Special report: Update 3 on El Hierro eruption in Canary Islands, Spain

I am going to fully integrate Canary Islands into my watch volcano monitoring system in the beginning of next month, but Canary Island won’t be part of my emergency system until I move to Canary Island (that is because of technical reasons mostly). When that happens, blog post regarding earthquake and volcano activity won’t be a special report. Just a normal blog post as with Icelandic volcanoes. I am doing this as I plan on moving to Canary Islands in about 10 years time (+- maybe few years depending on how my plans work out). A name change on this blog is planned in the beginning of the year 2012. But it takes a while for me to think up a new name for this blog.

The eruption in El Hierro volcano continues at the same phase as before. With little change so far. Currently the eruption seems to be in two vents, as it did when it started on Monday. There have been unconfirmed reports of new vents opening up closer to the coastline. But given lack of direct evidence that should be there. I do not believe that a new vents have opened up closer to the coastline so far.

Deep earthquake continue in El Hierro volcano. But that means a new magma is coming in from the mantle and is flowing upwards into the volcano. For long as deep earthquakes are being recorded the eruption is going to continue. It is impossible to know for how long this inflow of magma from the mantle is going to continue. But this means that the eruption is going to continue for time being. With the risk that new vents might open up at any time on and around El Hierro volcano. This inflow of new magma has also been confirmed by GPS measurements on El Hierro volcano (the island). But since the eruption did start, no major change has been seen on the GPS real time data.

The harmonic tremor in El Hierro volcano yesterday. Copyright of this picture belongs to Instituto Geográfico Nacional.

The harmonic tremor in El Hierro volcano today (until 21:20 UTC about). As can be seen by comparing the pictures between today and yesterday. Not much has changed since yesterday in terms or harmonic tremor. Copyright of this picture belongs to Instituto Geográfico Nacional.

If a eruption vents open up on a land. The following eruption is going to be lava only. No volcano ash and no explosions as El Hierro is a shield volcano like the one on Hawaii and that means only lava eruptions. If a eruption vents opens up on the shallow coastline, there are going to be explosions for as long the ocean water can get into the crater. The moment it closes up the explosions stop and lava eruptions starts.

Please note that I am on slow internet connection (3G). So I am not going to post anything if the internet connection is really slow, as sometimes seems to happen. I am going to try and solve this issue by using my 3G phone and connect that way. At least I am going to try and see what happens.

Blog post updated at 03:20 UTC on the 15 October, 2011.

598 Replies to “Special report: Update 3 on El Hierro eruption in Canary Islands, Spain”

  1. Henry Seamount together with the larger seamount to the SSW are remnants of an older volcanic episode. You can also see more seamount to the SSW trending downwards. Those are not produced from the current hotspot activity, those are believed to be from an earlier subduction phase if I understood things correctly. They are much older than the canaries.

    1. On my map Las Playas is 10km northeast of La Restinga. If that is where photo was taken then I’d supect this is a new event as the current runs from there to La Restinga (on the surface at least) But is ther another Las Playas?

      1. If that stain is 10 km away towards the “wrong” volcano I would be surprised to say the least. But… Volcanos do odd things.
        I still believe more in “The beach of La Restinga” untill proven wrong.

      2. It’s in other place but it’s not volcanic, the place is very shallow and it was allways there!

      3. I noticed, but… Doesn’t Las Playas simply mean “The Beach” and it could be Las Playas des La Restinga? Or in english, The beach in the Resting-place.

      4. But there is also an area on El Hierro named “Las Playas” – it is on the map: on the eastern coast, at the bay where the landslide has been.

    2. It looks new in the photo: i.e. no obvious spread from another area; and, if you enlarge the photo, there is a slight impression of the spot rising from below.

      1. It’s old and not volcanic… this is a shallow spot with remobilized sand, a beach… i see it in old pisc too.

  2. Maria,
    But there are lots of ‘Playa’ s . Are we absolutely certain where the photo was taken ? There will be local people reading this and it would be best to be confident where it is – can you ask the photographer where he was standing to take the photo?

    1. I totally agree with you Peter, let’s not get to excited.
      To me it looked like it was photographed from roughly around where the gas-bubbles where photographed, but at an angle down-wards.
      But confirmation is definitly needed.

    2. I trust fully in Tibi Perez Garcia and I she has just said to me that she was in the lookout’s beaches ( mirador de las playas) en El Pinar ( El Hierro)

      1. Thanks María!
        Then the eruptions seems to have taken a really unexpected turn if it has gone towards El Pinar volcano. If it keaps on trending towards that direction with new vents it is not good at all.

    1. Juan Ramon Marcelino commented on Avcans facebook page: “Also this place is one of the few places in El Hierro where there are sandy beaches when the swell is up sediment. In those days we had northeast swell. It could be this.”

    2. Aha, the very identical site – so a normal upwelling of sediment? Panic over. But best to be vigilant.

      1. But a little more upswelling of sediment than in earlier photos.

        Not saying that it is a new site but could this be a result of (new) currents caused by the eruption at existing sites?

  3. I see this comment: It seems that the tremor continues to fall as well say here that the deformation decreases, and earthquakes. If this is so, the eruption is ending so you do not see a course islet.

    Ok, this is supposed the eruption is ending or only decreasing, to increase latter? Thank’s to all!

    1. Normally the eruptions in the Canary Islands lasts for 2-3 months, and 50% have multiple vents,…..

    2. Luisport, remember that it seems that the tremor decreases every time a new vent opens up. I do think we had a new open earlier today at 10.54 and another at 13.23 local time.
      The spectral lines are the same as when the main vent opened up, and they both come with decreases in tremoring after. This according to records seem to imply that we now have 3 vents, maybe a forth that opened as the tremoring started (but I doubt it).



      And the opening of the first fissure vent that has given us the pyroclasticos des lava-bombicos…

  4. Meanwhile – is all the activity at Hengill man made? Are they being allowed to cause all those really quite big earthquakes so ner to Rekjavik?

    1. According to The Other Lurker there is no fracking or CO2 pumping going on now. So the activity this weekend was due to other factors.
      My interpretations is that the fracking done before destroyed the lining of either the fissure or the magma reservoir, or both, and what we are seeing now is “blocking” as the lining falls in on itself. This could potentially be very dangerous, and any fracking right now would increase the problems a lot.
      They have also stated that when/if they start the fracking again, they are happy to say that it will cause earthquakes up to 6Ms…

      1. They expect up to 6! They are mege irresponsible. Why doesnt the Icelandic Government stop them!

    1. No, that is the cumulative seismic release. Ie, the amount of energy that has been released through the earthquakes. So it cannot go down. It shows the amount of energy released through earthquakes before, and during an eruption.

      1. It is relevant in such as it tells how much cumulative seismic release it took before this eruption started. Then you will know how much it will take the next time around, whenever that will be. But for the current eruption it is irrelevant. But, if you all of a sudden see it go up it could be new magma, or a new onland vent opening up.
        But mainly it is interesting for predicting future new eruptions. Grimsvötn is pretty much on a clockwork on cumulative seismic release. As soon as it passes a certain value it erupts all over.

    2. In the absence of a legend to the graph I reckon it is a plot of the cumulative energy released by the swarm of earthquakes, incremented daily. The magnitude of the EQ and the number per day will give the amount of energy ( Joules?) by which the plot increments. EQs are infrequent at the moment so the plot has flattened off. It wont go down. Not sure what happened to cause the jump in the gap. A legend would help.

      1. Carl,
        It does not seem to me to add up – there were only about 20-30 shallow, fissuring EQs on 9th Oct and all low magnitude. Yet prior to 9th there were thousands contributing to the accumulated energy. The ‘jump’ is not in proportion at all. ???

      2. It’s the cumulative energy, so the strength of the quake is factored in! And, remember, M3.0 quake has ~32 times more energy than a M2.0 quake, and 1000 times more energy as a M1.0 quake.

    1. Interestingly there is a green band in the water along the west coast of La Restinga peninsula. Is this coming up from the main plume or are there vents that close to the coast already?
      What time was this taken, btw?

    2. The lookout’s beaches ( mirador de las playas) en El Pinar looks nice and clear. Do we know what time the picture was taken?

      But, as Ursula has commented, the green band hugging the west side of the ridge is interesting; it seems to have a focal point west of La Restinga. New activity or just local sea currents?

  5. http://www.avcan.org/

    On this at the moment there are clearly 2 lines of quakes visible now, from the same centre in El Golfo to the south of the island…

    I still see the main source as being in El Golfo, with the island tilted(?) so that the magma follows along below the sedimentary layer as the path of least resistance, coming out on the far side where the new land is forming from the outlets of lava etc.

    Eventually, if the El Golfo shield volcano still exists, there may be an eruption to the north of the island. This is just speculation, and I don’t know anything really.

    1. Hi Alyson,
      But they are still deep:
      and small, less than m2:

      I’ll add my bit of amateur speculation.
      Until we see EQs appearing above 8km I dont think we have any idea where an eruption could occur. Even then it may not happen at all.
      This EQ swarm might be normal nonproductive behaviour.The youngest lavas recorded are between Frontera and Sabinosa , but they are 12000 years old or more. So Hierro could have undergone hundreds of the EQ swarms we see now – how could we know? If uplift was 30mm in each swarm then one every century over 10,000 years would only uplift by 3metres. I dont know if that could be detected – I’ve not read of it. This could all go quiet and Hierro waits another century …..or maybe not.
      The 15-minute periodicty of the submarine activity suggest to me that the effusion there does not have the magnitude of heat flux/power an island-forming, Surtseyan eruption would have. More like a submerged geyser.
      Would be good for the island if it is.

      1. There have been shallow EQs in the area Alyson is discussing. Take a look at avcan.org and run the animacion (note it now takes a long time to run so you may just want to look at the cummulative to date and then end of days for starters).


    2. May be speculation but I can see why you are doing it, especially if you look at the whole sequence of the quakes from 19/7. There were also several shallow quakes near Frontera, which have not produced an eruption.

      But there have also been shallow quakes on the NW ridge and near the summit of El Hierro.

  6. I found this clip on Youtube.
    Kavachi in the Solomon Islands.
    I think it may be similar to what is happening off the coast of El Hierro. The ridge that has formed is really interesting.

    I am amazed that divers would actually enter the water near a volcanic happening as these have done. Careless comes to mind! Still I appreciate their footage!
    The other thing that is interesting are the fish!(I am a biologist!!)
    Some Tuna type fish in a shoal feeding maybe on the smaller fish and crustaceans etc disturbed from their seabed homes by the general turmoil caused by bubbles. Then come the Barracuda type pack, scavanging on stunned or dead or dying fish?
    Of course I am just guessing as I do not have a correct time scale for the clips.
    But it is interesting to see that the fish have not avoided the area of the eruption despite the gas bubbles and other possible toxins.


    1. Amazing video, Diana! Thanks.

      But, bubbles and green spot, just as now at El Hierro and these people actually go and dive there, wow.

  7. I think that’s close to the definition of ‘intrepid’ (without trepidation)

  8. Has anybody here any experience on column of water of 150 meter with a serious lava fissure beneath? Shouldn’t there not be glow visible at night ? This is super clear water or will the erupted material block all light ?

    1. Armand,
      Fig 6.18 here:
      Right panel- about 1.5% of green light would get to surface of clear, oceanic sea water from 150m. But turbidity kills transmittance hugely – left panel. And red light (650nm) is about half green: no more than 1% in clear water. But the current might provide a viewing angle free from sediment clouds and at night the dark-adapted eye has excellent sensitivity. On other hand getting the right viewing angle free from surface reflection means going out there, at night….

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