Special report: New eruption vent (or vents) might have opened up in El Hierro volcano eruption

The current tremor data now suggests that a new vent or vents have opened or are about to open up just outside north-west coast of El Hierro volcano. The depth where the main earthquakes have been taking place is about 100 to 300 meters (but might be more). So far the largest earthquakes to take place in this area was a ML3.9 with the depth of 22 km. What is important in this is not the fact that the earthquakes are at great depth. But also the fact that a more shallow might not take place. As that was not the case when the eruption started in El Hierro on 10 October, 2011. It is unlikely that there is going to be any shallow earthquake activity before a new eruption vents opens up. As that was not the case on the 10 October, 2011 from what I can remember.

Current harmonic tremor in El Hierro. So far there has not been much change in harmonic tremor as can be seen here. But that can change without warning. Copyright of this picture belongs to Instituto Geográfico Nacional.

I am not sure how strong earthquake this area can make. But I am guessing that it might well be in the upper Mb5.5+ range. The earthquakes that are now taking place are due to magma injection. Not a tectonic one. There is a difference between the two. But this rifting in El Hierro might trigger a earthquake close to El Hierro Island in near future, that earthquake would be a tectonic one. Not a earthquake created by magma movements.

So far the new vents are still unconfirmed. But there are signs in the harmonic tremor data that new eruption vents might be opening up or have already opened up. But at this moment I am waiting for a confirmation on this actually taking place. That is going to take a few hours, given the experience so far.

654 Replies to “Special report: New eruption vent (or vents) might have opened up in El Hierro volcano eruption”

  1. A little confusing – the replies does not arrive at the right place.
    @Brian, Inge made a comment about some stupid comment placed by somebody else, then Jón removed it. It had NOTHING to do with you!

    1. Newby-Punch your link then punch directly over the line thats spiking there on the right in the waterfall display. Yes, thats increasing tremor and damned big at that. Most magmatic stuff is less than 4.5 unless its the big pop. Jon, is I think going to be proven right in the next couple of days.

      1. Dunno.. I was on my phone last night and got confused by what looked like a honkin big increase in tremor. Turned out it was just another Mag 3+ quake that I was only seeing half of. Took a few minutes for my cache to clear so I could see the back side of it.

        But. I also think that you are correct in how this turns out. This thing isn’t over. Down in that cluster of 3+ quakes in my plot… more are occurring.

        It’s like some one keeps dumping tractor trailer after tractor trailer of cheeseburgers down there.

      2. The question really becomes now for me is whether its going to come with fries or not.

  2. Can someone tell me what this signal means on the British Geological Surveys Helicorder from yesterday 29/10/11:

    This started around the time that the whole of Iceland went quiet with EQs. People have mentioned that these are harmonic signals and that they haven’t seen this in the UK before.

    I had made a reply to Dianna further up in the comments but had no reply as of yet.

      1. Thanks Carl.. I am not yet asleep…I have had many visitors that all needed feeding 🙂 Sigh …Who said retirement was quiet? I seem to have less time to myself now than when I worked, raised a two families and did Voluntary Countryside Rangering!!

      2. Thank you Carl… it’s actually my knee that gave way and a sprained ligament was the result… all due to a very active life and my habit of kneeling to get closer to the soil, plants and small creatures when working in the garden.

      3. My knee will HAVE to be better soon as I have booked train tickets to London in November to visit my son Robert……Ermm! yes! He’s called Bob for short!! 🙂

    1. I see what you mean, its on the very long period graphs all over the UK, I have no idea, but I am just as interested as you are. At least we have no volcanoes here in the UK.(yet 🙂 ! )
      I would imagine it is probbably a question for an expert and is explainable and quite OK, I hope one will read this and put us straight on the matter, please.

    2. Do you think it could be post-reverberating caused by the Peru earthquake? After the Kermandec earthquake (or Turkish earthquake, don’t remember now) someone commented that after such large earthquakes the seismographs were useless for 24hrs after the earthquake occured, since its waves kept propagating for hours through the Earth and backwards…
      But I am no expert, so I dont know what I am talking about.

      1. Stoke is in an area sometimes called ‘the potteries’ and is known for having higher than average very small quakes.

    3. My reply came out way down there. Sorry Gary. Scroll down and you will see my reply for what it’s worth! 🙂

  3. Funny how, ever since there is attention for El Hierro, everyone freaks out when a seismograph of another Canary volcanoes has a tiny hickup. Please people, La Gomera is not suddenly reawakening after more than 10.000 years of dormancy (extinction, probably).

      1. We cant see the harmonic tremor on CHIE, its swamped, but can at GOM and EHIG . To me its a way of getting more info about Hierro – at least in amplitude if not frequency.

      2. I don’t now about anyone else but I wasn’t associating the oddity with La Gomera. I assumed it had something to do with El Hierro. After all it does appear on 4 different stations records but couldn’t appear on El Hierro because the gain is turned down.

        Anyway I guess it’s one of these wait and see things. The appearance of something similar on a UK machine does tend to downplay its significance.

      3. If this were the case I would expect to see a similar signature at monitoring stations elswhere in Europe or the globe. Unfortunately I dont know where to look to see if this is the case, but perhaps someone else does!

    1. Ok, thanks. I thought it was a reference to thread a couple of days ago about aluminium sulphate. Paranoid or what.

      1. How did that reply end up here?

        Well, I guess that many of us are experts in our various fields. But, most of are not experts of volcanology. 🙂
        My line of specialization is of course chromatosing 😉

    1. Jón –
      I am in awe of how well you monitor this blog. It is much appreciated. Thank you!

      1. Yes indeed so am I, most blogs this busy have a large group of moderators.
        One more thing the end of the world, its over rated 🙂

  4. From Diario el Hierro following this evenings meeting:

    “There, now, precursor signs of an impending eruption at border”
    The Pevolca notes an increase in seismicity at border but says that “it is still a considerable depth, between the mantle and the crust and, now, there are no other precursor signals, such as variations in the Earth deformation which can warn the existence of an imminent eruption at border”.

    The director of security and emergencies of the Government of the Canary Islands, Juan Santana, launched Sunday a message of reassurance to the population of El Hierro and secured, after confirmation by the scientists of the National Geographic Institute (IGN), “right now there are no other precursor signals, such as variations in the Earth deformation which can warn the existence of an imminent eruption at border”. ”
    Santana made these statements at press conference after the meeting held this afternoon at the headquarters of the Ceoci of Valverde by the Directorate of Civil Protection Plan by volcanic risk (Pevolca). The director of security and emergency appeared before the media accompanied by the President of the Cabildo of iron, Alpidio arms and security and emergencies, Carmen Morales Maria Island Councillor.
    Santana noted an increase in Seismicity in the North of the island, although he added that “is still at a considerable depth (about 20 km), and is between the crust and mantle and, on the basis of these data there is no precursor signal of an impending eruption”, said.
    In this regard, Juan Santana requested calm people “because they must give another set of circumstances as the ascent of magma towards the zone of the cortex, is say-clarified-between 8 and 10 kilometers deep (now is around 20 km);” “and therefore have to wait to see the evolution of the data,” said.
    Santana said, also, that remains constant over the island surveillance. “Keep in touch scientists with the civil protection authorities”, he noted.
    Security and emergencies of the Canarian Government director also confirmed that the Roquillos tunnel will remain open to traffic and recalled that the island is on yellow alert and red alert 1 level is maintained in La Restinga.
    Juan Manuel Santana insisted that the current situation does not imply a situation of risk for the population at the moment, and stressed that besides maintaining a constant surveillance of the eruptive process that would determine any important changes. In this line, the director-general of security and emergency reported that the situation today does not require to take extraordinary measures for Civil protection.

    1. They are unlikely to get inflation signals until just hours before the eruption starts (if they are really lucky). Or not at all, since this is a fissure eruption that is going to happen.

    2. In reading the above, note that the Spanish translation of “border” is “frontera”. They are probably referring to the town of Frontera.

    3. I do not like mr. Santana’s words: “on the basis of these data there is no precursor signal of an impending eruption”.

      He makes it sound like it is all not that bad.

  5. The harmonic tremor that can be seen on other stations close to El Hierro suggests that the new vent that is about to open is bigger. That means a larger eruptions on a longer fissure. But it might well happen that this fissure goes up to dry and out to the sea. I am not going to rule that out. As the earthquake data suggests that to be a real possibility.

    In my view they should evacuate this whole area right now. Before the magma reaches the surface. Better save then sorry in the matters of volcanoes.

    1. Is there a possibility it could open the entire north-south rift underneath El Hierro when it breaches the sedimentary layer? And if so would it disperse along the axis, or widen it, risking collapse, or super-heat the whole middle of the island, including Tanasoga? Would there be readings available for these different scenarios available to identify the risks more clearly beforehand?

      The circle of quakes just north of the island is very large, and clearly defined at times, despite the depth of the quakes. If it would vent to further north in El Golfo, then that would be the better scenario. If it blows just there, in its entirety, it will do a lot of damage, even without affecting any of the other magma chambers under the island.

    2. I agree with you Jon – hopefefully we do not see a quake showing up at USGS. Can you imagine that a serious 5 to 6 magnitude shock blocks the tunnel – and something starts in the bay – lets pray it will not be the case

    3. Yes, Does not look good (but I am no expert). Those spikes on CHIE tremour graphs in last hour have me worried. Lets hope for the best, despite apparent increase in activity. If new cousin of Bob surfaces on land, I suggest it maybe be called El Stubido or maybe EkkertaðgerastalltílagikveðjaSantanaogCo 😉



      Canaries Weather Forecast for tonight and next few days is favourable, only small breeze (12 knots ~ 6 m/s) wind from East North East, thus airport on east side of Island (and at La Palma also) should be open to all needed taffic, hope it has stable power supply for runway lights and navigation beacons, so planes can land and take off in the dark , if need arizes. This increase in activity surprises me. I had expected Bob to grow bigger first, but likely not from same magma source. Pity the world is not allowed to see full details. Hope citysens of El Hierro have good sleep. Best whishes from here.

      1. Hello Islander, could you please help out with a translation of EkkertaðgerastalltílagikveðjaSantanaogCo, it was a bit beyond my Icelandic to break that down into something I could understand.

      2. Translation should be:
        (Ekkert að gerast allt í lagi kveðja Santana og Co).

  6. Still no tremor update since 19:08 – anyone know why? or where else we can get the info?

  7. It has always shown up previously when it was in port and not moving Ursula. Even when it was in Spain for a few days, I think it was Vigo it showed up, so not sure. Should say I do not have any knowledge just interested in the situation.

  8. These tremors are seen on the Very Long period graphs all over the UK.
    I have seen them before.
    These graphs emphasise quakes and tremors from long distances eg look at the last large Quake in Peru on the 28th Oct 20011 on very long period graph

    compare this with short period graph for same day


    I have no idea what is causing the tremoring. It is interesting but I think it is caused by something far away or very, very deep. Is there anyone else out there that has more knowledge of the UK systems and signals?
    Maybe a query to the BGS could solve the mystery.
    I don’t think it is anything to do with Iceland unless the MAR is tremoring prior to a very large submarine eruption! 🙂

    1. Thank you for the reply Diana and others.
      Something just came to mind Drilling & Fracking:

      Shale gas firm finds ‘vast’ gas resources in Lancashire (Sep 21)

      Can’t find anything to say there extracting it yet but could they still be Drilling?

      Edit: Just seen your other reply about Ireland, guess it’s not the fracking then.

      1. I have sent an email to the BGS to ask about the source of the tremors. I will post any reply I get.

  9. I think it’s a rather risky statement to say that the ‘renewed’ earthquake statement is a precursor to a new eruptive vent. You give no valid arguments for this assumption except for ‘based on current tremor data’ and the fact that the last eruption occured with little shallow earthquake activity. Please give your arguments a little more foundation because stating that new eruptive vents have opened can also be considered as scaremongering.

    I’m not going to claim that I know what is currently happening, I’m just saying your arguments are completely unsubstantiated. False reports can lead to things like we now see; people make the same kind of statements without any rational fundaments.

    1. I do not really agree. There is ample examples of this pattern being a precursor of vents opening up. So I do not have a problem with it, but you are right that it should have been a bit better built up stylistically.

      No, actually I do not see it as scaremongering. I see it as a oposition against IGNs to laid-back way of running it.
      I do not think you would need to evacuate the entire Island, but they should instigate measures to speed up evacuation of the El Golfo area.

      1. The only arguments for the statement that recent developments are precursors to a new eruptive vent I could find were:

        -The current tremor (which isn’t an argument without any explanation why in his eyes this tremor is different from what we’ve seen before and especially WHY this should be a precursor to further activity)
        -The fact that no shallow earthquakes have to occur before an eruption (which is no argument for renewed activity either, because this is no new development)
        -Earthquake at a depth of 100-300m (which is false, as there are non, and it’s also contradictive to the previous ‘argument’)

        Jon even admits the harmonic tremor hasn’t changed yet. Why would that imply a sudden danger of new eruptions?

        Jon has claimed multiple times that the current vent would be ‘closing up’ which hasn’t been the case so far. Those statements had the same vague kind of arguments as this statement does.

        Please Jon, do not take this personally. I’m still convinced that you know more about volcanoes than I do, and than most of us here. My advice would be to expand your arguments by providing us of a more detailed reasoning of your statements.

      2. The first eruption vent is going to close up one day. It is just a question of time. For Eyjafjallajökull volcano (not a fissure type eruption like in El Hierro) that took about four weeks to happen. Before it did, a new fissure did open up nearby.

        For El Hierro volcano it is hard to know for sure when it is going to happen. But it is going to happen. When it does, the magma is going to find a new path to the surface. If it has not done so before oldest eruption vent closes up for good.

        There is still a lot of magma inside El Hierro volcano. Most of it has to be gone before the eruption finishes. When that might happen is anyone good guess.

      3. It is not true that ‘most magma has to be gone before the eruption finishes’. The current magma could as well for dykes or plutons beneath the island and remain unerupted. The fact that it will close up, ofcourse, nothing lasts forever. But the statement that a new vent HAS to open is nonsense, nothing has to happen. We don’t know how much magma and/or pressure is down there.

      4. With GPS figures up to 40mm up and something of the same in other directions. It has to do so.

        It is not until the GPS numbers are going down the eruption is going to slow down and stop. Until that time, it is going to continue with new vents when the older one closes up.

      5. Pieter, it all boils down to which fissure volcano you chose to compare the Bob(s) with.
        I think that comparing this one with Heimaey or Surtsey is a bad choice. I think (believe) that a better one to compare with is Krafla volcano. And if it is anything even remotly close to that one, it would be close to what Jón has hypothetized about.
        The vents would close over time. New vents would form, and so on.
        But this volcano is behaving a bit different. It seems to be behaving like a mix of Krafla and Eyjafjallajökull. While krafla had banded fissure eruptions as it had its rifting episode going from west to east, this volcano seems to have had its fissuring along the main rift. Secondly, the fissure that has opened up fully sofar came after a wide-spread quakeing, that turned into a focused quake-pattern.
        Now we have a new focii for the quakes under La Frontera section of El Golfo. So, I think it might have a new vent formation there with time. What is then time? Well, it is here it gets a bit hairy to guess. Anywhere from -12 hours to next year.
        But I would say that most likely is that the quakes will continue to slowly migrate upwards as the feeder tube is forming. Then it will hit the silent zone and we will have a large quake. And a little while later a new vent forms. The vent forming will probably be low in EQs.
        IGN on the other hand seems to be following some other volcanos pattern, I would guess they believe that they will have the same pattern here as they did during the last Canaries eruption.
        But, I would like to say that even IGN now seems to be back-peddaling like crazy and that they have started to hedge their bets in exactly the same way that Jón has stated. And, after all the pattern of harmonic patterning is related to magma movement in a feeder tube. Only problem there is that it could equaly well be magma movement into Baby Bob of The Broken Diaper over at La Restinga.

      6. I follow your reasoning, but as you’ve probably noticed yourself, there are plenty of possible scenarios and there is not a single thing that points towards one of them, therefor I think it is too early to state that one of them is going to happen. There has been a major swarm in the Golfo area before, this swarm migrated south, why wouldn’t this one?

      7. There’s alot of talk about magma intruding – is that reality? If it is then I dont understand why the magma that ( putatively) intruded during the swarm of 8000 starting in July has gone quiet. Bob has removed little of the GPS inflation at Frontera that accompanied the swarm.
        Most significant is that we dont see inflation during this recent deep EQ activity – confirmed today by IGN. Frontera is stable. So can we be sure it is magma intruding causing these bigger deep EQs? -or indeed, anywhere under Hierro? It would make a huge difference to the outcome if most of the 50million cubic metres of inflation is not fresh magma.

      8. Peter, you did not make a lot of sense here.
        “It would make a huge difference to the outcome if most of the 50million cubic metres of inflation is not fresh magma.”
        I would myself be a bit surprised if it was Norwegan Herring Oil that had mysteriously caused that inflation.
        And, 50 million cubic metres of inflation is just a rather odd way to state it. Inflation is CAUSED by intrusion, you seem to imply that inflation is synonymous with the intruded materals volume. Secondly, you nor me or anyone else for that matter has a clue about the volume of injecta into the system.

      9. Carl,
        If the GPS signals reflect uplift caused by a rebound flexure of the crust and erupted mass then we do not have require magma intrusion from depth. The volume of 50million cubm would be taken up by the upper mantle. In other words Hierro did not inflate it tilted.

    2. This is a rift eruption. Earthquake swarms are not going to happen without magma being on the move. In most cases there is going to be a eruption following that. It is impossible to know where a eruption vent might open up, and when for that matter.

      When this blog post was written a harmonic tremor pulse had started to appear on the tremor plots. They have continued to happen all day (from 10 to 30 min at the time). This means that magma is on the move. The growing earthquake swarm is also clear sign of this movement of magma. As the magma is looking and breaking a path up to the surface this moment.

      The problem with fissure type of eruption is where they are going to show them self. For that reason I rather want to get thing wrong then right in regards to El Hierro Island. Since the population is at risk in my view from this eruption in El Hierro volcano.

      1. Thank you for ellaborating. This clears things up.
        I still wouldn’t speak of real signs of a new eruption vent. This could just as well be a plutonic intrusion or just another blob of magma feeding the already open vent.
        Also, rather get things wrong then right seems kinda weird to me? What did you mean?

      2. Pieter, he meant that it is better to err in the way of caution, then being wrong in a fatal way. I think IGN is risking being wrong in the fatal way. But on the other hand, they have changed their minds again.

    3. But there is some support for Jon’s argument.

      1) Bob is described by the authorities as a fissure eruption.
      2) There were very few EQs, if any, preceding Bob at the site Bob erupted.
      3) There has been shallow EQ activity in the El Hierro area, if you look at the whole period from 19/07/2011 (a very short geological time span).
      4) The time line of EQ activity was Frontera to El Pinar prior to the eruption of Bob. EQ activity virtually stopped for a short period prior to Bob in Frontera (but that period again was very short) before resuming again – this time at a lower depth but stronger.
      5) EQs activity and accumulated energy is rising again.

      The supporting data is readily available on IGN and avcan.org websites (on the latter you can watch the animation of EQs from the start of the swarms to today).

      Far better to look at the facts. Because whether Jon is correct or not, something is happening and the signs are not good at the moment.

      The authorities need to make sure that they can evacuate the island fast if they have to – emphasis on fast. Evacuation and small eruption is just inconvenient compared to the failure to evacuate in time in the event of a larger eruption that leads to casualties. Not an easy decision but far better now to err on the side of caution, assuming that the worst will happen.

  10. What the undersea volcano is now producing is deodorant. Aluminium sulphate is what is sold as natural crystal underarm deodorant. El Hierro has become a deodorant factory. When are they going to get those people off?

  11. Has anyone seen or done a plot of the El Hierro earthquakes starting AFTER the birth of RestingaBob(s)? Would such a plot give any indication of where the next eruption could occur, or is that just too simplistic? I think it would be interesting to see that plot superimposed over a map of the island.

    1. Anyway, at the beginning of the seismic swarm, depth earthquakes began in north, migrated to south and only after that an eruption occurred at south at Restinga. Hard to know if current depth earthquakes locations can help finding a new possible surface location.

  12. I like this blog because it gives a lot of information in a very trustful way without scaremongering or anything of the sort, but I agree that perhaps it is a little bit to early to say if new vent will opened up soon, since there is no data about inflation or about gas emissions, not because you don’t search for it, but because it seems that the IGN does not like to publish all of its data (hope the IGN changes its data policy in the future). But I agree with Jon that a new vent might open up, but not right now perhaps in weeks or even months.

    1. Thanks, Vince & Vicki!

      I check the 3 and 10 day maps regularly, but obviously they change every day. It seems like these post-Restinga quakes could be the key to where the new pressure is building up and the activity might be moving to.

      Looking at that last map it seems to suggest a higher probability of another submarine eruption, so the question that poses would be in regard to the water depth, as it could be another quiet Bob-like event or a more explosive one closer to shore.

      We are indeed spoiled by Lurking’s plots, I know that some of the more elaborate ones even showed the ocean floor.

  13. AN EXTINCTION LEVEL EVENT…. of my brain cells. Possibly Carl’s also from the way he was talking.

    Anyway, here are the quakes from 10 to 30 October, 4D rotating plot. Yes, it includes the Mag 3.0+ ones. I made them into cure little stars so that they stand out.


      1. Oh Lurking! This one is pretty :)…but I felt slightly dizzy towards the end !. There seems now to be another layer of quakes at a higher level.
        I shall leave it to the greater minds than mine to interpret what I think I see but cannot find the right words…..
        Definitely time to go and start counting my sheep.

    1. Well, judging from my head today it was an extinction level event… Ay Caramba..

      Interesting that there is a smaller shape of quakes that is rather well separated from the large ovoid lump of quakes under Frontera/El Golfo. I would not be surprised it there is a rift forming down there, but if it is that it is a long and very deep one.

      1. In case you didn’t notice it, on the title screen in light blue down in the corner, is one of the many morphing names of Bob….

      2. I missed that one, lovely 🙂
        It kind of was a good name of the Stain.
        Before getting wasted I had the distinct honour of babysitting earlier during the day. When I changed the bleiju I found something reminding me of the stain of Bob… 🙂

      3. I think we should include your name into the next Bob event in recognition of your hard work and truly great plots….. Liggja í leyni Söguþráður Bob

      4. LOL, yes, I did notice that. I don’t think anyone will be using that name in a search engine though!

        This system is even more complex than I imagined, looks like it could keep us guessing for a very long time to come.

        As always, another fantastic plot. Thank you for doing this!

      5. Brilliant Lurking. I love your plots. They make what’s going on so much easier to follow for a numpty like me 🙂

      6. If the swarm of 8000 were added that clear layer would be even more apparent – I’ve been trying to pin it down all day but have no idea what it could be. Either very compliant upper mantle, or very a-seismic lower crust?

      7. Around 14km at the periphery. But the depression of the crust by the erupted mass would depress it – but there’s no data for Hierro, only Tenerife:
        Tony Watts’ work:

        If Hierro’ mass has pushed MOHO down to 20km then there’s the top of the silent zone.
        It would also mean that the swarm of 8000 was well within the sedimentary layer, with its base depressed from 8km to 14km . Indeed that might be why – in the flexure model- the swarm of 8000 was there, focussed in the easily fractured rock, taking up the strain of a flexure that lasted from July to early October.

    2. Very interesting. Looks as though the EQs may be starting to follow the N-S rift line. Time will tell.

    1. This are tremor pulses I think. They are from Hamarinn volcano I think. But it is hard to know for sure.

      It might well be that a new eruption is going to happen there soon. But it is a bit hard to know at this moment.

    2. SKRO has been acting odd for some time now. What these tremor pulses are is unclear, though to me they appear to be either magma related or due to hydropower installations. If they’re magmatic, the possible related volcano could be Hamarinn.

      1. I’m referring to the one at Hagonglon and/or near Kvislarvatn which both are far away from Vatnsfell. I’m still not sure if they are related to hydropower plants.

      2. Ah! I do not know of that one, I just presumed that Vatnsfell was nearest Hydro power plant and then there is Kárahnjúkar to the East.

  14. Ekkert að gerast, allt í lagi, Kveðja, Santana og Co.

    No prob, added a few commas for clarity. Hope will be able go again on holday, in Spain. Excellent clean Barcelona!

    captcha threw this one off track…

    1. Santana thing abowe explain was for Carl. Good to know one can even saturate Giggle-bender. I do not agree with Carl it will behave much or remotely much like Krafla, except I am wrong.
      El Hierro (usually) has eruptions that are rich in water-mix-content. Everywhere on the island we see the result as pumice substance we in Iceland call Rauðamöl (the red gravel) and this happens when high Iron content magma comes into cantact with water. Even on top of El Hierro there is such. This has white-r substance inbetween layers, like in mine abowe airport. It´s what we call Vikur (pumish) and this appears in larger Hekla Volcano events. Does this then come from the larger (caldera) events? I have not had time to read on this much. Does El Hierro maybe behave more like Hekla or Askja in Iceland? I whould rather like IMO running the show. Did they not get any advice at that conference, or did they not go. It now seems to be question on behavour. Another rift-and-fissure eruption? Yes, probably.

  15. Just to chip in here for a moment. I’ve been looking at the dear old seismographs again and I suspect that the only reason the long period harmonic tremor doesn’e appear on the Tenerife station is that it may have a high pass filter switched in. Looking at the frequency analysis there is a suspicious smooth roll off of the curve at low frequencies.
    On another note there seems to be a beat pattern in the tremor signifying that there are two closely spaced components in the freqency domain of similar magnitude. Suggests to me constrictions of a magma path at two different locations. It may not be coming up of course, just sloshing about from place to place.

    1. BTW KarenZ, dunno if you are into the math side of things, but a pretty close approximation of how IGN calculates energy for these quakes is:

      Joules = 10^ ((1.531 x (mgLb)) + 4.677)

      I gave up looking for a conversion from mgLb to ML or Mo. And the IGN references only take you to how it’s derived (based off of trace defection amplitude and time). Not knowing the A or the T you are sort of stuck. So, I tracked down a few significant events in their cumulative energy plot and found the quakes that went with them from the listing. That formula renders a pretty good imitation of their cumulative energy plot, so it can be used to derive the energy value of the quakes yourself.

      For all: I’ve run into this issue before. The problem is that each region of the globe has it’s own structural characteristics. A formula that works for Iceland won’t work here unless you can get the reported quake into the same settings. (yeah, right)

      Iceland uses M and ML in their listings. ML being “local magnitude.” I’m not sure what M is, but it doesn’t track linearly with ML.

      El Hierro, and IGN, uses mbLg. This is similar to the Nuttli magnitude used in the New Madrid region and the two are referenced at each other quite often. Kanamori 1983 addressees the aligning of mbLg, ML, MB and a few other ones. But the most significant observation was that Nuttli worked on getting East and West coast quakes into a common magnitude framework.

      On a global scale, Mw is the one you see most often, but that usually only shows up for the larger quakes.

      Rather than fight it, I decided to just root out what the professionals at IGN were doing and imitate their conversion.

      If your eyes have glazed over by this point, congratulations. You’re normal.

      1. I just used the figures provided by IGN. I have not researched the maths side of this yet but I do have a book on order.

  16. Maybe not evacuate now, but there are 22,000 people on the island give or take with tourists and residents. Like you say Jon, they arent going to get much warning. Maybe a few hours. The intensity of it is the question and Lurks latest on YouTube shows a lot of problems. IGN called a couple of larger quakes in the middle of the magma chamber tectonic. Okay, thats a politician hoping it will go away. If it does, no harm done. If not, well they might not make it off the island except in bags. Time and motion -125 passenger seats on 727 type of aircraft depending on capacity. It would take 176 flights, and 352 hours of flying time to get them out of harms way. In dollars it would take 1.14 million bucks to move them. In addition with ground time for turnarounds it would add two hours to each flight so really its
    double that amount of time. Basically put, it would take 29 days with a single flight per day, or with 3 flights per day it would take it to roughly ten days to evacuate. Thats a long time when HsO2 is burning your lungs out along with ash that might flame your engines. Thankfully the wind in El Hierro blows from the Northwest to Northeast most of the time. Above it though passing about 10,000 the westerlies take over and that would deposit the ash and gas over the top of them in a rain out scenario. Lots to start thinking about.

    1. Well, that’s if it goes real big.

      Personally, I don’t think it will. At least not that large. Valverde is only seven miles away and could easily function as a “shelter in place” region if it got that nasty. Sure, Puyehue Cordón-Caulle had a column 5km across at the base, but I don’t think that’s what we are seeing here. There is a lot of sediment there, broken up and chaotically fractured. If it goes it’s likely gonna be pretty placid in how it makes itself known. Puyehue was a hard capped volcano with no way to release pressure until it broke the cork and exploded. Of course, the biggest issue with Puyehue was that no body really saw it coming.

      1. The only real way to state that it is tectonic, is for it to have a focal solution that states so. So far, these quakes have been pretty far down on the size scale. Usually organizations don’t publish solutions for quakes unless they are over a certain size, and that’s provided that they can get enough data from the networks.

        IGN has access to their own data and may be running solutions in house from the “first motions” of the waveforms. I don’t know how many stations you need to get a good solution (statistically speaking) but you can at least get an idea about what it was from a few stations.

        But.. even if it was tectonic, that fits with the bending crust idea that has been mentioned here. In a region that is essentially the upper mantle… with no subducting slab or transform fault at play… you have to wonder.

      2. I have now read up on the bending crust issue. And I would just like to say that it seems to be really overinterpreted in this case. Yes it has an effect. Is it unique? No, all mounatinchains do this. Could it replace magma in the function of a volcano, no chance in hell.
        Well, it could have some minute effects on the dynamic of a volcano, but to do it like Peter does and use it as a complete theory of volcanology that replaces magma-infusion as a driving force of volcanoes is a biiiit to much.

    2. Hi,

      I’m amateur (to be honest not even that) in geology, but i know something about rescue.
      Well this number of people can be evacuated by ship. There should be due to the touristic infrastructure on the canary island enough capacity to ship them out.
      The problem is to transport the people to the habour, when the tunnel is closed. How many buses are on the island ? Is there a safe habour in the el golfo valley ?
      I think the spanish civil security is working on this.

    3. We went by Garibaldi ferry (Italian) from Genova to Sicily in 2004. Those ships are huge (similar to Stena Line but much closer to the Canaries) and take lots of passengers. But I do not find much about them on internet – have they changed their name?
      Mr. Armas, I tipped you about Garibaldi some days ago – did you already contact them?

      1. Oh, that is a Norwegian company. – They have many boats and I see they go regularly to Valverde so that woud be fitting very well!

      2. In the german Wikipedia Version are three ship companies mentioned.

        Again, the transport to the habour is the challange.

        The canary islands/ spain at all have enough touristic infra structure to house the people.

        Question to the experts: Are there any safe regions on that island ?

  17. Question: Should El Heirro actually blow and a landslide take place, are there any predictions on Tsunami’s for the US, CA or SA? I have seen programs related to this type of event and they were not very cheery. After Hurricane Andrew I no longer live in a coastal city of any sort and am very much inland at over 700 miles. Anyone out there with any thoughts on this possibility?

    1. The answer is no. El Hierro is not going to blow up and it is highly unlikely that there is going to be a landslide that is going to create a tsunami.

      1. There has been a discussion about this on an earlier thread which came to the same conclusion as Jón.

    1. No, two completely unconnected areas. That’s like saying ‘does mt. Etna have any influence on mount St. Helens’.

  18. Magnitude ML 3.1
    Date time 2011-10-31 07:13:12.2 UTC
    Location 27.78 N ; 18.04 W
    Depth 22 km
    Distances 186 km SW San cristóbal de la laguna (pop 139,928 ; local time 07:13:12.2 2011-10-31)
    98 km S Los llanos de aridane (pop 19,635 ; local time 07:13:12.2 2011-10-31)
    79 km SW Valle gran rey (pop 4,983 ; local time 07:13:12.2 2011-10-31)

  19. Just posted on Avcan

    Marcos Sosa #8206;
    3.2-1.2 km from the coast and 5 km from the roquillos tunnel
    a few seconds ago · Like · Original

  20. According to Takeshi Sagiya, Professor at the University of Nagoya, scientific collaborator of the INVOLCAN and scientific resposnable of the permanent GPS network of the INVOLCAN volcanic Canary surveillance, no significant shifts in the permanent instrumental GPS stations are observed during the last few weeks. On the other hand, data from seismic activity reflected a reactivation of the same under the North coast of El Hierro which may indicate a second magma ascent process. There are two possibilities to explain the changes observed in the GPS stations. One of them is Let’s see again signs of inflation (shifts eastward in FRON and westward in SABI). Probably the current seismic activity is deep and the deformation of the ground will gradually intensify as it occurred during the months of July – August… but we must also think about another possibility. Given that a fracturing has been created that already he has promoted magma as a result of the activity of July-August, the magma can be climbed without registering additional inflation. So far we have not seen signs of significant deflation, so that the amount of magma at depth can be large enough to continue to provide magma to positions more shallow under El Hierro. If so, the activity can continue.


    1. It is promising that at last the recognition of the quiet zone is registering with INSTITUTO VOLCANOLÓGICO DE CANARIAS. The Iron has a hard casing with many cones across the surface, and a porous limestone(?) sub-structure which is likely to be bending and melting, and including carbon deposits in some layers. Magma may be dispersing beneath El Hierro at an increasing rate today. The combination of rift zone, and ball of lava in NW Frontera, as defined by Caracedo on 29th September (El Golfo), gives a difficult to anticipate time-line to eruption(s) on land.

      Better safe than sorry – I hope the evacuation plans are coming together in time.

    2. Finally we have word from a real researcher into volcanos.
      Sagoya is good at what he does.
      Go figure, he pretty much has opted for Jóns prediction, but he hedges with an extra alternative that it can take some time before the new magma has come to the surface. But it is telling that he also states that it could come up rapidly and quietly in the way Jón stated.

  21. Magnitude ML 2.5
    Date time 2011-10-31 07:59:18.4 UTC
    Location 27.78 N ; 18.05 W
    Depth 21 km

    1. Has there been downscaling twice again? There seems to be twice of even three times some sort of rupture which can be detected in the overview of measurements. Or are these only strong earthquakes?

  22. Wow, I come on the compter to check the number of quakes in El Hierro and was amazed, 47 so far today. Things seem to be speeding up rapidly. Now it seems all we wait for is an eruption. I really hope it will be another undersea Surtsey.

    1. A must read for anyone who has to deal with an emergency involving a large group of people.

      A summary so the message does not get lost here:

      – Mobile phone networks and internet get saturated so data is lost and the emergency services cannot use them for themselves or to communicate to the local poplulation.
      – Alternative communication strategies are needed.

      1. This sounds as if that would always be the case after earthquakes, but it depends a lot on the strength of the earthquake. It is not always so that mobile phones can’t be used after earthquakes. And rescue teams normally are using other devices like radio transmitters or so.

      2. It is the volume of users exceeds the number that the systems were designed to handle.

        If there is an incident, the number of users significantly increases: those directly involved, concerned relatives and the curious.

        ReCAPTHA was “rchung much-used”……hmmm.

  23. https://www.facebook.com/permalink.php?story_fbid=267430539960352&id=156297191073688

    “El receptor HI04 ha tenido problemas de alimentación por fallo en sus baterías. Actualmente se esta procediendo a su reparación. Existen 7 receptores más en la isla que están registrando y transmitiendo en tiempo real la información al comité científico que analiza los datos. El HI03 es un receptor muy próximo al averiado en el que pueden consultar los datos. Esperamos en breve poder restablecer la información del HI04”

    1. Translation:
      HI04 had problems of chargin because one of its batteries failed. At the moment it’s being repaired. There are 7 other sensors on the island which measure continuously and transmit information in real time to a scientific committee, who is analysing the data. HI03 is the closest sensor to the damaged HI04, on which you can see the data. We hope that in short we will be able to give information from HI04 again.

  24. Meanwhile is there a storm in Iceland or is it really quiet? Quiet periods tend to end with big earthquakes because the pressure has built up. Mybe not though because the rumblings fron Hengill might have de-stressed the system?agasson, dintel

    1. Storms in Iceland have nothing to do with earthquakes! This is just plain nonsense! Totally different systems.

      Just the same institution (IMO) measuring them both… 🙂

      And real big earthquakes (up to 7 on Richter scale) happen in Iceland normally just twice or so in one century.

      1. The storms drown out the signal so they do in fact have a lot to do whith earthquake detection. Only the big ones can be seen during storms because the others are lost in “noise” created by the storm.

      2. But there would be a lot more of big earthquakes if they were always preparing during storms in Iceland. There is such a lot of storms esp. during winter time, but not many big earthquakes (over 5 ).

        IMO in most cases is able to recalculate removing background noices, see different qualities of earthquakes.

    1. does it correlate with working/daylight hours in Italy ?? human activity ?

      1. Human activity? If you click around on different times, these signals start after 8 and stop before 20h.

      2. Also, if you click on the station on the other side of Vesuvius, OVO V, there is absolutely nothing. So I vote for human activity as most likely explanation.

      3. Could well be. It seems to me that the station is not far from the visitors center (snacks, shops, etc) about 500m from the crater.
        Possibly it is noise from there – it looks pretty regular in shape, but not in time.

  25. One lurking Dutch girl here… I’ve noticed that IGN and Avcan sometimes show different figures: 84 quakes were recorded according to yesterday’s IGN list, but in its histogram from yesterday the total was 93. Avcan recorded 86 quakes… Which organisation is right?
    Keep up the good work!

      1. The fact that the numbers are not the same is probably because there are a lot of EQs at the moment.

        Suspect that IGN and avcan.org used different times to extract the data from their systems so EQs may have occured or been updated in the intervening time.

      2. @ KarenZ in reply to October 31, 2011 at 12:35 and 12:45:
        I did a manual count on both the catálogo and the listado pages from IGN, found the “internal” difference (glitch?). Afterwards I saw the different figures on Avcan. Like you all (just a guess), I tend to switch a lot between every available page and website. At this quake rate, it’s pretty hard work to keep up with the news 😉
        Thanks for your anwer!

    1. Avcan use the data IGN publish.
      Sometimes, data are corrected, EQ added or deleted,
      AVCAN change the data as soon as IGN publish the new data.

      1. Hello Sondebueu, yesterday the info on Avcan was most of the time better up to date than the IGN pages… that’s why I counted all the quakes myself, including the small ones.
        Thank you for your answer.

    1. Armand:

      what is your Paypal email address for ER??? .. the web donations page doesn’t work for me … Paypal probably it doesn’t like my browser/OS version ….

  26. Checking here, http://www.localizatodo.com/mapa/, Ramon Margalef is now just within the northern part of the excluded area around Baby Bob, south of La Restinga. Sort of circling in small loops, so I suppose it’s measuring something (although it’s probably not an acoustic survey, for that it should be moving in long parallel lines).

  27. OT. OT

    Question to Jon:
    Is it a big effort to sort the comments the other way around, so that the newes comments are at the top ?

    1. This is build in the WordPress blog system that I use. I do not know if I can have the newest comments on top.

      So for the moment. I do not think that this is a possibility.

  28. Good News! I am not debt free with the bank. I got a computer fixing job paid that helped me to pay up the debt. It was a complex computer fixing job with Gentoo Linux.

    The bad news. Now I have to collect money before I move back to Denmark. That is going to take at least ~6 months.

    In short. I am still broke (since I am collecting for the move to Denmark). But free of debt with the bank.

    My only debt now is on a bill paying account that the bank handles for me. That is going to be paid up by July when I quit with that service.

  29. With regards to the Helicorders picking up on tremors in the UK, Wales, Ireland & Alaska, could this be related to this possibly:

    Beerenberg Volcano, North Atlantic.

    2011-10-26 19:15:19.2 71.04 N 6.84 W 1 2.8 JAN MAYEN ISLAND REGION
    2011-10-25 23:47:40.8 70.94 N 6.81 W 1 2.7 JAN MAYEN ISLAND REGION
    2011-10-25 23:05:47.9 70.94 N 6.72 W 3 3.4 JAN MAYEN ISLAND REGION
    2011-10-25 10:33:54.0 71.06 N 6.79 W 2 2.3 JAN MAYEN ISLAND REGION
    2011-10-25 10:11:07.5 71.47 N 7.79 W 0 2.5 JAN MAYEN ISLAND REGION
    2011-10-25 03:06:37.6 71.24 N 6.79 W 10 3.2 JAN MAYEN ISLAND REGION
    2011-10-25 02:57:35.2 71.25 N 9.48 W 1 2.9 JAN MAYEN ISLAND REGION
    2011-10-25 02:47:37.7 71.05 N 6.78 W 1 2.4 JAN MAYEN ISLAND REGION
    2011-10-25 02:32:21.0 70.79 N 5.30 W 10 5.1 JAN MAYEN ISLAND REGION
    2011-10-24 22:27:13.5 70.63 N 7.28 W 1 2.6 JAN MAYEN ISLAND REGION
    2011-10-24 17:59:09.3 70.90 N 7.04 W 1 2.5 JAN MAYEN ISLAND REGION


    1. This article was posted on Friday 28th October:

      Goce satellite views Earth’s gravity in high definition

      Look at the Orange area that to the West of the UK and covering Iceland.
      Could this be unsettling the magma??

      Also, someone on my thread posted these graphs from Norway:

      [Link to godlikeproductions edit out. Reason: Links to godlikeproductions are banned due to spam risk and other security related (link to a alexia.com) matters. That is spyware and other bad things.] Edit by Jón Frímann.

      1. Sorry, article is from 28th June 2010. Couldn’t concentrate well as in a bit of pain.

  30. http://www.rapideye.de/images/flood/2011-10-26_RE2_ElHierro_RGB.jpg

    This is a better picture of what I posted on Saturday. A couple of things to be noted.

    The currents run consistently from the NE in October to January and the winds are from that direction too.

    Streamer plumes from these things initially ran in that direction. After that it filled the bay and then we were basically told to believe that it rounded the corner into El Golfo Bay and a trek of about 45 miles. The current is about 3.5 knots on the north side and about 3.0 on the southeast around La Restingas.

    Colorization-The color has changed from a light green to a darker green. Anyone who knows what that means beyond either less or more sulfur should pipe up. Its also distinctly brown at the origin point.

    El Golfo Bay-Intel gathering in the USAF you get to see a lot of pictures. After a while and being exposed to the PIF people you pick things up. Like what was there before, and what was there later. Look below at the spread out of the initial plume from La Restingas.


    Then switch back and forth between the two. You will note that the plume in bulk is theoretically pulling back from the NE, making the curl of the bay in Restingas, then pluming in its normal streamer from the SW corner of the island after curling around the corner into the face of a 3.5 knot current. That hasnt been the normal fan plume that we would expect to see. It looks to me like there is more coming from right in the bayEl Golfo. This is not windborne, its current born with slight affects from winds guys and not the other way around. The other factors that could be affecting it might be the convective heating as cold water is rushing in from the bottom, heating and rising to the surface. I would think that this is much more different than a black smoker on the bottom of the sea. But, another factor is the water temps. Maybe the whole bloody island from Restingas to El Golfo is heating up? I havent seen diddly about water temps but THAT would pull it up against the island and trump the currents.

    The sea vessels are avoiding this area because of possible HSo2 and the fact that this crap will burn the bottom out of a boat. So there really isnt any testing of the water beyond a little quick sample here and there. Testing gear would be eaten up pretty quick. But its El Golfo now thats disturbing.

    The same initial plume seems to be cranking up there in the SW corner. The only difference is the color. If the bay around Las Restingas isnt heating then the only logical conclusion is that the vents have already opened else the colorization would not be correct in the face of all the physics of it. Comments?

    1. You can’t really tell what is sourcing the stain at the end of the NW ridge. It may be sourced from near the bay or it may be sourced from a point further south. Remember that when Bob first erupted the authorites said that there were two eruption sites off La Restinga. However, whatever the source, the green stain is a bit too close to Sabinosa and Frontera for comfort.

      Have you got a more up to date picture?

      1. Although it’s tempting to think that the stain around the point originates on the El Golfo bay we haven’t had any earthquakes near the surface that far west in the bay. It’s unlikely to erupt completely silently.

      2. If you look closely you have a current vortex up at El Golfo. That happens as two currents meet and one goes out victoriously in the tug of war. In this case it is the northern current that wins and carries the hole sheebang back and to the south.
        There is no vent open yet at El Golfo. Not that is showing on these images anyhoo.
        Yes, the heat emited of the erupting El Bob de la Restinga is creating a convective up-current that sucks a lot of gunk from the bottom.

        The fluid dynamics part of it is quite clear. This is all from the original El Bob de la Restinga eruption. Trust me on this one.

      1. Thank you. It does appear as though something is in El Golfo Bay on the true colour pictures for today. Not too sure about the rest of the coastline either. Hope they are taking sufficient water samples.

        But I couldn’t say where the source is because the cloud obscurs the view.

      2. This paper could also be interesting: http://www.soest.hawaii.edu/krubin/GG711/gg711-lect3.pdf . It’s a lecture from the School of Ocean and Earth Science and Technology, Hawaii.

        And NASA describes the a.m. El Hierro alias Bob plume as follows:
        ”The plume is likely a mix of volcanic gases and a blend of crushed pumice and seafloor rock.” http://earthobservatory.nasa.gov/NaturalHazards/view.php?id=76229.

        I ‘d think that the dark colours near the eruption vents would be from pumice and rock particles, whereas the green colours would be gases. But during on-land eruptions (diagnosis by volcanologists of Eyjafjallajökull plume e.g.) and also with small plumes of geothermal wells like Deildartunguhver in Borgarfjördur, more sulfur always meant darker colours of the plume. But then I am no geologist. With Deildartunguhver – which I often had the possibility to observe, there was always a heavier sulfur smell when the ”plume” went darker. So the darker colour could also mean more sulfur in the water.

    1. And, 92 EQs so far to day (15:08) per AVCAN – including two <5km:

      2.1 magnitude; 0 km (event 1109094 at 12:53 NW Frontera)
      1.5 magnitude; 3.4 km (event 110875 at 06:05 Atlantico Canarias)

      Also some fairly deep ones on the island on the list.

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