Posted on by Jón Frímann

Short update on El Hierro volcano eruption

This is a short update on El Hierro volcano eruption. As the situation is changing fast this past few hours.

It seems that the eruption in El Hierro volcano is gaining strength and power. The harmonic tremor on the seismomter that is on the El Hierro Island it self has started to get saturated again. It also have been unconfirmed reports of the south fissure growing in size. But so far nothing has happened in the north part of El Hierro volcano. Even if there have been many earthquakes in that area. But this area fell suspicious silent this morning. So something might be up in that area. Update 1: A string of earthquakes happened around 12:00 UTC in this area. Suggesting that something is still up there.


The harmonic tremor at 13:52 UTC. Notice how the tremor has started to saturate the seismometer. Copyright of this picture belongs to Instituto Geográfico Nacional.

What happens next is anyone guess. But people need to be aware that fissure eruptions are sometimes long in terms of the length of the fissure. But that phase normally does not last long, as soon the eruption is going to isolate it self into few craters on the fissure. I also recommend that people read Erik Klemetti blog post about El Hierro from yesterday. If you haven’t already done so.

800 Replies to “Short update on El Hierro volcano eruption”

  1. (**) Localización
    1110231 04/11/2011 13:41:16 27.8118 -18.0496 21 Sentido 999.0 null NW

    IGN system struggling.. amazing how much info they must be handling

  4. Reffers to the espectaculars photos of the bubbles in La Restinga, it seems that they are coming to the coast. They were taken yesterday by an Army aircraft (SAR).

      1. There are to many organizations working in Hierro that I no longer know who works for whom, and when, where, anything…and each other seems work on his own way. It is a mess.

      2. Ya know.. I would gripe about the skill of the phonographer in aiming the @#$ camera… but I’ve tried shooting video out of a CH-46 and aiming a handheld camera in a bouncing helo isn’t the easiest thing in the world to do.

    1. Etna is so lovely and spectacular with it’s glowing paroxysms and yet here we are watching Little Bubbly Bob – all because Bob is fresh and new compared to the faithfully volcanic Etna…

      I suppose that reveals a great deal about human nature and relationships. Poor Etna, I will pay attention more, I promise.

      It also reveals that I love anthropomorphic volcanoes…

      1. I don’t think a paroxysm is currently taking place at Etna.
        “Tremore volcanico” are at very low levels.
        Maybe later?

  6. A short note for Jon. Mobile theme looks great, much more readable. But at least my phone have trouble coping with comment when they exceed 500-600. Then the page works better without.

    An for pics above of Hierro subsea eruption, impressive! I do hope this will stay a people friendly eruption.

  8. The new photos on ER posted by Joke Volta makes the jacuzzi look pretty close to the Islandm can anyone confirm is that closer and if so is it in shallow enough water to cause explosive reaction

  9. Difficult to work out from the photos the alingment of the jacuzzis. Anyone got any ideas? It looks like it’s running parallel to the coast. West to East?

    1. Another theory (not mine) suggest that this fissure could be bigger that it seems. That fissure would cross the island from south to north while new extrusions would take place along the fractura. That´s all what I could understand. I´m not vulcanologist. This theory don´t like to me, but my question is: is it a probability?

      1. Yes. In Iceland fissure eruptions have been recorded up to 25 km long. Last time that did happen was in Askja volcano, in the eruption episode of 1960s (If my memory is correct).

        But there would be some warning, so they would be able to get all the people out of the dangerous areas before the fissure would open. At least I would hope so.

      3. Thoughts like this worry me too. Old tubes / caves might under pressure start to serve as new vents. Do you think something like this might happen in the flanks of Tanganasoga?
        Anybody an idea what the 12km quake under T. two days ago has caused?

  13. So, nothing is happening, according to the authorities: turists are welcome to the island and life proceed as normally as ever.
    Preposterous!

  14. Today’s Aqua picture seems to be promising to show the locations of the new jacuzzis (very little cloud over El Hierro):
    http://lance-modis.eosdis.nasa.gov/imagery/subsets/?subset=Canary_Islands.2011308.aqua.1km

    However, annoyingly, if I try one of the better resolutions (250m or 500m) in real colour, all I get is an image that is cut with a vertical line exactly through El Hierro and all is white on the right of this line… Don’t know if it’s my computer or their problem (because other band combinations and NDVI – which don’t show changes in ocean colour – all work fine).

    Can ayone get the full 250/500m images?

    5. I get the same Ursula Grrrrr!
      Having read as much as I can from today’s news it would seem that the general information going out is that the tremors are less, more “mouths” have opened and this is the end of things. Some off shore small eruptions in the sea of Calm which now poses no threats to people either North or South.
      I do hope the authorities will play it safe. As I said in an earlier post the small ash cones are all on land round La Restinga. This fissure eruption could go off then on again repeatedly.
      This is a real mess. A very difficult situation to deal with for the decision makers. A nightmare for the people who just want to get on with living…Safely….They are Damned if they do and Damned if they don’t.

  15. The longer this all goes on, the more concerned i become about the possibility of a huge caldera forming eruption. Or is that just me? 😉

    1. Caldera is not going to form in this eruption. This eruption is not big enough, it is also important that shield volcano calderas form in a different manner then explosive caldera formations.

      From wiki.

      “Non-explosive calderas

      Some volcanoes, such as shield volcanoes Kīlauea and Mauna Loa (respectively the most active and the largest on Earth, both on the island of Hawaii), form calderas in a different fashion. The magma feeding these volcanoes is basalt which is silica poor. As a result, the magma is much less viscous than the magma of a rhyolitic volcano, and the magma chamber is drained by large lava flows rather than by explosive events. The resulting calderas are also known as subsidence calderas, and can form more gradually than explosive calderas. For instance, the caldera atop Fernandina Island underwent a collapse in 1968, when parts of the caldera floor dropped 350 meters.[3] Kilauea Caldera has an inner crater known as Halema‘uma‘u, which has often been filled by a lava lake.

      It is very frequent for a caldera to become emptied by drainage of melted lava through a breach on the caldera’s rim. The Caldera de Taburiente and the Caldereta, both in the island of La Palma (Canary Islands), are calderas emptied by a river of lava some 500,000 years ago.”

      Wiki, http://en.wikipedia.org/wiki/Caldera#Caldera_formation

      I think it is highly unlikely that this is going to happen in El Hierro at present time.

    3. Always good to put in ideas to see what others think.
      In this case, you might not find many sharing this vision.
      If I had to put a bet, I’d see Bardarbunga or Hengill or Yellowstone before a big caldera by the bobbies. But we all were so misleaded through the last 4 weeks… 🙂

    1. So they are on a line along the coast, dirction SE-NW in direction to El Golfo? Are all three new in the last days?

  19. I was just looking at todays Lance image of El Hierro (scroll to the right a bit and then down a bit) and noticed something strange further to the south of the island.

    http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2011308140500-2011308141000.250m.jpg

    There appears to be another ‘green’ stain in the ocean.

    Any ideas on what it is. I myself was wondering about wether it could be from the first stage of Bob. But it still seams too concentrated considering how far away from El Hierro it is.

    1. Yeah, its another vent because there are two distinct plumes and going in different directions due to currents. The one to the north just aint ready for prime time yet.

      Getting there though.

    2. Are those red circles the Jacuzzis?

      If so it’s tracking up the coast… paralleling the scarp face.

      2. How deep are those spots? what do the Bathymetric maps say? Can you enlighten us with an indication and a visual rendering as to what may evolve from these new yacuzi’s close to shore?

      3. I don’t have the actual chart and I don’t know what the bottom contour increment is.

        But the older Jacuzzi down by La Restinga is on about the 6th contour line out from the coast, the two up by Los Lapillas are on the 3rd contour line.

      4. I have a chart, but its a monster format that saturates my system, I’ll try to create one a little lighter.

      5. Its not important to send it. Take a look at the scaling of the contour lines and just state what contour that they sit on.

      1. Yes, but today there are new vents closer to the coast (see my comment with the Aqua image above) and you are measuring the distance to the old Baby Bob.

      2. May be closer, but two red spots on this map are only ~150 meters from the coast, and the another one ~820 meters, honestly I don’t think from the pictures I’ve seen that the “jacuzzis” are so close to shore.

    1. Well, if Bob’s friends are where I think they are… (the J in the screen cap), then I am a bit curious about the outcropping bordered by Bob’s eruption “valley” on the west and the little Bob’s on top. That slab/section could be destabilized.

      http://i40.tinypic.com/2d92r78.png

      2. Suddenly the video doesn’t look so lovely and little :/

        Oh, and Lurking, you’ve mis-spelled “Friends” in the graphic…. 🙂

      3. Could Bob, Babs and Bubba be ‘press studs’ which could pop and cause a flank eruption? I’m a complete novice, so be gentle with me..

      4. In a worst case… sort of.

        But here is an alternate less than catastrophic catastophy scenario for you. Not even a real hypothesis since it’s just me kicking it around an idea.

        The other day, someone made a graphic of how they thought the plumbing system under the island is oriented. Its a good graphic, and fits observation. It’s not proved, but it’s reasonably sound.

        To the southeast is an ancient submarine volcano called Henry Seamount. In all likelihood, it predates the Canary Islands. In some of the literature, the geothermal activity in and around that area supports lifeforms that are usually found around “black smokers” near midoceanic ridges and spreading centers. This is a bit odd considering that there is no spreading center there.

        One scenario to support the geothermal activity, is that water enters the crust in the vicinity of El Hierro and percolates down to Henry Seamount and emerges heated and mineral laden… thus supporting the lifeforms there.

        Now, if this is the case, that means that El Hierro has a pretty porous substructure. It’s the closest island to Henry Seamount and is the most likely source for the water.

        That would also mean that the graphic from yesterday is probably even more accurate since it assumes a similar crust that is capable of moving a lot of water. Per the graphic, the most likely location for the brunt of the magma is down where the big quakes are, and what we are seeing at the Bobs is seeping magma coming up the diagonal tube/cracks and spurting out in the “valley” of Bob.

        Personally, I don’t think that the “valley” is a valley, I think it’s a leftover crack from the previous collapse event (El Julan).

        This … “slab” if it is that, is not extremely large. There isn’t that much for it to cover. If it lets go, whatever is exposed there will interact with the water and it will be a frothy mess. I don’t think that you would see anything that fits the classic “flank collapse kill everything in sight” stereotype.

        No… just a spectacular mess at worst. Move away from it until it gets done and then go about your business.

    1. With regards to your links… I think Bill the Cat put it quite eloquently… “Akk!”

      Solid clipping…. at pretty much the lowest gain settings.

  25. Please dont groan too loud at the ignorance of my question – as a complete begginer I some times find it hard to follow the scientific stuff….

    Can I stop worrying about the folks that live on the Island?

    Does todays eruption mean that BabyBob is now very unlikely venture ashore – do we know/think whether he expending all his energy blowing bubbles – or simply biding his time before going BOOM?

    Thanks to the patient friend who bothers to answer this! XXX

    1. I seriously doubt there is gonna be a “boom.”

      Maybe some serious venting, but no boom. In either case there will be ample time to move away from what ever it is. The only people who will be injured are the ones who venture too close, or who suffer an incompetent decision by an official. Not that they are, but all governments have them and they usually become manifest in an emergency. (Hello Ray Nagin)

  27. Bubbles… shaking… something brown coming out of the ocean… Where have we seen this before?

    Presenting the real Bob: http://goo.gl/OUMYN

    Ok, maybe not, but since it’s not, can we tone down the drama…. 🙂

    1. I don’t see how changes in the dynamic of the fluid mix being the cause of the extreme Doppler shifts rather than a seemingly impossible speed is high drama.

      A chunk/slab/section of a slop being destabilized is also a real possibility, based on the pattern. That doesn’t mean that it is, just that some one in an official capacity really ought to take a look.

      As of yet, there have been absolutely no sightings of Mothra or Battra, so I don’t think he would be coming ashore so early…

  28. By looking for a map, I found these informations about the seamount Henry – I know it’s to the other (eastern) side of the southern underwater ridge. http://www.geo.uni-bremen.de/Ozeankruste/Research/Research_Henry.htm

    But to my inexperienced eye, the ejected products seem to ressemble these of Bob. The material is called Baryte. (Wikipedia: http://en.wikipedia.org/wiki/Baryte ; and more for the specialists among you: http://webmineral.com/data/Barite.shtml).

    Also, there is a little seamap. Perhaps it’s possible to use it and enlarge it.

  31. Just a little bit weekend dancing – and a lot of wind, I’d say. Nothing serious. 25 earthquakes in two days it not a lot for Katla.

  32. ====
    Lurking says: November 4, 2011 at 18:00

    I don’t see how changes in the dynamic of the fluid mix being the cause of the extreme Doppler shifts rather than a seemingly impossible speed is high drama.

    Because its NOT A DOPPLER shift.
    It’s the resonant frequency of the plumbing being affected by the density/stiffness of the fluid contained within (see the physics .FAQ I referenced).

    It starts off with 100% liquid lava, this then starts to foam, its no longer as dense nor as stiff (it will approach “gas” in sonar characteristics). Thus the resonant frequency starts high (speed of sound high = 100% liquid) then slows down (more gas, lower density, lower stiffness). Hence the organ pipe, whilst remaining the same length, resonates at a lower frequency.

    Anyone who has inhaled helium, and talked (here simple density down from molar 28 to molar 4), at a hysterically high frequency.

    NB A good use for helium balloons that no longer support themselves before binning!

    1. “Because its NOT A DOPPLER shift.”

      No shit?

      The term refers to how it was first noted by Carl. Unless you want to come up with a handy way of referring to the observation, like “Bob” or “BobJr.” I’m going to continue to refer to the phenomena as it was first noted.

      If you take a look at the chart I generated, and my comments, it’s pretty flipping clear that it’s not a doppler shift since the mechanics required to generate it as such in the realm of fantasy.

    3. Here, lets try this terminology…

      “Bob’s Tonal Flatulence” -> BTF

      There, better?

      In case you missed it, in order for the BTF to have a moving sound source that generates the observed frequency shifts, it would have to be moving faster than bullets. It would have to be in the realm of rounds from a high powered rifle if not faster.

      1. “Ah” – Yes, had one such moment now. Yes, indeed signs of some magma EXPLOTION(S) in Bob(s) craters then today as well. Not all that good regarding the eruption progress. Looking at some photos from today, I think (almost shure) the fissure swarm runs more or less constant almost to SW coast. BTW, Sonic waves in the air were observed and photographed coming up from the crater in Eyjo eruption.

    1. Yes looking at the 2-4Hz that will be put at around mag 1.0.
      I don’t think Katla is up to much at the moment, just regular small EQ’s.

  34. 11-11-11 is fast approaching any significance? I noticed Portugal’s islands near the mid atlantic ridge having quakes. All the canary islands are too. Water displacement as well as fissures add up to? Why would the US military be on alert status? When I see so-called experts say there is no possible tsunami from an El Hierro eruption well it kind a makes me want to puke! Millions of lives need I say more. Yes, I could be wrong and being cautious and having an exit plan might be for not, but?

    1. Pick up a some new crew members and material, and deliver their findings to the university for further analysis. And weather the storm that took place during the past few days.

  36. @Ursula:
    I did the same exercise also using MODIS / Aqua satelite image from today. But Aqua has low resolution, so it’s difficult and may generate errors whith the Google Earth layer, anyway:
    http://i.imgur.com/Qe86C.gif

    After doing this, I think that what we see an Aqua isn’t a “jacuzzi” but perhaps the debris plume, since the jacuzzi today are not green/brown and Aqua has low resolution.
    If what you spot on Aqua was really an active zone, that would mean that fissure would have some 5km long (distances from red points in my animation). But I doubt it.

  37. I’m off to watch some fireworks and a bonfire of the organised kind with my daughter and some friends now, as it is Guy Fawkes Night here in England. Stay safe good folk of El Hierro.

    Seriously Captcha, Carbon Jacklift???

    1. Er………….5/11/2011 is Guy Fawkes night in England. 4/11/2011 is mischevous night.

      1. You’re quite right! Our local Scout Group had their do a night early, confused myself there for a moment, sorry 🙂

    1. Easiest way to check would be to look at the ongoing amplitide of the tremor on the other islands and see if there is a similar reduction in intensity.

  44. On AVCAN fb people are now commenting that there was a strong earthquake at 20:37 (5 min ago): trembling, things falling off, stones falling, etc. Was felt all over, La restinga, the north of the island, El Pinar.
    No update yet on tremor/earthquake list.
    People joking that since politicans said the tunnel will only close after a 4.5, that of course now the 4.5 happened…

    1. They say this is the longest and strongest they have felt so far. People shaking. Children crying. AVCAN got more than 100comments within 5 min of this happening.

      1. Some people felt it in the car.
        Aha, now at AVCAN they got the info (although not yet on IGN website), it was a 4.4:
        ‎1110303 04/11/2011 20:36:28 27.7645 -18.0374 21 -1 4.4 4 W FRONTERA.IHI

      3. AVCAN comments:
        pictures falling off the walls, hanging lamps swaying half a metre, hearing various rumbling voices,…
        People reporting from all over the island, La Restinga, Valverde, Frontera, Belgara, El Molcanal, …
        They’ve got over 200 comments now, in 20 min since the quake.

      5. So they say, although now the IGN website has collapsed. But check the EMSC.

        Also on AVCAN they say it has been felt in various places in Tenerife, although only by people located in higher floors (e.g. 5th, 6th).

  46. en la fuga de Gorreta ha habido un desprendimiento importante, se oían caer piedras grandes
    There was a landslide in ‘La Fuga de Gorreta’, they could hear great rocks falling somoen in AVCAN-FB says

    They also speak of damage in the Tunnel of Rosquillos

      1. Don’t know is this is the same place, but AVCAN commentors say there have been falling rocks from the El Golfo escarpment (no wonder).

  47. The Spanish quake sight is giving only a 10 km depth for this one, hopefully this will be revised as they usually do. If not this will be a very big problem with such a magnitude and such a shallow depth in this area no doubt already weekened by earlier quakes.

      1. Thankfully 21km depth
        1110303 04/11/2011 20:36:28 27.7645 -18.0374 21 IV 4.4 4 W FRONTERA.IHI

    1. Don;t know, people at AVCAn are also wondering about that.
      But someone said the earthquake was felt in the North of Tenerife, at Los Realejos, about 90km away.

      1. Apparently was felt at La Gomera, Tenerife and La Palma. And of course all over El Hierro.

    2. Hi Una Canaria…The Tunnel will not be closed yet.. it was “only” a 4.4M and the depth was not shallower and the epicentre was not on land…to close it must comply with the stated rules……. It doesn’t matter that rocks are falling all round it!!! ;(

      1. It may be a coincidence but if they did put in some extra attenuation it seems to have changed the spectral record as well with some harmonics disappearing and others changing frequency.

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