No signs of a eruption at Grímsfjall volcano, harmonic tremors continue

Since 02:30 UTC on the 3rd of November 2010 there has been constant harmonic tremor in Grímsfjall volcano. It is currently unclear why harmonic tremors are happening at Grímsfjall volcano. But there have been some ideas that this might be because a small eruption has started at Grímsfjall volcano.

According to news from few moments ago (around 14:00 UTC) there are no signs of a eruption at Grímsfjall volcano at present time. But harmonic tremors continue at this moment like they have been doing since 02:30 UTC last night.

The possible reason why the scientists don’t see any signs of a eruption is because none are visible on the glacier at the moment. But until something appears on surface what is going on in Grímsfjall it is going to remain unclear what is going on at the volcano.

Icelandic News. Please use Google Translate.

Hlaup og órói í Grímsfjalli (Rú
Engin merki um gos (Rú
Gos gæti verið hafið (Ví
Könnunarflug yfir Grímsvötn: Engin merki um gos (Ví
Vísindamenn fljúga yfir Grímsvötn (
Engin ummerki um eldsumbrot (

International news.

New eruption could be looming in Iceland, experts warn (AFP)

Updated at 14:59 UTC on the 3rd of November 2010. News link added.
Updated at 15:22 UTC on the 3rd of November 2010. News link added.

33 Replies to “No signs of a eruption at Grímsfjall volcano, harmonic tremors continue”

    1. 4 earthquakes in the meanwhile, that indicates something is starting, but not a capital letter SWARM.

  1. There’s a big jump in tremor at GRF at approximately, not visible in other nearby stations. Ice on the antenna again or did something happen at that time?

    1. First Hi to all.

      @henrik from what i read something happen, but it is not clear what yet.

      1. Oh crap…

        Just looked at the GPS-figures.
        Grimsfjäll GFUM has risen 5 centimetres in ten days and 30 centimetres since 2004. One pregnant mama there:)

  2. Jon,
    So when in doubt you go to ground. Is the acidity level still increasing in the rivers? How about the temps? Are there any indications of increases in Co2, So2, HSO2, CO. This is something that should give more than a clue about it.

    This is climatology and environmental kind of stuff and they should have some idea of the levels on this by now.

    Are there any indications of collapse fractures on the surface of the glacier?

    1. I don’t have this information. But some of them might be a IMO web site. The only collapse that the news speak about is from where the water had collected before the flood started.

    2. Gígja conductivity.

      Seems like something changed in the water at about 10:30 UTC that dropped the conductivity.

      For the casual viewer: Higher acidity levels will lower the resistance of water… increasing conductivity. It has gotten up to about 560 mho (siemens) and then became noisy and dropped back down. Not sure what was going on there, they may have fallen in or a piece of debris/chunk of wood hit it.

      From what I understand, the Gígja is ine of the outflow channels for the glacier. This one predominantly receives from the Grímsvötn area.

      And increase in volcanic gas emissions (seeping up through the rock) can cause an increase in acidity. (which would be seen in higher conductivity in the water). SO2 and H2O yields H2So4, aka: sulfuric acid (as well as hydrogen gas)

      1. @ Lurking

        I would think that those spikes in low conductivity originate from regular meltwater of the glacier, since the spikes more or less coincide with the highest air temperatures of the day. Once that runoff had drained into the Gígja river the conductivity rebounded to its old (high) values.

      1. Average is 400 metres, but it might be a bit thinner over the volcano due to heatleakage. Remember that it is a subglacial lake under the ice ontop of Grimsvötn.

  3. Remember that in 1996, the eruption started while the flood water was still small. The large flood only occured one month after the eruption!!!

    Realize also this: the flood discharge from Grimsvotn is now 2600 m3/sec, which is nearly the same that occured with Eyjafjallajökull in April ! This is already BIG.
    Grimsvotn floods reached a peak 4900 m3/sec in 2004, and a catastrophic 50 000 m3/sec in 1996!! With Katla, the flood reaches an even higher and astonishing 300.000 m3/sec (twice the Amazon river). Can you confirm this data Jon?

    1. My conclusion is: first, we cannot predict when it’s going to be the maximum flood. In 1996 it came one month after. Also, these discharges are quite normal. This year there was already two floods from Vatnajokull I think around July. Geothermal heat melts water and this has to escape.
      So second conclusion, we cannot predict an eruption just due to the flood.

      However, the increasing tremors are suspicious that an eruption might be occuring soon. There is still a lack of (deep) earthquakes…

  4. @Irpsit

    “he flood discharge from Grimsvotn is now 2600 m3/sec”

    I really would like to know the source of this. All I have is the data on the Gígja channel which is showing ≈451.2 “cm” (m³/s ?). And, I can’t account for what appear to be scale shifts from the previous approx 340 “cm” value prior to the flood event.

    If anyone has an idea of how to resolve this please post. I’m gonna be OOC for a bit.

    1. Question: Regarding stream gauge measurements, “cm” refers to centimeters, right? (presumably depth in centimeters of still water).

      1. Then there really should be (logically) an indication of the size of the channel or a translation to the volume of the flow.

        Such as this Mississippi gauge at New Orleans:

        It’s hard enough dealing with the language barrier(s).

  5. As offtopic, here is something interesting:

    Volcano watchers across Indonesia are on high alert after Mount Merapi erupted once again today (Nov. 2). It was the volcano’s 10th eruption since Oct. 26.
    Rumblings have also been detected at 21 other volcanoes in the region, the Associated Press reported, stoking fears and prompting mass evacuations as a precaution.
    There’s some speculation that Merapi could trigger eruptions in other volcanoes. But unless they are very close, volcanic systems are generally isolated from each other, said Ed Venzke of the Smithsonian Institution’s Global Volcanism Program in Washington, D.C.

    Is it paranoia or something to watch carefully?
    My point: the recent earthquakes in Sumatra have affected a large lenght of the tectonic fault. Could it also have affected the volcanoes on it? Scientists said that the 2005 earthquake even triggered some activity in Toba.

    1. Buahahah!!!!

      From the link:

      “When the Icelandic volcano Eyjafjallajökull erupted last spring, a larger volcano nearby, called Krafla, did not erupt, even though in the past, both volcanoes entered an eruptive phase at same time.”

      1. Hehe..Well its all relative. Compare it to the distance of the sun Krafla is quite nearby. 🙂 Even though it is halfway across the country.

  6. Tremor seems to be decreasing. Is this a sign that there won’t be an eruption on short notice Jon?

  7. Is this normal for tremors to be continuous for such alonf time (over 24 hours)
    And any “speculation” as to why & what may be at the “root” of it?

Comments are closed.