Posted on by Jón Frímann

Earthquakes in Öræfajökull volcano

I do not have a time for long blog post about this at the moment. But here is a short overview of earthquake activity in Öræfajökull volcano.

Since the year 1991 there have been total of three earthquake swarms (with the one in last week) in Öræfajökull volcano. The two earthquake swarms where in the year December 2005 and in September 2008. Total of 70 or so earthquakes have taken place in this earthquake swarms. But only 30 or so earthquakes in the main crater of Öræfajökull volcano.


Earthquake activity in Öræfajökull volcano between the year 1991 and to 2011. Copyright of this image belongs to Icelandic Met Office.


Earthquakes inside the main crater of Öræfajökull volcano from the year 1991 to 2011. Copyright of this image belongs to Icelandic Met Office.

All pictures are from here.

Currently the earthquake activity in Öræfajökull volcano is quite low. So I am not expecting anything for a long, long time now. The reason why earthquakes are taking place might be new magma. But this also might be due the glacier and pressure changes on the rock because of that. But I find the later idea less likely then the first one. But it hard to know for sure at the moment what actually is the real case now.

319 Replies to “Earthquakes in Öræfajökull volcano”

  1. I see the fireworks on the icebergs. Those people on the ice were setting them up. No UFO…sigh

  2. At 11:00 (Icelandic zime) there is a great firework. I think the ligths are only a little show before…

  3. Hi anyone, @Jon, Carl, Lurker, Jack etc.. Just got an idea. Do not know if it is worth anything, but can not find a reference, if anyone knows (or anyone has seen it open up close). Does anyone know if (when) Hekla erupts, the crack itself, does it open first in the east (east-side) and then extending west, or the other way round?

    Just noticed, the SISZ-crack pattern “bend” just west of Bjólfell. This is visible on zooming-in-on IMO Skjálftavefsjá map, to near the Haukadalur SIL station.

    Hekla is situated on or just east of a bend in SISZ cracks, where crack alignment shifts about 30 Deg (from almost due N-S) to more NNE-SSW alignment. Seems to me then possible movement (perhaps coming all the way from “rubber band” area due expansion) of area North-of-the-SISZ versus “non-motion-of-SISZ” results in Hekla beeing “simply” torn open … If already loaded (by energy punmped in from the SISZ or other source) this might help in overloading its “bottom core”(possibly already “superheated” – but held back by resrainment of non-cracking areas, known to be around Hekla – to bring about reaching the critical pressure neede, causing Hekla “root core” to finally boil and thus creating the needed “from below” pressure…. ???) A pre-warning of this might then be in the form of the negative-transient (pressure relief).

    1. The SISZ in this area is almost in the EVZ that Hekla volcano is most likely part of.

      Since the fissures in the EVZ are in different direction then in SISZ you get this interesting results.

  4. Did anyone else notice the tremor pulse at Katla earlier today, or is everyone too focused on Carl’s Hekla hypothesis?

  5. Is it just me or is Katla departing the normals pattern? Every day there seems to be more and more EQ’s on the map.

  6. Katla seems to be quietly bubbling away as normal to me.
    However I am interested in this really messy chart, It’s in an area that doesn’t seem to have much obvious activity. Are the tremors from water flow such as a river or is there much human activity there?

    http://hraun.vedur.is/ja/oroi/vat.gif

  8. Sunday
    28.08.2011 09:35:04 63.653 -19.098 1.1 km 1.6 75.0 7.6 km E of Goðabunga
    Sunday
    28.08.2011 07:30:35 63.976 -19.974 3.7 km 2.4 90.09 15.0 km W of Hekla

  9. Tiny swarm at Katla, at a unusual place just W of the caldera rim, but just S-E of Godabunga.

  10. Are all small bumps on Jon’s Hekla helicorder earthquakes occurring at Katla? Impressive if yes, it looks like they’re many.

  12. Sunday
    28.08.2011 11:54:44 63.630 -19.308 3.5 km 1.9 58.55 3.1 km WSW of Goðabunga
    Sunday
    28.08.2011 11:53:10 63.629 -19.278 3.9 km 0.4 69.86 1.8 km SW of Goðabunga
    Sunday
    28.08.2011 11:49:08 63.632 -19.282 4.7 km 1.6 90.04 1.8 km WSW of Goðabunga
    Sunday
    28.08.2011 11:49:07 63.603 -19.151 7.6 km 1.4 74.17 3.6 km NW of Hábunga
    Sunday
    28.08.2011 11:41:24 63.629 -19.290 4.5 km 2.2 90.05 2.3 km WSW of Goðabunga
    Sunday
    28.08.2011 11:40:59 63.632 -19.295 3.9 km 0.9 61.3 2.4 km WSW of Goðabunga
    Sunday
    28.08.2011 11:34:22 63.634 -19.292 4.3 km 1.2 90.01 2.2 km WSW of Goðabunga
    Sunday
    28.08.2011 11:26:18 63.634 -19.287 3.3 km 0.9 90.02 1.9 km WSW of Goðabunga
    Sunday
    28.08.2011 11:24:58 63.631 -19.284 5.2 km 1.6 90.03 2.0 km WSW of Goðabunga
    Sunday
    28.08.2011 11:24:40 63.634 -19.278 4.4 km 1.0 51.43 1.5 km WSW of Goðabunga
    Sunday
    28.08.2011 11:19:05 63.634 -19.289 4.7 km 0.0 59.94 2.0 km WSW of Goðabunga
    Sunday
    28.08.2011 11:15:07 63.628 -19.296 4.8 km 0.6 32.47 2.6 km WSW of Goðabunga
    Sunday
    28.08.2011 09:47:52 63.634 -19.196 2.2 km 0.6 99.0 2.7 km ESE of Goðabunga
    Sunday
    28.08.2011 09:35:04 63.652 -19.080 0.1 km 1.0 99.0 8.0 km N of Hábunga

  13. I am going to post a update on the SISZ earthquake close to Hekla volcano later today. But also on the earthquake swarm in Katla volcano.

    I do not see the earthquakes from Goðabunga area in Katla volcano due to human made noise on my geophone.

    1. i am looking forward to that.. ! i suppose that there is something going on there..

  15. The interesting thing with the Hekla earthquake is what it affected.
    Normally quakes in this area causes a transient in the negative at Búrfell, ie. a sharp fall as the mountain “twitches”, this is the normal behaviour for the mountain if it tries to erupt. When an eruption occurs all other borehole strainmeters go the other way, and quite sharply to.
    In this case not much happened to Búrfell, but a heck of a lot happened to Geldinganá instead.
    Sunday
    28.08.2011 07:30:35 63.976 -19.969 3.7 km 2.4 99.0 14.8 km W of Hekla
    Here you have the transient at Geldinganá.
    http://hraun.vedur.is/ja/strain/str_corr/index.html

    It is a transient, but I cannot explain why it happened there, nor can I explain why Burfell didn’t go the other way. It is though really interesting that the strain went up like hell before the actuall quake.
    And even weirder, it fell after the 2.3 M quake and quake swarm at Godabunga…

    I would say that this might indicate that the area from the Sprungur towards Hekla do work as a pressure increase mechanism, and that as Jón said, the SISZ area works as a relaxation area.
    If this is so, I think we know why Hekla is 5 years late for an eruption if one only looks at the inflation rate. The activity at Eyjafjallajökull probably released so much pressure that there was not enough mountain-strain to open up the mountain. Or to use the best metaphor, to squeeze the zit.

    2. You know what that means? Even if the volcanoes are not connected mechanically (common conduits), the strain changes in the whole SW Iceland can “dance” the volcanoes, not only the other way around!

      That’s a pretty spectacular idea, as it adds significant complexity to the behavior of these volcanoes. On the other hand, it simplifies the overall picture as we have something to look for: Developments in strain changes vs. inflation can be used to predict eruptions on the long term (together with quaking activity).

      1. Exactly, that is what I have trying to get at. A uniform theory of strain connectivity between the fault lines and the volcanos.
        But not between the volcanos, they are not the ones really connected. It is the connections between the volcanos and the seismic fault lines I think makes the volcanos “dance the blues”.

        At least Hekla is I think basically an equation based on Influx (magma), tectonic movement and seismically induced mountain strain. If all 3 exist over threshold values you get an eruption.

    1. Interestingly, both the quakes at Hekla and the swarm at Godabunga. They seem to come out of the blue.
      We must keep a watch… and IMO still doesn’t show this last one, probably near Hekla too…

      1. Wind speeds have increased, probably th earthquake could be related to that.

      5. I would say that either they are recalcing them before showing right now, or it was someone slamming a door at the Helicorder-hut.
        The quake at Hekla was preceded by a shift in mountain pressure at Geldinganá. Which is an odd quirk… 🙂

      6. Renato, I am sure I forecast many unusual happenings around the volcanoes this weekend as I am busy and away from PC Most of the time. They always come out to play when I am asleep or busy!!

  17. Usually, during weekends, the doors are slammed at Jón’s helicorders quite often. This fact, plus the winds interference and the time for calculating all the quakes in the swarm have added up to the absence of the “mysterious” incoming quake at IMO’s records.

  18. Yep, that’s the ones, saw them as I was following the eruptive fissure and flow a bit further to the west.
    A

  19. While nwere waiting? There is not much happening at Yellowstone at the moment either, not one tiny earthquake the last week =P

    1. All reports of intense quake-storms at Thingmuli are false. No activity has been reported, sofar, that indicated anything happening at 0200 hours. The lights reported was just a weather-balloon. 😉

    2. No siesmic activity but somewhat rapid inflation at White lake. Ground must be mushy banana huh Carl?

    1. More bad jokes like that and I’ll sing another Queen song (badly):

      “Mama…”

  21. My friends, my hiking continues wild in Iceland.

    Yesterday I went to the top of the most fearful mountain: Hekla.
    Yes, that’s true, I was very undecided whether to go, but the weather was so good that I could not miss the change. The trek is actually easy, the only challenge is trying not to think that it can blow whilst we are at the top!

    Anyways, the top was steaming, as usual, nothing unusual was observed. Snow is still in several patches. I could see many fissures at the top and craters. But nothing unusual.

    I am sure that the 2.4 earthquake is because I pissed near the top of Hekla and she got seriously upset for my lack of respect for her. Or our footprints made some rock crumbling chain reaction, the likes of a butterfly effect.

    I am joking of course, now I feel mush less fear regarding Hekla and I feel I made peace with this volcano. It took me 1 hour down, so yes, you can run to safety if you feel the first earthquake.

    1. Wonderful description Irpsit. of the Mountain not your activities.! Interesting to know what is on the top. You say it is steaming. is that from the crater or just evaporation of snow.

      1. The steaming was from the soil still warm since the last eruption in 2000. There were some holes in the ground that were hot to the touch. And steam coming from it. But this is normal activity, and one can only see this activity from outside the mountain with binoculars, not in the Burfell webcam.

    2. You are a very very brave man…
      And I am not so sure you would have the time to run. Remember that you have to run further than the base of the mountain to survive.

      1. Yes I know. I was thinking about the giant lava rocks being thrown at me. There was no way one could survive. This was the second time I teased a volcano and a volcano teased back at me, within a week. Last week I hike close to Katla when she decide to bump a 2.0 earthquake.

  23. @ Carl
    Perhaps you’ll think me thick, but could you define ‘transients’ please! Make it simple tho, ‘cos I’ve had enough today clearing blocked sewers and ‘molecanoes’ from the lawn!

    1. Here is an image of the mother of all transients.
      It is the recording from the Borehole strainmeters when Hekla ripped open at the start of the 2000 eruption.
      The line that is falling rapidly is Búrfell/Isakot, all the other stations are going upwards with Geldinganá going upwards fastest and steepest.
      This movenet down at Burfell up at Geldinganá is the mountain contracting as pressure is building up almost instantenously and then the pressure starts falling as soon as the mountain is opened up.

      Up untill now we have seen transients like this on and off since January, but with the heavy action being at Burfell, the last day and a half though we have seen the heaviest action at Geldinganá. I interpret that as though something has changed within the montain.
      http://hraun.vedur.is/ja/hekla2000/heklumynd1.html

      2. Hekla’s deep magma chamber already filled, new activity moves away from the mountain?

      3. No, it is just that the other side of the mountain also has started to show “abortion” behaviour.

        Remember all, if both Burfell and Geldinganá has simultaneous and oposite transient we will most likely see and eruption withing minutes (if the transients are heavy enough).
        The 2000 transient was in combine 10e-9, just for reference.

      7. But why would the transient change at Geldinganá if this station is so far away from Hekla?

      8. Real daft question-is/are there map/s anywhere that locates all icelandic volcanoes so us who don’t know the locations do not have to ask, or are there too many for that, even done on a regional basis?
        I recall a week or so ago one of the lady followers I think, asked why no eruptions to the west in Iceland: have a look on giggle earth west 0f Grindavik, Eldvorp fissure-Reykanes peninsula, lovely geologically fresh fissure with cones and flows and near Bifrost – Hredavatn -Grabrok fissure c4000 yrs ago again ‘fresh’.

      9. I do not know why, but it does always move furtherest up when an eruption happens…
        But I have started to think about if it has something to do with filling of a hydro-electric dam or something…

      10. Activity on the west of Iceland is much less often than in the east, having long periods of dormancy, while in the east it is very active and often.

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