New swarm of earthquakes in Bárðarbunga volcano

During the night (26-November-2016) a swarm of earthquake took place in Bárðarbunga volcano. Largest earthquake had the magnitude of 3,8 other earthquakes where smaller in magnitude.

The magnitude 3,8 earthquake in Bárðarbunga volcano (green star). Copyright of this image belongs to Icelandic Met Office.

On 22-November-2016 a magnitude 3,6 earthquake took place in Bárðarbunga volcano. That earthquake took place in the south-west part of the caldera, close to the place where the dyke broke out in 2014.

The magnitude Mw3,6 earthquake in Bárðarbunga volcano on 22-November-2016. Copyright of this image belongs to Icelandic Met Office.

This type of earthquake activity is now so common in Bárðarbunga volcano that I can’t write about them all. If I did write about them all, there would be nothing but articles about Bárðarbunga volcano on this website.


Please remember to support my work with donations. Thanks for the support. 🙂

34 Replies to “New swarm of earthquakes in Bárðarbunga volcano”

    1. This is rubbish. Currently Bárðarbunga volcano is inflating due to influx of magma into shallower magma chambers, the new magma is coming from depth. When the next eruption in Bárðarbunga volcano is impossible to know, history shows that eruption cycles in Bárðarbunga volcano last around 10 to 20 years (at most). During that multiple eruption happens over with quiet time between them.

      1. What is garbage? What has a tremor in depth to do with magma? Nothing !!! Clearly Magma rises. Only until the magma chamber is full again does the decade elapse. And where are the GPS data, for example, which show the Bardarbunga fills itself again. Sure, Bardarbunga invites you again, but this is a normal process.

      2. Tremor only happens when two things happen in a volcano.

        1: An eruption starts.
        2: Magma moves inside the volcano in a such way that tremor forms. Why that happens is not well understood at the moment.

    2. Mike – Carl has many ideas and also some followers. Sadly, in my opinion, he is often wrong and makes statements about things he does not have facts to back up with. I suppose he doesn’t mean anything wrong, but I think there are many with scientific experience from the field you should listen to before you take what Carl says as the truth. He is a loud voice on the Internet that’s all, I say this since he has claimed to have knowledge in my own field of interest, and has expressed severe errors in that field = wild guesses. This has caused me to avoid reading his vulcanology articles.

      1. I always form my own opinion and will not be influenced by anybody. At Bardarbunga and Katla I am 100% with Carl. And I also read almost all the information from IMO. But also IMO is not always right.

  1. IMO says : Increasing activity under Bárðarbunga in the last months might reflect magma accumulation below the volcano. However, other explanations have been considered; for example increasing water pressure in the hydrothermal system inside the caldera, pressure changes due to changing ice load or increased friction on the ring fault due to increasing magma pressure.

    I know was tremor. But where can they see signs of tremor. I have seen zero signs of tremor at Bardarbung since the eruption. Google translator is very bad. I meant earthquakes and not tremor 🙂

    But we will see in the future.

    The last question: What have earthquakes at a depth of 0.1 km to do with magma?

    1. Nothing directly in Bárðarbunga volcano. The crust is just breaking (pushing up) in the caldera at 0.1 km depth (there is a error margin of +- 20 meters). This type of shallow earthquakes happens due to inflation of the magma chambers in Bárðarbunga volcano, that changes the crust stress levels.

      1. Possible. I think, however, after Bardarbunga has lost so much magma, the caldera will still lower for a few years. This is also known from other outbreaks in the world. The process of reduction is far from being completed. And all earthquakes in a depth of 0.1 -1.0 km are sinking earthquakes. The above-lying Magmakammer has completely emptied itself. Since it is only logical that the caldera collapsed further and it thereby comes to earthquake. And all earthquakes in a depth of 0.1 km – 1.0 km are the reason for collagging the caldera. But I also accept her opinion. 🙂

      2. As far as I’m concerned, most of the quake activity at Bardarbunga is the continued settling of the caldera, but the occasional upticks are likely due to the sporadic refilling episodes. Therefore, the volcano is both still recovering from Holuhraun and slowly preparing for the next eruption. We do need to remember how much magma was erupted (it would have been a VEI-5 if it was an explosive eruption), which is likely to mean it’s going to take quite a while to build up. Plus, with a likelihood of the next eruption being from the central system (now that the tension in the rift has been released), it’s going to need quite a lot of pressure. So, most of the very shallow activity is just the plug pushing down on the caldera walls, with periodic reshuffling due to inflow.

      3. The caldera and the volcano as a whole is inflating. It has not yet settled. It is dormant (not erupting), but it is restless (earthquakes) at the moment. As I sad before, this is an eruption cycle and they can last up to 20 years with long periods of quiet between eruptions. Expect more activity and eruptions in next few years from Bárðarbunga volcano.

        It is my view that next area to erupt is going to be Trölladyngja (north-east of the main volcano). That area has been having deep earthquakes (10 – 20 km) in past few months, suggesting magma movements in that area.

      4. MJF – you’re missing the key bit of the IMO statement from May. You say:

        “As far as I’m concerned, most of the quake activity at Bardarbunga is the continued settling of the caldera… most of the very shallow activity is just the plug pushing down on the caldera walls”

        But IMO said very clearly:

        “Seismic measurements around the Bárðarbunga volcano show that the seismic moment release on the caldera ring fault has been gradually increasing since mid September 2015… The analysis of the earthquake data suggests that the movement on the fault is opposite to what it was during the subsidence period during the Holuhraun eruption.”

        The ONLY ways to read ‘opposite movement on the fault’ (i.e. the ring fault bounding the caldera plug) are:

        1. The caldera plug is moving up and the volcano is stationary.
        2. The caldera plug is stationary and the volcano is moving down around it.

        For obvious reasons I prefer explanation 1! Remember IMO have the raw waveform available to them and can calculate the focal mechanisms.

      5. Mike Ross, sorry if I didn’t make it clear but I meant is that it is inflating but also still trying to push down, i.e. the inflating more than pushing down; in other words net inflation.

  2. Mike and mjf did either of you read the article? The article for those whose English may not be their main language is saying that during the “Holuhraun eruption” there was subsidence in the caldera. Since that time instead of continued deflation or subsidence there has been a “continued inflation pattern” This means that something is inflating not falling! The article goes on to point out the proof of this is the “Continuous GPS measurements show movements away from Bárðarbunga, suggesting inflation.”

    If you look at the quakes that have followed Saturdays 3.8 they are 2.5 to 2.9 range at depths of 8.2 to 10.9 . I would suggest those were being caused by the magma flowing into the space created by the 3.8 .

    Jon is there any indication whether the snow pack above the Caldera has been reduced lately ? It seems that the temperature up there has been cold enough to make more snow and it seems to me there has been more precipitation over most of Iceland this fall. I know that both coasts of Canada have been drenched this year.

    1. This time of the year new snow starts to fall onto the glacier. But given the current weather I don’t know how much fresh snow has fallen on the glacier. Snow melt only happens in the summer time, during the months of May to end of August. During the winter there is a lot of fresh snow there, but I don’t know how much falls each year. I did try to search for recent information about it, but I was unable to find anything useful.

  3. Updates and a show! Your back-and-forth is not only enjoyable, but educational. Thanks, Jon & Mike, Jeff & MJF!

    1. I suppose none of us truly know exactly what is happening in great detail since this is the first time we’ve been recording this sort of event in real time. There’s going to be some degree of uncertainty and debate until it eventually goes off again!

  4. Jon, thank you for your insight. I have been following since Bárðarbunga. I live in the usa and I’ve learned quiet a bit and found a new fascination in volcanic activity. Even learned to read seismographs. Thank you.

  5. Jon, where can you see the GPS data on inflation at Bardarbunga? I have not noticed any inflation. Apart from the earthquake in 10-20 km deeper, there is no indication of inflation. The new magma ascending is a very normal process that has been taking place in Iceland for millions of years. Show us the GPS data showing the Bardarbunga inflation shows Please.

    1. The GSP data can be found here. Due to some technical issues that IMO is clearly having the charts are not updating at the moment.

      You’ll have to look at the month graph to see the inflation and even so it’s difficult to read this images if you don’t know what you are looking for. But they show many of them some type of inflation taking place in Bárðarbunga volcano. This inflation is happening faster than in Grímsfjall volcano (last eruption in 2011) to compare it with some similar type of volcano.

      There is also a lot of ice on the GPS antennas, messing with measurements at the moment. This always happens in the winter time.

  6. Thank you Jon. Unfortunately I can not read the diagrams. I am unfortunately not a professional. But thank you again. 🙂

    1. Just had a quick look, there does appear to be some upward movement, but to me it seems quite temperamental, not quite as clear a pattern as we are seeing in Grimsvotn and Mauna Loa at the moment. In some ways it reminds of the slow recharging we saw at Mt St Helens in the 90’s. Certainly doesn’t suggest it’s about to transition from the post-eruption-unrest to pre-next-eruption-build-up stage any time soon.

      1. No. I basically meant it’s a bit all over the place, as in the inflation pattern seems to keep changes making the pattern a bit obscure.

      1. Swarms in the Tjornes Fracture Zone are common and there are (relatively) often earthquakes > M3.

Comments are closed.