The Hotness of Grimsvötn

How your ex glacier looks like in early june before the happily bobbing ice sheets melted. Image from Icelandic Met Office.

As far as volcanoes go, we like to think of them as immutable giants that rarely if ever change. We like to see Grimsvötn as a glacier covered giant of a volcano, that almost always produce moderate ashy eruptions, that are relatively speaking short-lived.

Yes, once upon a blue moon it will do something big, like the Lakí-styled eruptions, or even a Saksunarvátn or five. But hey, those are 7 eruptions in 13 000 years. Otherwise it goes like a clockwork in that ice-cowered medium range.

Another thing “we know” about Grimsvötn is that it likes to send a few Amazon River’s worth of icy water down the range in the form of Jökulhlaups.

Let us sum Grimsvötn up to make it clear: Glacier covered frequent eruptor of medium sized eruptions that needs continent sized diapers to hold its water.

There are two fallacies here. The first one is a general one that is valid for most volcanoes. About one eruption in three will not be normal for your average volcano. They are far better at throwing oddballs than we like to believe.

The more Grimsvötn specific fallacy is that we just need to look back 24 years to see that half of the eruptions are oddballs.

1996 was a definite oddball where Grimsvötn suddenly interacted with Bárdarbunga and created the Gjálp eruption on a radial fissure emanating from Grimsvötn.

1998 and 2004 was back to the same large VEI-2 to VEI-3 that Grimsvötn has done since the last Lakí eruption.

So, it came as a surprise for those who relied on 221 years of docility as 2011 came roaring around the corner with a borderline VEI-5. Now, remember that the Icelandic scientists are made of stern stuff, so as they tallied up the ejecta, they came up just a tad short, and being out of stern stuff it is a VEI-4.

It did not really end there, there is still a heated (pardon the pun) debate if at least a part of the Holuhráun magma came from the northern end of the Grimsvötn eruption in some sort of weird volcanic mating with Bárdarbunga (they should really get a room).

 

The Glacially Impaired Grimsvötn

The glacier fracturing as it calves off into the new lake. Photograph from EuroVolc.

As the mantleplume driven romance under Vatnajökull continues it has made Grimsvötn suitably hot and it has picked up sun-bathing as a hobby. Okay, I will stop with the puns now. Let us instead get down to the facts.

After a normal eruption the hole in the glacier normally heals up pretty fast. The geothermal energy output is not large enough to keep the glacier at bay since it is barely large enough to keep a bottom lake just above the freezing point.

Actually, it takes a lot of energy to keep that lake at all. The geothermal output of Grimsvötn was staggering at 250 Watts per square metre in 2007.

As a reference Yellowstone caldera has a heat flow of 100 to 300 Watts per square metre with peaks reaching up towards 1600 Watts in parts of Yellowstone Lake. So, in other words, Yellowstone and Grimsvötn used to have similar outputs, and here the takeaway is that Yellowstone has no problem snowing over in winter. So, we do know that 250 Watts is not enough to stop snow or ice forming.

I should point out that the data for Grimsvötn is from before the 2011 eruption and that to the best of my knowledge and google skills, there are no new figures out.

In the first couple of years the scar after the eruption started to slowly heal up, it was slow but that can be expected after a larger than usual eruption.

But, as we the decade started to wane we instead saw a reversal of the process, the scar started to become larger, during summer there was a little bit of open water (packed with ice shards, but none the less), and even a piece of the caldera wall suddenly became ice free.

By now Grimsvötn has turned into a true caldera-lake with almost 10 percent of the surface being ice-free during the summer months and an entire new section of the caldera wall is ice free. The glacier itself on all sides is looking like it has been struck by a sizeable blow and it is crumbling towards this new gash in the ice cover.

At the same time stories started to leak out about visitors and scientists having their shoes melted (anecdotal), but they have measured temperatures ranging above 70 degrees Celsius on that shiny newly exposed caldera face.

Scientist on the steamy rock side measuring gasses. This is the anecdotal moment when a shoe melted in sacrifice of science. Photograph from Iceland Review.

At the same time gas measurements taken show that the volcano is degassing at a pace that would make most volcanoes jealous during an eruption. Icelandic volcanoes are famously gassy during eruptions but having one degas as much as one of its erupting brethren, that is something for the history books.

The question is if this is a new thing, or if there was evidence of a change prior? In a paper released in 2007 Jarosch and Gudmundsson found that between 1998 and 2004 a depression that was 100 metres deep in the ice layer above the lake on the eastern side had formed with an associated increase in geothermal output ranging up towards 390 watts per square meter.

It seems like this increase in geothermal activity increased towards the SSW of the caldera after the 2011 eruption and that we can safely assume the heat flux now is well above even the figures given by Jarosch and Gudmundsson.

For those not familiar with Grimsvötn the scale of melting is incomprehensible. The glacier above Grimsvötn varies between 600 and 800 metres thick. This means that between 2 and 4 cubic kilometres of glacial ice has disappeared, with the bulk of it in the last few years.

An interesting sidenote is that in a previous article here in Volcanocafé, I and Andrej Flis found evidence for magma chamber expansion in under the caldera wall next to the area studied by Jarosch and Gudmundsson.

We then hypothesized that this expansion was caused by fresh hot magma heating this side of the magma chamber above the solidus point so that brittle earthquakes could no longer form, creating an expanding radius of earthquakes that had moved as much as a kilometre in under the old caldera rim.

It is not impossible that the same process is now occurring more to the SSW along the caldera rim, and we should get around one day to study that.

As some have noticed, there is a discrepancy in the GPS data for GFUM-station and the tilt data given for the GRVC station. As such this is not evidence of intruding magma since this would give widespread signals.

I would give everyone the friendly hint that until we know more, it is not that fruitful to ponder why GRVC is seemingly shooting upwards like a bat out of hell. My guess, if the signal is even correct, would be that it is isostatic rebound caused by a few missing cubic kilometres worth of ice. But, as of now that is just an idle guesstimate.

 

A little on Jökulhlaups

The 16th of April 2010 Jökulhlaup. Photograph from SwissEduc.

At this point I feel that I should write a short thing on Jökulhlaups since Grimsvötn is rightfully famous for them.

They are caused as melting water accumulates under the ice and suddenly pushes up the margin of the glacier and the excess water rapidly pours out forming the largest river on the planet for a short time.

I think that most people believe that the risk for Jökulhlaups would increase if you melt off a few cubic kilometres of glacier.

Let us first look at a couple of things. The first part is that due to continued uplift the caldera lake has domed up and decreased the size of the water reservoir. At the same time the reservoir decreased in size during each eruption since emplaced lava on the bottom squeezes out water.

This means that the average jökulhlaup will be smaller over time.

Now, let us put another nail in the coffin lid over the reservoir. Previous the reservoir had a solid lid above in the form of a 600 to 800 meters thick glacier. That lid now has a fairly large hole in it.

This means that the water pressure is regulated through that hole, instead of out under the glacier. Obviously, enough water and it will come out either way, but for now this is creating a problem for sizeable hlaups to occur. Smaller hlaups can though occur and might even become more common.

 

The near future of Grimsvötn

For reference, how the area looked a year ago. The difference is staggering.

That Grimsvötn will erupt in a not too distant future is not a big secret. But the question I have been asked is what these changes are and what the new data means for the upcoming eruption, and if it might be a sign that there could be a second Skaftár Fire around the corner.

I see the risk for a Skaftár Fire as slim to none currently. The reason is that the pent-up strain out in that part of the fissure swarm was well and truly released back when it happened, and that it will take a cycle or two more before it can rip apart again.

There is though a sizeable chunk of that fissure swarm between Lakí and Grimsvötn that did not rift in 1783 and several central volcanoes there. A sub-glacial mix between Gjálp and Skaftár Fires is not out of the question, but not the most likely option.

The second option is that we get a reactivation of one or more of Háabunga, Thordharhyrna, or that East or West Geirvörtur might erupt. Those might happen with radial fissure eruptions. These are fairly likely options. Either during the upcoming eruption, or during an eruption down the line.

A year later and we have happy steam. Photograph from EuroVolc.

Another less likely option is that Grimsvötn has a caldera extending eruption that is in the VEI-5 range (Icelandic sized VEI-5). It is in the light of the extending magma reservoir boundary a bit more likely than another Fire-style eruption happening.

Obviously Grimsvötn could pull of a standard sized VEI-3, and usually this would be the low odds option, after all it has erupted sizeably recently. I do not entirely buy into that, not when considering the changes in heat flux and magma reservoir expansion.

Now for the 3 options I do think are the most likely. These are in no particular order. The first one is that Grimsvötn suffers another radial Gjálp style eruption caused by weakening of the magma reservoir side, the most likely option for this is the case is down the radial fissure towards Hammarínn.

The second option is that we will see 2011 Redux with another brutal fast VEI-4. My favourite option would be that after a brief ashy Surtsey like opening of the eruption an island forms in the lake that transforms into nice shiny lava fountains.

Either way, Grimsvötn is quite able to do some more landscaping in the near future.

CARL REHNBERG

 

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/JB082i026p03719%4010.1002/%28ISSN%292169-9356.YLOWSMP1

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2006JF000540

52 thoughts on “The Hotness of Grimsvötn

    • I think there is a grand total of two cameras there, and they will go pretty much immediately when an eruption start.

  1. Very Intresting 👍thank you Carl
    The most curious I am about Grimsvötn
    is ( tons of sulfur a day ) thats produced now. IMO haves not given me any numbers on that yet in my own discussions with them.

    Its very clear now that This is becomming a very capable volcano.
    Upper magma chamber is also very shallow in Grimsvötn: the massive sulfur output, suggest that magma is very close to the surface now.
    The CSM plot is rather less steep after 2011: Probaly because the system is well heated up and produces less earthquakes now: ( expansion of the upper magma resovair )
    2021 will be a very intresting year

  2. Great article Carl!

    I was thinking about the bottom of the lake. Have the icelandians sent down a ROV or just sonar mapped the bottom of the lake ?

  3. ” VEI-5 range (Icelandic sized VEI-5). ”
    Is there a difference in the VEI scale between Iceland and the rest of the world?

    • Measuring the volume is not an exact science. The number has an uncertainty. If the range of uncertainty is such that it could be vei 4 or 5, the press may call it a 5 and a volcanologist may call it a 4.

    • “Is there a difference in the VEI scale…”

      Carl is alluding to IMO’s penchant for not taking a position on a matter unless they know for certain that it is true and backed up by the data. Hyperbole does not make for good public safety policies. Do it to much and people won’t listen to you when they should.

      Personal Opinion; Wasacane ISAIAS will probably cause more deaths in Florida due to the unwarranted intense media coverage than from actual wind and flooding. People will be less likely to heed warnings when an actual threat comes along.

  4. “Is there a difference in the VEI scale between Iceland and the rest of the world?”

    I sort of doubt it. Otherwise one eruption might be a VEI 1 in one country, but the exact same thing would be a VEI 3 in another.

    • There shouldn’t be a difference, but there is.
      The Icelanders tend to take the volume very seriously, so seriously that most often go with DRE instead of uncompacted tephra.
      Also, others tend to use peak columnal height instead of mean average columnal height…
      And so on and so forth.
      In Iceland and Indonesia they tend to use the strictest possible route all the time. Others not so much.
      That is how you end up with a VEI-5 with 40 percent of the volume of Grimsvötn 2011 and Kelud. Ho-hum…

    • It seems analogous with the way the surfers of the World measure wave height… And then there’s Hawaiian measurement… Something which appears to have a 3-4 metre face , I’ve heard Hawaiians describe as “Shoulder high”… Often talked about… Oozing testosterone . But if you know they’re Hawaiian, you just make allowances.

      • At surfing range the back side of a wave is usually about half the front in terms of height.
        Or so I heard from my brother who surfs. It might make a difference what the wave is breaking over e.g. a reef or a sand bar, or other features.

        • There is a riposte to that , which is “You don’t surf the back of the wave”.

          It all gets very tangled very quickly, but that’s what happens when you attempt to measure anything which has no fixed datum point.

  5. Thanks carl
    My brother thinks we will acually get a surtsey like Island in the caldera.
    Both me and he is very curious on how Grimsvötns lava acually looks like.
    In the car back: we went from Gothenburg to Stockholm: we discussed this the whole way 🙂

    Jesper haves a jar of 2011 Grimsvötn ash that he bought in Iceland.
    The ash looks like black powder and is very heavy. Very fine and lovely to toutch with the fingers. Using our cyclone – burner we melted a little Grim ash to a roud jet black glass pellet a few years ago. Jesper wants to move to Iceland later when he haves more job experience : )

    Our span deamon tends to put your comments in the dungeon. I am not sure why but do you perhaps have two accounts with the same email? -a minor dragon

    • Nope .. same account
      I just test diffrent names on my own name
      This name is a short-e- ning
      Perhaps in future it will just be my own initials

  6. I have to wonder if incandescent lava has ever been spotted erupting out of Grimsvotn’s caldera, Something like maybe what Lady E was doing while it was busy wreaking havoc with air traffic over Europe?

  7. Hi Carl,
    Nice article. Interesting comparison to Yellowstone Lake. The climate in Wyoming is not much like that of Iceland. They are both cold, but Wyoming is continental and Yellowstone is about 2500 meters above sea level. It can be -40 (conveniently the same in both F and C) and even colder there in the winter. It is also much drier than Iceland. Does that impact your “snow over” calculations.

    • Not at all.
      Grimsvötn is between 1300 and 1700 meters asl, and it can reach temperatures down to -40C or below. Being drier tips things the other way, it takes more heat to melt more snow.

      • I had no idea it was that tall.
        A Yellowstone park ranger told me a story about skiing from the lodge to the rangers cabin when it was -50 outside. Yellowstone can get very cold.

        I guess I was thinking that Grimsvotn wouldn’t get that cold due to relative proximity to the ocean.

  8. Icelandic Hlaup comes from the ProtoGermanic verb Hlaupan. In OldEnglish Hléapan, in OldSaxon Hlopan, in Dutch Lopen and in HighGerman Laufen.

    • Yes, that’s why Jökulhlaup translates to “Gletscherlauf” in High German.

  9. Carl, what do you think is happening to GRVC? I thought it might be the rise of the lake but the height of it puts it at some 100 meters above the lake. Well below the rim, but not on the lake.

    • It is placed on a position that is deemed as safe as possible on a volcano that is about to go boom. Also, it is good to remember that the rim at this spot is lower than the Nunatak on which GFUM is placed.
      This is why this part of the rim was previously below the glacier since it is lower than the GFUM-nunatak.

      Now to what is going on… and this will be at best guesstimates where I am indeed looking at tea-leaves.
      1. It could be isostatic rebound from the loss of 500 metres of glacial ice.
      2. Localized magmatic intrusion.
      3. Doming of a shard of the crater rim due to volcanic fluids.
      4. Heating of geothermal fluids (water) causing uplift.
      5. Rock expansion due to heat expansion.

      If I was spanked with a package of organic sesame seeds until I caved in, I would say that it is likely to be a combination of two or more of the above factors.
      There should after all be isostatic rebound, we know it has been heated up so magma is likely to have intruded, and that would have expanded the rock and inflated the existing water.

      In other words, I need to ponder this more to understand why it is showing so much bulging.

      • My tea leaf reading: it seems fast for isostatic rebound. It would need to be very ductile rock for that. Note also the lack of earthquakes. Fluids could do it, without earthquakes. Doesn’t say which fluid, but water makes sense. Rising magma should have been seen on other GPS stations.

        Do any readers have access to sentinel insar images of grimsvotn?

    • It’s in microradians, which means it’s a tilt meter and not a height measurement. It measures minute changes in the ground slope at the location of the device. A rapid increase near a volcano usually means inflation of a shallow magma reservoir. Long term changes can be related to other things, so take that graph with a good pinch of salt. Hekla is Hekla. She will blow when she feels like it and there’s a good chance she won’t give much warning when she does.

    • Another thing to keep in mind is that the tilt at Hekla has pretty much not changed since 2015. 2016 and onwards it has been moving around the same values.

  10. Is Grimsvötn the hottest magma in Iceland? and is there really any clues that Grimsvötn was involved 2014 s show? 2014 only Bardarbunga?
    Im confused

    • Let me try to clear things up.
      The temperature of a volcano in Iceland is depending on how far it is from the Mantleplume vs How short the path is from the mantle.
      The centre of the mantleplume is below Kistufell just north of Bardarbunga, that means that Grimsvötn is one of the hottest volcanoes in Iceland, but not necessarily the hottest.
      Grimsvötn has a very large magma reservoir, so the magma would be sitting there cooling off for some time before coming up, but that is the same for Bárdarbunga.

      A couple of years ago there was a paper published that showed the possibility that a northern part of the Grimsvötn Fissure swarm was involved, not Grimsvötn itself mind you. The spot that may have been involved is a proto-volcano named Greíp.
      The distance between the propagating dyke from Bárdarbunga turned right before hitting Greíp, and that paper hypothesized that magma at the Greíp reservoir might have helped to feed the Holurhráun eruption.
      I am not so sure that I agree myself with that paper.

    • Thanks Carl👍you are the expert on this stuff.

      Indeed Grimsvötn is not small.
      My own hometown just outside Borås can easly be placed inside one of its calderas.
      Being close to the center of the Iceland Hotspot, I imagines this volcano to have a huge magma supply. Lots of melting of the mantle below there.
      The magmas must have a ”highly thoelitic” composition because of large melt rates.

      How fresh was 2011? mostly glass right, with few mineral crystals?

    • Hi Im from Sweden too👍
      Grimsvötn takes up most the rifting in central Iceland.
      The magma comes from both rift and plume process for Grimsvötn. The supply is pretty prolific. The minimal supply is 0,09 – 0,1 km3 every year
      ( with 0,5 km3 as higher possibility) the magma is a titanium rich Thoelitic Basalt.
      Large melting rates under Vatnajökull and its very sulfur rich.

      The magma compositions for Grimsvötn and Bardarbunga is very similar to Hawaiis

  11. Grimsvötn caldera complex:
    is that explosive formation or is it an effusive drainage caldera? Its a pretty big crater complex. The maximum size for Iceland eruptions ( appears to be ) in the unknown? Nine years ago was pretty rad : )

    ”Grimsvotn 9 years ago blasted out
    1 km3 of magma in a week, that would give it an eruption rate of 140 million m3 a day, more than 10 times faster than 2014. Most of the magma appeared to erupt in the first day, which would give it an eruption rate of about 800 million m3 per day”

    • I don’t think that that is known. There have been major explosive eruptions of Grimsvotn in the early holocene, so that is a candidate. But with such an active volcano, the craters from these may have filled in already. Laki must have sourced its magma from somewhere, and may have contributed but can’t have caused the whole thing. And of course, you can’t rule out that it is the result of countless smaller explosions within the general area. It is related to the other question, why is this volcano so active? A third of all Icelandic eruptions come from here.

    • Purely basaltic volcanoes are often almost always drainage calderas. But Grimsvötn is a very large caldera complex, as well as Bardarbungas large caldera. If rift lava floods drained them, its very large lava flows indeed then.
      Many experts as Carl and others placed the Idea that Laki came from deeper depths and not a shallow resovair.
      Carl suggest the calderas was blown out by the famous ”Sakursunarvatn Tephra”

      Grimsvötn now seems to be in mood for more frequent small scale activity. ( I knows very little about volcanoes ) but Here is the debate point about large Icelandic calderas

    • The calderas formed in 5 cataclysmic eruption known as the Saksunarvátn Tephras, this is evidenced in the ash record retaken at Saksunarvátn a few years ago.

  12. https://phys.org/news/2020-08-iceland-volcano-eruption.html

    Carl – Albert here is Latest news from Grimsvötn! current status

    5 August 2010
    ”Grímsvötn appears poised for yet another, according to the Icelandic Meteorological Office’s (IMO).

    A Grímsvötn eruption—occurring roughly every 5-10 years—blasts through the glacial ice enclosing the volcano and the magma-ice interactions create a stunning explosion. “The lava melts the ice, it flashes into steam. There is a tremendous amount of energy being released in split seconds,” Ronni Grapenthin, a geophysicist at the University of Alaska, described to GlacierHub. Grímsvötn is also infamous as the source of the seven-month long Laki fissure eruption in 1783, which caused a famine that claimed 20 percent of Iceland’s population and lowered Northern Hemisphere temperatures by an estimated 1°C.
    While scientists are fairly certain another eruption is coming, forecasting the timing, magnitude and nature of eruptions is challenging because “each volcano is different and they behave differently, and you can have different behavior from one eruption to the other,” said Sigrun Hreinsdottir, a geodetic scientist at GNS Science in New Zealand. However, because Grímsvötn erupts so frequently, scientists see patterns that suggest another eruption is imminent. “Currently we have a state of the volcano which is very similar to the pre-eruptive conditions before 2011 and 2004 [eruptions],” Benedikt Ofeigsson, a geoscientist at the IMO, told GlacierHub.

    A team of scientists spanning Alaska to Iceland to New Zealand is carefully monitoring Grímsvötn. A high-precision GPS on the ground measures volcanic deformation—the movement of the ground—in real time. As magma flows into the volcano from below, the ground expands outwards from the magma chamber, like a balloon. According to Ofeigsson, Grímsvötn is “pretty much inflated to the same point as prior to 2011 [eruption] so it’s showing all the signs of an eruption well within the next month or year.”
    An additional piece of information suggests an impending Grímsvötn eruption: gas measurements. When magma nears the surface, the gases originally dissolved in the magma escape. “It’s a lot like opening a soda bottle. When you release the pressure, the gases come out,” said Terry Plank, a volcanologist at Columbia University’s Lamont-Doherty Earth Observatory. Since 2012, the IMO has periodically made gas measurements at Grímsvötn, but in early June, they “measured very high concentrations of SO2, CO2 and H2,” which Ofeiggson noted are unusual for Iceland. These measurements indicate that an eruption is near because the magma is just below the surface.

    Because Grímsvötn is completely covered by a glacier, it also has a subglacial lake—a lake that lies entirely below the ice. The heat from the volcano melts the ice immediately above it, and, as a result, a lake forms underneath in the caldera or crater. Periodically, the volume of water exceeds the capacity of the caldera, so a glacial outburst flood or jökulhlaup occurs, in which hundreds of square kilometers can flood. According to Ofeigsson “the lake [is] pretty full, so we also expect a jökulhlaup from Grímsvötn this summer.”

    When the volcano is ready to erupt, the eruption can be triggered by the flood,” Ofeigsson added. Grímsvötn has “a hair-trigger sensitivity to pressure,” so the pressure release from the removal of the lake water can start the eruption, explained Dave McGarvie, a volcanologist at Lancaster University. Therefore, for the first time, scientists are monitoring Grímsvötn’s subglacial lake level in real time. Because jökulhlaups triggered many past Grímsvötn eruptions, including in 2004, scientists expect the next eruption will also follow the flood.
    Despite the short window of warning—and Grímsvötn’s history of devastating eruptions—the next eruption is not expected to be bad. Every 150-200 years, Grímsvötn has a large eruption. Since the last big one was in 2011, scientists expect the upcoming eruption to be fairly small. McGarvie added that “most of [the eruption] in fact is contained within the glacier.” Because of the “magma-water interactions,” the ash is “pretty sticky;” it mostly falls within 40 km of the vent, hardly reaching inhabited areas. A jökulhlaup could be more damaging, but because they occur every 3 to 4 years, Iceland is well prepared for them. Bridges swept away by the 1996 Grímsvötn jökulhlaup were rebuilt to withstand flood waters, and roads in the south will close during the flood. Iceland will also have time to prepare, as the flood water must travel over 40 km under Vatnajökull first, McGarvie explained.
    In spite of scientists’ confidence that Grímsvötn will erupt soon, monitoring data is limited because the volcano is covered in ice. “As opposed to other volcanoes, we can’t really see as much as we would like to,” Grapenthin said. GPS instruments must be placed on bedrock because ice “flows much faster than the volcano deforms,” and there is only one site at Grímsvötn with solid bedrock ”

  13. Greetings from the Philippines! i love to read articles about the volcano. very interesting.

  14. How old is the Grimsvötn system and what was there before the Sakursunarvatn blowouts? Grimsvötn system hardly resembles the classic shield, or stratovolcano or even a avarge caldera system at all!
    Grimsvötn seems to be a pillow – hydroclastic lava plateau with a nested caldera in it. Infact its a mix of many types of volcanic edifices?

    • It is inevitable that any eruption under a massive ice cap will affect the edifice. That is seen even in Rainier. But it is hard to know the precise shape because of the ice. Grimsvotn is not a purely basaltic system: it is sitting on a thick crust which is affecting its magma. And the mountain is bigger than it may seem: the ice cap is hiding the fact that it is maybe 800 meters above the surrounding rock, and at least 20 km wide. Bardarbunga is bigger – but not by much.

      • If the dam thing blows Im going up there!
        I wants to see Grimsvötn in action from helicopter : )
        I rather be dead than be without it at all.
        IMO says magmatic pressures is on pair or even above 2011 s levels now

        • My guess remains early to middle of next year. Plus or minus 6 months. Do send us the videos!

  15. Three stars at Tjörnes, two M4 plus, not checked yet.

    Saturday 08.08.2020 03:52:58 66.251 -18.411 10.0 km 3.7 99.0 10.8 km NW of Gjögurtá
    Saturday 08.08.2020 03:42:33 66.250 -18.430 12.7 km 4.6 99.0 11.2 km NW of Gjögurtá
    Saturday 08.08.2020 03:42:32 66.248 -18.326 1.4 km 4.2 90.07 8.7 km NNW of Gjögurtá
    Source IMO

    Tjörnes and Reykjanes are taking turns now.

        • OK, then I say a week. Let us see who makes the best guess! Some more
          who likes to join in guessing??

          • No idea. But I think Grimsvotn will do another month of lowish activity. Does that count as prediction? And I am happy to predict the end of the world, of course. In 5 billion years time. Wake me up if it doesn’t happen.

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