Reykjanes: the second day

That was quite a day. After the fissure had opened early in the night, and everyone was scrambling for a view that was a bit more than a red reflection off the clouds, in the day time everything became clear. A camera was put up on just the right place, courtesy of RUV. Not even HVO managed to do it this well. The setup team even was on camera themselves, whilst they were working. The highlight was when one of the three went to his knees, it turns out not to pray he got it right, but in order to take a lava-selfie. It is almost the same thing, I guess.

We had (and have) a brilliant view of the eruption, the flowing lava, the intermittent snow, the helicopters and the small plane (presumably sampling the gas emissions), and very quickly the tourists. At one point a large group of people was standing around and doing something right at the edge of the approaching lava. They had to retreat as the lava advanced but kept doing their rituals. It appears this was a group of archeologists trying to rescue a pre-christian burial site. To ‘rescue’ means ‘to document’ to an archeologist. The burial site would have dated from the previous pghase of Reykjnes eruptions, before the year 1000. This valley was never affected but the eruptions. Now, finally, the luck of the buried people has run out. See https://twitter.com/astro_graph/status/1373596762565455875

There is a nice timelapse made by commenter astrograph99. The archeologists can be seen about 1 minute in.

https://www.youtube.com/watch?v=puSLSuIBbn4

And here is a lava layout courtesy of commenter chrnesset.

Other things we learned yesterday is Motsfo likes popcorn with her lava, that Alaska is cold and the Faroer is not, and that half of Reykjavik including commenters are planning to go to eruption today. Lava to an Icelander is honey to a bee. This is about as friendly an eruption as you can get, with lava that can’t get anywhere and stays in a valley and ridges provide excellent viewpoints. The only problem is that it involves a long hike. The weather also is not particularly viewing friendly today, bit this is Iceland after all. You have to accept whatever weather is thrown at you.

Posted by Bjarki

From the map above, it seems that the lava as of last night covered some 0.1km2. Assuming an average thickness of 10 meters, gives an average eruption rate of (very roughly) 15 m3/s. This is not particularly high and it adds to the touristic quality of the eruption. A much faster eruption would be much more dangerous. (The eruption rate normally decreases after the first burst, so by now the rate may be quite a bit lower.)

The fluidity of the lava is hard to judge from video frames. At times it flows quite fast, at other times it seems more sluggish. My impression is that the magma was a bit stale, perhaps already a bit cooled during the weeks of storage in the dike. But that impression should be taken with a big grain of salt. Of course the top stuff is erupted first, and that may be the oldest which was deposited first. If this continues for a while (that is an if), the younger and hotter lava may make its way to the surface later. Wait and see.

There were perhaps 6 or 7 vents during the first day of eruption. This is common in rift eruptions. All are building spatter cones (which are prone to collapse. be careful!). Over time, you would expect that one cone will become dominant and starve the other vents of magma. At the moment, three of the vents are active.

The wind is blowing the gas towards Reykjavik: https://dispersion.vedur.is/map.html. IMO writes that “gas pollution is not expected to cause much discomfort for people except close up to the source of the eruption.” They do have a stern warning: “The area of the eruption is considered very dangerous – the eruption site can change without notice and put people at risk unexpectedly.” We recommend that people follow all advice from the local authorities (which we are not!). If you go viewing, be well prepared (don’t expect a paved path – the only pavement is hot lava), don’t expect water on tap, and stay upwind from the gas clouds. And remember White Island.

A notable change since yesterday is that there are still earthquakes in this location, but they are now deeper, at 4-6 km. The shallow earthquakes have ceased.

How much magma is there? The dike was reported to be 10 km long, 5 km deep and 1 meter wide. That makes it about 0.05 km3 (and not 0.5 as was here initially..). Much of that is not accessible to this location: magma at the tip will not easily flow back to the centre. If there is no magma re-supply, it is unlikely more than a fraction of this will erupt. However, if the entire dike erupts, at the estimated rate, that could keep the eruption going for a month. (This has been updated to fix a catastrophic math error, pointed out in the comments. )

So it is back to wait-and-see! But the seeing is mesmerising. Or even magmarising.

Albert

https://www.ruv.is/frett/2021/03/20/beint-vefstreymi-fra-eldstodvunum

416 thoughts on “Reykjanes: the second day

  1. the cycle i’ve noticed for the cone self healing and a new breakout seems to be pretty consistent.

    A breach in the cone wall occurs, allowing an outpour of lava to leave the pond and erode a spot for the drain. Spattering continues to rebuild the cone, narrowing the breach point and eventually spanning the gap with a cover, so the exit point is now a drain hole.

    The hole continues to narrow, eventually not allowing lava to leave the cone as fast as it enters. The pressure behind it grows, and the pond level raises higher until the weakest point in the cone gives out.

    sometimes its the same point that was already draining, and sometimes a new breach occurs. If the breach is deep enough, after the pond drains the old breach will completely heal, and the cycle repeats with the lava’s new exit point.

  2. Curiosity is killing me looking at the lava field and wondering would it be possible to run across the top of it or would the surface crack underneath very little weight? 😀

    • I did see a video today of someone walking on the lava crust to retrieve a drone.
      I would not like to try it. One weak spot and you’d be walking on the seriously hot stuff.

    • You can walk on some lava flows, after the surface has cooled enough. Apparently, while doing so you can feel the lava flow underneath you, and can be rising while it piles up. Your extremely sturdy shoes will still melt – don’t be tardy. On a lava flow like this, the surface is liquid enough for you to loose your balance. You won’t sink (lava is dense) so your body might still be retrievable.

  3. In regards to the possibility of the fissure having crossed the valley floor and opened up the other day on slope the left hand side. This 360, zoomable, drone photo may help provide an answer, or perhaps muddy the water further….

    https://www.iceland360vr.com/panorama/geldingadalur-volcano/?src=hp

    iceland360vr.com/panorama/geldingadalur-volcano/?src=hp

    It is possible there is a collection of material in a gully, basically a peat bog, and that has been burning? The scorch marks are what you expect from a moorland burn, but…., it does also look as if there is a fissure like feature running up the middle of the organic material and then onwards up the slope, and that the area in general has slumped down the slope by a couple of meters. The question i guess is if the fissure like feature is genuine or erosion from water flow?

    I’d now say what we saw the other day was a peat fire, but i’m still not sure.

    • I agree with you, having viewed the same image, it looks like burned peat collected in a water eroded gully. The slump may also be erosion.

  4. Ahhh. A snow squall ! Makes me feel at home. I live near one of the great lakes and this is familiar.

    • Thanks. And it is with sound, which is quite scary at the moment.

      (If you listen carefully you can hear a person whistling somewhere in the vicinity)

    • the tripod or mounting is a bit to wobbly for icelandic wind, but very nice to have a second angle!

  5. Scientist on ruv (icelandic tv) talk about the lava coming from more than 17km depth…more than they expected.

      • Eruption rates have increased alot… this is similar rates to a Puu Oo pit vent…

      • The lava is very fluid… but perhaps… not as fluid as basalts can be on earth.
        Pahoehoe yes near the vent…. but as soon as it spreads out or trys to form small pahoehoe lobes… it becomes Aa… perhaps simiar visocisty to some Piton eruptions

        • Remember that there is not much slope, so the flow is slower for the same viscosity.

          • But still forming Aa and the pahoehoe is a little rough close to the vent

        • In Hawaii a’a forms in any flow that has an effusion rate of over 5 m3/s, even on flat ground. This eruption is above that so to have the lava turn to a’a is to be expected. There is also fountaining so the lava is degassed, and its flowing initially down a very steep slope.

      • If the main lava channel keeps going.. it may tube over and form a lava tube?

    • Yes, this was pointed out and published in the comments. The story had grown a bit in the telling. It may be a bit early though to decide there was nothing there based on the fast survey.

    • I reached out to the author of the article Snorri Másson from morgunbladed and I put his information, about this being a single person researching a probably non human made hill in a reply to my twitter thread: https://twitter.com/astro_graph/status/1374007538857951235

      I didn’t expect the tweet to reach such a wide audience.

      I don’t read icelandic, so the number of archaeologists was lost to me in the google translate.

  6. Been wondering here, in some article it was estimated 15-20 or so days before the valley was filled up, however so far pretty much only the northern part is being filled. What if the northern part gets filled to the rim first, (obviously some lava will go south, it being liquid and all) and then the lava will start escaping through the pass as the main flow, instead of into the valley.

    Hopefully that made sense. Anyways, the question I had in mind, how many days at the current activity would that scenario potentially take to happen? Any bright minds out there?.

    • With the main body of Fagradalsfjall behind to the north and west, there’s either behind the cone opposite the RUV webcam to the east, or over the saddle to the far right of shot, the south(ish). Not completely sure of my directions here, there’s a good contour map in this article above.

    • What direction is the camera facing? I was under the impression from maps that we are looking SSE. Does your question relate to the area behind the splatter cone from the camera angle?

      • Yes it relates to the area behind the cone. I’ve marked roughly where the camera is in the image below, and the view we have in black. And by northern part of the valley I mean more or less the area to the north of the green line. How long will it take for that area to fill up, and the lava decides to “screw this I’m escaping through the gap!”, instead of completely filling up the southern part.

        • Obviously lava is fluid and as such should fill up the entire valley first before going through the gap, but since is possible that it hardens and such, the scenario I’ve dreamt up should be possible

        • The exit to the southeast is visible over the top of the two smaller cones, so the camera has to be futher east than in that diagram. otherwise it wouldn’t be visible. The vents are more of an open V than a line, with the point of the V facing the camera. In one article, the camera was also described as being at the head of the valley, which is also further east.
          The exit to the southwest, eventually comes to a dead end, parallel with Nathagi.

    • The valley can’t fill much higher than its lowest point, so I imagine that was taken into account calculating the 15 to 20 days,

  7. What’s with the camera pulsing from colour to greyscale? Batteries running low perhaps?

  8. Amazing rendering of Þríhnúkagígur with LiDAR data

    “~3500 ybp Thrihnúkar erupted in Brennisteinsfjöll fissure swarm, leaving an open conduit & cave #InsidetheVolcano. LiDAR data from inside & outside show the geometry of the eruptive system.”

    https://twitter.com/volcano_dr/status/1374072224299294727

    • My knowledge of volcanology was limited to an postage stamp, but now it is an envelope thanks to the wonderful people here at VC. What is a Dyngjugos? What are it’s defining characteristics? Apart from an ancient event, what are the geological implications perhaps worldwide? I have seen a number of potential big volcanoes waking up in recent weeks. Even Etna is a bit angry…

  9. There is evidence that the eruption of Mount Fagradals is a dynasty eruption, a species of eruption that has barely been seen since the end of the ice age. Eruption surveys indicate that the dynamic flows up from a depth of about 17-20 kilometers and is much more primitive than has been seen.

    The flow of dyngjugosum is traditionally possible, but they can last for a long time, even more years, and cannot be ruled out that that will be the case in Geldingadalur at Mount Fagradals, according to Magnús Á. Sigurgeirsson geologist. The flow of the lava is thought to be about 5-10 cubic meters per second.

    Among the known dynasties in the Reykjanes peninsula are The Desire Shield, which formed about 14,100 years ago, and Mount Skjaldbreiður, a 9,000-year-old lava.


    https://www.mbl.is/frettir/innlent/2021/03/22/visbendingar_um_dyngjugos_sem_getur_varad_i_ar/

    • Its comming deeply .. perhaps we will get a small lava shield after all

    • From what I read in the article, this is purely speculation right now. I’d be inclined to wait and see.

  10. Shame that the other came stopped working just as it was getting dark. Probably looks alot better at night than the first cam.

  11. Someone is taking pictures. Middle of the night, miles from a road, freezing cold, smelly with the worlds best sight before you. Now that’s a romantic night out!

  12. Albert, how can I privately communicate with you? I mentioned some posts to Dr Freysteinn from people here and he’s interested but he wants me to contact Dr Pall Einarsson. Some science has been done on this website and I believe that Dr Einarsson would be interested. I am not sure how to proceed here, hence the reach out to you.

    • Best is to email the VC contact address listed on the site. It will be looked at and forwarded to me

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