Special report: Update 5 on El Hierro eruption, Canary Islands, Spain

This is a special report on the eruption in El Hierro, Canary Islands, Spain.

From the harmonic tremor data during the current eruption in El Hierro. It seems that the eruption has dropped in strength during the past 48 hours or so. But that most likely means that the current eruption crater is closing up. But this does not mean that the eruption is over, as new fissures might open up without any warning close the El Hierro Island or on the island it self. It is impossible to know that for sure at this moment. As it currently stands it is unlikely that a new Island is going to form offshore of El Hierro island, as the current eruption crater does not seem to have the energy to break the surface of the ocean. Earthquake activity in El Hierro volcano remains about the same as it has since the eruption did start on 10 October, 2011.

Harmonic tremor in El Hierro volcano at 18 October, 2011 at 23:26 UTC. Copyright of this picture belongs to Instituto Geográfico Nacional.

For the moment, the only thing that can be done is to wait and see what happens next. But it is clear that the eruption in El Hierro is far from over from the data that I have seen so far. But this eruption might pause for days to weeks, as that is not uncommon thing for a volcano to do during a active eruption cycle.

101 Replies to “Special report: Update 5 on El Hierro eruption, Canary Islands, Spain”

  1. And yet again I post on the end of a thread.

    Brought forward from there to here.

    Using the latest data from Prof. Sagiya’s GPS network, and obtaining daily rates both from actual measurements and interpolated 2 day rates for missing data, I then took ten midpoints for those stations and the average rate of the two endpoints in order to lock in a more realistic deformation set.

    The reason is simple, DPlot uses a simple quadratic function to fit the surface (that or linear) and there is no way to account for the stiffness/pliability of the crust. I don’t have the skill needed to fabricate a more realistic deformation model and am not really sure how I could apply that to a spread sheet once I figure it out.

    Meanwhile, this should be closer to reality that my previous vertical deformation plot.


    1. Great plot.

      From this it looks as though the parts of the island (north western ridge)which were the remains of the old El Golfo caldera have dropped in relation to the north eastern ridge (Tinor volcano) and parts of the southern ridge, while La Restinga has risen.

      This fits with the theory that Bob is a new volcano (or at least a new flanking volcano).

      Where do the IGN GPS stations sit on this plot? I am a bit puzzled by the pink areas.

      1. There is only one IGN GPS station on the plot with firm positional data, FRON. HI01,02,03 are estimated locations from one of their graphics, and HI04’s location is anybodies guess.

        Prof. Sagiya provides location data for his stations.

        I included CHIE seismic station for reference.


    2. I am curious also, the data from IGN FRON HI04(especially) looks different .. obviously(?) you are using different data ? Could you post a link to Prof. Sagiya’s GPS network ?

      Robert Somerville

  2. Hmmm – I wonder if it’s significant that the areas showing the greatest subsidence are all along the ridges above the areas that have historically failed at Las Playas and El Julan. It could be just a cumulative effect of interpolating the data, but if not an artifact might indicate a compaction – perhaps due to the large number of earthquakes…

    1. Well, there was inflation, and then the system started emptying to the South.

      What I find more interesting are these

      10/18/2011 0:57 30.1 km
      10/18/2011 10:25 23 km
      10/18/2011 12:56 20.1 km
      10/18/2011 13:00 34.2 km
      10/19/2011 2:08 19.6 km

  3. Quite stable tremor during the last 24hours. The subsea lava eruption seems to have settled at a lower steady pace than in the initial days starting on monday a week ago.

    1. A day or so ago, the entire spectra shifted to a higher frequency and has been slowly subsiding ever since.

      This shift could be seen on other seismos in the area, and I did cut baselines on a few of them. EHIG was a total wash and was seemingly offline at the time. (La Palma). EGOM was up, as were a couple of other stations that showed the shift.

      Since both of my other TMA style cuts used EGOM and EHIG, I didn’t feel comfortable in presenting those baseline cuts. They both indicated a source somewhere in the known venting area, so there wasn’t much more that they could have added.

      This summary is an FYI for anyone who was interested.

  4. Hi guys!

    I wonder if the ideea that El H vent closing is a real one….
    What if the case is that the vent becomes so open and due to the type of volcano that is in fact is in a stable system only??? I mean it expels lava as a shield volcano does…smooth….the water around is in a hot state in a larger area therefore that jacuzzi is only in the top of vent….
    Am I so wrong?

  5. Update 19/10 – 07:41 UTC: Scientists are quoted as “a new step could be visible in 48 hours. The volcano may close the current rift, he opens a new one even on land or the eruption is simply shut down forever. Everything is possible in the development of a volcano.

    1. Giggle translation:
      “”GUERRA PEDRO No trace of basalt. Scientists studying the volcanic process that occurs in El Hierro for ten days, with tremors felt in the island that have caused a seismic crisis since last July, have not yet found the magmatic material has been ejected in the other eruptions along the history of the Canary Islands: the basalt. After a preliminary analysis of volcanic bombs were taken as samples in the stain of sulfur Meridian around the island from the Sea of ​​Calm at La Restinga, which have killed many fish of different species, are confident that these stones, thrown to the surface after the emission of gases, are in no basalt, the material was ejected in the Canary Islands and other eruptions that generated these spectacular landscapes of volcanic rock can be seen on Lanzarote, La Palma and even in the same island of El Hierro, whose last eruption occurred more than two hundred years.

      Scientists believe, the material is taken from the sea surface and bottom that has appeared due to the existence of sulfur stain covers the Sea of ​​Calm could be composed of a precipitate of minerals among which are is silica, aluminum and possibly iron. This is a bomb-shaped rocks that have been found in surface after supposedly the underwater fissure eruption produced a hundred and fifty feet deep that have generated gases emanating this material out. They’re kind of all-black rock on the outside and white inside, it also breaks the slightest contact with a solid surface. Outside the black stone, according to scientists, the material is exposed to high temperatures and is burned.

      In any case, given that the eruption of El Hierro is the first volcanic process that occurs in the deep sea in the history of Spain (which can be documented), scientists are puzzled by the absence walking, for the moment, remains of basalt, the detail that would clearly indicate that from the depths of the earth comes out really magma, as in the past has occurred in the Canary volcanic processes.””

      1. No, the eruption has started, but any basaltic component stays on the bottom. The lightweight highly gaseous bauxites though float to the surface.
        No we know that the eruption is a flood basalt of the icelandic type. Eldja and Veidivötn contained in volume ten procent bauxite and olivine lava flows, there they are represented as separate lava streams due to the different viscosity and melting point. Sadly the bauxites and olivines of Eldgja and Veidivötn are not worth mining.
        So hell yeah, there is an eruption, otherwise modern volcanology, minerology, and mining is wrong as sciences and practices 🙂

      2. As I said, your basic bauxite, which is a volcanic material, the same as olivine, but with a aluminium part instead of the magnesium.
        But what those “experts” are saying is BOLLOCKS. Complete and utter Bollocks. Why? Both olivine and bauxite are metall ores WITHIN the basalt eruption families.
        All of the Icelandic flood basalt has large parts in them that contain bauxite and olivine, though not in any mineable quantities on record.

        I am not a geologist, but I horkingly well know my mining…

      3. Could it be that the erupted material is of higher silicat content, like rhyolite or andesite? It seems this is also existing in submarine volcanoes (e.g. Kermadec islands).

      4. Actually it is probably not, rhyolites are often, dirty, ie that they contan inpure ores. Inpure ores often contain rarer minerals like copper, chrome and so on.
        You should also remember that olivine and bauxite are lightweight, so according to that they are often ejected among among the first and most juvenile lavas, and most often from fissure wents where there is no, or little magmachamber involvement.
        At Eldgja and Veidivötn, you first had basalt, then you had episodes of “pure” olivines ejected.

    2. My understanding of the article is that it says that the lava balloons which they analysed were not basalt, but contained silicates, aluminium and possible some iron.
      From what I know, these components you’ll find in magmatic material including basalt and dacite, for example.
      So while they have not found basalt – which is typically ejected during eruption at El Hierro – they may still have found magmatic material. The article isn’t very clear about that.

    1. Wow, this is telling. If more are to come we might have an eruption on land. Cool!

      1. I wouldn’t say it’ll be cool to have an eruption on land with so many people on the island and the kind and exact position of eruption very unclear as it is.

      2. Seen like that, it’s not cool to ride electric bikes with batteries from lithium mines in south africa we don’t know how to recycle and electric engines crafted by underpaid asian friends.
        Someone here saying it’s cool to have an eruption never thinks it in a disrespective way towards the locals. Isn’t it cool to have snow in the Alps? Nooooo, there are people dying in avalanches… It’s not necessary to live only in moan for all the bad that can be interpreted in anything. Don’t think we are cold or insensitive because we enjoy watching the power of nature.

      3. Inge I didn’t mean to sound angry or like a teacher. But I work in hazard prevention, and it’s my passion for nature that motivates me to understand hazardous phenomena, and it’s this understanding that makes me competent and efficient when it is about analyzing situations and deciding to close roads, evacuate people or take measures. I take protecting people and their goods very seriously, but I couldn’t do my job if you took me the passion, and with it pleasure, to observe nature and her impressive powers.
        That’s why I “defended” our friend “looking forward” to an eruption. Don’t take it bad or get me wrong.

      4. GeoLoco, I like your example of snow in the alps and the risk of avalanches. Of course we all want nobody to be harmed and I would be happy if there never was an avalanche ever again but it is one of the risks in life that all humans must weigh up and make their own decision about. Similarly people from La Restinga would love to go back to their homes but have to live with the fact that at the moment it could be very dangerous indeed to do so. Also if another volcanic vent opened on land then people perhaps in another location may have to evacuate and whilst I sympathise with their plight if such a thing should happen, still the fact remains that we humans are puny in comparison with the awesome power of nature. As no human has any influence on a storm or on an eruption then personally I don’t see that such a fact should stop our enjoyment of watching the power of nature, whether it be unleashed in a storm or a volcanic eruption. So like you I would take no offense at someone calling such a thing ‘cool’. It really doesn’t mean they are an unsympathetic person in my view.

      5. There’s an even harder point in some living situations. The island wouldn’t be here without eruptions. It’s terribly normal to have eruptions on an active volcano. Who doesn’t notice he’s on a volcano when he’s on Bob’s daddy can’t really blame anything else than himself for such an “incomplete” perception of his environment. It’s fabulous luck that modern science allows to warn habitants before they die. We have to learn some basics again. Mankind has to adapt to nature. Our silly trying to change our environment to meet our wishes for comfort will not go on for eternity. Don’t want eruption, try not to live on a volcano. Don’t like rockfall on your roof, keep away from big walls… Afraid to slip on snow, wear decent shoes. 2 days without an iPhone or 3 days without easyjet are NOT the end of anything. Humility. A sense for reality above the perception of average occidental citizens that base their view on the 30 calmest years in earth’s history (speaking of natural hazards, 1960 to 1990, I think we could say). Erm, yes, you know what I mean. No point in insisting about that.

    2. That is close to Jon’s earlier predicted site. However, there have been earlier ones near there before Bob burped.

  6. Experts concerned with abnormal seismic activity – Azores

    Posted on 13 October 2011. Tags: Azores, CVARG, Fogo and Congro lakes, João Luís Gaspar, Sao Miguel, seismic activity

    Experts in the Azores have alerted the population of São Miguel Island for seismic activity which they considered to be above normal. The seismic events where located in the system of Fogo and Congro lakes, the central region of the island.

    “The situation is ongoing and the number of microseisms is slightly above reference values” said Wednesday João Luís Gaspar from the Center of Volcanology and Geological Risk Assessment (CVARG) of the University of the Azores.

    He also said that the seismic activity was the result of “very low magnitude earthquakes” adding that “none of which have been felt by the population.”

    Declining to comment on what the evolution of the crisis could be João Luís Gaspar recalled that “seismological activity is difficult to predict,” but that the possibility could not be eliminated of an earthquake occurrence which may be felt by the population. He said, “It does not mean it will happen; only that one cannot eliminate that possibility.”

    According to the CVARG website, the Fogo-Congro system is one of the most critical seismologic areas of the archipelago where accumulated tensions exist resulting from the lithospheric interplay of the Eurasian, African and American plates.

    The Azores are sitting on the so called “Azores triple junction” area where the North American, Eurasian and African plates meet. This area is responsible for frequent geological and volcanic activity on the islands. Periodic volcanic eruptions and earthquake events, with occasional tidal waves, can have devastating effects on the Azorean islands.

    1. Yet another crisis. Oh, no!
      I have friends living in San Miguel.
      Obrigado pelas novidades, só espero que permaneçam por aí.

      1. It will be ok Renato…we can’t change, end it or hurry it up. You are a wise man and know the difference, besides the sheep said it will be ok.

      2. Don’t worry, Renee, I was just thinking about the nights spent awake over El Hiero and the fact that this would start over again.

    2. So may be it is plate movement that is causing the magma movement in El Hierro?

      @Renato Rio, good luck to your friends. But the authorities are monitoring the situation; they have published the report.

      1. No. El Hierro is located inside African plate. But this earthquake and volcano activity in Canary Islands is because of hot spot activity at that location.

    3. The Fogo-Congro IS the tripple junction, and the hotspot is right under it… Not a good place to have an eruption. It is like Bardarbunga of the Azores.

      1. Meh, they are on a rift in the MAR, two of the icelands are on the american plate, the rest are either in europe or in africa, depending on side of the pentupple junctioning maze there.
        For all intents and purposes, think Iceland, but that started where the see is lower, so not all of it sticks up out of the water. Then you have it 🙂

        Azores is my second volcanic place, and also has what is probably the worlds largest caldera.

  7. Looking at the combined results of Lurking’s plots of horizontal and vertical displacement, the following seems to be occuring:

    – the north west ridge moving downwards, with SABI moving SE and FRON moving SW. Note SABI and FRON may be showing more vertical displacement than the surrounding areas, but can’t be sure of that;
    – the north east ridge has not shown much vertical displacement, but VALV has moved SW
    – in the southern ridge REST has moved upwards; initially NW, then SW.
    – PINA may have moved downwards, but has moved SW.

    Most of the island seems to have moved SW, with the exception of the end of the NW ridge which has moved SE. This raises the question of what is happening between SABI and FRON on the north west ridge. Could be plate movement in addition to magma?

  8. @ Lurking:

    I understand you are still searching for FRON-IHo4. This I posted a couple of days ago but don’t know if you saw it. It is worth a try:
    Maybe you (or someone else who speaks spanish) could ask the Instituto Geográfico Nacional (IGN) directly about this, if the location is not secret they might tell you.
    Email adress on this page:

    1. If it’s of any use, here is what AVCAN just said about HI04, including its approximate location:

      FRON – HI04: No ha parado en ningun momento y sigue hinchandose, acelerandose en los últimos dias, ojo a este sensor que puede indicar algo importante en esa zona, habra que estar muy atentos a este sensor situado al Noroeste del Tanganasoga, en la zona de costa (Enrique)

      FRON-HI04: Did not stop for a moment and continues inflation, which has been accelerating in the last days. Keep an eye on this sensor, which could indicate something important in this zone. Pay close attention to this sensor, situated north-east of Tanganasoga, on the coast.

      1. Hi Jon and all contributors to this blog! Excellent updates and comments shared!

        Ursula, ‘Noroeste’ is actually Northwest.

  9. AVCAN data are now updated today at IGN deformation, where you can see that the continuous deformation, indicating that the supply of magma from continuous depth, which are corroborated by deep earthquakes located and LP seismogram possible. – FRON – Alájar: Follow the same, does not rise, but not down … about 40mm. – FRON – LPALM: Unchanged, socila with a pulse but still … I 40mm. – FRON – IZAN: The system reaches 45mm, 7mm and low back up to 41mm. – FRON – HI03: still swelling, 36 mm in maximum. – FRON – HI04: There has stopped at any time and still swelling, accelerated in recent days, look at this sensor may indicate something important in this area, there will be very attentive to this sensor Northwest Tanganasoga located in the coastal area (Enrique)

  10. Jon, what specifically draws your focus to the Canary Islands, in terms of your planned watching of them? Do you have a particular interest there.. e.g. future volcanic activity on Tenerife / Teide? Landslides? Tectonic processes in the area?.. just intetested 🙂

    1. Black/dark on the outside and white on the inside?

      Thats sort of like what a methane hydrate looks like. But those things evaporate out the gas and the ice melts when you bring them to the surface … nothing much left other than a collection of sludge after that.

      “They’re kind of all-black rock on the outside and white inside, it also breaks the slightest contact with a solid surface”


      1. Look sort of (but is not) our Silfurberg (e. Icelandic Spar; kalcit or kalkspat)

    2. Possibly the 3km thick layer of sedimentary rock under Hierro has something to do with this. Some of it is limestone which when heated would release CO2. Perhaps that when depressurised created the ‘aerated’ material? Is it siliceous, or magnesium/calcium-rich?

      1. They are mainly silicate alumnium oxide with a iron silicate oxide coating. It is a version from the bauxite familly.
        I have baught a couple from El Hierro to have them analyzed fully. What I want to know is gaseous contents, and a bit of other things like istotope decay series.
        They are definitly not carbonitic, so they do not have anything to do with anything sedimental or organic.

    3. These stones are just what is left from the smoking lava bombs (the “pyroclasts”), I think – or did I miss something important today? Please tell me, I can’t wait!

  11. Some guys are saying they could be rhyolitic magma? Is it possible?
    There are fearsof an explosive eruption, but many contradictions over AVCAN blog.

    1. At first thought until now I don’t see an obvious reason why the composition of the magma should have evolved. But I must admit I don’t know a lot about the Canaries.

  12. OT: Been planning my trip to Island this coming summer…been a frequent guest at this lovely site. Many thanks to you Jon for all your efforts!

    Want to share an absolutely smashing timelapse on Island…some volcanoes can be seen too:

    1. Thank you for that Link Johan.
      What an exquisite Video. I think the most beautiful I have seen yet. Truely Iceland is beautiful and all thanks to Volcanoes and the sub Arctic weather. Mother nature may dish out some fierce and frightening events but, by Golly! she more than makes up for them in sheer, unadulterated beauty.

      Oh! and I recommend the glimpse of super fast SHEEP! 🙂

      1. It’s not mine, but I have been at some réttir – as the round up events in Iceland are called – too.

  13. And from Irish Weather on line – one more to add to the Atlantic islands movements:

    ‘A 5.2 magnitude earthquake was recorded along the southern Mid-Atlantic Ridge at 11:40 AM GMT (06:40 AM EDT) on Wednesday.

    The quake was centred 544 km northwest of Edinburgh (pop 271) on Tristan da Cunha, often referred to as the world’s most remote inhabited island.

    The earthquake was measured at a depth of 2 kilometres, according to the EMSC. The USGS put the depth of the quake at 9.8 km (6.1 miles).

    Tristan da Cunha is located midway between Cape Town, South Africa and Buenos Aires, Argentina. Queen Mary’s Peak (6760 feet or 2060 meters) on Tristan da Cunha is an active volcano that last erupted exactly 50 years ago in October 1961, causing the evacuation of Tristan da Cunha’s residents.’

    1. Evening Lava Lovers
      Total shot inthe dark here, but could these rocks be derived from somewhere in the Jurassic sediment pile as ‘baked/superheated’ limestone/evaporites, cos they look remarkably like the lavas from Ol Doinyo Lengai -the carbonatite erupter in Africa, NO I’m not saying these are carbonatites just cooked carbonate/silicate material; floating ? from CO2 release from high temperature degradation of carbonate material at c800+deg C
      Still nothing I’ve seen in UK media about El Hierro or EfððBob

      OT now, a site I like looking at – Iceland’s roads!
      Has a gorgeous Icelandic term for ‘wet snow’—–Krap (!!)

      1. Yes, there is a sedimentary basement below El Hierro …
        you can actually see it on the available seismic, except where the landslides have mangled/distorted the imaging .. don’t remember where the geologic description & seismic was but maybe back a few days ago on this blog …

  14. Que the earthquake swarm at Katla. Though still only poor quality there seems to have been a few deep quakes tonight, one in the centre of the Caldera. Should these be confirmed i reckon a swarm will occur within the next 3-5 days.

    1. Not the stations Lurking was looking for. These stations HIE01, HIE02, etc. belong to “INVOLCAN” and they are geochemical stations. They have a similar code but with an additional “E”.

      Lurking was looking for GPS stations as HI04 , etc., which belong to “IGN”.
      But seems that absolutely no one can find their exact locations…

  15. Hi sheeps counters!
    I think that somebody on El Hierro area got some insomnia and start to count too many!!!
    Tremor increase easly…
    She/he should let them sleep not to force all this jump around, aren’t they afraid of wake-up that naughty volcano???

  16. This morning on a Christian Talk show we heard,” This will cause a tidle wave that will wipe out the whole east coast. From Miami Fl to New York City “. What is wrong with people to tell others one tiny nation will be the end of life as we know it here?????.
    This makes me CRAZY, what ever will be and happens is going to happen. NO one can make changes and we all have to accept it. GOD is in charge.
    California has had rummbles and quakes and every moron will tell you its going to fall off in to the ocean when the next one hits, crazy is crazy and you just have to ignore it.

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