Posted on by Jón Frímann

Something odd is going on at Krýsuvík volcano [speculation]

Please note! What goes below here are speculations based on what I am observing. Nothing might happen, but then again something might happen. We just have to wait and see what happens when it comes down to it.

I have been observing a slight change in the lower frequency band (0.5 – 1 Hz) at Krýsuvík SIL station. This change reminds me of a harmonic tremor of short. But it is not strong enough to appear clearly on Krýsuvík SIL station. But that SIL station is directly on top of Krýsuvík volcano. There have not been a lot of earthquake following this change in the lower frequency bands at Krýsuvík SIL station.


Picture from Icelandic Met Office web site. Copyright of this picture belongs to Icelandic Met Office. This plot was saved at 02:11 UTC on the 05.03.2011. The changes can be seen on 0.5 – 1Hz close to the end.

I am not sure what is going on. But there might be a small chance that this is a magma that is on the move. The second option might also be that a new hydrothermal area did appear close to the Krýsuvík SIL station. If this is magma, then a volcano eruption in the area is not far off (days, weeks, months?). But only time is going to tell for sure what is happening.

Other note: The activity in north Iceland and in the highlands are frost quakes. But it is extremely cold in this area of Iceland at the moment. More frost quakes can appear on IMO maps in the next few hours.

28 Replies to “Something odd is going on at Krýsuvík volcano [speculation]”

    1. This change in the 0.5-1Hz band is not strong enough to appear on the higher band due to noise that can be found there.

      But this is interesting change. But what it means is a good question. But so far it is ongoing far as I can tell. But I agree with you that this might be hydrothermal activity in Krýsuvík that is starting to show up on Krýsuvík SIL station.

  2. What might be causing the 12 hour cyclical pattern in the 1-2 and 2-4 hz bands? It has been occurring since before the last few swarms.

  3. Other note: The activity in north Iceland and in the highlands are frost quakes. But it is extremely cold in this area of Iceland at the moment.

    Oh.

    That would explain the countrywide attack of measles. 🙂

      1. Iceland is now turning from yellow to blue as it freezes its killer tomatoes off.

        Very appropriate.

        Surely the frost that makes the quakes, isn’t also seizing up the tectonic quivers? That would just be too coincidental. 😛

  4. You know what, I was in this area last year. It looked very similar to the hot springs near Krafta. Same colours and stuff.

    So we know this place erupted 700 years ago last time so the records wouldn’t be crash hot. But essentially the way of this area looks, it looks very sticky like, with the yellow type sulfurous deposit. Could it be this area could be quite explosive instead of the just pouring out lava. Especially with the big lake nearby, but I also recall the large coloured Maar not to far away. From memory there was also a psychiatric institution, but it was vacant at the time??

    Interesting time. The other hotsprings further away near the geothermal plant looked a bit wild. I remember from my visit the weather here was very crazy, very windy and stormy. I love Iceland, I hope to visit again sometime 🙂

    1. These geothermal areas look all like this around Iceland. So this is nothing unusual -also the deposits of sulphur are pretty normal. Btw: Most of the yellow color of the mountains is not sulphur but rock and clay, which has reacted with the acidic gases from below.

  5. Looking at the GPS data that would definitely indicate some magma moving or pressurising. The “up” component is going strong and the North/East components has started a rapid movement as well.

    http://strokkur.raunvis.hi.is/~sigrun/SELC.png

    Seeing that North/East started moving more rapidly in connection to the large swarm we saw a few days ago it would tend to rule out that the tremors was purely tectonic in nature. Maybe started out as tectonic but as the system is already under pressure and has shown magmatic activity recently with an impressive inflation a few years ago maybe the tremors converted from purely tectonic to magmatic/tectonic and the activity displaced the magma and/or opened some new conduits?

    Caveat: Not a geologist and so on..Just curious.

    1. The data in the GPS plot actually shows south movement until after the quake swarm the it turned and shows north movement.
      The east component was just accelarated after the swarm.
      But still it really looks like the area is “bulging” given the directions on the plot.

      Is there any report on how big the area is?

    3. Someone posted a picture of the gear that shows that plot, taped to the bottom was the plot just before the last Hekla event, BUR had taken a quick and pronounced negative trend then it went off.

      In this case, it’s wobbling back and forth.

      My money is on the storm.

  8. Tides?
    I can only think about tides.
    If the Moon can push several meters of our oceans, it could probably also push also magma upwards and downwards.

    1. Unlikely. Magma is highly viscous.
      But the tides may play a role. The sea is relatively close by to Krýsuvik, I think its possible, that the earthquakes opened some cracks which now correspond to the sea and the tide. So we would see here some geothermal reaction.

    2. How about the changing weight of water on the plates? That would change immensely with the tides, possibly enough to slightly distort.tip them. Any experts comments on this?

    3. I like the idea of tides affecting Krysuvik area.
      The quakes might be indeed caused by tides, but not pulling/pushing the magma itself, rather the water around the area flowing in/out of the magma reserves.
      The underground reservoirs could be directly connected to the sea through cracks. As the see level increases above a certain height, the water flows deeper into these cracks.

  9. Tides: I was referring to the 12-hour cycle in harmonic tremor at Krísuvík, and I am just speculating.

    Frost earthquakes:
    Well, it was cold this last night, and the earthquakes seem pretty shallow, but they also seem to align by Askja fissure, south to north. Maybe it’s a coincidence. That would be still another unexpected swarm in a normally calm area in recent months (after Esjufjoll, Blondulon, Langjokull, Krísuvík). But Iceland is like this.

    About Hekla strain changes, I also think it might be storm-related. Although it would be pretty cool to wake up tomorrow and having Hekla erupting from my bedroom window (some 60km away).

    1. Wasn’t Hekla “overdue” 2 years ago, when I was in Iceland in July last year tour operators were not overall y keen to climb it lol

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