Posted on by Jón Frímann

Fresh earthquake activity in Katla volcano for the past 48 hours

Today (17-October-2016) and yesterday (16-October-2016) small earthquake swarms have happened in Katla volcano. Most of the earthquakes that happened where small, with magnitude 1,0 or less. Three earthquakes had magnitude above 2,0.

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The earthquake activity in Katla volcano. Copyright of this image belongs to Icelandic Met Office.

In the news in Iceland today it was mentioned that this earthquake activity was due to heavy rain last week in south Iceland. I don’t agree with that assessment, since I recorded the strongest earthquakes and they show a clear sign of being volcano earthquake. I’m not able to record glacier quake activity at distance of 56 km (Heklubyggð geophone). The problem with volcano like Katla is the constant earthquake activity, over time there is a risk that geoscientists start to look at it as the normal pattern of the volcano and there is nothing to worry about. Current earthquake activity is of this nature and in my view its highly dangerous activity, while it has yet not resulted in a eruption there is nothing saying it is not going to do so soon. I remind people that is not possible to know when a eruption starts and it’s not known how an eruption in Katla volcano starts, besides what is know for historical recordings after the eruption has started (magma pushing towards the surface).

63 Replies to “Fresh earthquake activity in Katla volcano for the past 48 hours”

    2. Conductivity is still rising. Over 220 as we speak.

      Gauging station called ‘Múlakvísl, Léreftshöfuð; V414’ also shows significant rise in water level since 16:00 this afternoon. About 8 meters!? Why is this?
      http://i.imgur.com/l3bdGqb.jpg

      1. Sorry, my bad. that is CENTIMETERS, and is nothing out of the ordinary. I must be tired.

        Here’s what it looks like with the time axis set to 2 months. Perhaps we can atleast see some significant changes in waterflow since late September.
        http://i.imgur.com/8bvIv3t.jpg

  2. But still, almost all earthquakes are only 100m down. That is not lava movement.

    Jon, you said earlier that it might be gas expanding, which could make sense. Especially as conductivity in the rivers is high as well. But why would the gas come in clusters? Freed up due to rifting? But then why only in the caldera?

    Something interesting is happening ere, we just don’t know what it is.

    Rain making the glacier crack and fall is not likely either, the heavier earthquakes are a bit too large for that.

    3. The notorious behaviour of Katla. About the types of eruptions (7), the view of a volcanologist who happens to be also a blogger (non peer reviewed but with listed sources):

      https://davemcgarvie.wordpress.com/2012/11/06/katlas-next-eruption/

      Interestingly under type 1 a comment is made that the probable 1955 and 2011 ‘events’ could also be geothermal based.

      There are still no signs of caldera deformations or gas releases

      https://www.wired.com/2016/09/earthquake-swarm-icelands-katla-raises-alert-status/

      so this more than background noise could all also very well be the proverbial storm in a glass of water.

  3. Thanks for the update Jon. Is this the same sequence of events which happened about 5years ago ?. Also small point is the number of quakes at depth in Askja ?.

  5. Would you still visit iceland or is the risk to great heave the chance to go in 2 weeks. Sorry for the stupid question

    1. I would always visit Iceland, no matter what.
      A bigger risk is maybe a terrorist attack by IS!

  7. Hi, Could someone explain the mechanism behind river conductivity and what the significance is? thanks.

    1. When minerals or gases come in contact with water will dissolve. As example , fresh water has little or no conductivity, but sea water has verry high !! In volcanic regions, the increse water conductivity occurs when gases (SO2 or CO2) will dissolve. And high level of those is a good sign of fresh magma inbound.

  8. Looks like a couple of more heavy thumps, 2.3 and 2.9 less than an hour apart.

    1. Negative is the other direction then what it says on the image. For instance, north is positive and south is negative.

      Note: I think it works like this and I learned this after the 2010 eruption in Eyjafjallajökull volcano.

      1. Thanks, that makes sense. So what kind of changes can we expect in gps graphs when/if an eruption is imminent? Is there gps data available of the Eyjafjallajökull eruption somewhere online?

      1. Ok, great! That explains it. Did they have anything to say about the high conductivity levels in general?

  11. More rain is in the forecast later this week, as the remnants of Hurricane Nicole move in. In fact, another weather warning is in place.

    When the Katla area was shut down recently, one of the concerns was the gases in the rivers and glacial meltwater. So if it is correct that the gases are causing earthquakes now, it seems to me that all this rain is indeed a problem. This is not a typical fall. The once-hurricanes have brought a lot more rain. Than normal. A lot! Extreme rain, gases moving, glacial melt, eruption?

  12. If you look at the earthquakes, they have moved from East to West. What is this implying?

    Opening of the plug? Rifting below the ice?

  13. If my memory recalls, a large-ish 2+ quake at depth of over 30km depth happened about a month to 6 weeks ago. Do you think this had an impact on the overall situation

    1. The largest climate changes that the earth has had lately came from the removal of the ice-cap. That must have impacted much more than further global warming.

      Typical alarmist article.

  16. Is it just me or are we now seeing a slight trend towards deeper seismicity in Katla?

    It seems to me that we’re seeing more quakes in the 1-3km depth range where previously they had almost all been in the 0-1km range…

  17. There was one earthquake at depth of 15,8 km. That is not a good sign, as it suggests that magma pressure inside the system is getting close to a critical point (based on the earthquake activity so far).

  18. Is there a connection between Hekla and Katla because there has been eathquake activity as well ?

  19. Jon which part of Katla do you think will let go and what kind of magma will that vent produce? Sorry I know it’s maybe a million dollar question Jon

    1. From what we’ve seen in the last few days I would say it will happen near the caldera centre, most likely it will be basalt with a small possibility of dacite or rhyolite.

  20. Today there have been two deeper earthquakes of 1 magnitude, at 1.2 km and 3.6 km depth near Godabunga area. Any thoughts?

  22. In hardware failure news, the UPS battery that I have on my Böðvarshólar geophone station has failed. It costs 95,08€ (11.950 ISK) to replace it. I don’t think I’ll be able to do so until December at the earliest.

  25. And the earthquake activity continues to go around the center of the Calder and have now come to the northern part of it (East to South to West to North).

    Is the plug loose soon?

    Actually, I have no clue regarding the last part, it just seems peculiar that it goes in a circular motion around the center…

  26. I also woonder perhaps if the whole plug might not pop but perhaps a portion of it breaks loose what effect that would have ie would that reduce the size of any event ?

    1. This is just normal background activity. At the moment it is quiet in Iceland when it comes to earthquakes. Nothing interesting happening and it has been like this for days.

      I’m using the time to attend to my other writing works and such things.

  32. Came just home from a week long journey to Iceland. I’m very impressed about the fantastic landscape and nature. We stayed in different places where there were during our stay some earthquakes up to 3 magnitudes, but we never noticed any of them. When can you really feel them? (I’m really not disappointed but only curious…)

    We also saw a short but impressive documentary film about the eruption of Eyjafjallajökull. At the visitor centre of a nearby farm we could also read about the lava, magma, stones and about the volcanic prosesses. All of that was very interesting for a non-geologist. I’d be interested to know if the Islandic volcanos have a very own geological nature, I mean is the lava much different from the lava types of other volcanos in the world or do they share about the same consistence?

    1. That is quite a question. There isn’t one single type of lava in Iceland, because lots of things can happen before the below-ground molten rock (magma) erupts to the surface to become lava. For example, it can sit several miles below the surface, some rock components crystallize out and settle upwards or downwards, and the remaining liquid portion can then erupt. Or it can melt some of the walls of the chamber and become different as this source of rock is incorporated. The basic source of magma for Iceland is the mantle, and this magma does have a distinctive mix of elements if I am not mistaken.

    2. I think it’s generally reckoned that earthquakes lower than magnitude three aren’t felt by human beings unless they are shallow and you are right on top of where they actually occurred.

      Icelandic geology is fascinating. A couple of books I (a complete amateur) have found useful are Thordarson and Hoskuldsson’s Iceland book, and for more the more general geomorphological context, “Living Earth”: https://www.amazon.com/dp/178046021X/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687702&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=1903544068&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=10KY6WXP96NZCKMBTM8M

      https://www.amazon.co.uk/Living-Earth-Outline-Geology-Iceland/dp/997933360X

      The former is the better, clearer of the two but the latter complements it.

    1. Thanks Gary I noticed the quake on the USGS site but could not find a way to tilt the map they use to actually see its true location.

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