El Hierro volcano eruptions ends (again)

Based on the harmonic tremor data in the past few hours it seems that the eruption in El Hierro volcano has ended again. How long or if the eruption has really ended now is impossible to know at the moment. However it is clear based on the tremor activity that all eruption activity has ended and it did so suddenly and after sharp increase in activity several hours before that.


The activity in El Hierro volcano today. Notice the spikes when the eruption suddenly gains energy and how fast it dies out based on the tremor data. Copyright of this image belongs to IGN (Instituto Geográfico Nacional).

Even if the eruption has ended. For the moment anyway. The area where the eruption took place is going to have hydro thermal activity for several months to comes, and up to many years if there are any shallow dike intrusions in the base of El Hierro volcano (and Island). I do not yet know if the eruption has ended, or if this is just an brake in the current eruption cycle. But next few hours to days are going to make it clear if this is an break or not. But I would not be surprised if the eruption started again at the same location, or an new one. As this is shield volcano and there eruption pattern often have breaks in them for shorter and longer periods of time.

Update 1: It has been sad that the graph has once again been re-scaled. To what size I do not know for sure. But in an comment on Facebook it was sad to be around -36dB. If that is the case. I am wrongly interpreting the data. Because of that. I have no idea what is going on in El Hierro volcano at the moment.

Update 2: It seems that activity has renewed again in El Hierro volcano. It started around 04:06 UTC and lasted until around 10:00 UTC. Then it started again at 16:00 UTC and is currently ongoing. This is now an eruption that happens in episodes. That means there are going to be longer and shorter breaks between eruptions in El Hierro volcano.


Activity in El Hierro volcano today. The increase in harmonic tremor marks the start of new eruption in El Hierro volcano. Copyright of this image belongs to IGN (Instituto Geográfico Nacional).

Blog post updated at 00:50 UTC on 20.01.2012.
Blog post updated at 19:31 UTC on 20.01.2012.

28 Replies to “El Hierro volcano eruptions ends (again)”

  1. Fonix, since Jon posted a new article, here goes my reply to your previous comment, regarding off-Iceland mainline activity. Regarding El Hierro, I think it is behaving like Hawain eruptions, they keep going slow but for a very long time (even years), pausing the lava eruption once in a while and then restarting.

    “Interesting vortices. I have no idea of what they are.

    There were no never earthquakes detected in that zone out in the sea, although the area of those vortices is far from the mainland and earthquakes could go unnoticed. As far as we know this are is non-volcanic.

    However recently we have seen signs that indicate that there could be more geological activity that we dont know much about it, out there in the sea. Like the recent activity 90km southeast of Hofn, or some earthquakes that sometimes occur south of the SISZ quite out in the sea.

    Iceland has two volcano-tectonic rifts and several off-rift volcanoes, and even old volcanic rifts to the west and north (even active ones, like Snaefellsnes). It could be that maybe there are other volcanic systems further away from mainland that we are not aware of.”

    1. Perhaps the vortices are plankton swirls (just an idea), i had seen something similar in the sea when i flew to Iceland a few years ago!

      1. It crossed my mind that this could be something connected to the fissures that created the Westman islands, Surtsey and some submerged mountains and islands in that area.

        Something plankton related is also not unlikely.
        It is interesting that those vortexes all seem to swirl counter clockwise, as a vortex would do, i wonder if plankton would do that ?.

        http://rapidfire.sci.gsfc.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl2_143.A2010146132500-2010146133000.500m.jpg

      2. Interesting NASA video, makes you wonder when you get roses flowering in january (as mine still are) and the first frost of the winter in my area was last weekend, bring on the cold!

  2. Jon: Compare the CHIE tremor graph to EGOM tremor graph, and the rescaling points become obvious.

  3. The Greeks are at it, too! Hiding data…

    On Dec 21 2011 I provided this link, and asked Lurking to make a plot on Santorini. Guess what, the link has now been removed.

    http://geophysics.geo.auth.gr/ss/CATALOGS/preliminary/prelcat.cat

    The english page does not have any recent data anymore, and the Greek page provides only M3+ data. Seems, they do not anyone outsider to see what’s really going on under Santorini…

  4. Just as an off-topic – Jon – When I look at this blog now people’s names are covered over by their pictures. It didn’t used to be like that, only for the last couple weeks. I can usually guess who is who, but not always……………..

  5. It actually looks as if the eruption is shifting. Harmonic tremor may have ceased but EQ’s are picking up, and this morning there appeared to be a second vent opening (an infrared image on Earthquake-report.com seems to confirm this). El Hierro will stop and start many times before it’s ok to declare this “over”.

  6. CHIE is not the best source to confirm whether or not the eruption is continuing because IGN change the settings. It is better to look at the other Canary stations to see what has happened to the spectrograms below 2Hz.

  7. I use IE 8 and also have the names of posters covered by the logos, however I also use Mozilla Firefox and on this the problem does not exist.

  8. It’s most likely due to recent ie update. Before it thetext column was in centre of page, and everything worked fine, after update half of pages i visit tend to crash/not show correctly etc.

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