewhere along the Bárðarbunga volcano caldera rim or in it slopes. I don’t have any confirmation yet, but this is what the tremor data suggest at the moment. This minor eruption appears to have lasted around 30 – 55 minutes in total. If there was an high amount of glacier melt the glacier water is going to start appearing in Jökulsá á fjöllum or other glacier rivers that come from Vatnajökull in next 8 – 18 hours. Depending on the router the water takes. I don’t know where it is going to go, but the highest chance is that it is going to appear in Jökulsá á fjöllum glacier river. This minor eruption was followed by a minor earthquake swarm, the largest earthquake in that swarm had the magnitude of ~4,5 according to automatic results.

150129_2350
The earthquake activity that followed this harmonic tremor (the red dots). Copyright of this image belongs to Icelandic Met Office.

dyn.svd.29.01.2015.at.23.55.utc
The harmonic tremor spike can be seen on Dynjuháls SIL station at the end of the blue line, where it spikes up. Copyright of this image belongs to Icelandic Met Office.

skr.svd.29.01.2015.at.23.45.utc
The harmonic tremor spike as it appears on the SIL station on Skrokkalda. The spike is clear based on other activity that appears clearly on this SIL station (earthquakes). Copyright of this image belongs to Icelandic Met Office.

dyn1_trem.svd.29.01.2015.at.23.58.utc High resolution image of the harmonic tremor on Dyngjuháls SIL station. This is the signature of eruption under the glacier. Even if it was just a small one. Copyright of this image belongs to Icelandic Met Office.

If anything more happens I am going to post update soon as possible. I am going to write about the earthquake swarm on the Reykjanes Ridge tomorrow.

29 Replies to “Possible minor eruption in Bárðarbunga volcano caldera”

  1. Hmmmmm . . . I wonder how much water has to be released to avoid freezing currently about as soon as it reaches to glacier or open-air river.

  5. Interesting that borehole strain data is rising again at Hekla and burfell http://hraun.vedur.is/ja/strain/1sec/index.html

    M3+ eqs at reykjanes also in same time period as this swarm and tremor.

    Whatever happens in bb, we must not forget to keep a weather eye on larger area, if Jon is correct it is unusual that a subglacial eruption takes place during a relatively calm period in eq and GPS activity. The IMO and emergency services have been preparing for a flood so there has been an official presumption this is likely.

    The cauldrons on bb have been getting deeper and we know magma is close to the surface. It being at higher altitude than holuhraun means it has not gravitationally drained, so it increases the likliehood that other chambers are not empty either.

  7. IMO’s update is coming late. They’re probably considering what to announce without having more detailed information available.
    http://en.vedur.is/photos/jarvatj_rit/150130_1245.png
    It looks to me like that you saw this correctly, Jon. The exact location and extent of this small eruption has to determine whether to expect or not to expect a jokullhlaup. The highest peaks of the rim might only have a thin layer of ice and snow.

      1. Look at the location: Grimmstadir.

        I *know* that farm. I interviewed the farmer about his plans for floods when I was filming there last year. I’ve seen the civil defence maps; from the time a flood leaves the glacier it takes around 8 hours to reach Grimmstadir. The water was rising even before the apparent eruption started; not saying there won’t be a flood but the timing doesn’t quite add up.

      2. The event is progressing ,continued heating of the caldera ,melting ice which is possibly contained in a subglacial lake or lakes?

  8. Friday
    30.01.2015 12:31:46 64.669 -17.472 0.4 km 4.1 99.0 4.1 km NE of Bárðarbunga

  9. 30 January 2015 11:00 – from geoscientist on duty

    A rather intense earthquake swarm occurred at the Bárðarbunga caldera (nothern part) last night, January 29th, between 20:50 and 22:30. UTC. Most of the events were small but the two largest events were of magnitude M4.4 at 21:22 UTC and M4.6 21:45:29 UTC.

  10. The clear area of Mila Cam 1 is showing a lot of steam coming from the river in front of the camera.

  12. Jón writes about a new tremor spike on twitter 1/2h ago.
    Are there news on it?

    A M4 (+-) quake happened around that time, too.

  13. If there was an high amount of glacier melt the glacier water is going to start appearing in Jökulsá á fjöllum or other glacier rivers that come from Vatnajökull in next 8 – 18 hours.

    Possibly not. If the eruption was INSIDE the caldera, it can remain trapped in there until water level reaches a point where it finds a path through the caldera wall.

    1. And even then it would have to be warm and sufficient enough to get anywhere, never mind leave the glacier

    2. But there is a significant rise of water levels in the last hours and also the water is warmer than usually compared to air temperature.

  15. Are you located in Iceland? Are you aware a solar eclipse will occur (80% visible) in March (not sure on the date- near end of march?) prior to the next 4 Blood Moon occuring. Apparently the last solar eclipse occurred over the African area (just prior to the outbreak) where the Ebola problem is at.
    Tks for info on this Iceland volcanoe- keep us informed.

  16. Friday
    30.01.2015 18:16:01 64.660 -17.397 0.1 km 4.0 99.0 6.6 km ENE of Bárðarbunga

  17. IMO has put out a very comprehensive update for today with numerous charts and graphs; just keep scrolling down past the normal text report to get to the details of activity over the past five months.

    1. That is an excellent, very informative update. Thank you Univ. of Iceland, IMO, and Dept. of Civil Protection

  18. Sorry, poor access via phone. Which station are you seeing this at and are you looking at a 30 day graph to get a good comparison?

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