Is it a plume? Is it a cloud?

While we are waiting for developments, many of our readers are watching the Mila webcams and commenting on atmospheric disturbances over the vast Holuhraun and Vatnajökull landscapes. What comes up over and over again is the question of how to distinguish between cloud formation of all types (small fluffy clouds, elegant lenticular clouds, convection clouds over the glacier) and a potential plume from eruption in Bardarbunga.

Well, we can tell you from experience in watching the Grimsvotn eruption in 2011 on webcams that, if anything happens in Bardarbunga now, you will not have to ask. You will know. When Icelandic central volcanoes erupt, they do not do small and they do not do fluffy nor elegant. They also do not do big. When it’s for real, all they do is enormous.

Here is a timelapse taken as the Grimsvötn 2011 eruption started. During the start of this eruprion, one nuclear bomb equivalent of energy was released every second. So forget puffy fluffy clouds. Think an enormous atomic mushroom going up, expanding to fill in the entire field of view. Like this:


Timelapse by Ingolfur Bruun, Grimsvotn eruption, 21 May 2011.

Two more pictures of how Grimsvotn’s eruption looked like by VC reader Bergsveinn Norddahl:


Grimsvotn’s 20km plume on the first day of eruption. Photo by Bergsveinn Norddahl.


Grimsvotn’s wall of ash engulfing the landscape. Photo by Bergsveinn Norddahl.

Consider also this: Grimsvotn’s plume height was 20km. Using the formula for estimated mass ejection rate (Mastin et al. 2009), this results in 9,701.4 m³/s of ejected mass every second. That is about 288 one hundred ton trucks like this one every second. Think about this, 288 trucks EVERY SECOND.


Haul truck, image from Wikimedia Commons.

So, if something happens in Bardarbunga, you will know. Because what you will see is something of a similar size as Grimsvotn produced and it will be unmissable.

And where to watch? Here is a handy decorated screenshot of the Mila 1 cam, that shows where Bardarbuga is (the large bulge-like extended mountain in the back of the view) and the approximate direction of where Grimsvotn is located, should something happen there.


Screenshot of Mila 1 cam, evening of Sept 13, augmented by Ursula.

And if something does indeed happen, our reader sCyborg produced this visualisation of what can be expected on the webcam (note that this is photoshopped):


Photoshopped imaginary eruption cloud. Screenshot and editing by sCyborg.

Will we actually see something like this? Who knows, volcanoes are unpredictable and what is happening in Bardarbunga has never been observed before, as we all know. However, *if* it does happen, you now know what to expect. No fluffy clouds around, but a serious, enormous plume.

/Ursula & GeoLurking

Reference: Mastin et al. 2009, A multidisciplinary effort to assign realistic source parameters to models of volcanic ash-cloud transport and dispersion during eruptions. Journal of Volcanology and Geothermal Research,186(1-2):10–21,

Additional annoucement: since yesterday VolcanoCafe is also on Twitter. Find and follow us here: @VolcanoCafe or you can see our latest tweet in the sidebar on the right.

Clues appended to the remaining riddles!
There are still a couple left… and one involves a basilisk!  Head to the riddle page if you think you can figure it out!  (Click the link at the top of this page.)


1,398 thoughts on “Is it a plume? Is it a cloud?

  1. Thread copied over so Dr Webley’s awesome work won’t be missed:

    Peter Webley September 16, 2014 at 17:47
    new imagery

    Spica September 16, 2014 at 17:55

    Thank you!!!

    schteve42 September 16, 2014 at 18:01

    Hi Dr Webley
    Very nice images as always, thanks for sharing them here.
    If I have understood your work correctly:
    Surface activity in/at the fissure is confined to a smaller area than previously, with the small outlying fissures now reactivated.
    Kind regards,
    The Libraridragon.

  2. Well, I’m lurking about, but had to go and fill my car with water as it tried to mimic a phreatic explosion on the M23 (UK) on the way home. I think it’s OK now. Interesting about the mud hole going up (earlier).

  3. One thing puzzles me. None of Ye Olde Le Strange Lurking music lovers, have found THE theme song. 😉

    “I can see that it won’t be long
    You grow cold when you keep holding on
    You know you’ve changed
    And your words they lie
    That’s something you can’t deny”

    “I know there’s something going on
    I know it won’t be long
    Won’t be long before you’re gone”

    • Well, I don’t know to which song you’re referring, but this is an apocalypse song with a nice beat and that you can dance to. (nod to the late, great Dick Clark) It’s got hurricaines, overflowing rivers, earthquakes, etc., and even mentions an “eye for an eye,” so as not to leave out the bible/koran. It’s my “go to” “we’re all gonna die” dance party oxymoronic song. Thank you Creedence Clearwater Revival! 🙂

    • Interesting timing…U2 released their new album yesterday (Songs of Innocence) which contains a song titled “Volcano”. :). If you have an iphone and icloud backup, it was automatically downloaded onto your iphone yesterday.

  4. Good luck to people in the area, three to four days of very light winds to come and already the cameras are looking choked up. Sincerely hope there’s no significant escalation within that time frame.

  5. Would you look at that at least one thing right 😉 “looks like it’s pooling on the south side, would be interesting to see pictures tomorrow” or something like that i said XD

    • I thought that colin said that (just kidding). anyway since south is down hill that was a great guess! if this keeps up it should pool upon pool until we have a mountain. that’s my prediction. *no expert*

      • then in a million years or so it will have its own magma chamber, then erupt, then collapse to form a caldren, then more tourists will come. then will see if i’m right.

        • and by then they might have figured out a way to actually look down there to see what is really going on and they won’t have all this fun guessing.

    • Well, there’s the problem.. There’s two red arrow looking things, are they a new type of fisher?? And they seem to extend into the sky.. Daaaaamn. 😉 How many meters high are they? lol

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