Earthquake swarm on the Reykjanes ridge

16 Replies to “Earthquake swarm on the Reykjanes ridge”

1. A cpuple of biggies, M2.5+ at Katla overnight. They are not revised manually yet. Time for Katla to get her star?

   http://shrani.si/f/D/hj/32PWxE4k/hvo.png

   1. Yes… Tuesday
      22.09.2015 02:15:36 63.617 -19.119 0.1 km 3.3 99.0 4.2 km NNW of Hábunga

   2. And yes, there it is, a star for Katla! 🙂 For the first time since I remember, we have 3 stars at 3 volcanic systems, within 24 hours. 🙂

      http://shrani.si/f/2s/AH/3zA6q149/1509220825.png

      http://shrani.si/f/l/da/3HGs3ac0/1509220825.png

2. A 3.3 near Habunga, which volcano could that be?

   1. You trollin or asking for real? 😀

3. I was asking for real! When I posted that none of the above posts were visible.

4. Would the event at katla be geothermal since the depths are not very deep

   1. Could just as easily be simply tectonic since there was no tremor detected.

      1. I don’t really know how to read the tremor plots, but there’s a spike yesterday evening and again early this morning. Is this harmonic tremor – and therefore magma on the move? (I think I understand what HT is, but I’m not at all sure I can spot it on the plots.)

      2. PS, on the Godabunga plot.

      3. The spikes are just the quakes. HT has a very distinct and obvious signal. 🙂

      4. Ah, great – thanks Down Under. I’ve searched off and on for a picture that shows what HT looks like on the Icelandic plots but haven’t been able to find one. Do you happen to know of one and if so, could you provide a link, please?

         Cheers.

      5. If one thinks about it, the term ‘harmonic tremor’ is kind of self-explanatory and is ever present, everywhere, all the time. I guess you can think of it as a very deep continuous hum (far too low and faint for the human ear, of course). It’s when the harmonic tremor picks up (at the different measured frequencies) that one can suspect something is going on in the crust.

         Earthquakes show as distinct spikes in the tremor plots, while HT shows in the ‘fatness’ and rise of the graphs over a longer duration.

         I often go to this site and scroll through all (well, not everyone is presented) the stations, looking for something out of the ordinary.
         http://hraun.vedur.is/ja/oroi/allarsort.html

      6. Thanks very much, Z. As I said, I think I understand what harmonic tremor is – and you have confirmed that I do – Result! 🙂

         I’ve been watching the plots and lurking around here and VC for several years but I’ve never been confident that I have grasped the elements of differential diagnosis that would enable me to say that I have actually *seen* the HT that others refer to. But I’ll keep lurking and, hopefully, learning.

5. I’m back from work. I’ll write about this later tonight after a I’ve gotten a little time to rest.

   1. On your work Jón and the number of sheep, was it a good haymaking season in Iceland?

      http://www.youtube.com/watch?feature=player_embedded&v=W59Q_m7zv_U
      (Haymaking season in full force on the dairy farm Kvíaból in Þingeyjarsveit district, north Iceland, busy cutting grass, drying it, and curing it for hay.)

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