Increased eruption activity in El Hierro volcano

I was going to post this yesterday. But I fell a sleep at 17:00 UTC and I didn’t wake up until 03:00 UTC.

The eruption in El Hierro volcano continues as it has been doing for past few weeks with little change. The first eruption vent that did open south of El Hierro Island has continued to erupt. But so far no Island has formed and it is unclear if it is going to form, as the depth is great in this area. Since yesterday around 06:00 UTC the harmonic tremor has been increasing. But this suggests that new vents have opened up in the south eruption area. I got some pictures of that yesterday in the email. But they did not show anything new in my view. Thanks to the readers how did send me those pictures.

The current fluctuation in the harmonic tremor from El Hierro suggests that magma is on the move in the north part of El Hierro Island. Both off the coast and maybe inland on the Island where earthquakes have been taking place. It is impossible to know how this is going to develop during the next few hours to days. As that depends on the rock structure of El Hierro Island and earlier eruptions.

Earthquake activity

During the past two weeks the earthquake activity have been growing in the North-west part of El Hierro Island. The reason why this is happening is that a new fissure is about to open in this area. As I have mentioned before in earlier blog posts. When and where is impossible to know for sure. The largest earthquake so far took place this morning, it size was ML4.0 with the depth of 20 km. But this is the automatic data from IGN. This pattern of earthquake activity is most likely going to continue during this eruption process in El Hierro volcano. Since the eruption type here is a fissure eruption.

It is worth noting that earthquakes in once place does not mean that the eruption is going to happen in that place. As the magma can travel in dikes all over the El Hierro Island and show it self anywhere on the Island it self. So the general risk is high in my opinion. The only action that can be taken is to be prepared for sudden eruption of new vents on El Hierro Island. Since there is a good amount of magma on the move inside El Hierro volcano.

The harmonic tremor in El Hierro at 08:54 UTC (when picture is saved). The spikes are earthquakes, and harmonic tremor spikes are the “waves” in the harmonic tremor pattern. Copyright of this picture belongs to Instituto Geográfico Nacional.

Update 1:

* When I wrote this blog post. This two earthquakes took place.

1109584 02/11/2011 08:37:11 27.9267 -18.1084 3 1.7 mbLg NW FRONTERA.IHI
1109582 02/11/2011 08:36:00 27.5986 -17.9594 1 1.9 mbLg S EL PINAR.IHI

This are the most shallow earthquakes that I have seen so far. From the depth it is possible a magma has found a clean path to surface in this two areas. Sadly there is no map. So I am not sure where this earthquakes took place in El Hierro volcano.

Update 1b: The earthquake have been revised. Now the depth is 9 km for the ML1.7 and 22km for the ML1.9.

The shallow earthquake.

1109584 02/11/2011 08:37:11 27.9304 -18.1107 9 1.7 mbLg NW FRONTERA.IHI [+]

I am going to post more information when I know more on what is taking place in El Hierro.

Blog post updated at 11:24 UTC on 2 November, 2011

1,078 Replies to “Increased eruption activity in El Hierro volcano”

  1. Jón, since there is a new post I am going to rewrite this.
    Since there seems to be a trait that many of the new commenters on your blog finds an interest in connecting a lot of things with EQs and Volcanic activity, things like sunspots, solar eruption and so on, and so on… And Lurking has to prove that there is no findable connection each time with a choice number of plots. Therefore I suggest that you let Lurking “Guest-blog” one piece about this. I think that would really save time and energy because then we could all just link to that blog-post in the future when the next bunch of them comes around.
    Would save them energy, and all of us energy. Because then they could look for something that would perhaps be more usefull. But, it is up to you since this is your Blog.

    1. I also think this is recommended – the blog is so succesful that it has grown very fast. It might as well grow even more in the future.
      Splitting up different topics to different blogposts would make things easier to access and avoid cluttering.

    2. I would not bother with that. This type of people, in my experience anyway. Never, ever listen to a well laid out argument. They just ignore it and move on with the same nonsense as before.

      It is a problem. But I do not think that a lot can be done about it in terms of speaking with this people.

      Due to the ignorance factor.

      1. Well, I think some of them would actually. One thing we should remember is that many of us have played with the idea and discarded it, at least I have and I know Lurking have. And since he really tried to prove it, and failed. I think that at least half would listen and learn quite a lot. I just think it would save time.
        Sometimes it is good to be able to give a link and say “RTFM!” Love that computer phrase 🙂

        Just my five cents.

    3. That’s a nice idea! At least saves some effort typing all these arguments over and over. They probably won’t listen, but then we can at least say we did our part in helping them becoming sane again!

  2. Carl, I swear to god, I am not crazy waking up in the middle of the night, posting a comment here. You see, I understood what you meant last night, but when I check this : on my phone, It actually looks like HUGE changes, but they seem to even out with the rest of the small spikes there at the strain. I swear, I’m not crazy… It was a looooong one going rather far down there, and one going very high there. But at next update, it’s normal again. Same happened just 30minutes ago.. So I now pulled my sick body out of bed to get to the computer….

    Could it be just errors they’re just fixing on?

      1. Hey Christina!

        I sometimes it auto corrects. Let me just say, if you see that scaling all of a sudden look like this, 4.8E + 7, or something such, then you know that it is a very large transient and that you should hold your breath.
        Even if you would see a transient that is 500 negative for Búrfell and 200 up for Hella, even then it is a very small transient.
        The above given number is the largest sofar since the eruption in 2000, it was 32 times smaller than the actual eruption transient. Still it caused IMO to post their latest warning. It was recorded on July 7 and occured at the same time as there was a 2M quake in Hekla. That time it was very very close to an eruption.
        Right now Hekla is a bit relaxed, but it could go at any time really.
        But, the statement, you will never doubt it when it happens. If you look and see a very large transient, rapid small quake-swarm, then you will probably say “Oh shit!!!” within an hour as the Búrfell Dalek cam is blown away… 🙂

    1. And also one more question, Carl. Is it sure that Hekla would do the exact same thing as she did in 2000? Isn’t there a tiny tiny chance that it could have a different patterm before an eruption?

      1. Everything is possible, but she has been pretty consistant in her behaviour since 1947…
        Let me just say, that if she erupts out of behaviour, then I would get really concerned.

        She is mysterious, wild and the most Beautifull Volcano in the world, and as such, she can at any time turn on you and kill you like the female she is.

    2. In my eyes, using what I’ve learnt from Carl, I’d say that it’s a rather small transient. This one is about 125 straincounts/sec while the largest we’ve seen were something in the order of 1*10^5 I believe.
      About the Hekla question, we never know untill it happens! What has to be remembered is the statement that Hekla is a constant, regular erupting volcano (the once in 10 years thing) is actually false. This statement can only be made when looking at the past 40 years, which ofcourse is a tiny part of Hekla’s magnificent history. Hekla seems to deviate from the pattern as it’s interval is currently approaching 12 years. If that also changes other symptoms is a matter of random guessing, we’ll just have to wait and see!

      1. Could be, I’m sorry but I’m not really experienced on this field. Carl will have a much more sophisticated answer than I do! 😀

      2. It is just the algorithm of the software, it sometimes seems to almost project a prediction of where it would go if it continued. Therefore I always wait untill the 10 minute update.

        But, the motion patterning is pretty large, remember that we are regularly seeing strain counts up to a hundred several times a day, and that is without transients.
        I know that IMO has a cumulative strain count chart, and that is running upwards fast now since the average motion is getting larger and larger. I still stand by my prediction of an eruption coming within the next 7 months. She is still moving along as if she where moving on a track to an eruption.

  3. Jon,

    How can you draw a conclusion as solid as you just did based on EQ’s happening in de 20-30 km depth region? What information/knowledge do you have that others don’t have that enables you to make such a bold claim.

    During the past two weeks the earthquake activity have been growing in the North-west part of El Hierro Island. The reason why this is happening is that a new fissure is about to open in this area.

      1. Yes, magma is on the move, that’s pretty clear. But as you state, it has to contain the energy and pressure to erupt. That is one uncertainty, the other is that it might just erupt through the current vent, if it would even erupt. That’s a heck load of uncertainty, therefor I think the statement ‘The reason why this is happening is that a new fissure is about to open in this area.’ is completely invalid and just a random speculation.

      2. It is clear that you have not been doing this for a long time.

        Eruptions are always, and I repeat always uncertain. Ask any professor in this field and he is going to tell you the exact same thing.

        The entry and where the fissure opens depends on earlier eruptions, the rock that make up El Hierro. But a fissure or a eruption vent is going to open up there. It is just a question of time and where. This is not a “if” issue as you clearly think.

      3. Ad Hominem, nice.
        You’re still contradicting yourself. On the one hand you state that eruptions are uncertain. But on the other hand, without any real argument for WHY a new vent has to open up so badly, you state that it WILL occur. I’m just not getting that. Once again, I’m not saying I know better, but I’m saying it would be wise to be a little more carefull with making statements.

      4. You have not made a argument for your claims. Make your argument here, until then you are just claiming something just to contradict me here. Why I do not know.

        Claiming that you have not been doing this for a long time is not a Ad Hominem. Know your fallacies before your claim them.

        El Hierro is not a single vent eruption. This is a fissure eruption. Fissure eruption always make a lot of vents when they are active. They also almost always make earthquakes before new vents open up, or if a fissure opens up.

        This is both common in Iceland and in the Canary Islands that are build on eruption fissures. Those two Islands that I know are like that are El Hierro and La Palma.

      5. And there we go again with the contradiction.
        Compare these two sentences of yours.

        ‘Fissure eruption always make a lot of vents when they are active’


        ‘Eruptions are always, and I repeat always uncertain.’


        Also, I’m not making any statements, I’m giving my opinion. Yes, that is contradicting. Why? To remain critical to whatever anyone says and therefor try to raise the quality of the discussion.

        (a bit offtopic, but I’ll go along:)
        Ad Hominem:
        ‘an attempt to negate the truth of a claim by pointing out a negative characteristic or belief of the person supporting it’

        You are trying to say my arguments are invalid by saying I’m unexperienced. That is a negative characteristic. I’m not offended by your statement in anyway, just dissapointed by the fact that you have to bring up such things in a critical, but still a decent, discussion, suddenly making it rude.

      6. Contradictions ? This is a claim that you are making. It is not a opinion. I do not know why you think you can get away with this nonsense with me.

        Because you cannot do so.

        Now. Here is what USGS has to say about fissure eruptions.

        “This eruptive fissure broke out on the northeast rift zone of Mauna Loa about 15 hours after the eruption began in the summit caldera, about 15 km uprift (toward upper left). Initially about 1.6 km long, lava fountains along the fissure were soon restricted to six vent areas. These vents built a spatter rampart, a cinder and spatter cone, and a lava shield along the fissure. The most productive vent is in the upper left.”

        This took place in Hawaii, you can find a link here with a picture.

        Now, on Wikipedia they have this to say about fissure eruptions.

        “A fissure vent, also known as a volcanic fissure or simply fissure, is a linear volcanic vent through which lava erupts, usually without any explosive activity. The vent is usually a few meters wide and may be many kilometers long. Fissure vents can cause large flood basalts and lava channels. This type of volcano is usually hard to recognize from the ground and from outer space because it has no central caldera and the surface is mostly flat. The volcano can usually be seen as a crack in the ground or on the ocean floor. Narrow fissures can be filled in with lava that hardens. As erosion removes its surroundings, the lava mass could stand above the surface as a dyke. The dykes that feed fissures reach the surface from depths of a few kilometers. Fissures are usually found in or along rifts and rift zones, such as Iceland and the Great Rift Valley in Africa. Fissure vents are often found in shield volcanoes.

        In Iceland, volcanic vents are often long fissures parallel to the rift zone where lithospheric plates are diverging. Renewed eruptions generally occur from new parallel fractures offset by a few hundred to thousands of metres from the earlier fissures. This distribution of vents and voluminous eruptions of fluid basaltic lava usually build up a thick lava plateau rather than a single volcanic edifice. The Laki fissure system produced the biggest eruption on earth in historical times, in the form of a flood basalt, during the Eldgjá eruption A.D. 934, which released 19.6 km³ (4.7 mi³) of lava. […]”

        Your Ad Hominem is weak. As it really means this thing here, “ad hominem: Latin for “to the man.” An arguer who uses ad hominems attacks the person instead of the argument. Whenever an arguer cannot defend his position with evidence, facts or reason, he or she may resort to attacking an opponent either through: labeling, straw man arguments, name calling, offensive remarks and anger.”

        From here,

        Now. Back your claim with arguments or stop this. As this is a annoying and waste of my time.

      7. A claim is stating something IS the way it is without any possible discussing. An opinion is what someone thinks, leaving the opportunity to reconsider. As you wish, I will once more ellaborate my OPINION with the argument I’ve previously given:

        Opinion: With the given information, it is not possible to know for sure how this eruption will develop.

        -Various scenarios (for example: sudden decrease in activity, with the remaining magma turning into a pluton, or continuous eruptions through the current active vent) are possible, all scenarios have the possibility to occur.
        -Historical data alone is not a reliable source when it comes to volcanism. It gives an indication, but in no way a complete certainty.
        -Even considering historical data as a valuable source, the data from El Hierro is extremely limited as there are no certain witnessed eruptions.
        -Using other volcanoes as a reference is possible but on a very small scale. Yes, other similar volcanoes have a had multiple-vent eruptions. But other similar volcanoes have also had monogenetic single-cone eruptions.

        Whatever, I’m having the feeling this is an endless argument if someone is not willing to admit that claiming someone is unexperienced is ad hominem (which it is, once again, and it is invalid, because you someone with less experience is not neccesarily less credible than experienced people. It’s like claiming that since I’m 18 and graduated grammar school I know more than anyone younger and less educated than I am.

        Well, as I’ve said, this is endless and therefor I expect this to be the last comment. The only thing I’ve left to say is that it has dissapointed me that you apparently are not able to cope with critism, while critism should be applauded as it is an attempt to bring a discussion to a higher level.

      8. I think Jon says, that:

        1. Typically fissure eruptions create many vents.
        2. Earthquake activity precedes the opening of new vents.
        3. It is not unsure, if these vents open. It is unsure, where and when these vents do appear.

        I see no contradiction in these three statements.

        So, Pieter, can you state simply and clearly, where the contradiction lies in your eyes?

    1. I totally agree, this post is again lacking background information. Again stating that new vents have opened and that this is a precursor to a fissure? Completely unfounded. It’s simply a summary of the data we all have acces to, combined with random speculation without any ellaboration of why you think those scenarios might occur. I’m not saying all these things won’t happen, but with the information and lack of background reasoning it seems like a random guess.

      1. I think it’s better to make no statement that to make an unfounded statement. Making statements without any clear explanation or reasoning contradicts everything science stands for. I understand that it’s hard to do ‘real science’ on these kind of blogs, but we can at least try to pursue it and try to think that way.

      2. I have not contradicted any science here as you claim.

        But you are not doing any science at all. All that you are doing is to flame me because you think that I am wrong. While you cannot make an argument for your claims. Your claim being that I am wrong and nothing is going to happen.

      3. You’ve seen me claiming nothing will happen? No, on the contrary, quoting myself:
        ‘I’m not saying all these things won’t happen, but with the information and lack of background reasoning it seems like a random guess’.
        In addition, I’d like to say that I’m not stating that it’s a random guess, it just looks like it is. You probably have considered your statement very well, as you’ve explained in your previous post, but I’m just curious about WHY you think these things.

        I’m sorry if you perceive this as flaming, as I’m just trying to be critical to any information given.

      4. Pieter, relax a bit.
        Jón is speculating, yes, but he is doing it over what is considered scientifically as normal behaviour of fissure eruptions.
        It is always okay to speculate a bit in science as long as you are clear about doing just that.
        Hell know, I made a career out of speculating.
        Perhaps Jón should give examples when he does his speculating to give a base for it. But that is in this case more a case of style.

        All science in a way starts with speculation, than you try to gether data, and then you can either have corroboration or negation of your hypothezis.
        I can (I think) promise that I, Jack, and Peter have done so when we wrote our dissertations, journal papers and so on. And I guess that goes for all the others that might have a ph.d. that regularly writes in here.

        So instead you should probably say, “could you please give a couple of examples as a base for the logic behind your theory of a new fissure building up.
        If Jón had written, my addendums within parenthesis, “A fissure will (most likely) open up in El Golfo or onland (because that is how rifting episode fissure volcanos like for instance Krafla behaves)”, then you have a better chance to opose and coming up with your own fissure volcano that does not do like that (Hekla), and then Jón could have (rightfully so) said that she is a fissure volcano, but not a rifting one. And so on, and soforth.

        Do you see my point? And remember, this is a blog, and we are as far as I know all amateurs.

      5. Pieter, I think you go way too far when you say “but with the information and lack of background reasoning it seems like a random guess”. Personally I’m very happy that there are some very experienced people who are able to see see upcoming danger. Without them nobody would think of an evacuation in order to protect the inhabitants.

      6. I’m as happy as you are with the information and insight given on this blog both by it’s author and it’s readers, but I’m always going to try to be critical whether it’s about a statement by a reader or by Jon, the author, himself.

      7. Pieter, your replies are not what I would call “critical” but my English is not good enough to express what I feel.

      8. I think here is a bit too much of personal feelings coming in instead of logical and scientific reasoning.

      9. I’m not, I wouldn’t have any advantage in doing that as I have learnt, and still am learning a lot from this blog. I’m just trying to stimulate people to be able to doubt their own views on certain scientific things. As National Geographic would say: ‘Think again’

      10. I’m also very happy with the knowledge, insight and information shared here on this blog. Luckily there are a couple of very knowledgeable people here, who dare to make predictions and warnings based on the evidence that is presented to us by the various institutions, be it research, EQ-measurements, experience, images, etc etc.

        However, I have not seen any evidence based reasoning as to why a fissure will and must open in the area where the EQ’s are happening at great depth.

        I’m sure Jon has some amazing blue eyes, but blue eyes alone is not enough for me to accept any statement, however well informed and knowledgeable someone is. I like to remain critical at all times, as all scientists should.

        Even if I or someone else cannot do a better job in analyzing or predicting volcanic events, the reasoning or proof will still have to be presented before the claim can become credible.

      11. Deep earthquakes do not mean that the magma has not moved up into the crust.

        Few hours before the first eruption in Eyjafjallajökull volcaon there where a lot of earthquakes taking place at around 15 to 20 km depth. That was just few hours before the eruption.

        All that the deep earthquakes tells you is that there is new magma flowing into El Hierro and expanding. But it also tells you that the risk of a eruption has increased. In this case there is also the risk that the two pockets of magma are going to merge at around 20 km depth, or shoot dikes into each other.

        What that means for the eruption I have no idea. But it might make it more powerful (most likely outcome I would guess).

        Historical data (from earlier eruptions) show that this area is going to have fissure eruptions. This is how they start and always have started. When and how big is impossible to know at this moment.

        So far the eruption in El Hierro has been limited to the sea. But that might change without any warning at all.

      12. @Nathan, yep, that’s exactly what I’ve been trying to point out.
        @Jon, thank you that is what I’ve been trying to know, youre reasoning behind your statement. I’m still not agreeing with ‘historical data’ as a valid source, but you seem to be convinced of that, so I’ll leave you with that and consider it as a difference in opinion.

      13. In my opinion, it’s dangerous to use words like “always”, especially in science which is so young as volcanology.

        Scientific reasoning here can just take in probabilities not iron laws.

        For example, what do we know about the volcanic edifice of the seamount buried under the current volcanic island. Have there “always” been fissure eruptions at this place? Is there any scientific literature about it? Some scientific proof? If so, which one?

        And then: Volcanoes may ressemble each other, but all of them have their own characteristics. El Hierro fissure eruption is not exactly the same as Fimmvörðuháls and neither as Krafla in the 80s. Even if these are all fissure eruptions.

      14. @Sissel i cant understand how you can call constructive criticism as “it looks like you like toe tear down what others carefully have built up.”

        On a science blog like this you must really stand to discuss the science behind your statements. That’s the reason I’m reading (lurking untill now..) this blog. I like all comments and theories behind whats happening.

      15. @Shaky Tim
        I do understand your reply.
        I did not claim this sentence to be constructive criticism, like you suggest. Maybe you did not notice that it started with the word “Sorry”. Sometimes it hurts to say what you feel inside, at the same time it hurts to keep silent.
        The way Jón was “critiziced” made it too difficult for me to keep silent. As I always will speak up in a situation like this.

      16. It will be lost this deep in the thread but can I just take issue with your use of words Pieter. To describe what Jon has been predicting as a random guess is wrong. Guess it may be but random is ridiculous. It might be random if he suggested that the island was about to be consumed by hoards of giant jellyfish but the scenario he presents is well within the realm of probability and so is definitely not random.

      17. Hi, just thought I’d put in a couple of calming thoughts

        I get the impression that some of this confusion is caused by people speaking english ‘quickly’ or when it is not their mother tongue.

        ‘criticism’ is not always an insult – it is trying to give ‘a critique’ of something – working out whether something is right or wrong.

        Jon wrote the word ‘always’ but should probably have written ‘has historically (in this and other similar vlcanoes) lead to ‘ insead.

        Pieter is (I think) reasonably asking for clarification – but didn’t phrase his critical analysis in a way that got the right response fron Jon.

        Pieter – in future I’d suggest saying ‘can you explain what you based this on’ rather than ‘it seems like a guess’ 🙂

      18. Lets just say that if I tried to write in Icelandic, everyone would be laughing. Sometimes translations from “mother tongue” to second language or third or fourth– are not exact. Jon your efforts are to be commended not to be critical of. If others don’t agree, there are plenty of other blogs for them to use, or..start their own. Its just too time consuming to have to keep responding to nae sayers–and it raises blood pressures as well. Keep up the good work Jon!

    2. There are two reliable sources: IGN and

      The latter publishes animacions on its website so you can watch all 11,000 EQs as they develop. Make sure that you click on the cummulative option.

  4. Heres something interesting, what did happen to the poor little fishies…

    Dead fish began to appear on the surface of the mar de las Calmas along with the stain of the volcanic eruption of El Hierro died of natural causes and, in principle, cannot be ruled out that they contain toxic substances in their bodies. Even so, the Canarian Government maintains in force recommendation to the population, made public last week, not consume fish from the darkened Hierro coastal waters.
    The result of the preliminary analyses carried out to dead fish collected in lathe to the island of El Hierro do not show traces of cadmium or lead or mercury. Examinations of the Institute of Animal Health and food safety, University of Las Palmas have ruled out the presence of these three heavy metals, which would be particularly harmful to consume confused among the meats of old, cabrillas and moray eels, among other types of marine fishing in the area.
    In addition, the study of these fish demonstrates that the most common injuries are bubbles of gas in the cornea, ocular haemorrhages, burst eyes, unpacking stomach and congestion in organs such as swim bladder, liver, and gills. The Canarian Executive says all this injury is consequence “of the own explosion by both changes in ambient pressure at sea”.
    The Canary Islands authorities consider this data to guarantee that “in principle, the causes of the death of the fish not must cause illnesses in people”. However, as a precautionary measure, “recommended not to eat fish caught in areas affected by the volcanic eruption”. Prudence because these fish are still is analyzed to rule out other types of toxic elements that could have affected the animals that lived the mar de las Calmas marine reserve

  5. “Sadly there is no map. So I am not sure where this earthquakes took place in El Hierro volcano.”

    Here’s a tip:
    Simply copy the coordinates in google maps and you wil get the exact location.

    Below the results for the quake that occured at 02/11/2011 08:52:50

    27.7936 -18.0538

    Calle del Matorral
    38911 Frontera, Spanje

    1. Coordinates put the 1km earthquake at La Restinga just below the Harbour I think

      1. Yep, and another one beneath the far northern flank of the island, which is quite interesting! I’ve been wondering if there is a 4th, northern, undeveloped flank of the island.

      1. That is about the only place that could slide down from the island… Not god.
        BUT!!! There would still not be a large tsunami even if it did. Only danger would be for someone standing ontop of the slide, or below.

      2. Trouble is that GoogleMaps usually gives you nearest approximate address on land, you have to zoom out to see big green arrow (in this case pointing to somewhere in El Golfo). Seen in couple of posts in here that people are easily misled by Gmaps into thinking that EQ location is on land when it’s in fact out in the sea.

    1. The “bumps” in the harmonic tremor are tremor pulses. They happen when magma is on the move. As you say it also might be when the magma is breaking its path up the surface. But that is currently creating earthquakes that are taking place in El Hierro volcano.

      1. That depends on the rock and path taken by the magma. It is almost impossible to predict it. But there might be a sharp drop in earthquakes few hours before that happens.

        But that sometimes happens in this type of eruptions.

  6. Current volcanic Canary Islands (AVCAN)
    For a while, the tremor has become more unstable and has fewer earthquakes and is having freatomagmaticas explosions, indicating activity at lower depth and which is very possible that we have explosions in the water. This morning discussed the possible opening of a new mouth and now explosions… do no by la Restinga to see if they see something weird or that can confirm that they see something different.? (Henry)

  7. A question for the locals. I assume that to get to Hierro, the main way is by boat from la Palma, right? Or is their a large runway that accommodates a good size passenger jet?

    Where is the main ferry/boat dock for hierro?

    If in Golfo, it could be a problem if/when evacuation becomes desirable, no?

    Preguntas, por favor. Como llegas a hierro? Donde esta ellos? Fronterra? O otro sitio? Lo siento pero, no puedo hablar espanol muy bueno. Gracias.

    1. I believe El Hierro has an international airport which can accomodate passenger jets, yes. For El Golfo, the options are limited when the tunnel near Las Puntas is inaccesible. On Google Earth you can however see that there is a road up the mountain, so there would be other options.

      1. There are a few roads out of the Golfo Valley, the main road with the tunnel, the ‘old road’ that may be prone to lansdlides when a major quake hits, and a road to the El Julan area. Then there are a number of smaller roads, paths rather, that are not really suitable for cars or heavy transport – for walking yes. Airplanes are nice, but with thousands of people to evacuate in an emergency that’s a problem – the airport is not that big for huge planes to land. Boats cannot reach El Golfo, there’s just a jetty for very small fishing boats, the sea is too shallow there. The navy is sending ships, and probably – my guess- one of the Canarian ferries will be sent down to pick up people.

      1. Found them, thanks.

        If any threatening eruption occurs, by definition, air evacuation becomes problematic anyway. I was more concerned about the port and it seems to be on a side of the island where the water would remain clear from volcanic acids due to currents

        Thanks for the replies.

  8. As for the above flame war, Gobcan just officialy published the data about the rapidly increasing carbon dioxide emissions – information I put here on the blog in translation already last night – and stresses that the increase in carbon dioxide levels is a very good indicator that an eruption may be at hand.

    In vulcanology there are no certainties, just probabilities – like in any science btw., just even more so when predicting the behavior of volcanoes.

    1. Do they know whether CO2 is from the Restinga area/waters or some other new area ?

    2. I was up late last night trying to find saturation and exsolution data for CO2.

      About all I could find was that at 25km, CO2 really starts coming out of solution. Pretty much like you cross a node point on the solubility curve.

  9. Anybody in here got any idea as why those shallow EQs today (1 and 3km) been taken off the list? They’ve been there some time ago but can’t find the anymore…

    1. Suppose IGN corrects the lists afterwards just like IMO does, only IGN do not have the system with dark lines around the dots to show a quake has been verified.

  10. Headline from Diario el Hierro. The link is below to the whole article.

    The analysis of the pyroclastic provides “clear indications” of one greater explosive potential
    A report prepared by Professor of Petrology and geochemistry of the University of Barcelona, Sunday Gimeno stream, which has had access journal EL HIERRO, concludes that the analyzed material, “not presents the characteristics of a rash of type surtseyao, which is the stage repeatedly proposed by the Scientific Committee to follow up”.ÍSMICA&id_registro=140639&Id=26496&BDi=INICIO&nt=p&Md=&rf3=1&rf3=1

    1. It is about a report from the head of department of the faculty of Petrology and Geochemistry at University of Barcelona, professor Domingo Gimeno Torrente which implies magma mingling.

    2. Giggletrans:
      From: Spanish
      To: English
      Translate text or webpage
      Type text or a website address or translate a document.
      Spanish to English translation
      The pyroclastic found in waters of La Restinga provide “clear indications of a more explosive potential, so far not publicly mentioned by anyone.” This is to a report, which has had access DAILY IRON, prepared by Professor of Petrology and Geochemistry, University of Barcelona, ​​Sunday Gimeno Torrente.

      The professor adds, furthermore, that this material “does not exhibit the characteristics of a surtseyano like rash, which is the stage repeatedly proposed by the scientific monitoring committee.”

      In the study of pyroclastic found during the submarine eruption of La Restinga, conducted by Dr. Gimeno at the request of the City of El Pinar, states that “the inhomogeneous mixing of different magma compositions (‘mingling’) is a phenomenon widely reported in the literature as increasing the explosiveness of magma, and on many occasions, such as triggering an explosion. ”

      In its report, Gimeno Torrente argues that pyroclastic, “can (and should) look in a matter of hours,” and wonders why so many days later still not knowing what they are. “If they know they have not said, and have no evidence that anyone involved in his study rather have avoided, told DAILY IRON.

      According to this professor at the University of Barcelona, ​​”it has underestimated the potential explosive.” “They have drawn all the time surtseyano volcanism hypothesis (all 4 phases), trivializing its potential explosiveness (10 hours of beautiful white column before anything happens), and before that an effusive volcanism hypothesis (lava, non-explosive ) deeper, and indeed since the surface began to appear in the pyroclastic should have understood that it was explosive submarine eruption and a different type, and if, moreover, implied magma mixing was potentially much more dangerous, and rhyolitic magma if it meant even more, “Gimeno said.

      Pyroclastic ANALYSIS

      The report by Professor of Petrology and Geochemistry, University of Barcelona, ​​Sunday Gimeno Torrente, who has had access DAILY IRON, it is stated that, the sample is “that have shown over the last few days in the media, which consists of two parts, a dark green or black preferably located in the outermost part of the body falls, massive-looking glass (sideromelana) but with areas of macroscopic and diferentesfragmentos vesicular texture completely white, very hard microvesicles, thus being very porous and very dense. ”

      According Gimeno, “phenocrysts are not observed with the naked eye. The lines of contact between the two products are net and the first impression is that a product is black basalt and pumice differentiated product.”

      Chemical analysis by Dr. Gimeno notes that, once classified by the IUGS TAS diagram, which is to use internationally accepted “that the product is black costata is a basic rock (basanite) and white a differentiated product (alkaline rhyolite), “he says.

      According to this professor, “checked against databases internationally published the first product was already known in other samples from the island of El Hierro from previous eruptions, while the second is comparable but not identical, to what is known in other eruptions are less frequent in El Hierro (slightly richer in silica) “, contains the report seen by this newspaper.

      Microscopic characterization

      The study leads to the conclusion that this pyroclastic magmatic fluid consists of two very different compositions and viscosities, coexisting as such without chemical mixture feasible at the time of the eruption.

      The basanite liquid appears as a porphyritic microvesicles with a low percentage of phenocrysts of mafic minerals, whereas microvesicles rhyolite is very hard, with very thin walls of glass between the casts of gas bubbles are essentially constitute this portion of the rock and probably give global buoyancy.

      According to Dr. Gimeno, “to conclude this characterization must be added that it would be advisable to perform a systematic sampling and characterization of pyroclasts that are being expelled by the volcano, as the compositional characteristics and the degree of crystallinity can vary along the eruption and the evolution of this condition, so this task is useful in the face of crisis management, “he advises.

      Also, Professor Gimeno holds Sunday in his report that the determination of chemism and the degree of crystallinity of the rocks formed during an eruption, “as soon as possible should be done in the course of this, since both factors influence the final Explosive and therefore the associated volcanic hazard. This truism, he adds, is widely recognized internationally, both for the expert scientific community by agencies such as the IAVCEI “he says.

      According Gimeno, many of the Spanish public universities and the CSIC have different equipment and fully qualified technical personnel capable of performing the same work we’ve done in the UB in times comparable (within 24 h of receipt of the sample) and I honestly can not understand how this characterization was not carried out since the first time by the commission or commissioning scientific monitoring of the eruption, “says the professor.”””

  11. Pablo, there is an airport near Valverde at the north east of the Island, also the Ferry and only dock, is near by the airport.From La Frontera is impossile evacuating by boat,the only way out is through the tunnel, wich is not much safe of course, or driving all the way up the mountains on a 50 minutes trip arriving to airport or dock.
    Not much to say….

  12. What I’ve been wondering lately, did they stop the drilling near Hengill? Or is it just not resulting in fracturing anymore?

    1. As far as I know they have not been drilling, just injecting water and or various chemicals. Depending what and how much is what mag quakes we see. They (the people doing the injection) were told to stop what ever they were doing by the local authorities, when they made quakes that were felt in Reykjavik. So they stopped injecting or slowed the rate down. The boreholes were drilled a while ago, not recently. That is how I understand it anyhow.

    1. The report says that the analysis indicates a possible pyroclastic eruption of an explosive type and not a type surtersyana, as experts said.

    2. Gracias! Acabo de lleerlo, indica también que el desgobierno y los sus involucrantes tan manejando el crisis un poco malo, no?

      My synopsis:
      Analysis of the pyroclastic materials spewed out by Baby Bob indicate that there are different types of lava mingling below, what may indicate that a more explosive type of eruption is in the making. May not be Surtseyyan at all, as nearly the whole volcanology community has assumed till now.

      The professor from Barcelona also givesharsh critic on how the crisi is managed. This kind of analysis needs to be and can be done within 24 hours after getting your hands on it. There are many Spanish universities who can do this pretty simple analysis, and knowing what pyroclastic materials are in play is of the highest importance in a crisis like this because they are important signals for what is brewing.

      1. It’s just incredible that such things come out that late. Two possibilities. 1. There was for some reason I can’t figure out no way to be sure earlier, ant they didn’t want to lead to panic for nothing. Special in regards to the importance of the question, but let’s say in this case they had a choice to make and we’re not sitting on their chairs. 2. They didn’t care about this kind of analysis earlier and underestimate what this means, then don’t know how to deal with this info. Well that leaves me speechless.

        But always and again, never really cared about canaries geology and know nothing to really dare judging the local “experts”.

      2. A couple of points here.
        They are now testing the later pumices that has been ejected after the first aluminium based Millosevichites that we analyzed. But the professor is absolutely correct in one thing. It only takes 24 hours, we did it in a mining lab with equipment that is not entirely suited for it. Mining test equipment is primed to look for specifics like copper content and such, not to look for really unusual minerals. A university lab is built for wide searches, we need to do hundreds of tests in a day, and we only want to know a few things. Even with these drawbacks we did exactly what the spanish professor said.
        So, I agree, the entire show has been run in a very amateurish way.
        It is good that Professor Sagiya and Professor Torrente has taken active lead on this now. It will most likely make a big difference if things take a turn for the worse if they have their hands on the scientific rudder.

    3. Professor Gimeno finding’s indicating the presence of rhyolitic magma is interesting. This could be supported by the initially disappointing pictures from the Roman Margalef. This showed it picking up a dead star fish; but it could not pick up fine volcanic ash. Volcanic ash is associated with andesitic and rhyolitic magma’s.

      The analyis Carl Le Strange did (small sample inferred from what he has said) indicated the presence of andesitic / basaltic magma.

      Professor Gimeno says that more analysis of the pyroclasts is needed.

      But for emergency planning, I would take into acccount the fact that there is a mix of magma and that the eruption could be a lot livelier than hoped for.

      1. KarenZ,
        that was the first pyroclasts, and they have since long changed quite considerably. Then it was Millosevichite, now it is something else entirely. The origins are different, and so is the chemical content. The only thing that seems to be the same is the high gas content in the pyroclasts.

  13. @Diana
    A friend, silent reader of this blog, told me you once asked me for something about rockfall/tunnels or anything in this direction. I missed it as I function in some way of “wild peering” in here between activities I’m more thought do do…
    Do you still have an interrogation you think I could maybe help to clear or is this “tempi passati”?

  14. According to this report, there is a seemingly clearer evidence that the cause for the floating smoking pyroclast is related to its chemical composition, containing both black basalt and a portion of pale alkaline rhyolite, which would point to the possibility of an eruption, not of the Surtseyan type, but of the other, more explosive kind. Therefore, there are strong recommendations that a further analysis should be performed on these minerals to get a better perspective about what is going on under the crust of Hierro.

    1. Complementary info that is very useful. Thanks Renato. Let’s hope they just don’t wait to long to DO the further analysis.

      1. All this magma being injected in the deeper mantle boundary acquire the aspect of a fissure intrusion which is possibly interacting with the sedimentary layers from above.
        I don’t see a peaceful outcome of this present activity in the future. And from the last, really deep quakes , we notice that magma is not stopping to intrude, providing the necessary conditions to a Fimmvörduháls- Eyjafjallajökull kind of evolution from this event.
        I really understand the concerns of people living on the island.
        I wonder how long it takes for the different types of magma to get mixed together and for an eventual dangerous rise of this kind of silicic mixture.

      2. I have no clue of how long it can take to get the fatal mix. I understand no one wants panic in any way. But let’s do what I do when I’m asked if a road should be closed or a house evacuated. I analyse the context and facts. That we did. Then I often come to the conclusion that an uncertainty remains and that I’ll not have the luxury, in the often too short time given by the situation, to completely clear things up. Sorry, guys, it’s reality despite all scientific will to do right. At this stage I decide I somehow did my rational work, digest it, keep everything in mind, forget all the limits scientific reasoning force me to respect, and just think “if it was my house, with my kids having to sleep there, or me with the kids in the backseats having to use that road, would I evacuate / close?” A lot of time I give my advice on this basis. Like it or not, I think it’s a fair way to deal with emergency situations and heavy decisions.
        Now we don’t all have the same “need for security”, and society sets “standards” the governments have to apply. Maybe from this point of view the spanish colleagues do it completely right. But then comes the individual, his perception and responsibility for himself. Despite every scientific argument, now comes my personal “gutt-based” opinion. Knowing the little I know, I wouldn’t let my kids, my wife and my dog stay in La Restinga and wait to see who of all the experts is right.

      3. Rhyolite is indeed a reason for concern. But what I don’t understand is how a volcano which is known to erupt basalt to trachybasalt suddenly is capable of erupting rhyolite. Is it geochemical evolution within a volcanic system we are seeing here?

      4. Do you think that this possible geochemical differentiation can be wide spread or a local and minor one that will not affect the eruption much? Forgive me if this is a silly question…

      5. @luisport, I’m not sure, but I know that chemical composition can differ between 2 different eruptions in the same volcano, it can even change during an eruption, so I think that’s a bit hard to say.

      6. The mechanics of it is differentiation.

        As magma moves back and forth across the changes from liquid to mush to solid the different components (compounds) go to a crystalline state at different temperatures and pressures. The speed that this happens and how long that the material has to do this determine what kind of crystals you get. This separates and concentrates the different types of magma.

        Essentially, a volcano is a rock still.

      7. Specifically, you’ve got a large reservoir that hasn’t erupted for a very long time. I don’t know how much this has cooled while sitting there, but the thing to fractionate out first will be the high melting-point minerals like olivine and pyroxene, leaving a more strongly silicic residue at a slightly lower temperature. Raising the temperature and pressure from below might be enough to make that do something surprising.

        My worry here would be that Bob’s gurglings represent a mixture of new basaltic magma, and bit of more fractionated stuff remobilised from the base of the long-standing chamber. It should be possible to get an idea of the density of the chamber material through seismics, but I have no idea whether this has been done. Looking for phenocrysts in the erupted bits from Bob will also help to constrain the magmatic evolution, and it may be possible to see signs of resorption or remelting *if* there has been mixing going on.

        Again, not scaremongering in any way – but I agree this needs to be taken seriously, just in case.

    2. Does this also mean that there is a chance that at one point in the future a stratovolcano could develop on the island? Like the ones on La Palma?

  15. It is my guess that the 4.3 at 20km opened up NW Frontera to the 1.7 at depth 9km.

    There will, I’m pretty sure, be 2 kinds of magma – the crystallised stuff that has been there for a while, and hot magma from the mantle, newly arriving. The newer stuff will most likely be pushing out what was there before, and following hot behind it.

    Perhaps the professor in Spain should have spoken up earlier.

    The experts are now looking at the science. I just want for the people of El Hierro to be safe.

    1. I really hope this does not end the way quite typical to many Spanish authorities, i.e. acting too late…

  16. @Lurking (in previous thread): In principle, I think yes, it is possible. There’s one difference, which I do not really understand or have anything to value it, if it is important at all.

    At the Canary Islands, the “flip-flop” oscillates perpendicular to the direction of plume motion, and the relevant islands are about 100 km apart. At Hawaii, the volcanoes mentioned are on the same island (maybe 20-30 km apart), and they both lie along the direction of plume motion.

    There’s got to be a physical reason for this difference in alignment. It seems to me, the “flip-flops” are aligned roughly along N-S axis for these two cases. Is this coincidental? (added only here) Are there any other similar cases?

    Edit: @Carl: Any ideas?

    1. I only know of the Hawaiian example.

      There is a graphic (that I can’t @#$@ find) that illustrates this through the entire history of the Hawaiian hotspot. You can see the dual volcanic regions form, close back to single active areas, then split again.

      If I could find the graphic it would be handy to measure the average offset distance of the two lines.

      Why the difference? Dunno. It could be related to plate speed. If any one has another example of dual volcanic areas off of one hotspot please sound off.

  17. Now IGN , to show more transparency, has made a public announcement that, from now on, they’ll open all sources of information they have been concealing.
    Lurking, I can see more plots coming!

    1. Giggle trans
      “”For now, the seismograms and spectrograms CHIE stations, CCUM, CTIG, CRST, CMCl, CJUL, CTAB, CTAN and CORC (El Hierro), NACC (Tenerife), EFAMA (Lanzarote), EOSO (Gran Canaria), CFUE (Fuerteventura), Egome (La Gomera), EHIG (La Palma), the menu can be viewed on the web seismograms AVCAN (””

      So nothing new at all.

      1. CCUM, CTIG, CRST, CMCl, CJUL, CTAB, CTAN and CORC (El Hierro)
        The new was that we can see 9 stations in el Hierro, not only the old CHIE, a SHZ station.

        But at 17:30h, they protect it with password

  18. Well just to point out the difference between the two types found.

    Basaltic magma: Low viscosity, low gas content (under 50% i think). The low viscous magma frees gas pretty much unhindered as it is so fluent. This makes for hawaiian style eruptions which is mostly made up of basaltic magma.

    Rhyolitic magma on the other hand has a higher viscosity and a higher gascontent. Basically the magma is less prone to release the gas. This results in a more explosive eruption.

    Now a mix of the two could result in andesitic magma which can be quite explosive. It commonly erupts from stratovolcanoes and can be quite explosive with resulting pyroclastic flows and so on. The magma in Krakatoa in 1883 was Andesitic.

    Note that this is absolutely not a fearmongering post just stating the ugly..

    I really hope that they will look in to this fast..

    1. And of course as far as I know El Hierro is definitely not a stratovolcano. 😉

      1. Nope, that’s what strikes me the most. The classification shield volcano is based on the fact that it emits low-viscous magma. As soon as it starts emitting rhyolite, which will not gently flow down the mountain but violently erupts, it sure looks like a stratovolcano.

    2. It explains the pumice behaviour of the “restingolitas” – floating like regular pumice do to this high content of vesicles with trapped gas within. A perfect mix for an eventual explosive eruption. 🙂

      1. I read somewhere that Taganasoga had some characteristics of one… And an eruption there is not ruled out.

      2. This is not intended in any way as scaremongering, but is there any way to tell from the evidence if the el-golfo flank collapse WAS a flank collapse? Could this have been caused by an explosive eruption i.e. could there be a precedent for this sort of explosive volcanic activity in its past?

      3. There are some evidences that both of the old volcanic structures in el Hierro, El Golfo and Tiñor erupted in a more explosive way at the end of their lives. In the upper part of el Golfo scarp build by layers of basaltic lavas end with layers of trachytic lavas of a more explosive fase that interestingly form not only the upper part of the scarp, but also the Roques de Salmor, a series of large rocs, that lay in the sea near the coast. So it is possible that the landslide was triggered by a large explosive eruption.

      4. So it is possible that the rhyolite being seen here is a periodic characteristic of eruptions in this area?

      5. Add in steam and CO2 from the 3km-thick Jurassic sediments
        ( shales, clays, limestone).

  19. The State Agency of meteorology (Aemet) activated at 8 p.m. today the yellow warning for coastal phenomena in the North and West coast of La Palma and the coast of La Gomera. He is expected to swell from the Northeast with waves which may exceed three meters in height. From five in the morning of Thursday and until midnight on Friday the Aemet increases the warning level by heavy swell at the Orange level on the coast of Fuerteventura, Lanzarote, El Hierro, on the North coast of Tenerife and Gran Canaria, and in the coastal North, East and South of La Palma.

    Prediction points to waves of between four and five meters, in these areas, due to the swell of the Northeast. In the coast of La Gomera and La Palma West will be in yellow notice by waves up to three meters in height. Looking ahead to the Friday, the notice will happen, from midnight on Friday until 00.00 hours on Saturday at the yellow level on the coast of Lanzarote, Fuerteventura, El Hierro, La Gomera and the northern coast of Tenerife and Gran Canaria.

    1. Really? Sure that this is not weather related? Or a tsunami warning in disguise?

  20. Now, I want told you a interesting fact that perhaps you don´t know. Professor Takeshi Sagiya assists in the ITER -Institue energy renowable technologies- with Professor Nemesio Pérez, geologist and canarian volcanologist. He has been studying the events in the island of Hierro since the beginning. It also he found
    the rhyolitic origin from piroclastics rock from La Restinga. But all his theories and warnings were ignored by the rest of volcanologists, especilly for Mr. Carracedo ( political reasons and others…). For that reason Nemesio Pérez uncheked but he is still continues his investigations in the bacground with professor Sagiya. That´s all.
    Now you know more about how works things here. Incredible, isn´t it?´
    I´m only hope that the responsables of the situation will be able to resolve it. And and soon as possilble.

      1. This entrevist is older. Even before La Restinga events. Even the best scientists can rectify.

      2. I see – Perez could have changed his mind in the time el Pais took to put out the english version.
        Where did you find the Sagiya information on rhyolytes?

    1. So… you’re saying that they are gonna drop in some boreholes and start hydrofracking on the weekends?

      Well, I guess a triple armed rift resembles the triple junction up around Hengill…


      1. – have a read of what Professor Perez says about Spain’s ‘third world’ seismic alert system.
        Outspoken guy, pity he does not post on here.

      2. That´s the answer to your last question about Nemesio Pérez.
        As you can see, the date from spanish article El País is 29/9/2011.And the information on rhyolytes of Professor Sagiya in colaboration with Nemesio Pérez, I know it by references to a member of my family who knows professor Pérez and his work. I can´t say any more.

  21. Really hope that they evacuate the island soon. This is not sounding good at all. (But that’s just me. I’m no expert)

    1. I wouldn’t say all the island, but expand the red alert to other areas along the “fissure”.

      1. Yep. However, a rhyolitic eruption can be accompanied by pyroclastic flows and heavy explosions, which have wide reaches. I’m so gratefull I’m not in the position to make those hard choises.

  22. If there is magma mixing taking place in El Hierro it is because of old magma from earlier eruptions that is getting mixed with a new hotter magma. It is the same thing that did happen in Eyjafjallajökull volcano last year, and in other volcanoes that do the same. This is always a risk with volcanoes that only have eruptions every several thousands of years or more.

    Since it takes the magma no less then that to cool down and crystallize like that to become rrhyolite. But the changes happen when the magma melts rock from its surroundings bedrock.

    If this is the case with El Hierro this eruption got a lot more complex and dangerous to the people who live on the El Hierro Island.

    Currently there is a second magma sill forming off the NW part of El Hierro volcano. So far the activity suggests that this is new magma, not re-mobilized magma from earlier eruptions. But there might be older magma in there that is not making any earthquakes at the moment, for that reason it is impossible to know where and how big the amount might be there for the moment.

  23. @ Renato. the pumice you spoke of. Were they gas rich? If so that would indicate a pretty violent event where the pressure on the magma was dramatically released which in turn would make the magma frothy. But this is contradicted by the fact that nothing was seen on the surface of the ocean. A violent eruption which was not noticed for a while? hmm..

    1. According to the article, yes, the lighter coloured rhyolite was spotted with high gas content vesicles.

  24. I want to note that so far I only think that this is going to be normal Hawaii type of eruption. Until proved otherwise. So my comment above is more of a speculation then fact in terms of the current eruption in El Hierro volcano.

  25. Via de comunicacion con la isla del Hierro. Transporte, Ferry Fred Olsen, Los Cristianos, sur de Tenerife, Puerto de la Estaca, oeste del Hierro. O via Puerto de Santa Cruz de Tenerife, Cia Transmediterranea , puerto de la Estacaa, Hierro.

  26. Whoah, what just happened at 1430 and 1440 on the spectrogram and seismogram? A couple of very long-duration tremors. No depth posted yet.

    1. No EQ data published yet on either IGN or AVCAN, so possibly increases in the harmonic tremor. But they would be checking out any changes in the spectrogram.

      1. There is no sign of EQs on the other stations at the same time. So suspect that this really is magma related.

    2. They look a significant step in the process, Josh.

      Has anyone got any thoughts about the 39km depth quake? What is down that deep? And how is it connected to the 25km depth source of this event?

      1. “Has anyone got any thoughts about the 39km depth quake?”

        No, they had some like that pre-2011.

        “What is down that deep?”


        “And how is it connected to the 25km depth source of this event?”


        One is shallower and occurred in a confining pressure field of 668 MPa (6.7 kbar) and the other happened at 1040 MPa (10.4 kbar)

    3. 02/11/2011 14:41:58 27.7894 -18.0494 22 2.3 4
      02/11/2011 14:29:46 27.7926 -18.0645 21 2.3 4

      1. Right. The magnitudes and depth are unsurprising. What is different about these last two (particularly the first) is the apparent duration; to me that is more suggestive of magma movement than plate-fracturing… But I welcome a more informed opinion.

  27. Another theory on the “pumice”: I remember Carl did some chemical analysis some days ago,with the result of a very high amount of Al2O3(70-80%). Why that? Old basalts- mostly consisting of alumosilicates- were leached by fluids, containing Fluorine or Fluoric acid which is able to dissolve alumosilicates completely, with exception of Al2O3. SiF4 is built, which is a gas under normal conditions, but under pressure it might remain in the stone crystallin. If it is moved to the surface, SiF4 degasses, leaving a porous structure of Al2O3.The black crust is built by heavy metals(iron and manganese) dissolved in the acid, but dropped out in contact with sea-water.

  28. I think they have added some stations from El Hierro to AVCAN seisomograph view – namely these:
    CHIE: zona de Las Playas.
    -CCUM: zona de la Cumbre del valle de El Golfo.
    -CTIG: Tigirote, en la zona de Los Dares.
    -CRST: zona de La Restinga.
    -CMCL: zona de la montaña de El Mercadel.
    -CJUL: zona alta de El Julan.
    -CTAB: zona de La Tabla, entre Los Llanillos y Sabinosa.
    -CTAN: zona noreste del Tanganasoga.
    -CORC: zona del faro de Orchilla.

    I didn’t noticed them before, the only station available was CHIE I think.
    Makes very interesting viewing set the station to CRST (Restinga) and date to 10 – 13.10. when the eruption started and compare the graphs to the CHIE and others.
    Now we can only wish and hope they will update IGN own page ( with these station as well as it is easier and more comfortable to navigate.

  29. New tremor data for Hierro here:
    Select the estacion in the box.
    Sation identifiers below:
    CHIE: zona de Las Playas.
    -CCUM: zona de la Cumbre del valle de El Golfo.
    -CTIG: Tigirote, en la zona de Los Dares.
    -CRST: zona de La Restinga.
    -CMCL: zona de la montaña de El Mercadel.
    -CJUL: zona alta de El Julan.
    -CTAB: zona de La Tabla, entre Los Llanillos y Sabinosa.
    -CTAN: zona noreste del Tanganasoga.
    -CORC: zona del faro de Orchilla.

    1. Interesting. The three stations showing most activity are CHIE (Las Playas), CMCL (El Mercadel) and CRST (Restinga).

    2. CRESTinga tremor looks lower than CHIE – but note top right of the plot:
      “”A new = A/5″”
      – does that mean the Amplitude is set 5-fold less???

      1. Probably – starts on 18/10/11,
        17/10 is without “A new = A/5” note, then on 18-th there is sudden drop in tremors…

      2. George,
        Thanks, IGN are not generous with legends to their plots – would not get past peer review!

      3. You’re welcomed Peter
        So, by the looks of it – this station was in fact attenuated twice, once on 12/10/11 along with other stations on El Hierro and then again on 18/10/11.
        Why? Was the signal too strong again to justify this?

  30. Anyone know what the tremor is in Heklubyggà? Human made I reckon since it started at 08:00 this morning and doesn’t show up anywhere else.

      1. Thanks for replying.

        I’ve seen storms affecting the station before, but not as severely as since 8 this morning. The spikes are clogging the entire graph. 🙂

      2. Mid Atlantic Ridge, Katla, Portuguese Islands off rift, Crete, Canary Islands all seem active at the same time. 33 year Volcanism cycle worldwide is eye opening. US mlitary on alert status east coast areas. Nasa moving from Cape in Florida. I’m just an average joe but these occurrences are unnerving. My question is why are our government officials silent? Storing food expanding deep tunnels not to mention other abnormalities. I sense we people have to be vigilant cause help from those in charge ain’t happening. Lots of mega-tsunami theories floating do you see any possibilities on above references, volcanoes, quakes, or great rift?

  31. AVCAN Giggletrans:
    “”The tremor signals are very unstable and giving explosions that appear to earthquakes but they are not, are increasingly strong explosions, indicating that the eruptive mouth in the South in the Restinga or in the Northern Gulf area should this activity and interaction with the water .. (Enrique)””

    1. Yes, look at the Seismogram:

      Since 1430 there have been 3 (one ongoing as of 1607) anomalous events that do not seem to deserve an earthquake magnitude, and are therefore (I would suggest) clearly magma-movement-related.

      They are at 1430, 1518, and 1606. Three samples isn’t enough to tell if the 48 minute time gaps are a pattern (or if they suggest manmade activity), but I guess we will see if there is another event at ~1654.

  32. Pumice, by definition, is gas rich – volcanic froth. It is full of gas pockets which initially enable it to float in water. These same holes will eventually
    become saturated with water and at that point it will sink.

    I have samples of both pumice and obsidian from a trip to Teide (Tenerife Canary Islands).

    Much better explained by the experts here:

  33. I have collected litre-sized pumice on El Teide with low density, crumbled between the fingers.

  34. team of Geologists from the University of Barcelona (UB) has found that magma emerged from the submarine volcano on the island of El Hierro, currently in eruption, is the most explosive, and they have warned of the potential danger associated with these eruptions, “the risk of be underestimated”.

    As reported Wednesday by the UB, a team of this University, directed by Professor Sunday Gimeno, of the Faculty of geology, he had access from October 27 to a sample of material ejected by the submarine volcano in the sector of La Restinga, on the island of El Hierro.

    The first analytical results on these materials indicate that the eruption has expelled a basaltic magma – which produces a dark colored rock – and other – portion of white rock – riolítico, which have been mixed in the final stretch of the exit to the surface.

    Geologists have warned that “the ancient magmas are potentially much more explosive than the basalt, and mixing of magmas of different compositions also increases the burstiness of the eruption”.

    “As a result – add-, he warns of the risk of having underestimated the potential danger associated with it, which is still currently in full swing during the first weeks of the eruption.

    On the island of El Hierro, the municipality of Frontera lives with extreme excitement of recent developments, following the earthquake of 4.3 degrees of magnitude on the Richter scale and intensity IV registered today 20 km of depth in this herreña town.

    This earthquake was perceived in some localities of the island, Valverde, El Mocanal, El Golfo, Los Llanillos, Las Puntas, border, and Taibique, in the municipality of El Pinar.

    The earthquake of magnitude 4.3 is the highest intensity recorded so far after the episode, Eruptive in waters of La Restinga and has generated special excitement among the population of the Valley of the Gulf, in frontier, which stays alert to indications of the competent authorities and the direction of the Plan of Civil protection by volcanic risk.

      1. Enrique from AVCAN thinks this are not eartquakes, but explosions, increasingly strong explosions, from interaction with water, in the south of Restinga vent or in a new one in the north/ El Golfo area.

      2. That would be one explanation – an explosion in water might generate a long-wavelength bulge and might not show up on a seismogram… What other explanations could there be?

  35. Hmm great, looks like the openness of IGN didn’t survived for too long 🙁
    If you’ll try to change the station on AVCAN page to anything else than CHIE, IGN site requests a password now to view the data. The same is when you try to modify the link (HTMl request) on IGN website. No joy then…

    1. Anything else on El Hierro I mean, any of the newly added stations (CCUM, CTIG, CRST, CMCL, CJUL, CTAB, CTAN, CORC).

    2. Yes. Bad PR. It looks as if they try to hide something when it may just be lack of server capacity. See Prof Perez’ comments to el Pais from a month ago about third world seimic alert capability in Spain.
      Or they might be blocking access from outside Hierro/Canaries?

      1. Maybe too much traffic? Interestingly enough – older data (yesterday and so on) are still accessible without password :-/

      2. I see – for me the only station working normally is CORC (and CHIE obviously) right now. I think they are gradually restricting access to the data, not good 🙁

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