Posted on by Jón Frímann

Two pictures of the 1918 eruption at Katla volcano

Here is a pictures of the 1918 eruption at Katla volcano.

This is not the most famous pictures of the 1918 eruption in Katla. But they do tell a lot of story what we can expect next time Katla erupts.

Here is what we can expect in terms of ice that is going to come down with the flood from next Katla eruption.

There are two people on top of the glacier ice-bergs. Gives a idea of the scales in question.

Pictures are from various sources on the internet.

19 Replies to “Two pictures of the 1918 eruption at Katla volcano”

  1. Jon, when Katla goes will it flow out to the north or the south?
    Is it even possible to know before it happens?
    How far away from the volcano did the flows go………
    i’ll go do a websearch…. be back…
    Best!motsfo

    1. The flood will go south Mýrdalsjökull and down Mýrdalssand. But that is the normal pathway for the flood. But it can happen that the flood goes east and down Markarfljót. But that is the same flood route as the flood from Eyjafjallajökull did go earlier this year.

      But that has not happened since human population did start on Iceland far as I know.

  3. Renato, as Icelandic eruptions go Eyjafjallajökull’s was not innocuous but fair-sized. As it happens, so too are most of Katla’s.

    Of the 126 listed/credited eruptions since 6380BC, i.e. over the past 8380 years, only five are listed as VEI 5 while sixteen were listed as VEI 4. Now, the assigned VEI is based on the calculated amount of ejecta, not actual VEI. In this case, using this as the criterion, the following is arrived at:

    Of the 126 listed eruptions, only five were larger than Eyjafjallajökull’s 2010 eruption. Sixteen were as large and a whopping 105 were smaller! The reason Katla is so feared is because of the devastating jökulhlaups associated with her eruptions, not the eruptions as such. Furthermore, going by past form and since the 1918 eruption was a VEI 5, the chance that the next eruption is going to be as large (or larger) is very small indeed.

    You Katla-mongerer, you! 😉

  4. If you count the amount of ejecta (DRE), it meets the criteria for VEI 4. That said, the explosivity is said to be more like VEI 3. Over at Eruptions we’ve been through how bad a system the current VEI one is, especially for historic eruptions. Even if the DRE can be calculated fairly accurately, it’s well-nigh impossible to say exactly how violent an eruption really was.

    Take Lady E as an example! If she had had a similar eruption 5000 years ago, what VEI would be assigned? Ejecta might be calculated at, say, 0.2 cu km but as ash has been detected as far away as Finland, Russia and Spain, some experts would argue that the eruption must have been far larger and eventually a tentative VEI 5 might be assigned. We know it’s a VEI 3 or 4 and that the spread of ash is accounted for by its piezoelectric properties. This to my mind highlights how unreliable a guide the current VEI is.

  6. @Henrik: Hey there, Mr. Formidable: Katla mongerer, me? Poor me. 🙂 Considering the zero death toll and the relatively low damage caused by the eruption, it was pretty much innocuous. As for Katla, for the amount of ice involved and the jokulhlaups that you mentioned, a lower VEI would cause much more hazard. But thank you for the statistics. Always learning from you guys.
    @Jack: Checking on tremor plots.

  7. If you are looking for “scary” volcanoes in Iceland I think that Katla could qualify for one of those but if you look at its most recent eruptions and if we assume it will follow that same pattern I think there are other volcanoes which are of greater concern. For example Hamarínn..there are not much information about this one since it was along time ago it last erupted. It is connected to the Bardarbunga fissure system as well as Laki and Askja…Those three are really nasty or could be really nasty. Grimsvötn erupts relatively frequently and is more of a study object since it wont pose any real threat to anyone if it goes. My greatest concern would be the less known volcanoes like Hamarínn or even Tindfjallajökull where there has been some activity albeit small..And as far as i know not much is known about the volcano beneath it.

    Jon..You are most welcome to correct me if im wrong about anything above. 🙂

  8. And to spin on the VEI discussion in my opinion it is a really bad way of “characterising” a volcano. The time aspect is not considered and that is a crucial factor. Examples below..

    A VEI 5 erupts and lasts 5 weeks.
    A VEI 5 erupts and lasts 5 months.

    Same amount of tephra but the sheer timeline would make the explosiveness of the eruption drastically different.

    So in my opinion a VEI number is just the amount of tephra ejected, not how violent the eruption is.

  9. http://live.mila.is/jokulsarlon/

    Take a close look, please! (use “Ctrl” & “+”)

    Looks as if two low clouds are generated by the glacier from at least two if not four points. If nothing else, good practice in “cloud recognition” as opposed to “eruption recognition”. On the other hand… 😉 🙂

  10. All gone now after 2½ hours of “phreatic mimicry”. I just love this planet and the conundrums it throws up!

  11. Wow, that is an amazing picture of the ice blocks! Yikes, that, more than anything, gives me an idea of the results of an eruption.

    1. A fabulous scene. There was no idea of the scale until I saw the cars driving to the shore of the lake. Amazing natural beauty.

  12. Isn’t it just! It’s been added quite recently and all the regular Eyjafjalla cams (Thorolfsföllur, Hvolsvöllur, Thorvaldseyri) have been taken off for “upgrading”. Could it be that Mila, that most laudable corporation, is setting up cams ahead of the expected Grimsfjall eruption?

    2. That would be nice.
      Although… because the place where an eruption takes place is not always there where it was expected, it is very possible the webcam looks in the wrong direktion. But one can always hope.. 🙂

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