Posted on by Jón Frímann

Special report: Update 6 on the eruption in El Hierro, Canary Islands, Spain

Special note: Please notice that my (personal) watching system is also going to include the mainland of Spain (mainland Spain has two volcanoes that I am aware of, along with some earthquake activity) when I change it next month, along with Canary Islands. Everything else is also going to be a subject to a special reports if the event is important enough. That is not always going to be case however. But I am going to post more details on this in the beginning of next month.
****
Little seems to have changed in the eruption of El Hierro since my last update on it. That was on 19 October, 2011. Harmonic tremor is constant, but appears to have dropped a little in the past few days. But with the fluctuation that is often increases again before it drops down again. This means that the eruption is ongoing, but is loosing power to continue at current eruption vent. This was not unexpected. This has however not slowed down inflation in El Hierro from what I can gather on GPS data on El Hierro.

As the current eruption vents close down it seems that earthquakes have started again under El Hierro. But the earthquakes have the depth from 28 km and up to around 5 km. This strongly suggests that new magma is entering under El Hierro and is again increasing the pressure inside the El Hierro magma sill (or chamber, but note that El Hierro does not have a stable magma chamber it seems). This increases earthquakes while the magma does not have any good path up to the surface. When a new path for the magma starts to form again, a large earthquake swarm is going to take place in El Hierro. It is not going to be anything bigger then already has taken place in El Hierro already. With the largest earthquakes going up to Mb5.0 in size. That is at least my opinion.


All the earthquakes that have happened in El Hierro since magma intrusions started in July 2011. This pictures clearly shows in my view the amount of magma (in terms of size, not volume) that is under El Hierro at the moment. As it is marked on the outer layers by the earthquakes. Copyright of this picture belongs to Instituto Geográfico Nacional.


The harmonic tremor in El Hierro at midnight on 21 October, 2011. As can be seen, it fluctuates a little bit. Copyright of this picture belongs to Instituto Geográfico Nacional.

The major risk in the current eruption cycle of El Hierro is the risk that new eruption vent is going to open up nearby a human population without warning. But El Hierro has a lot of cinder cones from earlier eruption cycles. That creates the risk that a new eruption vent is going to open up on dry land without warning. But it is impossible to know when and where that might happen.

Claims that this eruption in El Hierro is going to create tsunami due to landslides are false and have no basic in fact or reality. As landslides are unlikely to happen in this eruption episode or if a eruption happens on dry land.

920 Replies to “Special report: Update 6 on the eruption in El Hierro, Canary Islands, Spain”

  2. I assume you’re right but then why all of this station are baffled?
    Anyhow shi, kvo and gha are the single messed up stations.

    1. This is just noise from what I can tell. It might be instability in hydrothermal areas that are in Krafla volcano. But it is impossible to know for sure.

      2. I am not so sure, we saw a spike like this, but smaller, the day before the quake-swarm a couple of weeks ago. The quake swarm was at the initial eruption site for the first Krafla fire.

      3. It will be so much better the sooner IMO get their earthquake page up and running again. I would like to if there have been any earthquakes in the past 12 hours in that region.

      2. Looking at the scale in the morning, one can see the difference between the Etna noise and the EQ far away.

    1. Yes, the H104 at Tinganar seems to be sitting on the beer-belly of a Bavarian lederhosen merchant during oktoberfest. I guess SvampurinnBob is soon back to erupt in the pool of Cabildo Presidente Maximalis Perfidio Armas.

      2. Yepp, that be the thing.
        My current theory is that the bellies of German men are actually mutated urin-bladders. That is the only explanation to the fact that a tent that holds 2000 Germans can make do with a urinal that is only 2 metres long without a que outside of it… I needed to run and pee all evening from those mamoth-sized beers called stein, or more to be precise, 1-litre humpensteins. Mix that with kartoffelsalad mit bratwurst and you have a leathal mix. Even I started to sing to the Umpa-umpa-music. And by gosh, in the end of the evening I coul jodle with the worst of them…

      3. The Bavarian word for “stein” being “a Moaß” 🙂 – just another language to learn – I know …

  6. Curse of the Ruminarian.

    I’ve been sitting here looking at the Mw 7.3 Van, Turkey quake on the Canary seismos.

    Yet again, CHIE barely even flinched. If you remember, CHIE hardly registered anything when the waves from the Kermadec Mw7.4 rolled through on the 21st.

    This pretty much proved that the gain settings for CHIE are rolled back.

    Much gnashing of teeth went on after that as we discussed the logic and specifics of how this gain settings worked on the IGN equipment. One idea that came up was that since EGOM showed a simultaneous drop in signal when the suspected low gain setting kicked in, that it might be a system wide setting changes.

    Well… now that I’ve thought about it, I don’t think that it fits. IF it were system wide, then why to the outlying stations still make notable responses to large quakes on the other side of the world? Why is it just CHIE that seems to be oblivious to stuff away from El Hierro?

    Whatever gain changes that have been made, have been made only to CHIE.

    1. Looks to be right Lurking. The peak is pretty clear on all other stations – except CHIE. Do we take it then, that there is little change to the activity around El Hierro ? Has this been ‘dumbed down’ for PR purposes – or does it just make it easier to analyse ?

      1. I lean towards “easier to analyze.” Saturated gear can’t tell you squat other than when something stops.

        Remember back when the tremor went full bore, I noted that the gear had started clipping. That’s bad in that you can’t tell whats going on after that. It’s like putting blinders on.

        For us, it’s just something we need to keep in mind while oogling the traces, that way we can keep variations in the signal in context to what we have already have seen.

      2. You can toss out one of those “have”s. Doesn’t matter which. They be.. “redundant.”

        😀

    2. Or could there be something about the nature of the harmonic tremor or magma at / under CHIE that cancels out / absorbs these large EQ’s? The spectrogram does not show any change at the time of the Turkish quake.

      Has IGN commented?

      1. Dunno. But the quake from Turkey would have hit the seismos in this sequence

        CLAN 47.49 °
        EFAM 47.52 °
        CFTV 48.28 °
        EOSO 49.58 °
        GGC 49.62 °
        CTFE 49.94 °
        EBAJ 49.97 °
        GUI 50.15 °
        CCAN 50.33 °
        EGOM 50.82 °
        EHIG 51.10 °
        TBT 51.12 °
        CHIE 51.61 °
        EHRO 51.72 °

        Hot rock attenuating the signal? Well, in this case probably not. All the rock temperature does is change the speed that it goes through, and that change is going to be very very nuanced. not something that we would see on this gear. You would have to have a few specialized algorithms and raw data to find that.

      2. Those are the central angles from the Turkey quake to the listed seismo… provided I didn’t screw up the calculation.

      4. Scrap that Lurking I got muddled up with the time. That must be a local Quake at 04.00 way before the Turkish one. You are right it is hard to read anything through the intense tremoring on these graphs.

      5. 1107147 23/10/2011 04:52:33 27.7760 -18.0442
        21 3.1 NW FRONTERA.IHI

        But it is interesting that one showed and the Turkish one did not.

    1. Poor, poor people! Poor people – poor buildings – poor constuction – back to poor people.

      1. EU intends to help it seems. That would be a very decent use of our tax money for a change.

      2. They is still have money?

        Whoah.

        They probably have a similar printing press to the one the Geitner and Paulson used.

      3. Depends on which part of the EU.
        In reality it is mainly Greece, Italy and Spain that has a problem. Spain will survive, Greece no one gives a crap about, and Italy will get kicked out sooner or later.
        Basically, the further to the north you get the better it gets.
        As usuall it will be the Scandinavian countries that horks up the cash to pay for it all. And no, once again we haven’t even noticed any crises, but we like to moan about crises while we go and collect a new company Merc to cry in.
        The only thing worse than us are the Norwegians (non-EU members).

      4. And no, no printing press. We cleaned up our economy back in 91′. Paid hell to get back up again. Now the economy runs like a clock-work and we went plus even in 08′.
        But we learnt the lesson so hard that we still believe that we have a foreign debt (not true) and that we are poor beggers.
        Kind of a lesson somewhere here… Ah, yes… It is never to late to actually clean up the economy, it is worth it in the end.

  8. Diana, tthe turkish quake was at 10:41 UTC, that chart showed 04-05 UTC so I can only assume it must have been a very large local tremor.

      1. No worries LOL . I just realised that the time was very wrong. It’s getting late and my sheep need to be counted soon.:)

      2. Have to go on the decaf coffee now. 😉
        By the way, the IMO earthquake site is updating again with a 1.1 in Katla.

        Haha, the captcha was Lamb!!!!

    2. If you look at the upper right side of the spectral plot you will see it is a 10-11 hour at the 50:00:5 an look at the lower area of the plot you can see the arrival of a chunk of energy
      now is the travel time of ~9 min realistic?

  10. Hi all, i’m new here and i’m follwing all the posts on there, i’m learning a lot.

    One thing to say, I read that Anak Krakatoa registered about 5000 earthquakes in a day and i don’t know more info about this. Anybody knows any website to follow the activity of this dangerous volcano?

    Thanks!

  13. Just wondering if the magma increasing under El Hierro absorbed the Turkey quake, so that it didn’t impact on the solid rock in the same way as it has elsewhere. If the localized quakes we are seeing, thanks Lurking, are estimated to be the effects of the moving magma on solid rock, then there could be more magma in those areas than previously. Could this be a predictable correlation?

    1. Not likely. The only thing that magma would do is to slow the wavefront down as it passed through it. P waves don’t slow as much and this tends to increase the time differential with the trailing S waves.

      Researchers use this phenomena to do seismic tomography, but it take a lot of well measured events and some rather flexible mathematic juggling to do it.

      From our perspective, we wouldn’t notice it in the traces… other than one station having it’s gain turned down.

      1. Maybe the are filtering strong non-local quakes out because its not relevant to the events at El Hierro? The station at EHIG may have recorded it, it was just filtered out when they processed the data to draw the chart. Just a thought.

      2. Well, how could you do that as the spectrum of a local quake and that for a remore quake are pretty much similar?!

      3. The same way seismologists determine were (how far away) a quake happened. The data on the charts is delayed by as much as 20 minutes, there would be ample time to run some routines on the signals and weed out everything that doesn’t contribute information.

        From a signal processing view, it would make sense to do that, because you are watching the tremor and local quakes – everything else is just noise, so you’d filter it out.

        Whether they do it and how exactly they do it, I do not know.

      4. One of those ideas that are much more easier to describe than to do so that it works reliably…

    2. From; “Routine Data Processing in Earthquake Seismology” by Havskov, Ottemöller

      http://i54.tinypic.com/2quhzq1.png

      Here you can see what the phase arrival times would have been at El Hierro for the different phases for the Turkish quake. P waves are the compression waves, S waves are transverse. The various paths from the point of origin to the destination determine how the phase is annotated. Waves that have a K in their nomenclature have interacted with the core on the way to the destination.

      1. Note, the only two images available were for a 600 km deep source and a 0 km deep source. Since the Turkish quake was somewhat shallow, at 20 km, I used the 0 km image. The times will be a bit off, but not by much.

    3. Continuing…

      (actually beating the crap out of a dead horse, no one is into this @#$ so what am I doing?)

      …anyway… on the off chance that someone wanders through here who really wants to get into it, here is a link to the AK135 travel time tables.

      And, here is how you use them. First, find the latitude and longitude of the source event. Then locate the position of the seismic station that you have traces from. Find the distance between the two points. Divide that distance into the circumference of the Earth. I use 2 × π × 6,371.01km (IUG listed radius), this yields 40030.2 km. Take that value and multiply it times 360° and presto, you have the central angle from the event to the station.

      From the tables you can now look up what the arrival times for the different phase should be and be able to identify what that squiggle probably is on the seismogram.

      Other than that, I don’t what you can do with it… other than amaze your friends.

      1. I forgot the link to the tables. I’ll post it tomorrow, or you can do a google search on AK135.

      2. I am amazed! I am also Mathphobic….. I can now see why!
        Seriously, thanks Lurking. All your plots and equations actually help me overcome my fear of Maths because the numbers mean something and their use makes sense. I wish you had taught me Maths and Physics at school!
        For the first time in my life I now almost understand Logarithms..
        I have be wondering about why we had to learn them and what was their use in life for over 50 years now!!
        This is my sort of Maths.
        http://www.google.co.uk/imgres?q=logarithms+funny+images&hl=en&sa=X&biw=1014&bih=606&tbm=isch&prmd=imvns&tbnid=vGkfSGDA1ekXCM:&imgrefurl=http://sci.tamucc.e

      3. Heh… that’s a good one.

        I also hated math. Hated it with a passion. It wasn’t until I took a required analytic geometry class with Mr. Pendergast in high school that I overcame the hated.

        He showed some neat things you could do with math, such as determining which direction two colliding cars or billiard balls would go if they hit each other. (Law of cosines).

        Later I found out about derivatives and integrals and the relationship between acceleration and speed. Eventually, I developed a two facet approach to it. Use a @#$ calculator for the mundane part and focus on the more useful side of it.

        Then I had a message from God. While leaving “History of the Old Testament” class, a bird shit on my head and I packed it in and joined the military.

    1. Forgot to add : note depth of top of chamber layer (fig 11)and compare with Lurking’s plots.

      1. Not much effort from me- pinched it off Erik’s site.
        Many thanks for your plots. It must be a lot of work for you, so its good to see you getting cited.

      1. Lurking,
        Fascinating comparison.
        Their cartoon (fig11) indicates that they conclude there is a lot of small magma chambers – the majority in fact- below the lower bound of your EQs.
        Why should that be?
        Could it be that below 15km ( = MOHO) there are many “small, intermittent, magma chambers” that allow migration of magma while generating relatively few EQs compared with shallower levels? But there is I think a hint in your plot of a gradient of magnitude , increasing with depth ( trending from blue to green as depth increases) – which is the other way about.
        Peter

  15. Okay, which of our two most northely volcanos have gone berzer on us?
    I can not decide what is happening or where.
    It is showing on the Krafla SIL (KVO) above the transverse Graben, which it would do if it was a fissure rifting event. It is heavy enough to be influx into a system like that. But it is here it get’s bizarr.
    Becuase I see equal strength signal for the Theistareykjar volcano (SKI). But with a hell of a twist. Krafla only shows on the northern side of the transverse Graben, if it is heavy enough to show that large at Theistareykjarbung it should show at the southern Krafla SIL (REN) since the noise would be powerfull enough to knock through the Graben. But, it shows up at the Krafla reference SIL of MEL.
    Back to theistareykjarbung, the northern SIL of Theistarykjarbunga (DIM) doesn’t show squat. But that is also audibly dead from activity inside the Theistareykjarbunga fissure swarm. It would only show if it was the northern leg of Theistareykjarbunga fissure swarm that was active. Okay, then if I go to the reference station of Theistareykjarbunga (GHA) that one is showing so massive counts that it is clipping now. With clipping I mean on the level of Grimsvötn earlier this year.
    What am I carping about?
    Well, we are seeing tremoring on a level normaly only seen during an eruption. But there are no quakes at all in the area. I guess that theoretically Krafla could do a Hekla, but it is not likely. Theistarykjarbunga no way in hell, she would need to warm up for months first. So I will rule out a sneak eruption for now.
    But something is definitly happening up there.
    Either we are seeing the mother of all magmatic fissure loads in the northern fissure swarm of Krafla. Or some still open conduit leading up to Theistareykjarbunga has all of a sudden started shooting magma into his magma-reservoir at a pace never recorded before.
    Which of the 2 options is more likely?
    Well, now I turn into divination here. Krafla is a nice cozy party volcano. I can not see her having an allready open fissure that has the size to take that much magma without having a quake-swarm to open it up first. That leaves us with Thestareykjarbunga, He is a behemoth of a volcano. Only Bardarbunga has ever ejected more magma, the magma-reservoir is tremendous, almost reaching from surface to MOHO. Could there be a conduit still open in a volcano that has snoozed for 2800 years? Well I guess it is possible, He is after all seismically active. And who knows what that one has been up to during the last couple of hundred years before instrumentation. For all we know Theistareykjarbunga could have had an inflation 50 years ago and risen a meter or 2 and nobody would have noticed.

    Problem is just that I am having a problem with both alternatives. Krafla would need to quake a bit first before she opens up a new part of her fissure swarm. If it had been in the part that was active during the Krafla-fires I would have voted for Krafla. Thestareykjarbunga, well… Nah… She is probably dormant under her shield-volcano. I just don’t buy that a pipe would be open and all of a sudden start to gurgle up a hell of a lot of magma. But weirder things has happened. So, I have voted away both of the options, but it must be something happening in one of them.

    Gah!… 🙂

    I have a problem with both option

      1. It’s still going on as far as I can see at MEL and KVO, wouldn’t this indicate some magma movement at Kröflu?

        At the moment, I can’t see SKO clearly, perhaps stopped, perhaps restarting, anyway not as much action there than at Krafla. This would support the Krafla theory.

        Anyway still no tremor at REN and DIM.

      2. But would we really need to see a sudden concentration of earthquakes if a slow rifting fissure were opening, with magma flowing deep underground into any subterraenean fissure that had opened? Couldnt there have been quakes spread over time such that we wouldn’t notice them rather than a single large event concentrated in time?

      3. Well, I think Theistareykjarbunga should need quite a few quakes to start rocking, but Krafla could perhaps do a semi-Hekla on us and sneak-start something. And Krafla had a seismic episode a couple of weeks ago.

        I now think it is Krafla that is active. Todays data support that.

    2. What if Theistareykjarbunga (he or she, you use both) behaved like Hekla? Except for main type of eruption, of course. Would it help to explain it better?

      1. Theistareykjarbunga is definitly a he, I should have been in bed by the time I wrote that.
        H and T is alike in such a way that both are fissure volcanos. T is just a bit more refined since he is a male, so he has a shield-volcano as a blanket. While Hekla has a fissure masked an elongated stratovolcano.
        Difference then being that T is on a main riftzone and Hekla is not.
        But my biggest thingy against them being alike is that T has been snoozing for 2800 years, and Hekla goes every decade or so. So, the bedrock should be to hardened by now for a sneak-eruption. But… T is seismically active.
        In short, not really sure 🙂

      2. Hekla currently erupts every decade, and Theistareykjarbunga currently sleeps…

      3. Yepp, biiiiig difference there. Hekla is also very explosive, and Theistareykjarbunga coughs out 10km^3+ in large blankets of lava. GVP, only gives one +10km^3, but the Theistarhraun and the “other”hraun was also also in the tens.
        Two very very different volcanos. But, I would not like to see Theistareykjarbunga wake up from his sleep. A bit to much gas in those basalt lava floods.

    1. This again shows yr. craft, thank you, Lurking. Regrettable that some data are not available.

      Perhaps IGN should hire you …

      1. Nah, too many meanings for the word “cake.” In some dialects of Spanish you will get slapped.

  17. Good morning all you volcano-lovers and sheep out there.

    Is IMO gonna give out the earthquake data from their down period? Or is this data lost?

    I’m really having my eyes on Hekla, as I think there is not long until she blows.

    As Carl said yesterday, something ALMOST happened there..

    When that is said, this is just a feeling I have 🙂 Nothing more.

    When it comes to the spikes around Krafla last night – could that be something else but volcanic activity? Cause from what I understand, it’s not her time to blow – yet!

    Have a great day everyone.

    -Christina

    1. Up to now, they didn’t give out the missing data – and I think they normally don’t do it in this cases. Depends perhaps on what went missing of them.

    2. Had to double check if you were talking IMO or IGN.

      For IMO, I usually pull data from the flat file off the server’s week listing. Those are the ones that make it into the official record and are as reviewed as they are gonna get. When doing “breaking” stuff I augment that with whatever shows up on the website. Those tend to be error ridden.

      If you have a specific time frame, let me know and I can poke around to see if it’s there.

      2. Well, here is what made it into the list.

        523 20111023 103713.508 64.01655 -19.50218 11.740 1.11 1.19
        524 20111023 105108.464 63.64542 -19.33054 0.136 1.35 1.99
        525 20111023 105207.879 63.65181 -19.34581 0.136 1.14 1.78
        526 20111023 110634.747 63.61694 -19.12524 0.136 0.47 0.13
        527 20111023         143649.274 63.68986 -19.29839 9.214 0.52 0.32
        528 20111023 195028.341 64.04342 -21.37840 1.761 -0.01 0.26
        529 20111023 211735.035 63.60955 -19.13201 3.190 1.11 0.89
        530 20111023 215220.648 63.54718 -19.10945 0.145 1.02 0.93

        Now, I have seen this list get backfilled before. That’s one reason why when I update I go back an extra week in order to catch what may have been changed since my last data pull.

        Just because it’s not there doesn’t mean it’s totally gone.

  18. Monday
    24.10.2011 07:13:34 63.663 -19.142 1.1 km 3.3 73.45 5.9 km ENE of Goðabunga

    Guess it’s a ghost. Nothing on Jons Helicop…erm Helicorder.

  19. Monday
    24.10.2011 07:13:34 63.663 -19.142 1.1 km 3.3 73.45 5.9 km ENE of Goðabunga

    Thats a Strong one! need to check jons helicorder

  20. There was a 3.3 earthquake at about 6 km to the NE of Goðabunga now (not yet confirmed).

  22. What is going on at Jons Helicorder at Hekla now? Seriously, there is NO strong winds there, looking at IMO’s weather forecast…

  24. My opinion about CHIE.

    1. Start: CHIE authomatic gain is set to x10
    2. Tremor started 10/10 at 04:20. CHIE authomatic gain maintains at x10
    3. Tremor increases progressively.
    4. At 11/10 06:10 tremor increases abruptly and almost saturates CHIE, but not enough for an gain authomatic change. Gain maintains at x10.
    5. At 12/10 12:00 tremor starts to suffer drops and peaks. Gain maintains at x10.
    6. At 12/10 14:28 occurs a big explosion and a peak at all frequencies.
    7. At 14:30:30, the peak is so intense that CHIE is fully saturated and an authomatic change of gain occurs, reducing gain to x3.
    8. But it was just a peak, at 14:31 the tremor decreases, but the gain maintains its setting to x3. Just look how tremor decreases between 14:31 and 14:33.
    9. From there onwards, gain is maintained to x3.

    So the most intense tremor recorded occurred at 14:30:30-14:31:00 of 12/10.
    I would affirm the following equivalents looking at this

    http://www.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-10-12&estacion=CHIE&Anio=2011&Mes=10&Dia=12&tipo=2

    Peak 12/10 14:30 equivalent to 12/10 16:50
    Meseta 12/10 04:00 equivalent to 12/10 22:00
    Low 12/10 11:21 equivalent to 12/10 14:43

  25. This would be the explanation of the gain change at CHIE in a nice figure.
    Gain change ONLY affects CHIE, and not other stations, since I imagine its just a matter of an internal gain change (“click”) of the instrument in the field.

    http://oi54.tinypic.com/105w42b.jpg

    1. A nicely logical and clear explanation DrG. This makes real sense to me and it graphically demonstates what I have suspected but could not put into words.
      I did not uphold a conspiracy theory here 🙂

      1. Conspiracy is for loosers like bitter grapes for fox.
        In my opinion, yes, as a good response, it could be a lot of stupidity and a lot of bad management.

    2. Looks like a good guess for me.
      I would like you to ask just what about Turkey event noise?
      Was it less then let say regular noise tremor from La Resigna? At least that my guess. But I’m not an expert. Just confirm me if I’m right, please.

      In this case it means, of course, that the active vent is still throw up material (gases) in a constant way.

    3. I would suggest another sequence of events. At 14.33, your second C, a gain change to 1. At 14.36 gain chance to 3. At 16.00 back to 10. At 17.15 gain to 3 and remains at 3. Then the peak at 16.30 is actualy a decrease in tremor.

      But your easy solution is normally the best.

      1. Peter, note that the EGOM decrease occurs due to the decrease at my point 8 above (14:31) and that we can’t compare the pre 14:30 clipped part with the post 14:31 unclipped part.

    5. Could this be because IGNs main interest prior to July 2011 was on predicting landslippage on El Hierro (as per Carl’s earlier suggestion) not on a volcanic eruption? Once a landslip had started any subsequent filtering of the published data is less likely to be of such significance.

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

    “Data update 24/10 – 07:31 UTC: IGN reported 62 volcanic earthquakes in total yesterday, up from 50 the day before. So far today we noticed 12 quakes who are gradually getting stronger. 7 tremors were M2 or greater! The depth is however at a safe 16.4 to 25 km. Almost all of the epicenters were located in the El Golfo / Frontera bay, in other words this is the area where the magma is most active at the moment.”

    “Update 23/10 – 23:06: Overview of the most important points from today:
    – the colored stain in the Las Calmas sea was not as outspoken as last week, also NO jacuzzi
    – The number of volcanic earthquakes is still increasing : The first 20 hours of the day we have counted 58 earthquakes, the most since October 10. They are not only increasing in number but also in strength.
    – The epicenter of the vast majority of the earthquakes has continued to be in the El Golfo / Frontera area.
    – We noticed 1 earthquake at 7 km depth today.
    – The strongest earthquake today was a 3.0 earthquake!
    – If the earthquakes continue to become stronger, it cannot be excluded that the Los Roquillos tunnel will be closed again
    – Harmonic tremor have increased slightly but has been more or less stable all day long.”

    There is also a video from yesterday of the eruption area. Not sure that you can tell from this that the stain is not as pronounced as it has been because the shots are too close. Also interesting shots of either bubbles (or floating rocks) and shots of “bubbly” areas later towards the end of the sequence.

    And there are more pictures of rock samples.

    1. IGN have increased the EQ depth displayed to 25km.
      Magma pockets may weel be at that depth of deeper–
      – see response to Lurking at 00.57 above

    2. “The depth is however at a safe 16.4 to 25 km.”
      Ahem, what the Horker are the going on about? They should know that the main bulk of the quakes have been at that depth ALL the time. That is not a safe depth, that is the same unsafe depth that we have seen since July.

  28. I see the same effect in the CCAN signal:
    http://www.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=CCAN_2011-10-12_14-15&estacion=CCAN&Anio=2011&Mes=10&Dia=12&tipo=2&hora=14-15

    and the EGOM signal:
    http://www.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=EGOM_2011-10-12_14-15&estacion=EGOM&Anio=2011&Mes=10&Dia=12&tipo=2&hora=14-15

    though not as pronounced. But its clearly visible that a change occurred after a certain event. The times differ though. EGOM and CCAN have the change about one minute later, which would make sense, considering that those stations are a bit away from CHIE.

    And there is another thing: If they had done rescaling, they would have had to adapt the vertical (frequency) scale as well, otherwise the chart becomes simply wrong and misleading.

    What does the IGN say about it anyway? Maybe they can shed some light on what happened:
    http://www.ign.es/ign/layoutIn/contacto.do

  29. Repost:
    I see the same effect in the CCAN signal:
    http://www.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=CCAN_2011-10-12_14-15&estacion=CCAN&Anio=2011&Mes=10&Dia=12&tipo=2&hora=14-15

    and the EGOM signal:
    http://www.ign.es/ign/head/volcaSenalesDiasAnterioresHora.do?nombreFichero=EGOM_2011-10-12_14-15&estacion=EGOM&Anio=2011&Mes=10&Dia=12&tipo=2&hora=14-15

    though not as pronounced. But its clearly visible that a change occurred after a certain event. The times differ though. EGOM and CCAN have the change about one minute later, which would make sense, considering that those stations are a bit away from CHIE.

    And there is another thing: If they had done rescaling, they would have had to adapt the vertical (frequency) scale as well, otherwise the chart becomes simply wrong and misleading.

    What does the IGN say about it anyway? Maybe they can shed some light on what happened:
    http://www.ign.es/ign/layoutIn/contacto.do

  31. About changes at CCAN and EGOM at the same point at the suspicious change at CHIE. Numbers refer to my sequence of events above:

    8. But it was just a peak, at 14:31 the tremor decreases, but the gain maintains its setting to x3. Just look how tremor DECREASES between 14:31 and 14:33.

    This natural decrease [and not the gain change at 14:30] is the sudden decrease observed at CHIE and EGOM. Note that pre-14:30 at CHIE is clipped, and we can not observe, although it is, that pre-14:30 tremor is more intense than, for example, 18-19h. These can be observed at EGOM and CCAM.

  32. Anyway, it is just guessing. As Richard Weierink suggests, maybe there are even more gain changes around. I am quite familiar with computed authomatic gain changes in geophysical signals, and these are difficult to correct if not recorded in (most probably) the heading of raw data.

  33. About multiple magma chambers beneath Hierro:

    Peter 09:32:
    “Their cartoon (fig11) indicates that they conclude there is a lot of small magma chambers – the majority in fact- below the lower bound of your EQs.
    Why should that be?
    Could it be that below 15km ( = MOHO) there are many “small, intermittent, magma chambers” that allow migration of magma while generating relatively few EQs compared with shallower levels?”

    Forgive me for comparing this text with the description of the Cueva de Don Justo (which is an old lava tube) at http://myelhierro.com/en/cuevadonjusto.php :

    “Its interior is a real labyrinth. The corridors, created as a result of prolonged volcano eruption, often crosses and intersects. In some places there are even eight parallel arranged tunnels.”

    Sounds to me like two descriptions from two different points of view of one and the same structure.

    1. I get the impression that El Hierro is very complicated: rifting and at least two volcanoes, with possibly a third at La Restinga.

      I do not see that the descriptions conflict. We seem to have a magma reservoir which is showing rising activity underneath the island and we have a system of old lava tubes near Restinga from old eruptive activity.

      1. So how has the magma got from the reservoir – I presume you mean the plume in the mantle- to the level of Lurking’s plots (8-15km depth) without making EQs in the complex of magma pockets/sills/dykes from 36km up to 15km. The depths from 15 to 36km are clearly not occupied by a plume of magma , but corresponds to the greatest density of magma pockets/sills/dykes. Can magma move silently – not making EQs through these deep sills and dykes? In the past few days we do see EQs at 20-25km deep, but in the first three months, no. I find that odd.

      2. What about the fact that maybe lately the magma chambers, dormant for a lot of years after this new feed start to “eat” themselves. The walls were heated at high speed due to the new magma plum push…
        I suggest that this new swarm of 2+ is in fact an speed up process of magma chambers enlargement. A magma collecting giant reservoir buil-up under El Golfo.

      3. The some magma was probably already above 15km as shown by the paper you quoted above. But there have EQs deeper than 15km since 19 July 2011 (check avcan.org).

        The question I have is what started the activity in July – increasing pressure from magma rising from beneath the reservoir or rifting?

      4. Sorry typo – meant to say that there have been some EQs >15km since 19 July 2011, these are not just recent.

      5. I suspect that the EQ activity from July to a week ago – as in Lurking’s plot – was motion of magma that had filled the lower 15-36km of pockets/sills/dykes at a much earlier time , prior to seismometers being there to record it. That could be decades or hundreds of years earlier. The last week of deeper EQS to the north of the island could be the pattern we’d expect from fresh magma off the top of the mantle plume entering the complex system of pockets/sills/dykes ( or creating them) .

      6. @Peter & Lurking:

        Have you read about a theory of globules of magma that comes moving around untill it hits a soft spot to go up? I do not remember the name of the theory nor the name of the protagonist. But Lurking might since he has an almost edeitic memory (I have noticed). That theory was rather talked about during the Eyjafjalla eruption. I think you might find it interesting.

        Personaly I would do a one up on your theory, I think there has been magma parked under El Hierro for quit some time, and it has been pushed into the system in waves since the last eruption. And it is not untill now that the pressure has become to great for the bedrocks (magmatic and sedimentery).

        And, I do not really believe in that globule theory, but it is an interesting thought model.

      7. What I imagine is that there is a tube system from depth (how deep? No idea!.) up to the surface, maybe here and there ending in cones. Molten magma might pass silently through intact tubes – like tooth paste – makes sense to me. And where the tubes are closed, magma will force a new way out and new quakes to occur.

      8. At those depths the pressure is so great ( and temperature) that crustal rock will be so deformable that there will be no tubes in the conventional sense, certainly nothing like lava tubes on the surface. Sills and dykes will be the weaker regions within the bulk in which magma could move. But I would expect to see EQs as the rock fractures during magma motion.

      9. Not really Peter:
        That rock would be to much like the muchy banana to be brittle enough for a quake to be possible due to the heat. So the sil would widen fairly silently.

    2. See my eternal harping about magma-chambers not existing in reality. A magma-reservoir (singular or plural) is warrens maze of tubes, nooks, crannies, sils, dykes, fissures, caves and your occasional Wombat thrown in…
      Never ever chamber it, guns have chambers, volcanos have reservoirs.

    1. Thanks Jon and thanks for all the effort you put in this blog – I’m learning so much and really enjoying the discussion here.

    1. On second thought, I think this must be journalists reporting wrongly, because both from Lurking’ s plots and from AVCAN maps, the vast majority of the latest eartquakes was in El Golfo, so not on the coastal Frontera region.

      1. And actually AVCAN agrees with me that there is “no new front at La Frontera”, so please ignore the above link (or read it for entertainment purposes only).

      3. I’m waiting for the IGN list of tremors to reach the 12.39 one that shows on the spectrogram as a double line.

      1. Thanks. What confused me in the article is this sentence:

        “Los datos del Instituto Geográfico Nacional reflejan que de los últimos 117 sismos registrados en la Isla, 112 se han localizado entre la costa y en tierra dentro de Frontera.”

        Data of IGN show that out of the last 117 earthquakes registered on the island, 112 were located from the coast towards the land inside Frontera.

        Clearly not true. 😉

      3. Not true because the translation zux:

        “Data of the Instituto Geográfico Nacional make clear that from the last 117 seismical events that have been registered on the Island, 112 have been localized within the coast and inside the earth underneath Frontera.”

        Not a native speaker, but this seeems more in line with what I’ve read so gar on the AVCAN FB-group etc..

      5. Just because the listing says NW FRONTERA.IHI that doesn’t mean it’s near Frontera. It’s just that side of the island.

        Reporters. You can dress em up, you can even spray them down with perfume, but that’s not gonna stop them from slinging poo.

      6. In all hernesty, many reporters work hard at trying to write about things as well as possible. Problem is just that there are always more subjects to write about than any newpaper can hire experts to write about. So, you call a scientist, and they are not always the most easy to understand… So, reporters are good about writing that something has happened, but the details can become iffy.
        Imagine yourself being thrown all of sudden to write about the world championship in rabbit-jumping. Not that easy really. Those fairly honest journalist that try to do an impossible job I can feel respect.

        Then we have the lying shit bastard journalists (often brittish I have noticed) that lie for the hell of it. They are a disgrace to their profession. Those ones I would like to sling poo on.

      7. hernesty… well honesty is better then hernesty I guess. I would say that Hernesty is what those beforementioned brittish journalists was practicing.

        Hernesty, to induce a hernia instead of trying to write the truth.

      8. Every reporter I have met is a sleazy low life self aggrandizing bastard.

        It’s gonna take quite a bit to change that opinion.

  37. I just wanted to share an animation I did to visualize how the seismic activity of the recent days has moved to the north of the island and how that activity is mostly located under the 20km zone (I used the latest graph from the IGN website and the one here in this blog post from Jon; 20-24 oct):

    http://i.picasion.com/pic45/cfb09abda6c8ec40946334d63372f861.gif

    Not sure if this shift means anything at all as I’m no expert.

    1. Please use a valid email address in the future. As this pattern of non-valid email address is coming to a end on this web page soon via email authentication sent from this blog.

  38. El municipio herreño suma 63 sismos de los 66 registrados en las últimas 48 horas.
    El Hierro municipality sums up 63 earthquakes from the 66 recorded in the last 48 hours.

    Hope this clarifies the number of earthquakes. 🙂

      1. Yeah, that makes more sense, the ‘adentro’ from the translation I did above, should be read as “within the boundaries of the municipality of La Frontera” Thanks Renato!

  39. @Krafla:
    After re-viewing the activity at the SILs for Krafla and Theistareykjarbunga it is now quite clear that all of the activity seen during the night and today is emaneting from the Krafla northern fissure swarm. The fissure is not a part of the radial fissure swarm that erupted during the Krafla fires that lies to the NNW. The much bigger fissure runs NNE towards the sea East of Theistareykjarbunga.
    I have tried to calculate the length of the current active fissure, and it seems to be about 100km long. And with that in mind the level of harmonic tremoring is quite believable.

      1. Yes, I can see the difference.

        But I think that there is some real action at Bárdarbunga, too http://hraun.vedur.is/ja/oroi/skr.gif – also if it’s by far not as much as in the Krafla volcanic system. What do you think about that, could it be root filling? I thought that Icelandic geologists were of the opinion that Krafla would be dormant for the next 200 years – but perhaps she is good for some surprise … – as women are sometimes, putting on her lipstick and then going to dance …

      2. Yes, but when I checked the previous rifting episodes they seem to have lasted about 50 years in about half of the cycles. So, I would not rule out a new eruption there at all. I would definitly say she could throw a surprise or two.
        There was the regular tremor spike at Hamarinn. It is quite common since Bardarbunga is getting closer to an eruption.

    1. I do not think so – these relatively deep swarms are occurring below the Mauna Kea at irregular intervals. The general accepted explanation is that the weight of the 4000 meter high volcano is the reason from the cracking below the 10 meter high volcano (from his base in the ocean). I have written an article on it in ER

      1. Did you see Lurking last plot of it?
        I am not so sure actually. I think one can see a feeder tube shape in the quakes, but it then needed more quakes to make sure.

      2. when writing that article i was guessing the same Carl, but after some research (don’t ask me where …) i was convinced that it is a returning phenomena. If not, that would be the year of the dormant volcanoes coming to life again? Nabro, El Hierro (we still hope – best in the sea for the people of course) and finally Mauna Kea !!! 🙂

      3. Up that with Krafla, if it is not Theistareykjarbunga. That would really make my day. Imagine an english speaking news-anchor trying to pronounce that one 🙂

  42. DIARIOELHIERRO.ES, writing (24/10/201)
    Scientists currently monitor the seismic activity in the volcanic island of El Hierro are very aware of the rise of earthquakes in the border area, although at the moment, the largest quake was of 3.1 magnitude on the Richter scale and at a depth of 20 to 25 kilometers. Until yesterday, Sunday, volcano monitoring network monitoring 24 hours of National Geographic Institute (GN), recorded and located 78 seismic events, one of them slightly felt in the epicentral area. The maximum magnitude recorded in this period is 3.1. Most events are located in the area of the Gulf at depths of about 20-25 km. Almost all are located in the sea and are aligned NNW-SSE. The rash of RESTINGA,””END IN PERIOD Meanwhile, the president of the Cabildo de El Hierro, Alpidio Armas, told the Cadena Ser said that according to scientific analysis of the volcanic eruption in the Sea of Calm at La Restinga, “is in period of completion”, and it looks like there is “no possibility of reactivating” the undersea volcano . Right now “we have a new front” in Frontera, where they are concentrating all the earthquakes that are occurring, and for now, its progression is unknown, said

      2. Ok, it’s your desire and i respect it, but let me tell you that Alvin it’s a respectfull guy and his site it’s not doomish! He only quote good information places like this one, or local media. For example, he don’t to quote nothing of GLP site there or from doomish places. He belives that our planet is in a transformation process that is visible in wheather, volcanoes, and strange things happening everywere… he tries to read the signs that planet give… i know you don’t belive it, but it’s not a crime to belive. I learn a lot with you and many people can too, but i respect your will. Sorry.

    3. It is giggle. Sometimes you can also see translated articles talking about “weapons”, while actually meaning mister Armas.

  43. Just catching up with the day’s events, this site is invaluable but the only problem is it then gives me more questions lol

    So, from what you guys have already said the chance of my witnessing an eruption is pretty slim, but now that Krafla appears to have woken up does that chance of witnessing change? Sorry for all the questions, I’m a newbie but really appreciate your advice/thoughts.

    1. Krafla will most likely not erupt in the very near future. I though think that Krafla could erupt sometime during the next ten years.
      If one volcano would erupt, it would at more than 99 percent of the times be Hekla right now.

      2. Hekla would be more than welcome! I’m a bit tired of Katla teasing us and probably leaving us waiting for at least another year.
        Also, are you really that sure of Krafla? I wouldn’t make the bet. Krafla’s eruptions seem to occure in episodes, just like in the 18th century, and it pretty much like we’ve had our piece already.

      4. Re. Krafla, you can believe Carl, he is the Krafla expert here.

        There was found magma in a surprise pocket – or even some pockets some hundreds of meters nearer to the surface than had been imagined before in Krafla caldera about 2 or 3 years ago.

      6. Thanks, in a way I don’t want to see an eruption, must be pretty hair raising to say the least, but of course the other part of me is thinking it would be a once in a lifetime opportunity (from my personal perspective).

  44. Thanks all, an amazing blog here as always!

    Just wanted to say I don’t think magma is moving deeper, but drawing up with fresh and hotter material, while the long-standing magma in the chambers, which is thicker and slower-moving, tries to move into the spaces in the sedimentary rock that gases have cleared. I speculate that this slower-moving stuff may or may not surface on land, while the pressure in El Golfo, from the hotter stuff, may rise faster.

    Just guessing though. Thanks for the brilliant science, experts.

    1. Sorry I should have specified El Hierro. Iceland is so much more complex, and well-mapped.

      1. Ahem, Iceland well mapped?
        Not really, Iceland is so complex that I think we really are further away from understanding Iceland than El Hierro.

        Remember that El Hierro is a rift volcano, so the magma-reservoirs are mainly driven around those. So, fresh magma can either mix, or go around old magma since dykes can spring into existence very quickly.

  45. Jón, why did you choose Spain to report on? With a bit of luck you’ll have an eruption every 25 years or so. Plus, except for El Hierro, there is not much realtime data online like IMO has. Also, with all respect, I personally think your at your best covering Iceland and it’s geology, because you have quite an advantage being a native and knowing much more about Iceland than most of us!

    1. You might have missed it, but on the long run, Jon is planing to move to the canary islands in some years time. I think thats one main reason.

      1. I know! But I guess the main reason for moving to the Canaries would be the volcanism, on which my former argument is valid. Also, considering job opportunities moving to any mediterrean country wouldn’t be very wise now, and most probably not within decades as their financial problems are pretty severe.

    2. I am going to move to Canary Islands (one of them) in about 10 years time if my plans work out in that time frame.

      For that reason I added Canary Islands and Spain to my watch program on volcanoes and earthquakes.

      1. Jón, could you kindly ask user Luisport to not quote me at sites as extinctionprotocol and 2012forum(dot) com?
        People in your blog is a curious and calm group that can take my posts for what they are, amateur speculations, and they also can ask me question and so on. But out there in those speculation sites, my comments out of context, will just cause a lot of useless anxiety among people who have a problem seeing the difference between hypothetical speculations on my part, and pure doomsday mongering.
        Sorry to disturb you with this, but I have tried twice asking him to stop it, without result.

        Once again, I am fine with sites like Armands and Marías when they quote me. They are after all based on a scientific base that I can respect.

      2. Carl, Sadly I cannot stop this. As this is there web sites. I also know that they are taking what I am saying out of context and propagating fear for there own gain (there is no other reason why they do this). Since I do not have a army of lawyers or the money to work on this. I just ignore it and continue to do what I do best. Work with facts. Since the scaremongers are just going to look stupid when there fear fails to materialise in the real world.

        But scaremongering on my site is not tolerated and it would be nice to get to know about it.

        For those how are interested. The comments are not part of the Creative Commons licence. They belongs to anyone how write them and are there responsibility. I am not responsible for comments that people make here.

        I am also happy to let you know that from 1 November, 2011 all links to scaremongers web sites are going to be deleted without warning from comments on this blog.

      3. I don’t think it is polite to quote any of us readers here, Jón being an exception, and if I do so I quote the blog, not Jón himself (basically at AVCAN, Tuff Team, on FB and Vince’s blog, or Erik’s, of course).
        If the fellow reader is common to both blogs, then I would feel free to quote.

      5. You don’t nead to hask to Jon… you can tell me and i respect your will… sorry it was not my intension to disturb you… but please read my statement above.

      9. Sorry Carl, but i don’t see what you was telling me… many people are posting and i don’t read everything. Please Maria i’m a respectfull person, don’t refer to me like this “person”! I think this site don’t nead my postings… i will not do it again or use info from here. by

    1. I’ve been waiting for that! It’s a lot more convenient like this. The N-S perspective didn’t really make sense with this earthquake pattern.

  47. Citing the link from Inge (which is very interesting!):
    http://www1.nams.is/jardfraedi/eldfjoll2.php?id=380

    Around ~9:05 it shows a map of the relief of N-W Vatnajökull. The interesting thing: the ridge that runs from Grimsvötn to the N-W to Hamarinn/Bardarbunga. I believe we saw a distinct earthquake link between G and H/G at one of Lurkings plots.

    1. The film is actually about volcanism in Iceland generally, for schools and so.

      They show also Hengill and Laki.

      But the centerpieces are the effusive Krafla volcano-tectonic series and the explosive Gjálp eruption from 1996 (which was seemingly initiated by a 5.0 earthquake in Bárdarbunga). http://www.earthice.hi.is/page/ies_gjalp1996

      To Sam:
      I actually have had the opportunity to watch 2 volcanic eruptions in Iceland – rather a mingled experience.

      1. Seriously envious… I have so far missed a lot of eruptions with a couple of weeks.
        Sofar I have missed a Tonga underwater eruption (and sailed through the pumice), passed a week before Soufriére Hills eruption started, Etna, Krakatoa (2 times) and of course Eyjafjallajökull with a month. I am the champion volcano misser 🙁

  48. Evidence that magma ascent is FAST:
    Extracts from Stronikc et al.
    http://eprints.ifm-geomar.de/7993/1/915_Stroncik_2009_TheMagmaticPlumbingSystemBeneath_Artzeit_pubid12801.pdf
    page 11:
    “”Using a simple one dimensional diffusion model
    [see Klu¨gel et al. (2000) for more details of the diffusion
    model] calculations yield an upper limit for the time
    interval needed to produce olivine zonations. Based on a
    diffusion coefficient of 1.3 9 10-16m2 s-1 we obtain
    maximum time intervals of 2–588 days, with some of this
    variation probably reflecting oblique cutting in thin section
    and anisotropy of D in olivine. However, despite these
    uncertainties, we can conclude that the magma ascent from
    the mantle to the seafloor, including the mixing events,
    occurred within days to a few months for the various lavas
    investigated.”””
    (page 12 of pdf):
    “””The plumbing system beneath El Hierro in comparison
    to other oceanic islands
    Even though the barometric data presented in this study
    cannot be used to locate Recent magma reservoirs beneath
    El Hierro or deduce their sizes, some inferences on their
    spatial distribution can be made. The calculated pressures
    of last clinopyroxene-melt equilibration indicate that major
    fractionation of magmas occurs within the uppermost
    mantle, with magma storage and fractionation in the crust
    playing only a subordinate role. On the other hand, the
    relations between magma and mineral chemistry discussed
    above point to the existence of small, ephemeral interconnected
    magma chambers. The existence of ephemeral
    interconnected magma pockets was also invoked to explain
    the frequent occurrence of strongly zoned eruptions of
    comparative low volume at the neighboring island of La
    Palma (Klu¨gel et al. 2005). The lack of any apparent correlation
    between sample localities and fractionation depths,
    mineral composition or melt composition can best be
    explained by a more or less random distribution of these
    magma pockets in the upper mantle beneath El Hierro. Our
    data also suggest that melt transport within the rift zones
    affects the petrogenesis of the magmas only to a minor
    degree. Therefore, their main effect is focusing of the
    ascending magmas along the different ridges that are the
    surface expression of the rifts, suggesting that the rift
    structures may be simply maintained by gravitational forces
    as proposed by Fiske and Jackson (1972). This
    interpretation is also supported by the ridge morphologies
    becoming less pronounced and submarine eruptive centers
    becoming more irregularly distributed with increasing
    distance from the island, which is explained with a
    decrease in gravitational stresses (Gee et al. 2001; Mu¨nn
    et al. 2006).
    Our model of the magmatic plumbing system beneath
    El Hierro is depicted in Fig. 11. We propose that the
    edifice is underlain by a plexus of partly interconnected
    magma pockets and sills and dikes within the uppermost
    mantle between about 14 and 30 km depth and most likely
    extending to deeper levels. Here, incoming magma batches
    fractionate and become mingled or thoroughly mixed with
    other ascending batches. Such a mixing event may involve
    moderately to highly fractionated melt pockets, and may
    trigger further ascent of the magmas and ultimately lead to
    eruption. Magmas from the mantle reservoirs mainly
    directly erupt without stagnation in crustal reservoirs.”””

    So magma ascent is fast:
    “…. magma ascent from
    the mantle to the seafloor, including the mixing events,
    occurred within days to a few months”

    But does a gravitational rifting ( landslide?) have to happen first?????

    1. We have one in my hometown. It has taken 3 years. Of course it is not even close to the scale of El Golfo. But it was interesting to see about half a square kilometre slid away in small, small pieces.
      A couple kilometres away a piece as large as the first disapeared in minutes.
      So, my guess is that it could take anything from a few minutes to tens of years for a landslide of that size to happen.

      1. Whereas I think that the gases and lighter ‘stuff’ make small holes, which leave caves, and in the long-standing crystallized pockets the magma is too thick to get up through them, so, with the hotter stuff pushing from below, then I fear the pressure may blow a section first, potentially catastrophically, even if the magma then finds a different exit for the main eruption.

        This concept comes from the different ideas proposed in the Muenn paper, and the Hernandez paper on the volcanic caves, and the Day paper on the magma pockets and J C Carredo on topography and rifting.

        There are caves all over the island and I wonder that they may be weak spots for further landslips to be ‘burst’ from.

        Just my two penn’orth, but it worries me nonetheless.

      2. Down “there” the pressure is normally way to high for gasses to release from the magmas. So, things are working down there in a rather different way.
        But the ejected magma can be pretty “fluffy” from gas-release, with pumice being the fluffiest.

    2. Great! I think I begin to understand the whole mechanism, which explains the lack of shallower earthquakes and extensive landslide events.

    3. I don’t know. But I can see that a landslide might facilitate an eruption as it did for Mt St Helens; if it causes a blocked vent / conduit to open; or, if it puts additional pressure on magma in the wrong place. And I can see that an eruption could cause a landslide on an unstable hillside.

      For a landslip to trigger an eruption, I guess the magma has to be near enough to the surface or to any large vent that was opened and the magma probably has to be under pressure. The $64million is how near is near enough.

  50. @ALL:

    Theistareykjarbunga proven to have woken up.

    Since a minimum of 4 (Four) years Theistareykjarbunga has had an uplift of 3cm/year. This could have gone on for a longer time, but the GPS-network of Sabrina Metzger, Sigurjón Jónsson and Halldór Geirsson was not installed untill 2007. The uplift is in Theystareykir Volcanic System. It is verified with ENVISAT Interferograms as a transient uplift signal.
    For the 4 proven years that gives 85 million cubic metres of magma infused into the system (low count model). But, as said, we do not know when the uplift started.
    With this newly published paper I would say that it is more likely that the last day of activity is caused by Theistareykjarbunga.

    Locking depth and slip-rate of the Húsavík Flatey fault, North Iceland, derived from continuous GPS data 2006–2010, in, Geophysical Journal International.
    http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2011.05176.x/abstract

    Armand:
    This was really the year where the sleeping giants arose, and the giants do not come bigger than this in real life.

    1. Well, I only hope she (she?) will give me enough time to learn how to pronounce it as correctly as I managed to say Eyjafjallajökull. I was good at it.
      Theis-tar-eyk-jar-bun-ga. :0
      Can’t wait to hear TV anchors doing it!

      1. I think it is Þeistar-eyhkjar-bunga. Þ pronounced as ‘th’ink.

        For once I am going to say this. Let us not hope He erupts. It would be as bad as Eldgja/Laki/Veidivötn with flood basalts in the 10km^3 class of magma being ejected with the obiquitus gas-release.

      2. “bunga” is a “she” actually in Icelandic. Means a shield volcano. Let’s hope she doesn’t feel offended now!

      1. It quakes now and then, but remember that this is a rifting fissure volcano, for all we know He could be very much like the Dead zone and the small quakes we see are it.
        And, the size is so large, that it could probably fill and stretch for decades before the quaking picks up in number.
        But when I say woken up, I do not mean as in erupting, I use the word as in yawning and having a bit of coffee in the morning, and an eruption is a late nightclub and being roaringly drunk and vomiting on the bouncer and then starting a fight and winning over the bouncer and his friends.

      3. Looked at Teide after this. It’s formation is interesting. At one stage it looked a bit like El Hierro (three ridges after the accretion of three volcanoes). Later it went onto develop a caldera. May be El Hierro will do the same?

        http://en.wikipedia.org/wiki/Teide

    3. Actually, it seems to have started, or really started to affect the GPS:es north of Theistarekjarbunga in 2007.
      You can see how RHOF and ARHO starts a mad dash to north, and west component of Akureyri accelerates a lot, and ARHO shifts east component to a mild west component.
      At the same time all three of them roars up with 30 mm, and here we are talking about GPS:es quit far away from Theistareyjarbunga. But the shear size of Theistareykjarbunga is so large that is shows everything around.

      I wonder how much of the activity during the last few years in the rift zones above Theistareykjarbunga have been caused by this immense volcanos inflation.
      When I say dome, think of the top of a very very large ballon starting to expand in all directions.
      Scary.

      1. Is it bigger than the shield volcanoes on Reykjanesskagi, e.g. the one Keilir is placed on? I remember driving from Ásbyrgi through Reykjafjöll to Húsavík once, but I have not yet been at Þeistareykir.

      2. Now I have to get yet another bottle of Whiskey.
        I guess Teide would be a nuisance, but it would not even be close to one of the Icelandic Bad Bunch 🙂

        It is bigger, and the really stumping part of it is that it was created in one single eruption. The 2 other known moe miniscule eruptions was lava-floods about the size of Eldgja. She is a brute.
        She has probably had a couple of small and slightly explosive vent eruptions that created a small Viti and a rather nice crater, but those are not even listed on GVP. By the way, GVP does not list the magma amount of Theistareykirhraun and Borgahraun. They also do not count the two other shield volcanos that is a part of Theistareykjarbunga, Storahversmor (370 meters) and Storaviti (540).

        So there has been at least 7 eruptions, but the amount of hrauns seem to indicate many more. In a way she is a trap-formation of her own.

        Data on the main shield volcano, 564 metres, created by the ejection of 30 cubic kilometres of lava in one juicy eruption, which as far as I know is the largest basaltic eruption on Iceland since de-glaciation (not Veidivötn Tjorsahraun at 25 cubic kilometres).
        So, we are talking about a volcano that has had a minimum of 5 instances of more than 10 cubic kilometre eruptions.
        That she has awoken from her deep slumber is very bad.
        Just the amount of tremoring that she throws up without even (probably) being even close to an eruption is a sign of what could come if she not goes back to bed.

        Then we have the little piddly thing that Theistarykjarbunga is (if I got the map right) the southern part of the Húsavik Flatey Transform Fault. For those who do not know it, in 1872 it produced 2 instances of 6,5M quakes roughly at the spot of Theistareykjarbunga, and in 1963 the adjacent TFZ produced a 7.0M quake. I would not be surprised if it was one of the 1872 quakes that started to wake her up.

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