Off-topic discussions for weekend 43

This is the off-topic discussions for the Weekend 43. Everything volcanic or earthquakes around the world.

Let the discussions begin.

48 Replies to “Off-topic discussions for weekend 43”

  1. @Jon Why the move to Denemark I thought that in the future you’d mentioned that you wanted to move to Italy…but I could be wrong.

    1. @renee, I dedicated this after a advice from Boris. As it turns out Sicily is a bit of loose and a hard place to live in. So I need to prepare a bit more before I can move to Sicily. So I did make a new plan. Move to Denmark first and then see if I am ready to move to Sicily, Italy in five to ten years.

      I also need to learn Italian before I can move there, as english understand is a bit low in Sicily according to Boris.

  2. Jón: I have a question concerning Indonesian and Icelandic volcanoes. Feel free to answer it whenever you please:
    I understand that the type of magma in both volcanic zones and concentration of populations nearby make a big difference, but do you have records of any Icelandic volcano erupting as dangerously as present Merapi’s eruption? So unpredictably?
    Thanks in advance.
    PS: Wish you luck with your plans of moving to Denmark. But just don’t leave us!

    1. @Renato Rio, Last dangerous eruption (explosive) was Eyjafjallajökull April – May 2010. But it was dangerous in different way then Merapi current eruption.

      But last really dangerous explosive eruption in Iceland took place in 1727 to 1728 when Öræfajökull erupted. But that eruption was smaller then the eruption that took place there in the year 1362 (June to October). That eruption had pyroclastic flow(s) according to GVP. More information can be found here on Öræfajökull,

      I am not going to stop watching Icelandic volcanoes even if I move to Denmark.

      1. By the way. I am estimating that next eruption in Öræfajökull is going to take place around the year 2070 – 2120. But I don’t expect to be alive to see that. But I hope that my grand children do (If I have any that is).

    2. Dunno, but Jón might.

      I read about an eruption in Iceland that very nearly closed the harbor of one of the cities. The thing happened right next door to it. After it was over, the harbor was still there, and better protected from the ocean waves.

      It’s in one of those arcane sites/references you run across when stuff gets to flying about.

      1. i think you are referring to the Vestmannaeyjar eruption in 1973.
        The icelanders managed to restrict the lavaflow close to the town by pouring on large quantities of water.

  3. Iceland too cold Jon? 🙂

    Seems they have installed new stations at Eyja/Katla region; Slysaalda, Rjupnafell, Asolfsskalaheidi. And how come there are so many small spikes in the tremor graphs lately?


  4. As long as this is an OT thread.
    @Renato, I feel the same, it feels like voyeurism in the worst sense, because we watch while people suffer and even die.
    BUT have you followed the indonesians conversations on evacuation routes and their safety? ( I am sure you did)
    If blogs can be used to help, it is a very cool thing. I told you long ago that i saw the earthquake which caused the 2004 tsunami and knew ( even though i am not expert) it would be really bad and cause a tsunami and felt helpless.
    If global communities can provide help and advice for people directly involved, i think this is a very good thing.

    1. @Birgit: I remember telling you I was in Salzburg that day when I saw the huge 2004 EQ . In fact I was also online (maybe you were too) when this 7.7 happened. Though, in this case, I didn’t imagine it would cause a tsunami. Not even a local one. But you are right: we now have twitter that could be a quick way to provide this kind of information, even faster then the far more complicated (and slow) buoy system.

      1. I had been to Hawaii and checked the tsunami musem in Hilo, That why i feared a tsunami

      2. Oh, yeah. Hilo is a tsunami “hotspot”.
        I remember back in 1960, when the Great Chilean EQ struck, that we couldn’t relate Hawaian tsunami to the Chilean quake and we were very intrigued by the “doomsday scenario” set by earthquake + volcanic eruptions + tsunami in differnt parts of the world. Than it was later explained that they had all the same origin.
        Another coincidence: I was online too and saw the recent Bio BIo 8.8 EQ happening before my eyes. And then I “knew” that a tsunami was to be formed, as it turned out to be true.

  5. Hi Jon

    Thanks for this off-topic topic. I was wondering whether Lurking, you might make a chart of the Indonesian volcanic depths – without scaring us all half to death of course?The instability in nearby Indonesian volcanoes and the fairly recent depth earthquakes are difficult to visualize, if indeed they are connected.

    It was nice to see the camera was still working on Eyaf this morning, with the sun shining on the ice and the wider crater without its features of ash and steam.

    1. @ Alyson: which camera did you look at for Eyafjalla ? Wenn I try to acces the Mila webcams all give a notice that they are “upgrading” (?) the camera…

      I miss it.

      1. Yes, that is a great cam site with the visible and IR cams. Well, we can imagine they are making some great upgrades of some sort.

  6. Currently there is a storm going over Iceland at the moment. This storm is big enough to have effect on IMO SIL stations. It also has effect on my geophones as can clearly be seen by the wind that is measured on them.

  7. Magnitude mb 5.4
    Date time 2010-10-30 15:18:42.8 UTC
    Location 56.45 S ; 143.05 W
    Depth 33 km
    Distances 3371 km SE Dunedin (pop 114,347 ; local time 04:18 2010-10-31)
    3395 km SE Oamaru (pop 13,020 ; local time 04:18 2010-10-31)

  8. Jon, when are you planning on moving to Denmark? This is the first I have heard of that. Of course, I have been over on Erik’s blog watching all that is going on with Merapi. I do check here to see what you have to say about what is going on in Iceland. Are the swarms still going on?

    1. @Diane N CA, I am going to move to Denmark in February 2011. I did decide this in September of 2010 so this is a bit of a new decision for me.

      This is will not affect this blog or my measurements of Iceland earthquakes a lot (just a minor for a while).

      But when I move there are going to be less updates on this blog and no updates on the webicorders that I currently have. For obvious reasons.

  9. @ Pieter – I think Bromo was referring to new monitoring stations, not webcams – but the one that Alyson was referring to, I don’t know about, sounds like the regular mila cam.

  10. @luis godinho

    That first link is to the KLA seismo on the SW side of Merapi (if I remember correctly). The smaller events (and some of the larger) have the shape of what might be “tornillos.” I have yet to get an answer on if that assumption is correct or not. If they are tornillos, (“screw shaped” waveforms) then it may signify cracks forming in the area around the magma chamber as the overlying rock adjusts for the additional magma.

    Not being a geologist or seismologist, I can’t give you a definitive answer, so that’s my best shot based on what I have read.

    As for the PACIFIC-ANTARCTIC RIDGE quake, it’s on a spreading center. They have them all the time. Usually you see those on the transform faults (the ones that run perpendicular to the ridge) as the crust overcomes it’s inability to bend to compensate for unequal spreading. (it does this by fracturing) The other possibility is that it was a quake along one of the faults associated with graben movement as the terrain “slumps” down and toward the spreading center. I think that is what happened on the Reykjanes area in it’s recent quakes. How often and how dramatic a movement you see depends on the spreading center’s accretion rate… in other words, how fast it spreads. Faster centers have less time for this to happen and as a general rule of thumb, are smoother, terrain wise.

    MEANWHILE… why I posted.

    The Swarm at the Lake in Iceland seemingly has two distinct groups as I’ve noted before in the plots. (upper and lower) After looking at today’s events and putting them in the plot with the others, in now appears that there are two sub groups in the upper batch. Each with what appear to be different lineaments. Not quite parallel.

    I’d elaborate further, but I have to go repair the toilet. (amazing what happens when someone flushes a candle.. and no, I don’t know why.)

    Quake plots will come later.

  11. Hello, I came over to find out about the Hofsjökull quakes, Merapi is very ugly now, I enjoy the subject of Geology because of the Volcanic nature of the Pacific NW U.S.
    Thanks for your opinions of the quakes, I enjoyed the Eldfell Wiki story, talk about
    making lemonade when handed a lemon..

  12. @Birdseye

    Thanks for your answer, but I believe the Mila webcams are still down unfortunately. Oh and do you know where to find these new monitoring stations? Because I can’t find them at the IMO stations.

    1. Hmmm, that Godabunga plot is very interesting, Bromo. Good observation! I was not aware of that plot, but now I’ll save it. Something interesting to keep an eye on. Thanks!

  13. Jón: Just picked this from an article on Merapi posted by Diana Germany over Eruptions blog, which I found better to post here for us to think about:
    “There is no assurance from the geologic record that Merapi will remain as quiet in the next century as it was during the 20th Century. Rather, it is suspected that a major explosive eruption will occur within the coming decades. Large numbers of people, both within and beyond the Forbidden Zone will be at serious risk. Public education and discussion of the intent of the Forbidden Zone, a willingness among all parties to accept some false alarms, and an ongoing search for precursors of a larger explosive eruption are needed to limit the risk.”

  14. Yes, that is something to think about Renato. I illuded to it on Erik’s blog.

    Jon, have the quakes settled down in Iceland or are they still going on? I have been out of touch with that.

    Be sure to send my your new email when you get set up in Denmark. I think all of us still want to keep in touch with you and I know you will be posting at Erik’s blog. You had better or the rest of us will come looking for you. 😀

    1. The earthquake come in waves. But there has also been bad weather so the sensitivity of the SIL network is a bit less then in a good weather.

      My email address is going to remain the same when I move to Denmark.

  15. A Mag 3+ quake in Katla’s caldera. That’s a lot stronger than the typical quakes there.

    But the GPS’s show no signs of any unusual deformation, so no reasons to be concerned about it.

      1. Thanks for clarifying that, Jon.

        Aha … now see the “quality” of the quake is only “30.7”.

        Earthquake table Date Time Latitude Longitude Depth Magnitude Quality Location
        31.10.2010 02:35:54 63.705 -19.176 19.8 km 3.1 30.69 8.1 km NNE of Goðabunga

        I’m surprised it hasn’t been screened out yet. How long does that usually take?

        How did you identify it as fake? … by the timing with the Blonduloni quake? Or the timing and the “quality?”

        Do Mag 4+ quakes in Iceland often or usually show up as fake quakes being detected at other seismo locations?

        An interesting post would be on the mechanisms of how seismograph stations can be tricked into believing a quake occurred near them, when really it is just an echo or something of a quake that occurred at a great distance away.

        And did the mag 4 quake show up at other areas also as a fake quake? If not, why did it appear at Myrdalsjokull as a fake quake and not also elsewhere?

        Hard enough making sense of all the real quakes in Iceland, now have to figure out if they are real or imaginary quakes. lol

  16. Our hosts first name is Jón Frímann . A double name. I did not get that at first too, but i think Jón Frímann is correct. Right?

  17. Chris: I noticed over month that he gets called Jon so often and i thought thats impolite and wanted to point this out.

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