Soufriere a VEI 4

La Soufriere in ashes

Howdy all. Long Time no Sea… 😀

I am one of your dragons. I lurk around in the back channel conversing with the other Moderators. My claim to fame here on VolcanoCafe is that “I plot stuff.” One topic that we have been kicking around, is just how large is the La Soufriere eruption. Albert threw out VEI 4 range as an estimate, I had no idea since I hadn’t been watching. I felt remiss in that, so I spent the evening rummaging around the VAAC reports. Now, first a note. VAAC Reports are SPECIFICALLY for the purpose of providing warnings and alerts for the aviation industry. They are not intended for any other purpose. What I do from time to time, is to use them for an unauthorized or sanctioned purpose. To estimate the eruptive rate of a volcano. Since my estimates serve no purpose other than for us to get a handle on what size an eruption is, and that I make NO CLAIMS as to their usefulness in a scientific or official realm, I think I may be able to slip under the radar and get away with it. The first thing you need to do is to weed out some of the errors.

First of all, VAAC reports are for giving appropriate aviation warnings. These guys are going to error on the side of caution. Warning boxes are of no use for what we are doing. The only data you want are actual reported plume heights. Note the yellow areas in this sample.

Sample VAAC report

This is the only data that is of real use to us. FL100 means “Flight Level 100” Essentially, hundreds of feet. TGMCoy may be able to elaborate on this since aviation is his field. (If he is still using that moniker). In order to convert that plume height to cubic meters of dense rock equivalent, refer to Mastin et al appearing in Journal of Volcanology and Geothermal Research. doi: 10.1016/j.jvolgeores.2009.01.008. The long title of the paper is “A multidisciplinary effort to assign realistic source parameters to models of volcanic ash-cloud transport and dispersion during eruptions”

Essentially, it is a method of getting usable data from what you can find. Their method is derived from work done by Sparks and is generally in close agreement with it.

What I do, is gather all the VAAC reports I can find for a particular eruptive sequence and convert all of the time stamps and data points to the number of seconds from a reference point. To fill in the gaps, I run a linear interpolation from point to point on a per second basis. This is a potential source for error, so keep that in mind. {note, I am not a glutton for punishment, so I used a software tool to do this… specifically DPlot by Hydesoft Computing.} → (Full Disclosure; this is an unpaid endorsement. He is based out of my home state and I’ve had great customer support from him.) Upon completing this step, I now have an eruptive rate estimate for each second of the eruption. I then run an integration step (same software) to obtain the cumulative DRE of the eruption on a second by second basis. This is what it looks like.

See that 4/10/2021 15:55 time stamp? (midway along the curve) that is where the column was reported above FL350, an eruptive rate of 639.68 m³/s.

At over 1.2 x 108 m³… I think it’s safe to say we are in VEI 4 territory now.

A VEI 4 is defined as between 108 and 109 m3 of ash and tephra. Tephra is a lot less dense than dense rock: you get a larger volume out than fits in the hole. To convert, we can use a factor of 2. That makes the current eruption 2.4 x 108 m³. We are in the lower half of that range. A VEI 5 may in the end be possible, if this continues long enough and especially if there is a bigger bang still to come.

Enjoy. Feel free to discuss.

Carl added some notes on misleading information doing the rounds on the wwww, in his inimitable style

I have to write about the eruption at Soufriere Volcano after all of the click-bait that has been written in the last couple of days, and to inject a piece of science into the debate.

But, first I wish to recognise that it is a disaster for the residents on the island. Especially the risk of there not being enough water is scary indeed.

There are 3 things that need to be addressed that is circulating around on the internet and that is amply wrong.

“VEI-5 oh my god we are gonna die!”

No, this is not even close to being a VEI-5 eruption. It is currently slowly moving towards a small VEI-4. There are not many videos of large eruptions, the closest that we have to a VEI-5 eruption is the 2011 Grimsvötn eruption that was borderline, but still not big enough. Please compare that video to what you are seeing Soufriere. The column is taller, and it goes into the stratosphere, it is continuous at this size for 24 hours before it slowly dwindles, total ejecta from the eruption was 0.9km3 of tephra. If you watch the video you will notice that Soufriere is not even scratching on being close size wise.”

“SO2 will cause a volcanic winter/global heating/my grandmothers cat to die.”

No, the eruption is too small for that. In the real world the current eruption in Iceland is about as gassy as Soufriere, and that is a small eruption. None of them will have any effect, you need almost 40 times more, and it must be injected straight into the stratosphere, and be converted into sulphates to have a cooling effect. We know this since Pinatubo injected 19MT+/-4MT into the stratosphere, and that caused cooling. So, way to little, and way in the wrong height…

Ash column is 60km high!!!!!!

Sigh, no… The tallest column registered was 17km, and it was short lived.

Now over to the video of Grimsvötn 2011, it is from the opening stage. It is taken from the edge of Vatnajökull 20km away from the eruption for scale.

Carl

VC is always happy to provide the facts and the fact checks. We do like to have our heads in the volcanic clouds, but with our feet on scientific ground!

490 thoughts on “Soufriere a VEI 4

      • Could a narrow lava tunnel exit produce enough jet like effect to show such fountains? — Otherwise this is indeed Gigur 5.

  1. There’s something going on in the middle here.

    Could just be jetting from the flow, or a new vent. Pity all the smoke is blowing against the other camera.

    • It is a new vent as small jetting and sputtering is going on to the right of the main area and several people are watching this

    • There’s something going on behind the small hill to the left of it too – there are gases coming from there.

  2. “The eruption is relatively small. The average flow of these first 24 days is about a third of what occurred on average in the first 10 days at Fimmvörðuháls in the spring of 2010, which was a small eruption. The flow in Geldingadalur is only 2% of what was in Holuhraun in the first weeks of the eruption and 5% of the average lava flow in the six months that the eruption lasted. The flow is similar to the average in Surtsey after the eruption began in April 1964 until the end of the eruption in June 1967.”
    https://www.mbl.is/frettir/innlent/2021/04/13/svipad_og_surtsey_gosid_i_beinni/

  3. Probably a really silly question but does the height of the cones influence whether a new fissure will appear? Looking at the MBL camera the cones all look to be at a similar altitude so when they reach this similar height a new fissure opens up. Obviously saying that the cones look to be the same altitude is not very scientific and the MBL camera is at a funny angle. Just a thought that popped into my head.

    • I agree more of the fissure is opening up and that area was heavily smoking but now it is a vent

    • Whole aria now well heated up now. For me little strange. Not like a fissure erouption i think of. this is more like it follow the line but pop up cones after the line. is it because of the high heat.? it just burn a hole up. not like cracking in longer fissure..

      • That was the pattern of the much larger Lanzarote eruption that Chad wrote about. New vents opening apparently at random along what eventually appears as a fissure row, but at no point was there a curtain of fire along the entire fissure.

        • Thing is, while it began with an initially typical eruption that was fast and declined quickly from high rate, averaged out over the 6 years the Lanzarote eruptions were only something like 30 m3/s, enough that it will form an a’a flow field and fountaining lava lakes as opposed to convective ones but it wasnt anything at all like Holuhraun, theres no gigantic laca rivers or calderas collapsing, its just seemingly endless flows of a’a, a bit like Pu’u O’o but with higher eruption rates.

          The 20 m3/s of magma as what is feeding this dike will turn into about 30 m3/s lava, so if the dike can completely fill the rift and there is no more space underground it will suddenly jump up to the true deep flux and that is actually a very comparable rate to Lanzarote.

      • And i have maybe have to eat that up.. look like it do zip up little now.. 🙂

    • It does seem to be joining the dots. I was thinking that vent 3 (hat made the little cute classic triangle cone edit: Queenie?) was struggling somehow to get going when 4 blasted out to announce its presence like Flashheart (AHAhahahahahaha!)

      The pattern is progressing along a path that I had been thinking of since 3 appeared between the first two,rather than further away. Then 4 appeared between 2 and 3, and now, more are popping up between 1 and 3. Can some maths y person help? Is ther some sort of concept about jioning dots in an alternate pattern but never quite getting filled out? Like a light particle travels half the distance to a point in a time interval, and by repewating ad infinitum neve ever gets to the point as there’s still half the distande to go?

      My brain hurts. I will have to draw this out.Can somer kind soul lead ths Bear of little Brain to a place to learn how to get photos and maps and charts up here. Because I know you’d like to see some geomorphology. (oooh, another ‘ology!’)

  4. I am glad I alerted volcanologist Thordarson last night about new fissures about to open up because of a certain type of explosive bursting at the north cone

  5. New fissure between Gollum and fissure 3. Partly under all the ponded lava so not very visible but there are some fountains above the lake surface. Theres also a small lava flow from the area.

    I almost think at this point there’s no point naming all the fissures individually as they and instead just calling the whole area Mordorfjall 🙂

    • Looks like I was too slow, but the hell machine is getting stronger 🙂

      Seems the only reason it periodically dips to 5 m3/s is because magma is rising into the fissure underground and temporarily takes pressure off the vents. Really the fact the eruption doesnt actually stop before new vents open shows there must be substantial magma flux, enough to fill the growing rift while still erupting. Should the rift reach its maximum dimensions and stop I expect we will see a noticeable increase in eruption, possibly quite a significant jump in fact.

      • I agree with your first claim, pressure is lowered due to new cracking

    • “Noooo they needs proper nameses or we won’t be knowing which one is being talked of, precious. Too tricksy. Too false.

      We needs to wait to see which ones win the battle to steal the precious magma underground from its neighbours. Then, we names them!”

      Profound apologies to JRR, whose shade has just been polluted…

  6. The output from fissure 5 is going to be directed straight to the low pass and exit out of Geldingadalir. All other paths are blocked either by the hill or by the fissure 1 shield. The white smoke is also extending much further north now, from fissure 6 and half the way up to 4. There may be quite an unzip going on.

    • I spent half last night checking to see if anything went east behind the twin fissure1/Northy-Southy/Gollum-Smeagol vent. (Please can some one pass the matchsticks and the coffee.)

      Nada, not a drop.

      There were plenty of small overspills just to the north west, but nothing went where Jesper’s hot tub was. I wonder if that is buried yet? I havent had a good view. I need photos or helicopter videos. Desperately so I can see and understand.

      If the scoria/spatter vent has narrowed the gap leading east at the pinch point, it’s entirely possible that the flow will all go round the horseshoe braided channels and exit at either of the southern silghtly higher cols/saddles.

      Again, depending on height and flow, the more northern col could send the lava either north or south, there’s a flattish area with shallow gradients both ways.

      If the most southern col is the (un)lucky one, ie the walking path saddle, then the lava goes south to Natthali(spp?) and a potential road breach and ocean entry.

    • Whoops.

      I missed out the option of lava creeping right around the horseshoe, then up along the notch left by the initial southwestern flow from Vent 1 when it was fountain 3 (iirc) right at the very beginning before the cameras were set up.

      We see repeated instances of where the lava overspills the channels, building up the levee banks and leaving a V shaped notch between the fresh flow and the original country rock landscape surface.

      Ye gods this would be so easy to explain with a diagram.

      All these scenarios critically depend on lava and levee and barrier height and their structural integrity. Each different option takes only a little push to set in motion; a butterfly’s fluttering wing to precipitate a hurricane of consequences.

      * goes to grab coffee and popcorn and get dressed*

  7. Please note that the steam has appeared on the flank of the north cone again

    There is a lot of vog coming up too

    • An indication that magma is really shallow underground there. How shallow the magma is became quite obvious 30 minutes ago, it would not have far to go.
      However, I don’t think the cone will be split by another vent just yet. The existing conduits into the twin cones are still too open for that. If they shut down, though, that will be an entirely different picture.

    • Uh oh… If the cone material isn’t strongly consolidated enough, lava may find the buried channel into the hottub and burrow it’s way to the east. A fifth option. And also, if the back walls of the Northy-Southy/Gollum-Smeagol double vent goes,the same thing happens.

  8. With hindsight, those people swarming all over the hill that hosted the original MBL cam weren’t as safe as they thought they were. VEI 0 doesn’t make you any less dead if it opens right under your feet.

    • The original mbl cam was up on the hill behind the original twins, quite safe from the eruption, it just got battered to death several times by the wind before it was relocated to where it was killed by lava.

      • I meant where it was relocated to, not the original location which I must confess I had forgotten about.

    • I was thinking that all the time when the S7R tent had to be rescued pronto when fissure 2/ Kraken opened. Nowhere on that line is safe. Fissure is like the farmer. “Get orf ma laaand!!”

      Thinks: that little steaming crack to the right of Smeagol/Southy is still doing it’s thing, unobserved and untroubled… Hmmmm. Does this show the location of the southern blockage of the intruded dyke?

      • Cool.. light plane big wing serface little uphill i think and wind against him, Can land almost like a helicopter. very nice..

        • Like everything people can do there’s contests.
          Search YouTube for ‘stol’ competition. It’s quite impressive!

    • See what you mean , looks as if a strong gust of wind could knock it over.

    • So this is the red plane that was spoken of earlier, perfect way to get there no walking or parking cars, go home again in 10 min 🙂

  9. Maybe we better forget about numbering cones and vents. The whole fissure line is able to produce lava. At the moment there are no less than 4 new places of lava spattering:

  10. It starts to look like the whole area around fissure 3 is ripping open. The new fissure north of the Twin Towers starts to creep all the way towards fissure 3 (Chimney of Isengard).

  11. According to the weatherforcast the view from Geldingadalir cam should start clearing up in the next hour or so.

  12. Any word from IMO on the unzip? I looked on the English website.

    • Yes!!!!

      I’ve only just got to this comment, see my predictions farther up thread.

      I knew I needed to get up earlier, but overslept because of checking for any eastern breakout.

      Why does it never rain but pour? 12 months of groundhog day, then all hell breaks loose in volcanoland and In-Law-land… I need a lie down

      • I had the same thing, just opened op the webcam and there were so may cones, I was so sad I missed it all today.

  13. Okiedokie I’m going to stamp my claim to fame on this one! A few pages back when the lava extruded from Sudri fell down a hole, I said it had likely gone down the rift and would meet fresh lava coming up.

    The volcanologists said it had lava-tubed off across the field. Pah! What do they know!

    And here’s my new rift just (a few feet from) where I reckoned it would come up! See my epic artwork a few days ago with a line drawn on the photo.

    Cliveagigur, if you please.

    (OK, the rift is just unzipping so I know I can’t really claim anything! 🙂 ) Still – fascinating to see this.

    • Maybe not draining down to contact with the dike but you could be right still, that pond did drain on its own not with any decrease from the vent or rest of the flow, it could have flowed into cracks from the rifting if that area just before the new fissures opened.

      There also was that one crack that was not erupting but glowing after the first vent opened, it is buried now but maybe finally erupted after so long 🙂

      • Thanks! You may all take my comment with tongue stuck well into cheek.

    • So, we have lots of little fountains unzipping between F1 and F3, filling out the gap.

      Let’s play a naming game.

      Twin Vent 1 has been affectionately called Smeagol and Gollum. F2, the Kraken, sending all that lava down the gully to Meradalir.

      And then there’s Vent 3, doing just enough to maintain her beauty and position, this just has to be Queenie.

      F4 appeared to spring violently out of the ground out of nowhere, and overtake Queenie in a flash – Lord Flashheart!

      And now for today’s fun and games, at least 4 or 5 areas + unzipping and heading down the hillside from Queenie towards Gollum and Smeagol. There’s a plethora of minor characters to choose from; Captain Darling, Melchett, George, Kate: not to mention all the LOTR minor royalty.

      As soon as I can, I’ll try to get something about levels and heights and options sorted into text and diagrams.

      Clive, I didn’t see your post about the drainage hole, but that’s the exact conclusion I made because only part of the lava pond drained, while the upper level was still so full it was burping some small overflows. Congrats and well done. The glow of satifaction is all yours. 🙂

  14. With the lava from the new vents flowing into the hollow NE of the original cones. How soon will it overtop the saddle into Meradalir and cut the walking route, isolating the MBL camera.
    Also will the RUV camera watching the flow into Meradalir be able to pan left enough to watch any new flow?

    • It’s currently flowing along the red line here, so it will need to solidify/overflow/etc a bit before going into Meradalir. And yes the RUV camera has on previous zooming in/outs shown that it can see the exit if any new flow should come from that direction

      • This is the critical photo.

        The lava is flowing from further up, behind the pretty regular cone Queenie, along the older flow towards F1 twin vents Gollum and Smeagol/Northy-Southy.

        Now the question is if the levees are high enough to dam the flow, and divert it back north and around the outside of the whole field, or if it finds a path into the rexisting empty channel system.

        Onward and upward. I have scrambled a coffee and drunk a slice of toast and jam. You just can’t get the staff these days…

      • That connection (the one you circled) is for the “northerly” pass out of Geldingadalir (the little stub going in between the two ridges in the middle right of your first photo).
        If the lava keeps mainly going for the “southerly” pass that your red line highlights, it would be going behind that ridge your circle is “resting” on

        • I know, the lava is currently towards the south, and not towards the pass into Meradalir. I could possible have made that clearer before.

    • From the 3d map, it has found another escape, in the opposite direction from Meradalir.

      It seems that the lava flow is too small to maintain 6 separate vents. We will now get musical chairs where vents are trying to secure their magma. Struggle for lava and survival of the magmest

      • The other time it has open up it start ramping up some time after new one open. remember many write it is fading. And then at night after it get wilder than ever.. So if it not ramp up in evening or night it can be for now a slowing process.. Any newer number of the inflow from the deep..? maybe i missed that..

  15. ‎Lava from the new craters that opened at the eruption sites in Fagradalsfjall this morning now flows over Hiking Trail A, which is the first-staked hiking trail. Despite this, it has been decided to open up public access to the area at 12:00 as planned.‎

    ‎Four new craters opened at the eruption sites this morning. Three of them are on a short fissure next to the lava flow, which runs from the northernmost craters down to Geldingadalur. Then one crater has opened between the third and fourth craters that had previously opened. “There’s a lot of lava flow there that’s rolling across Hiking Trail A,” said Hjálmar Hallgrímsson, field manager for the Southern Peninsulas Police.‎

    ‎’Interestingly, there doesn’t seem to have been any obvious change in the activity in the existing craters. It looks like it’s a pure addition,” said a post by the University of Iceland’s Volcanology and Natural Resources Group.‎

    From RUV
    https://www.ruv.is/frett/2021/04/13/hraun-flaedir-yfir-gonguleid

  16. A timelapse from the Melandalir and MBL camera from 19h to 6h30 this morning (no new vents yet)
    From midnight to the end both cameras play simultaneous.
    (I also removed a bit of the fisheye from the mbl cam in case you wonder)

    https://youtu.be/jFpcR9u02Z8

    • Thank you. The like button is not working for me since lately, so big LIKE from me. Nice with the two cameras fro midnight. 🙂

  17. Lots of closeups on the working RUV cam starting about 1630, including a look at the MBL cam. Some lingering shots of the new vents and an apparent attempt (successful) by the operator to dodge the banner-wavers (who are back).

  18. Lots of smoke coming for the far left hand corner of the MBL Cam 1. Lava flow just out site perhaps that has flowed out of the SE saddle of Geldingadalir? Just can’t see but certainly a lot of smoke – the sort from burning wet vegetation.

  19. RUV cam (the original one) shows the lava ponding well down with little lava’ river terraces’ on the sides and shiny flows heading left of the twin cones. Maybe finally lava from Geldingadalir is about to flow into Meradalir? Lots of people watching what’s going on on the MBL cam but it’s just not visible on any camera at the mo.

  20. What on earth are those poles on the hill beyond the twins? They look like vertical stabilizers on large passenger aircraft!

  21. Seems almost “insulting” that after all the ‘work’ our friends the Twins put into filling Geldingadalir, that the flow from Meradalir is doing the heavy lifting now, going as far as spilling into the original lava lake area and the newer fissure leaks now working to help the filling of the area to the SE exit!

        • Its actually not even the biggest lava eruption right now, Kilauea lava lake is about 4x bigger by volume, and was equal in volume on its second day.

          Piton de la Fournause also is erupting, not likely to last a long time but is going at about double the rate of Iceland right now.

      • Perfect they zoom out now,. all cones quit active as it looks

        • they are not all but old brave twins, the infamous cam terorist vent and the 3 new babies..that seems that rise the flag for the infamous one..hirr…let see tonight the twins action. for me it seems that they are the power injector of the hell machine.

    • The vents sound just like Le Piton de la Fournaise fissure eruptions, to the very sound. I wish that someone with qualified infra-red camera gear could get the temperature of this lava.

      • Temperature is about 1220 C, its very hot. But most of the lava tends to pool near the vents so cools down a bit.

  22. Interesting that vent 3 has clearly increased in activity today after the new fissures opened. It was almost completely inactive for the last couple of days. All 7 vents seem active now. Will we see activity slowly decrease until another fissure opens? Is this the cycle of the Fagradalsfjall eruptions

    • Also interesting that vents 3-7 have all occurred between the first two vents. Are those defining the edges of the shallowest magma at the moment? Will the be consolidation in this region or should we expect to see the fissures expand to the North along the dike?

    • Dont get this “like” thing to work so i write ‘Like” Have been waiting for view behind Twins so very nice.

    • Interesting to see some people walking in front of that one cone, gives a perspective of how big that thing really is. Without anything to compare it to, it appeared to be much smaller than it really is…

  23. There’s a small glow to the right of fissure two (far right) on the MBL camera. It isn’t in focus though, so I can’t tell if it is laval flow, another vent opened up or even vehicle lights.

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