Posted on by Jón Frímann

Katla volcano newest earthquake swarm

During the night of the 16th of November, 2011 there was a new earthquake swarm in Katla volcano. This earthquake swarm is a part of ongoing pattern in Katla volcano. This pattern started after the small eruption that took place in Katla in July 2011. It was observed yesterday that there was a deep earthquake in Katla volcano, with the depth of 28 km. This earthquake did most likely did happen due to a dike intrusion deep inside Katla volcano, but it might well be that this was just a normal earthquake. It is hard to know that for sure. But deep dike intrusions are well known in Katla volcano. Sometimes they are followed by a harmonic tremor for few moments or minutes.


The earthquakes from Katla volcano can clearly be seen on this tremor plot from Iceland Met Office. But they make the spikes that are on it. Copyright of this picture belongs to Iceland Met Office.


The location of last earthquake swarm in Katla volcano. Most of the earthquakes are inside the caldera of Katla volcano. Copyright of this picture belongs to Iceland Met Office.


The largest earthquake in this earthquake swarm. Its size was ML2.35 and it had the depth of 4 km. This picture is released under Creative Commons Licence. Please see the top bar (there is a link there) for more information on this.

This was a long period earthquake. But this is the only clue at the moment that Katla volcano is going to erupt soon. But when is still a unknown question at present time.


The frequency analysis of the ML2.35 earthquake. As can be seen here this earthquake has really low frequency component. But most of the energy goes into about 2Hz frequency. This picture is released under Creative Commons Licence. Please see the top bar (there is a link there) for more information on this.

It is impossible to know how many earthquake swarm Katla volcano is going to have before it erupts. But this is a one way street that Katla volcano is now on. For us humans, we just have to wait and see what happens next. Nothing else can be done when it comes to forces of nature. When the time comes, get out of the way of Katla volcano.

127 Replies to “Katla volcano newest earthquake swarm”

  1. Mias are peanuts or Katla starts in a slight increase of the harmonics
    Of the mediations Hekla tremor of STO is the station which stands a little more, you will not be detected in Katla movements it is the closest, almost half of the Hekla and Katla
    regards

  2. Copied from Avcan

    The truth is that the continuous tremor to grow, is more than 100% this morning and it is reaching levels that not we saw from the 12th of October, shortly before opening the mouths eruptive continue so and produce a sharp downturn will have a new mouth opening in the area of la Restinga… We’ll see what happens. (Henry).
    37 minutes ago · Like · 1

  4. @Jon, for the record.

    Any graphic that I have done related to these volcanoes that you wish to re-use and that I have posed here, you are more than welcome to use. The animated ones are under CC.

      1. Jón, try to get one of their ‘enterprise’ drives that are designed for server use. More expensive but very reliable. I use the RE4 range

  7. From the look of the map of EQ locations on El Hierro it looks a though the majority of the EQs from the last 36hr form a very good straight line. Could this be the rift forming that breaks the surface (below or above the water)?

    2. They appear to be parallel to the NNW-SSE rift. The other EQs are in the same area so probably do not need to be excluded. Suspect that this is probably continued rifting of the ocean crust.

  8. I thought that La Palma and La Gomera were supposed to be picking up the harmonic tremor from El Hierro (making it possible to tell whether the El Hierro tremor data has been rescaled). But there seems to be no correlation between tremor pulses at El Hierro and features in the signals at the other stations. Should the tremor be detectable elsewhere? What is its actual amplitude?

    1. I think the scales of the recordings we are looking at are for our purposes arbitrary though the instruments are no doubt calibrated to acceleration or amplitude in terms of distance. The best we can hope for is to be able to make relative assessments over time.
      I would imagine (truely imagine) that what you get at the other islands is coloured by distance, the presence or otherwise of intervening landmass and the depth of the source.

    1. Hi Jón!

      Seems to be pretty strong!
      I though they where forced to stop @ Hengill and to move the IDDP-experiment?

      1. This is not part of the IDDP experiment. The hydrothermal power plant operation permission demands that they pump down used water down to at least 800 meters into the ground.

        So they have to do this. Regardless of anything else. So man made earthquakes might be there to stay if this continues as is does today.

    3. @Lurking:

      Can you make a depth vs. time plot on these? Based on the table, my initial vague impression is that there’s a layered structure in it?

      1. Gonna have to be tomorrow… I didn’t see the request till just now and I’m off to bead… bede… that soft thing you plop down on to sleep.

      3. Cobbled together a 2D plot for my own interest from this latest swarm. Not shared here as a 4D plot from Lurking will probably be more useful.

        Do we know the time they started pumping the water?
        And is it possible to get the historic EQ data for the area from IMO – is there a link that IMO makes available for the general public?

  10. thats a pretty good swarm, is that really the contractors, thought they would lay back abit with worries by public. any chance thats somethi. or is it defo the pumping. so many small quakes in one hourng more

  11. Unless some of those tremors are mis-located it seems that there are quite a few far flung from the pumping location.

  12. hey jon. its great to see you interacting more:) it seemed like it was becoming carl le strange’s blog.

    2. The off topic chat had just gotten out of hand. I had to stop it. As it was annoying people how are reading this blog and its comments on the subject.

      Carl now has his own blog. I wish him a good luck with it.

      Now I have slightly more time to add comments. That time is going to increase as I am almost finished the school.

      1. Be interesting to see how Carl’s blog deals with a high volume of social chit chat without resorting to forums. Suspect it might not be easy.

      2. Well, he deals with it or he don’t. There are just two possible outcomes for Carl blog. Whatever the case, it is his blog so it is up to him what happens there.

        But lets wait after the honeymoon period is over (about 60 or so days) to see how that turns out.

  13. 28 km is not very deep earthquake wise. That is, when the causes are not linked to volcanism, kilometer precision is not important. So how accurate are the depth measurements of earthquakes in Iceland?

    1. I don’t have the error data, but I do know its pretty tight when the quality gets to 99.

    1. Think when you see it you want to be at a safe distance.. A hint –> water lots and lots of water 😛

      1. I know, I have seen the small variant with Fimmvorduhals. In the beginning there were lots of explosions as well, when the lava creeped over the ice.

        I have seen that clearly, from a large distance though, I was in the interior at that moment. First class view.

        Later when I was at the spot the explosions were over.

      3. Dear Sander,

        A view posts ago I read that you were travelling with a Landrover somewhere near the Vatnajökull. Was this your own LaRo or did you hire one. I’m currently restoring a LaRo 90 (1986) for driving in Iceland (of course!). If it’s your own, do you maintain it yourself?
        Thanks in advance for your answer! My emailaddress is: henk.maukie@hotmail.com
        Kind regards,

        Henk Weijerstrass
        ZWAAG (Hoorn NH)

      5. Since I cannot read you mailaddress, I answer you via this way, and in English for all who read along with us.

        Yes, we have been in Iceland with our own Land Rover 110, standard “Mariniers” version (Royal Dutch Marines). In 2005 and 2009.

        In march 2010 we have been dropped at Landmanna by hired vehicles in the interior due to the snow.

        You know Land Rover Prikpagina? I am quite active there. Nickname Puffino.

      7. @Sander Lelieveld, If you click on the envelope that is on the email address and enter the anti-spam code that you get up. You can get the full email address.

  15. ====
    Jón Frímann says: November 16, 2011 at 22:20

    Thanks for the advice. I do not remember what type of hard drive is in my main earthquake monitoring computer. But I am moving to WD now.
    ====

    WD also has a free clone verion of adonis, thought it had.

    http://support.wdc.com/product/downloaddetail.asp?swid=119

    Actually reports suggest both the seagate and wd versions are more reliable than the paid-for versions (they seem rock solid). NB Worth having a direct sata connection, hundreds of GB takes, like, forver to copy!

      2. Tomas, I would accept your offer if I where in Denmark. But for the moment I am not. Due to customs issues in Iceland (that I have to pay) I cannot accept any computer hardware as a support while living in Iceland.

        But that is going to change when I move back to Denmark. Until then, please keep the offer warm for me.

        Thanks for the support. 🙂

  16. I have one question about strong tremoring under El Hierro volcano.
    Where that mass of magma are moving now ?

    1. I think that a new fissure might have opened up somewhere in El Hierro volcano. But that might well be at great depth in the ocean. So deep in fact that is currently not visible on the surface.

      1. My memory might be faulty here but I thought the waveform clipped like this and the number of EQs fell just before Bob erupted.

  17. The harmonic tremor has saturated the the freq and seismogram for many hours today. The hypothesized auto rescaling has not occurred. So either the reading limits of the device has been reached, or auto rescaled has been turned off, or rescaling requires manual intervention, and no on has gotten around to doing so yet….

    My question is observational, and probably cannot be answered except by “boots on the ground” local readers, but what I’m dying to know is when the harmonic is this strong, is it felt by the residents? At this level of harmonic tremor strength does it feel like a continuos 2.5 or a 2.7 or a 3.2?…. You get the picture.

    Yes I understand that I’m truing to compare apples to oranges, and earthquake measures are of total energy release, but the felt movement comment is important too.

    1. They may well be feeling it: some are complaining of nausea and dizziness.

      In terms of energy release – a lot must be released by a sustained tremor like that. How much, I could not tell you as I do not have the expertise to calculate it. However, it must contribute something towards heating the surrounding rock and magma.

      Does anyone know whether it is included in the accumulated energy graphs IGN produce?

    2. Pablo, see Diana’s comment on Nov.15, 23:33
      “From reading AVCAN’s facebook page it would seem that not only are there constant vibrations but also sounds below their houses.
      http://www.facebook.com/pages/Actualidad-Volc%C3%A1nica-de-Canarias-AVCAN/163883668446”

      With the higher frequencies people of La Frontiera report almost continuous feelings of swaying of the floor, low sounds like a distant lorry, pressure in their ears, headaches, nausea, which keeps them awake at night. Probably as much as uncertainty and worrying.
      One woman is able to tell with some certainty the magnitude of earthquakes she felt, from about 2 on.

    1. Now that is marvellous! Do you know how I could watch it on full screen? And I super-like that it has sound too.

  19. Is there a link somewhere on how to read the tremor plots from iceland – and how they relate/compare to the el hierro ones (which I am now just about familiar with).

    1. IMO shows only selected frequencies from the spectrogram, whereas IGN show a continuous spectrum from 0hz to 15hz.

      On IMO’s plots: the red lines are frequencies: 0.5 to 1.0 hz; the green lines are: 1 to 2 hz; the blue lines are: 2 to 4 hz. The waveform for each shows the variation in intensity.

      ON IGN’s spectrograms, the intensity is shown by colour – low blue to high red / brown.

      2. that’s what I was guessing but I’m glad to have someone confirm it. thanks KarenZ

  20. Seems that Bob’s jacuzzi is pretty quiet on all the webcams right now… yet IGN’s tremor charts are fully clipped.

    1. May be wrong but I’d say it’s got to be erupting somewhere in the El Golfo area.

      1. for what its worth;

        I read yesterday from Avcan/Ign? that the tremor is strongest at Restinga

    2. Interesting article from Earth Quake Report on an estimated depth of the erupting vent at La Restinga:

      Update 17/11 – 15:29 UTC
      “Mexican reader and Google+ fan Martin Rey (also a contributor to our Nabro volcano report (Eritrea)), attracted our attention to a number of very interesting reports from the IEO (Instituto Español de Oceanografía). The Román Margalef belongs to this oceanographic institute. Most of the research of the Ramón Margalef is only communicated to Pevolca or to the IEO itself. The outstanding reports are giving a scientific insight in their research until now. The reports have been published from November 9 until today.
      .Martin Rey has created a very good image on the depth of the erupting vent, a question raised regularly in the comments. Why don’t we see a lot of action on the surface while everybody is telling that the eruption goes on ? Although we have no official confirmation of our version we expect that the present eruption takes place in at least 2 major vents. The red colored stream on the picture is the erupting magma which gradually changes into yellow when the magma it is cooling.
      Martin has calculated that the depth of the vent closest to La Restinga would be 156 meter. The second vent deeper in the Las Calmas sea is approx. 400 meter deep.
      The eruptive material from the La Restinga vent arrives at regular times at the surface (with or without Jacuzzi). The material from the deeper vent is picked up by the currents and is carried away at a depth of approx. 300 meter.
      Finally, the stain can well be seen at the image as the yellow color hanging at the upper part of the image.
      We presume that the days that we do not see any surface action from the vent, although everything indicates that the eruption is continuing, a strong sea current maybe the reason for a diluted stain.”

      Picture also provided with the link.

      http://earthquake-report.com/2011/09/25/el-hierro-canary-islands-spain-volcanic-risk-alert-increased-to-yellow/

  22. an artist came along in La Palma station 😉
    http://www.01.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=EHIG_2011-11-17&ver=s&estacion=EHIG&Anio=2011&Mes=11&Dia=17&tipo=1

    La Palma station was reacting more than the one on Gomera yesterday night and this morning.

    By the way, there were impressive series of very shallow earthquakes in western Turkey this summer, and again a huge list of shallow quakes in the region of Van, a lake surrounded by old volcanoes. Are there signs of renewed volcanic activity in the region?

    1. Looks like a technical fault on La Palma station.

      EQs in Turkey are due to tectonic movement of the African and Eurasian plates. The area is suffering aftershocks following on from the recent large EQ.

    1. Couple of cars driving around at bottom right is all I can see but I’m reassured by the lack of a red glow.

      2. or a data drop out , amplitudes look consistent across the data dead zone …

      4. Something certainly changed at about 08.20 because the spectrum content changed so, choosing between ‘rescaling or what’, I think I would go for what.

        My Recaptcha is ‘ewsava activity’. Is this the sheep reemerging?

      6. According to someone on the ‘other’ blog there are military exercises going on on La Palma including artillery 🙁

      7. robert, it does though look worse than I have ever seen it since this whole thing started.

      9. @newby;
        yes, i am not arguing that , I’m surprised we haven’t had a big belch by now, maybe today ? ….

  28. Jacuzzi appears to be reawakening – hard to tell with the low angle, seas and wind, but looks like a persistent whitening in the right place

      1. I thinks it’s sometimes the wind that creates little white waves:
        7 Bft.
        13,9 – 17 m/s
        50-60 km/h
        But the colour of the sea is clearly visible (darker/green).

      2. Mafl, no…its a bubbler. Not big but its there. I watched it for hours yesterday and it kind of fits in with the crazy pattern the plume is taking.

  29. Restingalitas pyroclasts
    I don’t know if this article has been posted here already (if so I apologise):
    “On the origin of the ‘restingolita'” by John J. Coello Bravo, geologist on Tenerife. Published 10/11/2011 on the AVCAN website.
    http://www.avcan.org/?m=Noticias&a=noticia&N=911
    With a working theory on how they may have formed, very interesting.

      1. Technical fault.

        Anything else that caused such large swings would be reflected on the other stations.

    2. I guess it’s some kind of art, created by mother earth with the help of some faulty equipment 😉

  32. Helium enrichment recorded between 4,000 and 35,000 times higher than normal. Much helium … But no oxygen to 100m deep. A layer deadly to marine life, is acidic (pH 5) and has no oxygen .. The IEO report today. http://www.ieo. es/apartar/ieoprensa/hierro/171111.pdf

      1. ”Noble gas and other isotopes
        Main article: helium-3

        3He is considered a primordial isotope as it was formed in the Big Bang. Very little is produced, and little has been added to the Earth by other processes since then (Anderson, 1989). 4He includes a primordial component, but it is also produced by the natural radioactive decay of U and Th. Over time, He in the upper atmosphere is lost into space. Thus, the Earth has become progressively depleted in He, and 3He is not replaced as 4He is. As a result the ratio 3He/4He in the Earth has lowered over time.

        Unusually high 3He/4He have been observed in some, but not all, “hot spots”. In mantle plume theory, this is explained by plumes tapping a deep, primordial reservoir in the lower mantle, where the original, high 3He/4He ratios have been preserved throughout geologic time.[13] In the context of the Plate hypothesis, the high ratios are explained by preservation of old material in the shallow mantle. Ancient, high 3He/4He ratios would be particularly easily preserved in materials lacking U or Th, so 4He was not added over time. Olivine and dunite, both found in subducted crust, are materials of this sort”
        http://www.godlikeproductions.com/external? http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FMantle_plume

      2. Okay so lets say that this is right and its “reaching down”. If the gases can come up, so can the bloody magma. I am wondering if they would like to share where they got those readings from.

        Bet it might match up pretty well with the large quake areas at the surface. Since this is a weird eruption they might be able to use it as an indicator of whats coming. High helium coinciding with a larger eruption at Bob Minimus or Bob Maximus would show us that things might be turning bad.

    1. But in IGN’s defence, I have to admit that I can find shallow quakes in the data so the data is publically available.

      However, as the shallower quakes tend to be small (less than 2.0), many may now be hidden by the harmonic tremor.

  35. Could this comment below in relation to the above link be correct?

    So…basaltic shield volcanoes usually pull from very deep in the mantle. Strato volcanoes normally contain cinsistent ingredients that are often, not found in baslatic types. However…Helium is now being found present in Hierro, and it’s more common in strato’s. Now, we’re seeing that the only helium eruption source in the Canaries was Tenerife. That means, it’s possible, the chambers beneath these islands are interconnected!

    1. I think that what the above comment implied was that if there is a high concentration of 3He vs. 4He , then the magma came from deep down in the mantle

      1. Remember what I said about the macro rather than the micro?

        That article just confirms the theory. How about this, does anyone know the ages of the islands roughly en toto? It would be interesting to know if they all went in short succession bursts or not.

        Might be seeing history made here soon if it is.

  37. wow sudden drop in the tremor in el hierro, what could this mean? decrease in eruption activity or a new vent?

    1. yup, something happened , you can see it on other charts as well, so not instrument downscaling

  40. Listening to these reports of landslides and falling rocks amid comments from this wonderful blog, I am bewildered by the lack of positive political action over what is going on in Hierro, with the population having to endure such a stressful level of uncertainty for so long now. Here on Tenerife, less than 100 miles away, there are literally 1000´s of empty tourist apartments remaining unsold (not available for rental) due to the recession or El Crisis as it´s called in Spain. I am convinced people here and on the other islands would welcome the idea of helping out their brothers on Hierro with accommodation. But hey, I am the most naive person I know. If this is OT Jon my apologies. I don´t know where to address my anger.

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