Posted on by Jón Frímann

Continued earthquake activity under Blöndulón and in Esjufjöll volcano

It appears that the earthquake activity at Blöndulón and in Esjufjöll volcano has not stopped completely. The earthquake activity at Esjufjöll volcano started on the 20th of October 2010. The first week there where about 70 earthquakes recorded by Icelandic Met Office, the following week there was continued activity but there where fewer earthquakes taking place in Esjufjöll volcano at that time. But the activity had not stopped completely. When this is written there are clues that there is a new earthquake swarm about to start in Esjufjöll volcano. I must point out that so far the earthquake swarms in Esjufjöll volcano have started out slow before they pick up the in size and numbers of earthquakes.

The earthquake activity under Blöndulón lake (man made lake) continues. The earthquake activity is intermittent since it started. But the largest earthquakes that have happened under Blöndulóni lake have reached ML3.8 in size. But the largest earthquakes where felt in nearby farms (up to 80 km away far as I understand). It seems that the earthquake activity continues at this location. But with long stops in-between each earthquake swarm. I do expect the earthquake activity to continue there for coming months. But sometimes it happens that earthquake swarms in the areas outside the main faults take a long time to finish. The longest earthquake swarm that I know of lasted for almost two months. This earthquake swarm at Blöndulón lake might well do something like that. But only time is going to tell us what is going to happen in that area.

62 Replies to “Continued earthquake activity under Blöndulón and in Esjufjöll volcano”

    1. Sorry for the double post. The “plume” seems to be gone by now. No smudge, this time. Maybe some people cooking at the spot.

      3. A beautiful moon is appearing to the left.
        This night offered a beautiful moonlit or maybe an aurora-lit landscape at Icelandic landscapes. Þórólsvell webcam was showing an amazing bright view of Eyjafjallaökul glowing in pink and green hues

  4. Take a look at the view from the Blue Lagoon, just a magic red horizon and the deep blue lagoon water

      1. Thank you!
        Well, than it is probably unrelated. Sometimes when you fill a dam you get quakes, normally both smaller and fewer. My thought was that it might be bigger and more since this is Iceland and not Sweden for instance. But it seems unlikely that it didn’t start withing the first 2 years after the dam was full.
        If it was completed in 1991 it was probably filling for one or 2 years. So it should have started in 1995 latest if it was related to waterpressure.
        Would be a horrible joke if they build a large lake on a budding volcano… Brrr!

  6. Monday
    22.11.2010 03:48:48 63.661 -19.282 6.8 km 1.3 99.0 2.8 km NW of Goðabunga

    A relative deep earthquake in Katla Volcano. It’s near Godabunga, but I believe this isn’t a regular shallow-earthquake. Is this also related to the possible magmatic movements?

    1. Yepp, and a whopping large one ontop of my head too… Minus 20 celcius and full moon and stary sky with a northern light that covers the entire sky. But it is a bit normal for us this time of year… 🙂

      1. This is my first “live” aurora. I’m very excited about that. What a wonderful thing!

      2. I’ve been to Sweden back in the 80’s and didn’t see any of those. But I guess they happen farther North than Stockholm, don’t they?

      3. They happen in Stockholm to, but it need to be winter and Stockholm is a bit to contaminated with light for them to be easily visible. You pretty much have to go outside of Stockholm to get outside of the light-contamination.

        But, the frequency is a bit bigger here than in Stockholm. And there is less light pollution here.

      5. Stockholm is at 59 north, high enough for aurora borealis, but not as frequent as up here at 63 where I live.
        Last year there was one visible down in north of germany.
        It is the intensity of the solar stor that decides how far down you will see it, enough energy in the particles and…

      6. Sorry if I seemed a bit blazé. For me it is a bit like you, and let’s say the Copacabana beach. The beach would impress me a lot, not speaking about all the beautifull women… 🙂

      7. I understand what you say.
        As for Copacabana women, well, I suppose I’ll need some more years to get blazé about them. 😉

      8. Ah…
        Ahem well…
        *sighs*

        And the northern lights are now gone and been replaced with a snow-storm. I really wish I was on a warm beach now with a drink.

  8. A small, but probably very stupid question…
    You guys haven’t hidden a volcano under Reykjavik have you? I just saw two small rather juicy deep quakes just to the south and to the north of you capital. Is that normal?

    2. And I found the answer…
      -Rauðhólar just outside of Reykjavik erupted 4600 years ago, tonight it had one small deep quake. 1.2M quake. Has some 80 craters.
      And Esja (gotta love that name, goes well with Hamarinn!), now it is an unusually dormant volcano (for being in Iceland), in the rest of the world it would be dead. Tonight it had a simultaneous quake with Rauðhólar. 1.4M quake. Even if it is dead we are still talking about a big hulking brute here.
      You just had to hide 2 volcanos just around the corner from the capital.

      4. Wow!
        Big thing then since Rauðhólar is just south of Reykjavik. 5.0 km SE of Geldinganes to be exact.
        Or perhap’s you meant the Rauðhólar of Grimsnes volcano? “My” Rauðhólar is just south of Esja and erupted 4800 years ago. Consists of 80 small cones, probably due to a minor fissure eruption. Some sources call the cones for crypto-craters.

  10. Question:
    Against what is the REYK GPS-station calibrated?
    It cannot be calibrated against anything on Iceland I hope.
    Why is this an issue? Well as you know there where two rather small and cute quakes near Raykjavik tonight. Probably it has nothing to do with volcanism as Jón says.
    But lets play what if..? Let us say that there is inflation under Rauðhólar, that would offset every GPS-measurment in the most crazy ways over all of Iceland AND it would probably go undetected for quite a while if it was slow and small enough. People would instead suspect that quite a few volcanos where active, kind of bring in the usual suspects.
    To paraphrase a bit:
    How do you calibrate the calibrator?

      1. Ah, then it is actually a problem. Because with only relative gps positioning the baseline of REYK is not calibrated to anything that is considered to be “stable”. Normally that would be good enough to determin the movements of other stations. But if REYK start to move the other stations data will be inacurate and will produce false reads.

        I think I can even pin-point a place where that acutally happened. And that is what gave me the reason to ask in the first place.
        Here is the link to the composite 61-day calibrated plot of all GPS-stations on Iceland. Look at up-component, notice that at late december 2007 or early january 2008 all stations on Iceland make a sharp turn upwards that continues for 6 months untill the end of the plot. (Sad that they havent updated those plots for one and a half year. Jón, perhaps you could ask them kindly to do that?)
        http://hraun.vedur.is/ja/englishweb/gps/cts/HM61allallaeq.html

        There are only 2 possible explanations for that upturn:
        1. Massive uplift of the entire Icelandic plate by an enormous increase in heat under Iceland, and/or a glob of lava sliding in under Iceland from west to east.
        2. That for some reason REYK started to sink down.

        Explanation 1 is of course impossible since REYK must be sinking to make the others seem to be lifting. But… Let us speculate that REYK was already lifted by either a “glob” or by mantle-plume or hotspot and what we actually see is the hypothetical “glob” starting to move under Iceland towards perhaps Vatnajökull, or the western edge of the mantle-plume/hotspot finally moving away for good from western Iceland.
        Thing talking for glob or mantle-plume/hotspot would be the eruption at Eyjafjallajökull and the renewed intensity under Vatnajökull. If so there will be interesting times to come.

        But remember, even though that the GPS-data and the sinking of REYK is pretty much a validated thing, the rest is just pure speculation on my part.
        But it also might explain a bit of the odd GPS-behaviour and impossible movements we have seen the last few days. It might be REYK moving and not the Vatna-stations.

      2. I would give away a Third solution:

        3. The western Side of the Icelandic Rift Zone sunk a little bit, and the Eastern side had a small uplift.

        Either way, i don’t think its a big deal, because you can even see, that there seams to be some kind of an anual variety in the data. (visible quite clear here: http://hraun.vedur.is/ja/englishweb/gps/cts/HM61emyraeq.html)

        Final Solution: http://hraun.vedur.is/ja/englishweb/gps/cts/HM61siszall.html

        “Vertical component of the stations since onset of measurements. Jumps in the time series at VOGS, HLID, HVER and OLKE are due to radome installation”

      4. Yes, but I removed the seasonal outlayers from those, my point was though that ALL stations tilted at exactly the same time during christmas/new years 2007/2008. And that can only happen if REYK is sinking.
        Your third explanation would require that the changed movement was larger at the stations to the east than those that are to the west, and that did not happen. So thereby it is “proven” that it is REYK sinking due to falsifying you number 3 explanation.
        One gotta love scientific use of pure logics 🙂
        But I will give it to you that you might be right if we prolong the time scale, but then we are back to number 1 explanation, ie that the movement is transitional from west to east due to movement of either heatplume or “glob” and that it started in 2007/2008 shift with sinking of REYK and that now we have the upligt at Vatnajökull.

        Be that as it may, something happened during the shift, and it might explain an increase in activitu under Vatna.

      6. They changed into radome on some, but REYK was not touched so the radome changes does not explain the shift.
        I still hold to that REYK actually shifted a bit down, which is after all just natural since the hotspot is moving to the east and as it moves away the ground starts to move downwards. But the shift is small, around 5 millimetres under 8 months, but uniformal throughout.

      7. In 2008 there was a Mw6.3 earthquake on the SISZ fracture zone. That might have played some difference into the GPS system.

        But this is old data, it does not go any longer then into 2008. Both 2009 and 2010 is missing from this dataset.

      8. That might really have changed things around.
        Yes, it is strange that they haven’t updated the long composite time-series graphs for so long time. The one day raw-data is still updated, but the 7, 15 and 61 day composites haven’t been updated sin late 2008. And you need the long composites to see trends clearly.
        I wish I knew who to contact to get them to turn on the auto-updater again. I guess you know Jón?

    2. Ah, I think see what you are asking about Pieter. If I may rephrase you question.
      “The green dots show as vertical lines that variate in height, sometimes they are many millimetres, is that the daily uplift or?”
      No, the variating height on the green “dots” is actually the uncertainty level of that reading. Some days the reading is very good with a nice signal and other factors also being good then the “dot” is a short vertical line, other days not resulting in a long green vertical line.
      Ie, it is about the margin of error.
      The slight black dash in the middle of the green vertical line is the probabillity window “hotspot”, ie the most likely uplift value for the orbit.

      Another coment, the green dots do not represent days, they represent orbit-cycles of a satellite. Now we are comming in to orbit-cycle 90 for this year.

      Hope I clarified things for you.

    1. I don’t think anyone is blocked. As I don’t have automatic blocking in place. I have manual IP block. But it is currently not being. I am also not seeing any IP-blocked messages in the error log, a lot of 404 errors. But nothing else.

      It sometimes happens that messages go into the spam box. But I monitor that and recover the messages from that.

  14. Yes I have seen them in Stockholm where I currently live but you need to get away from the \light\ pollution. Up north around Östersund where I originally come from and that’s about in the middle of Sweden they are more common and I have seen them many times especially during the winter.

    1. This was supposed to be in the Northen light part but some how ended up here sorry about that.

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