Posted on by Jón Frímann

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. COMENTARIOS RECIBIDOS
    desde barcelona, enhorabuena a tan buena prensa, me encanta como escriben tan clarito y ya no hay ni un solo dia que no lo lea felicidades 03/11/2011 13:13:22 Alias: regli
    responder

    Comentario en el Diario el Hierro, por nuestro buen amigo Alejandro.

    ¿Por qué no ha actualizado el IGN el verdadero valor de los dos terremotos de ayer en la página que está a la vista y en las informaciones públicas, cuando en el boletín de sismos histórico del Hierro figuran corregidos el de las 7:54 fue en realidad de 4.0 y el las 18:10 de 3.8 y no de 4.4.? La señal del tremor oculta e integra al tiempo varias circunstancias, una la de la salida de materiales por las bocas submarinas de La Restinga, otra los espasmos de la circulación magmática subterranea que lubrican diques y avanzan a empellones, y otra los pulsos de realimentación del sistema que probablemente provenga de una bolsa inferior de magma riolítico avanzado, lo que supone una peligrosidad más que evidente en caso de explosión o erupción cercana a la costa. No se en que está pensando el Pevolca, pero si la gente de la Restinga está sintiendo el tremor por momentos, lo más sensato sería volver a evacuar la localidad para evitar riesgos hasta que la situación vuelva a la normalidad. 03/11/2011 11:37:32 Alias: Alejandro

    ¿Por qué no ha actualizado el IGN el verdadero valor de los dos terremotos de ayer en la página que está a la vista y en las informaciones públicas, cuando en el boletín de sismos histórico del Hierro figuran corregidos el de las 7:54 fue en realidad de 4.0 y el las 18:10 de 3.8 y no de 4.4.? La señal del tremor oculta e integra al tiempo varias circunstancias, una la de la salida de materiales por las bocas submarinas de La Restinga, otra los espasmos de la circulación magmática subterranea que lubrican diques y avanzan a empellones, y otra los pulsos de realimentación del sistema que probablemente provenga de una bolsa inferior de magma riolítico avanzado, lo que supone una peligrosidad más que evidente en caso de explosión o erupción cercana a la costa. No se en que está pensando el Pevolca, pero si la gente de la Restinga está sintiendo el tremor por momentos, lo más sensato sería volver a evacuar la localidad para evitar riesgos hasta que la situación vuelva a la normalidad. 03/11/2011 11:37:32 Alias: Alejandro

    1. Karmela-The translation is for that to come from the “Daily Iron” is that really the news source? I have trouble with that one because I take it literally from Spanish.

      The general translation of the page is that these guys near Restinga need to be evacuated according to Alejandro. Especially in light of the fact that the vent near La Restinga started to bubble again.

      Saw some pictures and this is bright, bright yellow sulfurous something coming to the surface. Clearly reactive with the water too as a low level gas formed on the surface.

      1. The news source on the Island El Hierro – is I think best translated as ‘El Hierro Daily’ but google translates it as ‘daily iron’

      2. giggle translate says

        COMMENTS RECEIVED
        from barcelona, ​​congratulations to such good press, I love how so clearly written and there is no longer a single day that do not read congratulations 11/03/2011 13:13:22 Alias: Regli
        answer

        Commentary in the Daily Iron, by our good friend Alejandro.

        Why IGN has not updated the true value of the two earthquakes yesterday on the page that is visible and public information, when the historical earthquakes Bulletin of the Iron include the corrected the 7:54 was 4.0 and the reality of the 18:10 of 3.8 and 4.4.? The tremor signal while hidden and integrates various circumstances, an output the materials from the mouths underwater La Restinga, another spasm of underground magma flow and advance lubricating shoving dams, and other feedback pulses system that likely comes from a rhyolitic magma lower stock advanced, representing a more than obvious danger in case of explosion or eruption near the coast. No that is thinking Pevolca, but if people are feeling the tremor Restinga at times, the most sensible thing would be to evacuate the town to avoid the risk until the situation returns to normal. 03.11.2011 11:37:32 Alias: Alejandro

        Why IGN has not updated the true value of the two earthquakes yesterday on the page that is visible and public information, when the historical earthquakes Bulletin of the Iron include the corrected the 7:54 was 4.0 and the reality of the 18:10 of 3.8 and 4.4.? The tremor signal while hidden and integrates various circumstances, an output the materials from the mouths underwater La Restinga, another spasm of underground magma flow and advance lubricating shoving dams, and other feedback pulses system that likely comes from a rhyolitic magma lower stock advanced, representing a more than obvious danger in case of explosion or eruption near the coast. No that is thinking Pevolca, but if people are feeling the tremor Restinga at times, the most sensible thing would be to evacuate the town to avoid the risk until the situation returns to normal. 03.11.2011 11:37:32 Alias: Alejandro

  2. Ok. Thanks to all. I´ll came back in two or three ours. Plese, Bob, wait for me, if yo can.

    1. Apparently the only new thing is the “kacuzzi” come back to the same area, south of Restinga.

  4. They said they wouldn’t evacuate Restinga, at least for now, because unlike what happened in the first eruption, now they know where is the eruption focus. The first time was not known. Situation is stable and being continuously monitored.

  5. The volcano intensifiesand many neighbours are voluntarily leaving La Restinga, however the Consejal of Emergencies in El Pinar says “The situation now is not like before, now that we have located the eruption (at the start we didn’t know where it was and because of that decided to evacuate) at the moment the vibrations have reduced compared to this morning” he explained.

    According to the tweets of the Cabildo del Hierro Maria de Carmen Morales has called for calm and assured that at the moment there is no evacuation planned.

    What the whole island feels is fear, indignation and the desire to drag all the incompetent politicans to the area of La Restinga and that they along with farting Bob all…

      2. Yes, they changed the focus to another island to the east of El Hierro, it’s La Gomera.

      3. Sorry, looks actually more like Gran Canaria with a little bit of Fuerteventura to the east.

      4. No. They have moved the map, not the island. You can find El Hierro by using the navigation tool as normal.

      6. Well ya go to the page every day and theres this cute little island in the middle of the window with the quakes all around it. Naturally you are gonna freak out if it’s not there.

        The page script got you.

        Quietly, at a small desk in the back corner office off of the server room, sits a code writer surrounded by countless empty Mountain Dew bottles snickering to himself at the mind games.

  7. @ Jenny – we feel that too – maybe too much information for all of us. We make it very difficult for scientists to slowly proceed. Until now they are NOT wrong. People want clear answers but in the case of a volcano nobody can give them (at least not here). They hear and see the Avcam, our website, Diario El Hierro, Diario de Avosos, La Provincia and canarios 7 and we all are describing every detail of the graphs, quakes etc. Politicians are not to blame for anything here. They and all the other people do the best they can. Not asking advise at worldwide experts and many other things which have not been done are in facts things that could have been done better. The people looking at the data are not idiots but responsible politicians, scientists and authorities. Let’s hope that i am right

    1. It was a translation I did of Karmela post at 14.08 which got separated in the split.

    2. Yes, it seems to me that people is freaking out, it’s not easy for scientists nor politicians the management of this crises with a population that is obviously upset with a completely new situation in their lives, they sometimes shoot in all directions, criticizes everything. The situation is new for all, they learn in the process, day after day. Sometimes the media just add more confusion to all, and sometimes even outside scientists further increase the noise.
      The question of evacuation, those responsible for the order would be criticized in any way, for evacuating, not evacuating, etc..
      They must have courage, some calm and some confidence in the authorities as well. Otherwise, people, scientist and politicians, they all get crazy with the stress and that is the worst for everyone.

      1. You’re perfectly right. Panic and fear are no good advisors.
        But by all the calm that is the only way to deal with such a situation, there still remains the fundamental question one should ask himself by commenting the decisions in matters of evacuation: I loose credibility and local economy is seriously damaged if I advice evacuation and nothing happens – but with all I see and know of the situation (it’s much and little at the same time…), I’m on a small volcano; small, but a volcano; an erupting volcano, and I obviously see there is a potential increase in the activity I can’t exclude, this increase could happen in an explosive way… Do I stay here with my kids and wait at this very moment?
        It comes back to basics.

      2. There is a stress factor in between – a) i want to witness whatever show happens and b) I have to get away here to friends on another island. A difficult situation! I would stay, but my sister (with 2 children), would auto-evacuate to another island for a while until the volcano shows which kind of activity he is up to).

      4. As a volunteer emergency coordinator and first responder for a small rural village, I have a deep interest in this event. There is no choice without risk of failure. The risks can be minimized by careful planning, but they cannot be eliminated.

        The choice to declare a carefully planned evacuation puts the burden or responsibility on the government, thus assuming the populace cannot make a wise choice themselves, and will save lives should a major event occur; however, it carries the risk of being overly cautious in the face of a small or non event, thus disrupting lives and harming the economy.

        The choice to declare a voluntary evacuation puts the burden of responsibility on the populace while simultaneously sharing information, thus assuming they populace can make a wise choice themselves, and will relieve officials of responsibility should the individuals make poor choices; it carries the risk of chaos in the face of any event, thus resulting in more damage than have originally occurred, or a greater loss of life than the actual event might cause. It also carries the risk that a portion of the populace will not understand the risk and will die in an event should they choose to stay.

        The choice to monitor the information and use it to selectively inform the populace only when elite experts believe the situation warrants it puts the burden of responsibility on the experts in charge of information, thus assuming that the experts know enough to make wise choices and relieving the government and the populace of responsibility of making choices without adequate information, avoiding panic and rumor. It carries the risk that the experts do not know as much as they think they do and that the government and the populace will not be able to make choices for themselves without access to all information., thus resulting in death or disruption in the face of any size event.

        The first choice risks failure in a loss of freedom and lack of governmental credibility. The second choice risks failure in a loss of life and accusations of governmental negligence. The third choice risks failure in a loss of life and realization of elitist arrogance.

        The question all must answer: “What failure are you willing to live with for the rest of your life?”…

      5. I would say: run for your safety, and think it over afterwords.
        Safety comes first, regrets can be overcome with time.
        After all, how many lives do we have?
        I’d rather spend my life regretting than just loosing mine.

      6. Theory well explained. But Renato has quite a point with the number of lives argument…
        The thing with volcanoes is that we’re not simply speaking of some 10’000€ because you had water in your house. We are talking about life.
        Basically we’re cooking polenta and they sit in the pan. Bob on global scale is as dramatic as when we fart in our bubble bath, but when you are an and swimming in the tub you don’t want to be where the bubble comes to the surface… That’s enough stupid examples for now.

      9. Don’t forget that such events can last for months or even a year or two. And evacuate everybody, dropping their lifes and local economy for months ? And if nothing happens or just something weak? After the eruption of Capelinhos, Azores, between 1958 and 1965 about 15,000 people from Faial Azores emigrated to the United States.

        I’m sure the authorities when convinced that something serious is under way, they will take appropriate decisions.

      10. If I remember correctly, “Bob” is at 300 meters deep and 100 meters heigh, so it will take some time to grow up to be dangerously close to the surface. Surely this is something that is being well monitored, as the possibility of anothers vents near to shore or in land.

    1. Don’t worry.

      If it was about Iceland, we would blame the sheep. And as a Londoner, I could not even recognise sheep.

    1. How odd. I have been checking the BBC daily (search for El Hierro) but not found those pictures. The article is dated 25 October 2011 so relates to Bob’s first burp. But pleased that they report more than the Eurozone crisis.

      1. Same here, I’ve been checking the BBC daily and found nothing! I even chased up their Science correspondent, Jonathan Amos, to find out why.

  11. There is really not much new in the daily press either. Raised levels of CO2 but nothing dangerously high but I do like this created picture of Baby Bob. It is also good to know that there are emergency 4 x 4s in Frontera so the local people know that they are not being left all alone. As I said earlier, really there is no clear path of action until something is actually seen and can be evaluated properly and the calm and correct plan of action made.
    .http://www.elpais.com/articulo/sociedad/Fuertes/seismos/altos/niveles/CO2/elevan/inquietud/Hierro/elpepusoc/20111103e

    1. Diana, I have been trying to keep it cool for most of the time.
      Sorry, if I ask you, personally.
      But what would you do, if you were at those poor people place?

      1. I would pack my bags and head for safety until it is definitely all clear! However many may not have a place to go or the financial or practical ability to do so. I am just hoping that the government of the Islands err on the side of caution but I can see from both sides. A dreadful situation indeed.

  12. Armand,
    I agree – the scientists are doing a difficult job and have not had the best equipment. At the start of the jacuzzi they only had one site recording tremor ( CHIE) so could not locate its source. Now with the additional stations – the ones where we are denied access- thay have an ability to locate the tremor source approximately, even in depth.

    From the brief view we had of the data from those other stations it was clear that the tremor was strongest in the south, and is probably not associated with the deep earthquakes under el Golfo.
    The frequencies that dominate the tremor on CHIE are around 1 to 5Hz as we can see from the yellow and red bands on the plot:
    http://www.ign.es/ign/head/volcaSenalesAnterioresDia.do?nombreFichero=CHIE_2011-11-03&ver=s&estacion=CHIE&Anio=2011&Mes=11&Dia=03&tipo=2
    These frequencies are typical of hydrothermal tremor
    ( Review on tremor here: http://epic.awi.de/11598/1/Kon2003a.pdf
    – section 4.3. So I see the jacuzzi being a conduit of km scale that that fills with sea water which then boils and erupts periodically under steam pressure to cause the bursts of amplitude on the CHIE plot. The photos of the grey stain show a well defined periphery as if a jet of water has been pushed up in a geyser-like fashion, whereas a jet of gas would I think have a more diffuse, and bubbling, appearance. A few weeks back the jacuzzi was described as pulsing every 15 minutes. It would be useful to know if the gray stain expands periodically now, perhaps in time with the CHIE pulses.
    I offer these thoughts as an amateur.
    Peter

      1. Perhaps, but the magma under Hierro is in a labyrinth of small pockets, sills and dykes, so that might limit explosivity. Isee that as beimg distinctly different from water or ice melt enrtering an estabclished magam chamber/conduit or vent. I imagine a submarine geyser.

      1. Armand,
        Might be better to see what flak it draws on here first!
        But I would like to ask IGN if they have sought help from the principal author of that Nature review: Konstantinou. He devised the ‘semblance method’ for locating tremor sources.
        Peter

      3. I will flak it a bit. The conduit itself is filled with magma, but, that magma pulses out into the water. The water is now probably quite a bit closer to the surface, and that cause explosions part of the explotions, the explotions help to shake loose gas in magma, and then that magmatic gas functions as your “jet”.

      4. Carl
        Today’s photos of baby Bob show both gassy, blue stains and the dirty grey stains, in well defined circles, not a spreading stain. Maybe they are distinct burps from the same vent? Unfortunately there’s no video webcam, so we have no idea if the gassing or gray staining is continuous or in short-lived burps.
        There could be many possible oscillatory mechanisms given the labyrinthine crust- direct magma/water contact, water/hot-rock, water/gas etc, and on a length scale of 100s of metres that the published models propose. I just dont know, but have a geyser mechanism in mind, only submerged.

  13. When i have 10 minutes time in between the many updates, i will publish a very good article which the Frenchman Raymond wrote earlier today. The first version will be French the second the one i still have to translate in English
    +
    Tomorrow morning or earlier, we will have 2 recent RapidEye pictures. I am sure they will reveal again what precisely is going on. Putting images on each other would problaby say a lot on the location.

      1. Armand,
        On second thoughts go ahead with it – I’m not scaremongering, but putting up a hypothesis for IGN to comment upon.
        Peter

      2. Fig 8 in here does, I think, rather resemble the CHIE tremor, especially in the bursts of signal lasting a few minutes and in the frequencies:
        ftp://newportftp.pmel.noaa.gov/newport/mellinger/papers/DziakEtAl08-Seismicity+TremorAtBrothersVolcano.pdf
        The recordings were made at 1600m depth on a marine volcano using hydrophones ( hence ability to detect higher frequencies than CHIE). Fundamental frequency was 3Hz. One of their interpretations is that the tremor originates in a 500m scale conduit in a shallow subcrustal hydrothermal reservoir. Nor was the resonance triggered by EQs. It is thought to arise from fluid-filled cracks, Quote from p12: “”….. the
        Brothers harmonic tremor likely is produced by shallow
        (<2.5 km) subsurface ducts, or conduits, filled with gasladen hydrothermal fluid rather than a single deep magma reservoir. The acoustic resonance of the mixture occurs due to unsteady fluid flow from either degassing of the fluid or perhaps flow of the fluid through a conduit."""

        I remember that at the time of the Restinga stain starting a hydrophone was installed. So how do its signals compare with those reported in this paper?

      3. @ Peter Still busy with the Frenchmen translating his document – giggle is not good enough in this case. Will copy it for a little later or tomorrow morning. The pattern does not do away.

      4. @ Armand —
        I can do translations from French for you. The only issue is time availability as I work much more than full time. But if you need something important done, send it to me. You can ask Jón for my email address.

    1. ?Dónde vive usted en El Hierro Karmela?
      ¿Está en la zona de La Frontera o La Restinga?

      1. He nacido en la isla de la Palma, pero vivo en Tenerife, pero la siento desde aqui como si viviera en ella. He vivido ya 2 erupciones en la Palma, y aunque no es la misma forma de volcanismo, siempre se pasa mucho miedo.Soy como una herreña mas.

      2. Karmela is saying (as I understand this) that

        She was born on the island of La Palma, but is now living in Tenerife, but she feels like she would living there (on Hierro, I suppose). She lived through 2 eruptions on La Palma, which were each of a different kind of volcanism, she is always very frightend (by that). She is like a woman from El Hierro.

  16. I have been out of touch for some time but curious now. Is this new eruption that may occur potentially catastrophic or will it likey be just isolated to the islands?

    1. I am not sure what you mean by your comment, however any eruption that may happen will only affect areas of El Hierro, nowhere else at all I would have thought. Apart from any possible ash that may be emitted.

  17. Quakes seem to have started again after an almost 4 hour break,

    1110050 03/11/2011 16:47:36 27.8095 -18.0603 19 2.5 4 NW FRONTERA.IHI
    1110049 03/11/2011 16:44:04 27.7963 -18.0626 18 2.4 4 NW FRONTERA.IHI
    1110047 03/11/2011 16:26:19 27.8483 -18.0692 18 1.9 4 NW FRONTERA.IHI

    1. They just added another one in the middle of that list.
      1110052 03/11/2011 16:44:03 27.8249 -18.0696 20 1.7 4 NW FRONTERA.IHI
      So no quakes for 4 hours then 4 come along in one hour. Just like buses!

  18. I suspect that this will be confined to the area of sea, south of La Restinga in El Hierro. Nicknamed ‘Bob’ as the current eruption is called – we are likely to see him raise his head above sea level shortly. There is a lot of earthquake activity to the west of the Island and some have predicted an imminent eruption there but this cannot be confirmed as yet. When you say isolated to the Islands – one island – El Hierro. Nowhere else needs to worry at this stage (my view).

  19. Got it… Hierro in the Spanish dictionary is IRON, but its slipped its meaning to really mean the island.

      1. Wikipedia suggests that the island is not rich in iron.
        http://en.wikipedia.org/wiki/El_Hierro#The_name

        one of the references says it is absent on the island and that the origin of the name “El Hierro” (The Iron) is a mystery, th eother reference says there is no sign of any ore.

        don’t know if that affects any thoughts on the melt composition?

      2. looks like I got a link in the spam folder (or possibly it bumped further down the page) – but there is apparently no iron on El Hierro despite the name.

  21. Here’s a thought: In the last few days, we’ve been identifying and talking about two types of lava – rhyolitic and basaltic – and how there is evidence that they are mixing.

    One assumption has been that the two types of lava are from two different ‘layers’ of magma, an older one and a newer one (as suggested by the quake pattern in the last few days which have suggested the rise of a ‘second ball’). For the purpose of illustration, this hypothesis would look something like this:

    _/\_
    Surface
    —————————–
    El Hierro volcanic “plug”
    —————————–
    “old magma”
    —————————-
    “new magma”

    However, what if we are talking about is not a ‘layered’ situation, but rather a lateral division, in which the new quakes, centered mostly north of Frontera are not only a ‘new intrusion,’ but also a different magma type (Basaltic) compared to a ‘lighter’ magma south of la Restinga, which is causing the gaseous eruption and rise of ‘bob’

    I guess this is the ‘lava lamp’ theory, if that helps explain what I mean. In lieu of a better graphic interface, here’s what I mean (looking NE from from SW of el Hierro):

    North side _/\_ South side
    surface
    ———————————
    Crust \plug/ /
    —————– /
    / Rhyolitic Magma zone
    Basaltic Magma /
    zone |
    -mix zone (16-22km deep)-
    |
    |

    Apologies if this makes no sense whatsoever. Just doing some ‘blue sky thinking’…

    1. The bottom graph didn’t come out right, trying again:

      North side _/\_ South side
      ……………..surface…………………………ooBobo……………
      …..———————————/…………oo*ooo………………….
      …..Crust ..\plug/ …………./…….oooooooo*…………
      ******************** /ooo*ooooooooooo*ooooo
      *******************/ Rhyolitic Magma zone oooo
      Basaltic Magma ****/oooooooooooooooooo*ooooooo
      zone *************|ooooooo*ooooooooooooooooooo
      *****o***o**-mix zone (16-22km deep)-oo*ooo*ooooo
      *****************|ooooooooooooooooooooooooooo
      *****************|oooooooooooooooooooooooooo

      1. Your best bet is to draw it in a graphic progr, save it as a jpg or png, upload to tinypic and drop a link here.

        Html doesn’t treat ascii art very well unless its in the preformatted text tags and I don’t think the forum package supports that from user postings. (Security issue)

      2. I can’t say something about your thoughts, I have to think about it, but the “design” is +1! 🙂

      3. Josh, I think you are fairly close to the truth with that one, but I think reallity is even more complex. But you are definitly presenting the best “picture” so far of it.
        Good thinking there ol’ chap!

    2. It’s feasible, if the second batch of magma had another source – e.g from the old El Golfo volcano or direct from the mantle; or, it comes from the same source as the old but found an alternative route round the first.

      Both scenarios are possible if this is a rift / fissure eruption.

      1. But I would put the old rhyolitic stuff under Tanganasoga or the summit of El Hierro.

  22. Parece un “Coco partido a la mitad, yo tengo una mas pequeña que me trajeron del Hierro, ovalada, y con grietas en una de las caras. Preciosa y extraña, jamas habia visto una piedra volcanica como esta, pues tengo Piedra Pomez, piedra de Azufre , Obsidiana y algunas otra mas, muy corrientes en las erupciones de la isla de la Palma y de En las Cañadas del Teide en Tenerife.

    1. it is like a half coconut, outside white and inside black ( darker), and with superficials griets in both sides. ( I hope that descripcion will be good…)

  23. Como veis, mi analisis es sencilamente la vision de una amante de las piedras. Mi una ciencia se limita a una gran fascinacion por la Geologia y los Volcanes. Pero soy totalmente profana en la materia.

      1. así es divertido leer la diferencia de google produce!

        Hola, estudio Espanol en la escuela, pero hace muchos anos. Me gusto leer la lengua una vez mas !

  24. Giggletrans from:
    http://www.lavanguardia.com/vida/20111103/54237478866/los-cientificos-sobre-la-actividad-sismica-en-el-hierro-por-la-liberacion-de-energia-actual.html

    “”As hours passed, it appears that the seismic activity on the island of El Hierro booming again. In this regard, the Directorate General of Civil Defense and Emergencies of the Ministry of Interior has warned the State Committee for Coordination of Volcanic Risk, which follows the evolution of the seismic situation in the island. It seems that a new eruption could be a matter of a short amount of time. Without going any further, a little over 24 hours to two earthquakes of considerable magnitude (4.4 and 4.3 on the Richter scale) have shaken the place. The activity is now concentrated in the north of the island, unlike the first eruption was the south of El Hierro as the main protagonist. According to scientists, a significant amount of magma would be looking for a solution to the surface. “We believe what is happening in northern intrusion of magma, an episode similar to what happened in La Restinga, but with much larger magnitudes,” he told LaVanguardia.com responsible for the scientific dissemination volcanological Institute of the Canaries ( non-tip), David Calvo.
    “By releasing energy that we are seeing could be a rash of more entity. We are seeing a large supply of energy and that can translate into an episode of greater strength. This, however, does not necessarily imply that more explosive . But more entity, simply, “he adds. Interestingly, both situations (which is now living in northern and El Hierro and lived, and still continues in La Restinga) could be connected. “The two earthquakes on Wednesday that they have done is to change the pressure conditions within the system, and that today has come back bubbling in La Restinga and the tremor was again felt in this area. Very likely Both the north and the anomaly in the south have some sort of deep connection. The building would be doing screen island between the two, “says Calvo. “””” end of quote.

    1. Yes, they do seem connected – I’m uncertain about an eruption to the north/west. I think the extra pressure is forcing the magma through to ‘Bob’ which I believe is going to break the surface soon – hopefully relieving some of the deeper pressure in the system. Her’s hoping. (my amateur view)

      1. I would be concerned if we saw shallower EQs , but the zone above 15km is silent. Maybe there are mag.<1.5s up there that cannnot be resolved. But to get large amount of magma to the surface quickly we should surely see some sort of trend to shallower EQs. As 15km is the approximately the lower bound of the crust the magma has long way to rise, and the likely route is through a labyrinth of dykes and sills not up an established magma chamber and conduit.
        How their scientists have linked two EQs to increased acitivity of the tremor beats me- I guess they have better data.

    2. They would appear to be connected by a large magma reservoir(s) and a N_S rift. The magma reservoir seems to be centred under or very close to the NW ridge.

      We have seen de-gassing / mini eruption to the south of the ridge which had a very defined EQ pattern and we are seeing similar EQ activity to the north of the ridge. Possibly another de-gassing episode. Whether and how magma is erupted will depend on where it finds an exit route(s) – which no-one can reliably predict with any accuracy.

    1. I like the bit about the Cabary Islands are an “….ultraperipheral Spanish region…”
      As in “out of sight out of mind” I think.

    2. But they only studied La Palma, Lanzarote and Tenerife. They did not study El Hierro, primarily because it has not erupted in the period they were looking at. Three is a very small sample to generalise from. El Hierro is a younger island than these three and has a different history, including a long period since its previous eruption.

      However, they did note that eruptions tended to be basic magmas ranging in intensity from strombolian to violent strombolian, originating scoria cones and lavas. [And] in most cases, historical eruptions occurred on the active rift zonesalong eruptive fissures, occasionally generating alignments
      of cones.

      So just in case you can extrapolate the findings of the study to El Hierro, emergency planners need to take this into account.

  28. Christina,
    I’ve tried above. But there will be other views . Thats science.
    Peter

  29. I think that Katla is looking for attention. Please give her some. Then she’ll hopefully takes a beauty sleep again.

    1. I’ve just listened to the news on RTVC and they discused events and there was no mention of anything being seen.

  31. This reminds me of after EJ waiting for Katla, expect the unexpected?
    The reason I put that as a question is peoples thoughts are interesting.

  32. After the eartquake today which was between Gran Canaria and Fuerteventura please could someone look on the graphs for Fuerteventura and confirm if these are harmonic tremors on Fuerteventura or are the graphs just picking up movement from El Hierro.

    Thanks

    1. Not an expert but it looks as thought they are picking up the activity at El Hierro.

    2. I think its just the harmonic tremor from El Hierro which is showing up. But the strange thing is that the tremor signal on Tenerife (CCAN) seems to be smaller than the ones in Gran Canaria (EOSO) and Fuerteventura (CFUE), even though Tenerife is closer to El Hierro. But it might be that the graph on Tenerife is adjusted/downscaled or something?

      1. Possibly due to the location of the stations and how the signal is transmitted through land and sea.

    3. I believe that the narrowband tremor you are looking at comes from very deep in the source that is currently feeding the El Hierro event. It’s just got bigger because the flow recently got much bigger. It’s is present on all the islands seismographs except one where I think they may have a high pass filter in use. You might do such a thing if there was a lot of locally generated noise like pile driving.

  33. The big jump in higher frequency energy at 19:46 UTC may be of significance. I recall a post from early on in the El Hierro event that the onset of higher energy peaks steadily pushing into the 7ooo hz range would precede a shift in the behavior of the eruption. See if it keeps up…

  34. The recent 14km quake is interesting because it is right out on the tail of the N-S depth distribution. This tail is slowly but surely extending north and up. I wonder if we could ultimately see a submarine eruption well to the north of El Hierro. The best of all possible worlds.

  35. X1.9 solar flare 20 minutes ago, so now things are going to happen.

    Or maybe not 🙂

  36. The IGN earthquake map shows the depths in NS and WE vertical sections.
    These are not to scale with the map of Hierro:
    http://www.ign.es/ign/resources/volcanologia/html/eventosHierro.html

    This photoshop gives the depth scales expanded to match the scale of the map:
    http://s1122.photobucket.com/albums/l533/pecodwn/?action=view&current=EQmapJlyOctdepthsectionstoscalewithmap.jpg

    Its nowhere near Lurking’s standard – the blobs have swollen – but gives a better assessment of how far magma has to go to reach the surface.

    2. Very uselful, I did the same treatment for myself on the 3 day image and it gives you a goof feeling for what is down there, especially when you realize the island is only about 1.3km high.

  37. A R3 radio blackout did result, affecting HF radio and nav for about one hour, so yes things did happen :p

    Geomagnetically, we should be seeing some lovely auroras further south than usual…

    1. The spot that flared just rotated into view in the last couple of days, so any associated CME likely isn’t headed straight for us — still, it is a monster set of spots, so we may yet get some good auroras out of it as it rotates to put us in the bullseye.

      2. Yes, that site and VE3ENs solarham.com are two of my favorites space weather sites! 🙂

      3. This subject has cropped up over last few days, and not gone down well. I realise that this time was about Aurora borealis, but i set up this after the discussions 1 or 2 days ago. Due to work constraints it took me till now to actually set it up and just looked for a post of signifigance to add it to. Jon and others had a bit of a go on the subject being used on the blog here, and i agree there is a place and time for things, so just tried to be helpful.
        I know some experts in Geology hate the two subjects being linked. I think some dooms day sites have not helped thou.
        I have no intention of upsetting anyone

      4. Im going to try and do john a favour here.
        I know some on here really are against any discussion on solar influence effects geology here on Earth.
        To stop this site being blocked by arguments for or against this theory a forum has been set up to discuss any possible effect Solar energy has on earthquakes and volcanoes.
        I have an open mind as data is not clear enough to prove either way, some do say gravitational effects ( like those effecting tides) have some small effect.
        Discussions for an against will be allowed in the forum set up elsewhere at http://www.floodwarn.co.uk/forum/viewforum.php?f=42
        I think that is a better place for people to voice their opinions and collate any evidence either way on this subject. That will allow discussions for what the forum here is set up for to be used in the proactive way it was intended and yet allowing those with opinions on subject to still voice them.
        Solar storms effecting Geology on Earth can be discussed here at http://www.floodwarn.co.uk/forum/viewforum.php?f=42

      5. I think they were just discussing an interesting solar event and the prospect of a nice aurora. No one mentioned geology. I think you were jumping before you were pushed.

      6. Thank you for the suggestion… however I don’t believe there was any intention to tie this mention of solar flares to the discussion of space weather/geology theory. Rather it is a discussion on the effect of solar flares on instrumentation, emergency and radio communication. The well documented and widely known effects of solar flares on GPS and communications is not only pertinent to this discussion, it is important as well.

        To ban all discussion of other scientific disciplines based on the idea that someone might mention an unpopular or disproven theory would be counterproductive to true scientific research and emergency planning, wouldn’t it?

      7. Well, this was just about watching northern lights – if not live, then Diana told us about a webcam in Reykjavik, where you can see them:
        http://www.earthcam.com/cams/iceland/reykjavik/
        I also remember Renato once mentioning that he was watching Northern lights on the Jokusarlon Mila webcam.

        Absolutely nothing about geology there, but to some extent you are right that this is somewhat off-topic for this blog, except that you can see them vicariously on icelandic webcams…

      8. @Brian Smith

        “I think you were jumping before you were pushed.”

        No, I think it was an opportunity to point out an alternate location to air out that topic.

        Almost every time the sun comes into discussion the geology aspect usually winds up getting mentioned by somebody.

        Theres nothing wrong with setting up a site to catch that discussion topic. I don’t buy into it, but some do. No reason that they can’t have an area to talk about it.

        BRAVO ZULU to pyrotech

  38. Update 03/11 – 20:44 UTC :
    Pevolca has decided not to change their opinion. No evacuation will be organized and they stress that there is NO risk for the population at the moment (source Diario El Hierro).

    1. The decision to evacuate or not evacuate is one only they can make… But I believe it is a grave error to state that there is NO risk to the population.

      Absolutes have been know to make absolute fools out of those who make them.

      1. Oh I don’t know if it has to be Absolut, I turn into a pretty good fool with Jim Beam.

    1. Just a bit of more energy in the Búrfell strain. The scale on the corrected strain is very small right now, so pretty much anything will look big. When a real transient happens the scale on the corrected plot jumps into hundreds in value.

      1. I didn’t mean that I thought it was an eruption coming or something 😛 Was just wondering what it was?! 🙂 And, well, I got the answer 🙂

      1. I think, they say more like: “it could perhaps have a new source of material there”. Just a hypothesis.

      2. Google translates this as:

        “Cracks found in the north of the island by the rising material

        The ship of the Ministry of Education and Science has collected samples in the Gulf.

        Research continues on land and at sea with the ship’s ministry of science and innovation, the Ramon Margalef docked this morning at the Port of Los Cristianos in Tenerife. This is a technical stop to collect material and to relieve the crew. New scientists, including several from the University of Las Palmas, have jumped on board to begin the third phase of the campaign in El Hierro. Yesterday they were inspecting the Gulf with good sharpness and geologists have discovered new generation material, magma that for a few days could be coming in the bottom of the sea.”

      3. Jón;
        This could actually be a first step of confirmation that you where absolutly right.

        “Yesterday they were inspecting the Gulf with good sharpness and geologists have discovered new generation material, magma that for a few days could be coming in the bottom of the sea.”

        Sounds like they have found fresh magma on the bottom of El Golfo. And sofar Marglef dudes seems fairly reliable.

    2. If I understood correctly, she also seemed to think that the EQs in NW and W FRONTERA represented rebound from the gas emissions at Bob.

      Aren’t the EQs rather large for that as we are not seeing a large jacuzzi yet at La Restinga; also they preceded the re-emergence of Bob.

  43. Is this Bob or Bobette ? A different vent ? Maybe closer to the surface – it seems more concentrated than previous jacuzzi

    1. The images is of Bob getting towards the surface. I would guess that Bob is about 80 – 100 metres from the surface, at 50 – 75 metres Bob will start to look like Surtsey.

      2. According to this article,
        http://www.sciencedaily.com/releases/2011/10/111028103304.htm

        “Bob” sit at 300 meters deep with a cone of 100 m height, two weeks ago. I suppose that o have to grow so much, will be huge the ejected material needed for that.
        You really think he is a that depth? I have some doubts, I think if it was just 100 meters from surface as you say, we would see more and larger stones, and more steam at surface.
        But I’m just guessing, you know more of this science than me.

      3. Good for science daily.
        Admiralty chart have the depth 180 metres, do I trust the Royal Navy, yes. Do it trust spanish authorities on the canaries? NO!
        So, 180 metres plus 100 gives a depth of 80 metres. And coincidentally that also corresponds to the pictures from the Marglef.

      4. In December 1998 a volcanic eruption started about 10 km W of Terceira Island, Azores, at depths ranging from 300 to 1000 meters. The volcano never made up to the surface, but the material that appears on the surface was more significant than what we have seen in La Restinga so far, a lot of “Lava balloons” and steam. Of course, there are not two equal volcanos ….

  44. looks like its “clipping” for 5 mins with lower acitivity going on for 10 mins. This seems go on a regular basis. What can cause this?

  45. I was just trying to make an image, to scale – an elevation to show the depth of EQs at La Frontera and the possible magma chamber – just to show the difficulties in assessing where an eruption may take place. Many have made the assumption that there is a linear relationship between the location of earthquakes and where it will erupt. In reality the complex structures below the island make it impossible to predict. Unfortunately my skills are not up to drafting this – anyone want to have a go ? I made a simple graphic just to show myself that these EQs are very deep in relation to the island above.

    1. I think if you look at any of Lurking’s 3D videos, they show exactly that (I think he keeps the depth scale the same as the geographic map scale, i.e. the 1km in x/y directions is also 1 km in z direction).

      1. Not usually. That’s why I like to toss the island itself on top for visual reference. That’s also one reason why I designate what the units of the vertical scale are in. For me, typically km.

        If you are interested in getting the scaling dead on accurate so that the x, y, and z take up the same amount of visual space on the plot (a real pain) I recommend

        http://www.csgnetwork.com/degreelenllavcalc.html

        From there you will find that one degree of latitude at 27.5°N is 110.81 km and that one degree of longitude is 98.81 km.

        Other units are available. (miles, feet, nm etc)

      1. Please note that Lurking also provided a similar graphic matching EQs to the Petrology paper.

      2. That’s what I was looking for – thanks Peter but again the graphic appears to show almost vertical routes to the surface – when I would expect there to be lateral routes also. I know that this is bvery difficult to plot. I hear that they may have found some material at El Golfo today – so I may have to eat my words anyway !

      4. errr -yes ! It started moving – not good after last night’s suggestion by someone to check out the flight simulator on Google Earth. Spent an hour trying to land at El Hierro airport, then went to my bed only to be flying around the room for another half hour – not pleasant !
        It is more likely to be a much more complex structure underground than has been previously presented. Thanks for the link to the image Carl

      5. Aha, Calabi-Yau. Essential for M-theory: 7 extra-dimensions of space everywhere……..but really tiny. A challenge to visualise, even to Lurking.

      6. Seven room-dimensions and 4 gravitational dimensions and super-symmetric in size, so according to M-set theory both the sub-planckian space and the universe are at the same time the Same Calabi-Yau room simultaneously representing itself as the micro and the macro spacetime continuum. Quite brilliant theory.

      7. I’m more a fan of Lisa Randall. Two branes are enough for me. Wonder if that’s where those neutrinos went?

      9. The petrology she found means that the route from the mantle has to be fast – days to months -so the magma does not linger at shallow depths- hence the direct route up above the crust. Of course it will be more tortuos than straight pipes – its a cartoon! – but the important thing is it comes up without lingering much, and probably as fissure eruptions.

    1. http://en.vedur.is/weather/forecasts/atlantic/#type=prec
      I always look at the above precipitation chart because it has barometric pressure as-well as rainfall. IE :- the precipitation hammers the ground, close isobars in the barometric pressure equals stronger wind. Basically the chart I have linked to at the moment says yes the weather is bad enough for effect on sensitive tremor ‘ equipment.
      Note:- Always make sure the chart is on its earlyest setting at the time slider , that is more or less current weather

    2. There was tremoring at Krafla (Carl said so).

      With Eyjafjallajökull (Eystri-Skógar), I am not sure. There was a lot of wind in the region and still is. Depends on if the station is down in the valley, or more like up in the mountains. Would make a big difference. There were gusts today, past weather constellations and wind are not so good to see at IMO, better at vegag: http://www.vegagerdin.is/umferd-og-faerd/faerd-og-astand/faerd-og-vedur/sudurland/linurit/st029.html – 2:00 am: around 30 m/sec., and this station is at Highway No. 1 down in near the sea.

    3. Hey Ursula!
      Krokottuvötn is real, that is harmonic tremoring from north of the transverse graben of Krafla. It is tremoring from the same part of Krafla that erupted in the Krafla fires. Notice the station directly south of it, that one is quiet. It does not tremor together with Krokottuvötn since the Graben reflects it away. But, if it had been wind noise, then both would have shown the tremoring. Nope, that is Krafla awakening again.

      Eystri Skogar, well perhaps, but more possibly it is the huge storm that saturated Jóns Helicorders yesterday.

    2. That is the first surfacing of volcanic blast on that video. Significant moment?
      Also the rock pyroclast he was holding looked like halestone, rings like tree rings, that is very interesting. Leads the question does it form like a halestone in any way?

      1. We need an interpreter, please – what did he say?
        Was that baby Bob burping at the end of the video?

      2. Yes it was, after that was archival material. But that was Baby Bob.
        Also, and more important. That was a confirmation of the high rhyolitic content in the fresh eruptii from Bob mixed with basalts. They are also now worried about an explosive eruption, when Bob surfaces.
        Not an exact translation, but pretty near.

      3. He also described it as white spongey material, said it was the first time anything like it had been seen and would tend to describe it more as rhyolite than the other.

      5. just translating what they said. Might have been the presenter who said it, but it was definitely said.

      6. Dude… that’s not good.

        The white material is swirled around with the darker material… not broken off inclusions stuck in the black material. That means that it is definitely mixing and that both were in a melt state at the time that thing congealed.

      8. Looks like a rhyolite chippolata in dark skin- made as a continous rhyolite sausage, then pinch off balloons. Nice and fresh too? That process could be very local – hence why its highly unusual. Does not necessarily mean all the magma is rhyolite enriched under Hierro.

  48. The seismographs for El Hierro, La Palma, La Gomera and less well at Tenerife show a lergish EQ at about 18.11 but it doesn’t appear on the IGN list of EQ’s. Any idea why this would be?

    1. Perhaps it was obscured by the HUGE tremor that occured at the same time? Or perhaps it wasn’t a quake at all but just the tremor showing on the other stations?

      1. I suspect – but Jon will know -that the tremor is so big it hides the EQs so they cannot be resolved. Mag<1.5s have been hidden for days, now it couldbe larger ones getting lost in the noise.

  49. Milagra, Brian Smith , Ursula
    The original quote said nothing about Aurora and seemed more about effects on Geology, i added it below….
    xxxxxxx says:

    November 3, 2011 at 20:51

    X1.9 solar flare 20 minutes ago, so now things are going to happen.

    Or maybe not

    Plus the fact was lots of comments one or two days ago.
    It was coments prior that put me to add forum for subject, but working for a living means things are not done straight away, Seems when someone on here tries to be helpful they get shot down.
    Not quite what this blog used to be like. Attitudes have changed on here by some which is a shame.

    1. Pyrotech,
      ‘Not quite what this blog used to be like. Attitudes have changed on here by some which is a shame.’
      This is what we thought when we saw your post. Obviously we are all a little on edge. Can we call it quits?

    2. I don’t really think it has to do with attitudes in general. The topic came up hot on the heels of the Doom Preacher.

    3. Actually I think the additional forum is a very good idea. Cross disciplinary studies in science are always contentious – I’m sure Galileo, Copernicus, Einstein and others would be glad to know they were not the only ones who ever got into a heated discussion regarding theoretical discussions! 🙂 Free thought is fun thought and a dedicated forum is a delightful idea…

  50. Interesting comment from Avcan in Facebook, few minutes ago. I would like your opinion.
    “To those who wonder where can open the possible eruptive mouths or cracks in case of a hypothetical eruption … seismicity is leaving very clear that it will be along NNW-SSE axis, with an error of 1-2 -3 km on each side depending on the dip of the fault, dyke or fissure, with the highest probability to the left side, which it seems that dips to that side … (Enrique)AVCAN”

    2. For those of us who have trouble with directions is left on the West or on the East? And, could he give Longitude & Latitude?

      But, yes an eruption could occur anywhere along the N-S rift (what he calls the NNW-SSE axis) in the areas where the EQs have been occuring.

      Little Bob is to the East of the Southern end of the N-S rift, but he may have siblings nearer to the rift.

      1. As maps are aligned to the North pole (more or less), the directions are as follows: left is west, right is east, north is up and south is down.

        And when they are talking about an axis NNW-SSE, it would be an axis N-S tending in the upper part just a little bit to the west (left) and then logically, because it being a straight line, tending in the lower part just a little bit to the east (right). But this is just a imagined line, as of course natural phenomena normally are not geometrical. But if you take a ruler and place it in the general direction of the earthquakes in El Golfo http://www.01.ign.es/ign/resources/volcanologia/jpg/Eventos_HIERRO_2D.jpg, you should – I think – be touching Bob yngri in el Mar del Calma and that would be the line, they are talking about.

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