Hunga Tonga and The Supercriticality Event

The eruption at 14th of January. Picture borrowed from Stuff.co.nz.

As the numbers for the Hunga Tonga eruption continues to come in it is becoming ever clearer that something truly momentous happened, something not seen or heard in 139 years.

With a columnar height of 55 kilometres, an explosive pressure wave travelling several laps around the planet, forming a medium sized deadly tsunami, gouging out a few cubic kilometres of rock, ash and silt, and so on and so forth it was to all points and purposes quite something.

Problem is that when we compare this eruption to a more common caldera forming event like for instance Pinatubo, we do not get the numbers to ad up. With such an enormous eruption column we should see very high amounts of SO2, and we should see a lot more erupted material.

The explosion does not seem to add up to the eruption. We need to figure out how such a comparatively small eruption could create such an over-sized explosion.

Judging from early satellite pictures we can estimate the eruption to have been between a mid-sized VEI-5, up to a miniscule VEI-6. So, we are back to 1991 and between Cerro Hudson and Pinatubo. So, the eruption is only small if we compare it to the explosion itself, in any other way it is the largest eruption in 31 years.

As explosions go it was the largest explosion witnessed by humans. Now remember that we are talking about the “boom” and not the eruption, humanity have witnessed quite a few larger eruptions.

Prior to Hunga Tonga the second largest explosion witnessed by humans was Krakatau in 1883, it has been estimated to have been between 20 and 30 megatons of TNT-equivalent.

It took the machinations of Beria, the insanity of Stalin, and the bizarre genius of Sakharov, but it in the early morning of the 30th of October of 1961 an enhanced Sluika with the project number AN602 was detonated with a yield of 50 megaton of TNT-equivalent.

The world named it the Tsar Bomba, and humanity for a brief moment in time grew a brain and stopped that particular direction of the atomic race.

Problem is that Nature is not that easily out staged. It was at that time busily priming a small non-descript volcanic caldera in the Kingdom of Tonga, named after the two small and equally non-descript caldera-rim islands, Hunga Tonga and Hunga Ha’apai.

After a bit of ever more impressive volcanic activity Nature was ready for the main show, and on the 15th of January it was showtime. Judging from audio tapes the main eruption was best counted in seconds, and in those few seconds Nature delivered an explosion in the range of 55 to 60 megatons of TNT-equivalent.

Incidentally, as I was writing this article the agency tasked with judging sizes of Nuclear Explosions just issued their calculations. It turns out I was spot on with my number of 55 to 60 megatons of TNT-equivalent. Just to be clear, I calculated this number on the 16th using barometric pressure readings, having confirmation of not being a “loon” is though always nice. Insert your favourite personal snicker sound here…

All we are left with are two miniscule remnants of the original islands, a gouged-out caldera, and a load of questions.

I will here try to answer two of them, and they are intimately inter-connected. Where did the SO2 go? And, what in the name of heck caused the explosion?

 

The missing SO2

The SO2 dispersion cloud from Hunga Tonga. Image borrowed from Newstalk.

This part is fairly easy to answer, and it has a profound effect on the second question. SO2 is a volcanic gas emitted from volcanoes together with fresh lava. Old lava contains comparatively little SO2 since almost all of it is transformed into all sorts of organic and non-organic sulphuric compounds, and those do not readily transform back into SO2 if lofted skywards.

We know that during the explosion a bulk portion of the bottom of the caldera decided to go and watch the movie The Adventures of Priscilla, Queen of the Desert at location in Australia.

In other words, it was a mixture of volcanic rock, old ash, old tephra, old pumice, and silt, that was exploded outwards, and that very little of fresh material was exploded skywards. And with little fresh material we get little SO2.

 

The Eruption Purist Interlude

There is a particular brand of stupid that now will start to argue that it was then a very small eruption, a VEI-2 or a VEI-3.

They will now categorically claim that the definition of every conceivable eruption scale is the amount of fresh material erupted.

I invite them to go and stand at a VEI-3 safe distance from the next Krakatau style eruption. Arguing pointless semantics is not your friend around volcanoes if you wish to remain alive.

The rest of us are probably happy with the total amount of ejecta, and the implications that have on life expectancy. So, let us move on to the main question. At least I am positively wet from anticipation by now.

 

The Other Volcanic Fluid

Water in two forms I do not like. Ice and cold water. This is the Thwaite Glacier, aka. the Doomsday Glacier, it will be quite gone in 5 years time. Image borrowed from the Rolling Stone Magazine.

Most of our readers are familiar with the term “volcanic fluids”, but I should explain it the same. It is a term often used by volcanologists as they describe any unknown fluid inside of a volcano. Often in relation to inflation or deflation of various sections of very large calderas.

The fluid could be magma, water, molten sulphur, and so on. Basically, anything that is fluid enough to move around causing changes in a volcano, either by intrusion, or by being pressured into a new area.

In large dying calderas like Yellowstone this would be counted in as little as an inch or two over a year. But, in other livelier calderas it could be counted in metres in just a day or two. The latter holds true for calderas like Amatitlán, Campi Flegrei, and Tondano, just to name a few.

Typically, both laypeople and volcanologists are way more interested in the potential for magma movement, after all, that is what we perceive as the dangerous version of volcanic fluids. Turns out we may have been quite wrong about this.

Up until now the only type of volcanologist being arse bothered with the water part was geothermal volcanologists, and we are far and few in between.

So, to understand things we need to study water for a while.

 

Don’t tickle when wet

Water is an amazing and life-giving fluid existing in a surprising number of different forms. Let us get more intimate with those forms.

First of these forms we have the whisky cube form known as ice. The only version I like is the ice cubes in a drink, I come from Northern Sweden, and we hate Ice in all other forms. It has a magical property, and that is that it takes up a larger volume in frozen form and is thus lighter than water. This is why it is floating on top of lakes.

This is important to people from Northern Sweden since it makes it possible to drill holes in the ice to fish. It is a very miserable and cold version of fishing. It also gives us the opportunity to drive around on top of lakes with building material where there are no normal roads.

Then we have normal water existing between 0 and 100 degrees if we are at oceanic altitudes. We drink it, swim in it, drown in it, use it to cook, and so on. Most people use it to make coffee or tea. It is more often beneficial than not.

Above 100 degrees Celsius (there is probably some weird Imperial number for this that I do not know, and am to lazy to google) we enter the realm of steam. Victorians with impressively high hats understood steam, most of the rest of humanity do not. So, let us don a very high hat and barge onwards into our steamy business.

Isambard Kingdom Brunel with impressive hat, he understood steam well. Wikimedia Commons.

As your teakettle starts to boil you will see white stuff start to waft around, most people think this white stuff is steam. Alas, it is not. It is tiny water droplets that are suspended in the air. They form as the surface turns 100C and steam forms to instantly cool below 100C and the droplets form. The steam-layer is literally one molecule thick top-layer of water, so you will not be able to see it.

It is though amply possible to hurt yourself with your white fluffy wispy stuff. But, to get steam we need to raise the temperature beyond 100 degrees Celsius.

To go beyond we need to ad another force, more heat does not cut it, that would just produce more low energy suspended water droplets at a faster pace. We need to insert pressure into our equation.

Water is funny, it will boil at different temperatures depending on your elevation, this is due to the pressure dropping the higher we go giving us lower and lower temperatures for when the water droplets will form what we call “steam”.

If we instead increase the pressure, we well and truly reach into the realm of flash steam. This is any temperature between above 100 and 184 degrees. In the latter case we need a pressure of 10 Bar (atmospheric pressures, the atmospheric pressure is really 1.01325 Bar, but close enough). This is the same pressure you would find at 100 metres depth of water.

Now imagine being that 184 degrees Celsius pressurised water, as long as you are at or above this pressure you are water, but if you even drop a tiny amount below this pressure, you will instantly flash from 1 litre of water into 2100 litres of suspended water droplets. But if you are contained in a volume less than 2100 litres you will stay in true steam form above 100C.

If you are above that temperature you will get something called dry steam, it is an invisible mess of hotness. It is steam kept at high temperature and pressure, but below the flashover point.

Now, remember the poignant word for us is flashover, this is the point where any amount of water will explosively decompress from water into steam.

There is though one step up from this on the giggly tree of water. It is called Supercritical Fluid. It is water that is at such a high temperature and pressure that it simultaneously behaves as a fluid and a gas, while being neither of those things.

If pressure has the upper hand, it is behaving more like a fluid, and if temperature has the upper hand, it behaves more like a gas.

Steam and water up to this point has been manageable, you obviously need to treat it carefully, but you can safely build systems to power ships, steam locomotives, and all power generation plants with it.

Well, the safely part is not true. Those high hated Victorians literally blew up tens of thousands of workers during the industrial revolution before they mastered their craft, ho-hum history is fun.

Water in supercritical form is the suicidal psychotic giggling version of water, it not only wishes to not exist, but it at the same time also wants to take everyone with it in a big boom. If that was not enough, it likes to go through solids like they where made out of paper. It is also very good at dissolving solids. You need specialised materials to even contain it.

So, you want numbers on this branch of the giggly tree? Supercritical water forms at minimum of 373 degrees Celsius and 220 Bars of pressure. Yes, this is the minimum, in some volcanic systems the Supercritical water can be up towards 800 degrees with corresponding mind-numbing pressure values.

This is the only form of water that could have caused the explosion at Hunga Tonga. There may have been other more normal forms of water involved, but they lack the energy density to produce that kind of explosion.

Incidentally, 220 Bars of pressure is reached at less than 1 kilometre’s depth if we use the specific density of bog standard rock (2.3kg per litre of volume, it is probably something in Imperial that is really hard to calculate).

 

What was down there?

Hunga Tonga becoming Hunga Byebye. Image from Himawari-8.

If you are like me, you will often and fondly imagine that you are a piece of drill steel being drilled into a volcano. It is not as bizarre as it may sound, after all my daytime job is to plan how to best drill into volcanoes for geothermal fluids to drive geothermal power plants with.

Even though we do not exactly know how Hunga Tonga’s geothermal system looked like, we know a lot about geothermal volcanic systems in general. After all, people have been drilling into them for quite some time.

Most often the drilling has been down into more normal forms of geothermal water. But, at times we have found Supercritical water down there.

A caldera is most often a closed off geothermal ecosystem. At the border of an active caldera, you often have an active ringfault, the inner side of it is often filled with material that is easily permeable to water, while the outside tends to be more sturdy.

Int the case of Hunga Tonga this geothermal ecosystem had a free and endless supply of surface water in the form of the Pacific Ocean. And over time that water slowly permeated down through the crushed up rock that constitutes the roof of the magma chamber.

As it went down it heated up and started to pool in layers (geothermal aquifers) depending on pressure and temperature. The upper ones would be the flash steam portion, but that is not as such interesting to us.

We are mainly interested in the water that climbed up the giggly tree hellbent on throwing itself down, aiming to hit every single branch, in other words let us stick to the Supercritical water.

There was probably one such supercritical layer slightly below 1000 meters depth. This would have been the prime driver of this layered volcanic cake (Sluika = Layered cake in Russian, just another hilarious detail).

Below that there was at least another layer of even hotter and more pressurised supercritical water. There is circumstantial evidence of a third such layer, so let us say that there was 2 to 3 supercritical geothermal layers inside the caldera.

These layers often move about upwards and downwards as they go, and the water is circulating around in them in unexpected and intricate ways.

At older more mature calderas like Yellowstone the supercritical water will find ways upwards with time, and they form some of the more spectacular features like geysers, hot pools, and all the other assorted geothermal joys in life.

Hunga Tonga was young and probably had not had time to become a truly circulating geothermal system. Well, not as far as we know that is.

As long as there was no eruption the supercritical water was happy where it was, it was of course trying to run away to the surface, but it seems like it was very slow going. And that was a good thing since there seems to have been 0.5 cubic kilometres of giggling hell-water down there.

 

The recipe for doom

The reason that these explosions are rare is because you need a large eruption to kickstart them. A normal eruption will just punch a hole straight through the aquifer with the lava quenching the hole as it passes through. It is like the lava is wielding the aquifers shut as it passes through them.

Most of the water that was seen in the vent came from much more shallow infiltrations of sea water, so let us not mix them together. What little came up from the depth just worked as an additional driver of the eruption.

All was well up until the 14th of January. It was a typical fairly benign Surtseyan eruption slowly building up to an archetypical VEI-4 eruption. On the 14th we had the main eruption, a VEI-4 of some magnitude that removed quite a bit of the island the vent was located at.

It was this excavation of material that spelled the doom of the caldera. Instead of rockmaterial of various sorts compressing the first supercritical layer we now had comparatively lighter water on top. Instead of the 220 Bar we might have had as little as 100 Bar.

I wish we would have had instruments and a camera there when what followed happened. It would have shown a wild ride.

As the pressure from above was lowered the Supercritical water started to move from a more fluidlike state into a more gaslike state, in turn pushing what was above upwards. In the first hour the uplift was probably just a few centimetres, but in the end the ground probably bulged several metres an hour.

In the end the rock layer could not hold it back, instantly all of the supercritical water transformed into dry steam (flashover) and as it did so, it flung up the rock above it in a process taking a second at most. With this layer removed there was not enough pressure left to contain the next layer, and that went up a few second later, and most likely the process had a final third explosive decompression.

All that now remained was for the ocean to fall into the hole that had been produced. At this point there was just a little bit of boiling of the sea water, and the eruption was halted for this eruption.

In a while an “Anak Hunga Tonga” will be born as the volcano rekindles its work, but that is a story for the future.

 

Conclusion

The question that remains is as follows: Have we just been lucky? Is this a style of eruption that could be far more common that we previously believed?

I think we have been lucky indeed. It is most likely far more common than previously believed, because this type of eruption has a much more common form named a Maar-formation.

Unlike a normal Maar-formation (that can be quite ugly) any calderas contain large amounts of supercritical water, and in my view, it is imperative that we upgrade our risk-assessments to also include this style of eruption.

For calderas near cities like Campi Flegrei it is important that we drill deep into the roof of the magma reservoir to build accurate maps of how much supercritical water there is, and where it is located.

This was a fortuitous wakeup call for science. We need to learn, and learn quickly, because having Tsar Bomba going off next to Naples is bad mojo indeed.

CARL REHNBERG

847 thoughts on “Hunga Tonga and The Supercriticality Event

  1. Could this even be possible? Seems unlightly unless some never-before-seen effects were involved…?

    From spaceweather; “A SUNSET FROM TONGA? When the sun goes down tonight, take a look at the fading sky. If the twilight turns purple, you might have spotted a “Tonga sunset.” Heiko Ulbricht photographed this example Jan. 21st in Großopitz, Germany:”

    Seems improbable to me, but maybe a good time for the VC-community to keep a watch out and take photoes if it occours?

    Never-measured-before effects discussed here;

    https://eos.org/articles/the-surprising-reach-of-tongas-giant-atmospheric-waves

    Norwegian Broadcasting (NRK) had an article saturday with mentioning of possible effects on global weather. Sulphuric acids aside. It is a bit difficult to find which of the scientists who have stated “can effect weather in Europe” from the article and the links. Use uncle Google if Norwegian is gibberish to you. Will reduce gibberishness somewhat.

    https://www.nrk.no/urix/vulkanutbruddet-forte-til-noe-forskerne-ikke-kan-forklare-1.15821232

    GFS-forcast is trending down, BUT that has definetely a probability this early on of being a 100% coincidence. Worth following for a while though. 😉

    http://www.karstenhaustein.com/climate.php

    We need to see the “hole” this made. Need to analyze the fine grain particles. Need more data. Of all kinds. But I cannot stir the feeling of there being a whole lot else than SO2 to worry about in the mix “up there” now… Insert any amount of water you feel like into 300 km. x 300 km. x 3,14 x 35 km. (numbers used frequently here(9,8 mill. km3)) and one might be surprised how little say 5 km3 of water (Carl used 0,5) – even expanded by a factor of 1 000 adds up to of the total column…. It can perfectly well be a huuuge amount more water. But.

    Sunday thoughts and droodling…. 😉

  2. Really fascinating article…
    I am very dubious about the official data from NASA/USGS; especially when we have historical data from previous eruptions and live satellite measurements, if we bother to use them, from Corpernicus on sites such as windy.com. It seems as if the science is no longer science, but rather policy-based evidence making for corrupt governments. (excuse my cynicism). The two things that concern me is the amount of SO2 and the actual blast itself, VEI is almost irrelevant in this case (I am thinking it could be closer to VEI-7 than VEI-5).

    NASA gave a figure for the SO2 to be 400,000 tonnes, I think that is complete codswallop and is more likely to be between 150,000,000 to 200,000,000 tonnes (if my calculations are correct). A few days ago, using the lat/lon gridlines on windy, I measured a rough SO2 plume size (the main one to the west of Australia) at roughly 2,100,000nmi2. (7,500,000km2) I noted a series of measurements of the concentration of sulphur dioxide in the plume, averaging out at 200-250mg/m2, maxing out around 500mg/m2. Converting the km2 to m2 (7,500,000,000,000m2) and then multiplying it by the mean concentration, and then dividing by 10,000,000 to give me ~187Mt of SO2. Bigger than Tambora in 1815. Am I missing anything in my calculations? Taking a mean average and multiplying by the area?

    The other thing is the blast. Krakatoa in 1883 had an explosive force ≥150Mt/TNT and that sent shockwaves and around the world and was heard 3000miles in Western Australia. Shockwaves such as this, generally, have a sound level of >190dB. At 165km, Krakatoa was measured at 162dB and using inverse square law, I reversed the calculation to around 200dB at source. (may not be entirely correct). For it to be heard in California over 4600nmi away, in which police reports were allegedly filed, clearly in the ~120dB range. Therefore an equivalence only 6Mt/TNT seems to be, again, quite deliberately wrong. Are NASA/USGS expecting us to believe that only 4% of the explosive force at Krakatoa could take the blast further the 3000nmi recorded?

    Is there anything I am missing or not fully understanding?

    • Peter, I think it has been cleared up in the way that the “6MT TNT” quote just meant the energy needed to erode the islands. This is of course far lower than the total energy, and has unfortunately been mixed up.

      Also, the energy in the pressure wave of Krakatoa has been well established, it was about 34MT TNT (the paper by Yokoyama I quoted several times). The present wave was about twice as strong, give or take, thus the 60 or so MT TNT we are always debating. In the pressure wave alone(!)

      Now what does that say about the total energy now vs. e.g. Krakatau? Not a lot. Krakatau may well still win there, hands down. Longer duration, more material excavated. But to have a precise number, we first have to sum up.

      • It isn’t clear if the existing islands were even eroded that much. They might have merely sunk until only the highest elevations were left exposed. This was mentioned in the Science News article linked in a preceding comment.

      • I read somewhere, that the TNT was 150Mt/TNT, I stand corrected if it was only 34. If that is the case, then Carl’s figure of 55-60 would seem to make sense.

        • Total energy of the entire Krakatau-Show is sometimes given as 150 or 200MT TNT. That figure however is highly speculative for sure. And logically much more than the pressure wave. Pressure wave energy is calculated the same way Carl did it in the paper I quoted. 34MT TNT give or take.

    • “Is there anything I am missing or not fully understanding?” Possibly.
      You basically started of with an understanding of VEI, then scaled the volcano up to 7 though. The VEI is about the volume of rocky material, and it is certainly not a 7. Albert put it at a five, but he might have overestimated the size of the crater in relation to the mechanism involved. That is unimportant though as it will be seen by field work which is impossible at the time being. I guess it will in the end be a 4 or 5.

      TNT of 10 is an estimate of Jim Garvin from NASA Goddard Space Flight Centre. Normally they are trusted. TNT 10 is 500 times the Hiroshima bomb. That’s not enough to impress? I think it is outrageous.

      A finger like that in the middle going up to considerable heights is known to the Japanese, little wonder. A tsunami like this is peanuts for them. They have the best tsunami documentation in the world sitting on a setting which is in some parts similar to this one. It might worry them less, not more, about Iwo-Jima.

    • If we do with the nonsense that this was a primarily H20 eruption
      That means an awful lot of gas was involved
      S02 and Co2
      Possibly pinatubo levels

        • Perhaps better to say that there was very little magmatic gas involved.

          There was a huge amount of gas involved in the explosion but mainly because the explosion resulted from the phase change of that material.

          • I agree David.
            I was a tad sloppy.
            There was very little SO2 and CO2.
            The latter is not that unusual since volcanoes are not champagne driven (joke).

          • If their was no magmatic gas involved how did that level of instability occur to cause such an event
            Remember this volcano was erupting vigorously just days prior
            And magma needs gas content to erupt
            What you say makes no sense

          • Where did I say that there was no eruption leading in the days before?
            Where did I say that there was not an ordinary eruption leading up to the big detonation?
            Nowhere, and at no time, did I do that.

          • So, you dig out a paper on a one of a kind monogenetic cone where basalt have gone through a carbonatite layer.
            And you missed the part that 89 percent of the volatile mass was water (if I remember the paper good enough).

            Sunset is though impressive in it’s uniqueness, it is like if the Coca-Cola Company had decided to build a volcano.

            There was very little volcanic gasses at Hunga Nomore. That little fact does though remain.

          • I think you might have misread the 89% from;

            “The total dissolved H2O and CO2 content of the Sunset Crater magma was 4.6 mol% at the time of MI entrapment, of which 89 mol% was H2O and 11 mol% was CO2.” In the paper.

            But you basically do not think insane amounts of S, CO2 and H2O could be in melt inclusions (MIs) ? I for one am curious to see dust analysis, ash analysis, barymetric data, pre/post-mappings aso.

            What do you believe the watercontent to have been as % of the column Carl?

            Crazy almost cherry-coke coloured moonrise over Turkey here tonight btw. Darker and more red than the normal Harvest-moon in autumn.

          • Since we do not know the exact amount that was gouged out it would at best be a fairly large amount of guesstimation to any number.
            Let us say the 5km3 in volume was gouged out, and that it was propelled by 0.5km3 of water.
            But, guesstimate.

      • From what I heard, Tonga was reporting sulfur smells all during 2021.
        So there must have been a lot of degassing in the months before the eruptions.
        Which matches Carl explaination.

    • I think that is for you to decide! The lack of people within 50 suggest no short-range impact. It seems severe impact only at 70 km, and a little impact much further away

      • I am thinking VSI 3 or 4 then…Thankfully this was a relatively isolated eruption, so the only major Impactor was the tsunami.

        • I am actually impressed how well Tonga weathered the eruption. Very few casualties, and well organised. They obviously had trained people to respond to the tsunami warnings (I think they had ten minutes). They will need help, but this could have been a lot worse. Of course, had they been 10 km from the outburst rather than 70, no training would have helped. They were lucky as well, but luck does not help if you are unprepared

          • I read that Tonga and Samoa had activated a tsunami warning as early as 14/01 due to untimely ocean movements on local tide gauges.

            As soon as they perceived the explosion, people fled the seaside. (very clear in one of the films).

            The others waited for confirmation from the warning buoys that it was serious.

    • A second scale like this would make sense. Tambora today would kill an estimated 8 million I read, so be 12 on your scale.
      The link to the New Yorker, under Jesper who will most certainly like it, is about a neighbour of yours, Robert de Palma from Florida, and his discovery. He is the nephew of filmmaker Brian de Palma. The way the fossils are arranged there shows signs for a flash flood.

  3. Alaskas Pavlof Erupting .. woff! wvovovo!! woff! bark, bark! 🐕

    • Never change, Jesper. I mean that sincerely, you crack me up.

      Looking forward to your Nyiragongo article!

    • Yes, that was interesting and I am sure people will look at images of Hunga Tonga of November and December, prior to the eruption. It is similar to measuring enhanced outgassing in land-based volcanoes. You do compete with run-off from the islands which also discolours the water around it.

      • I suppose it’s like any monitoring, regular samples to see any patterns would be needed to indicate a change versus background. Given the prevalence of satellite images and how much area they can cover it doesn’t seem impossible that a lot of submarine volcanos could be monitored say once a week. Especially the ones closest to population. And zoom out can sometime show things that you don’t see when too close in.

    • Some entertainment. The Day the Dinosaurs Died:

      “I called, and he told me that he had discovered a site like the one I’d imagined in my novel, which contained, among other things, direct victims of the catastrophe. At first, I was skeptical. DePalma was a scientific nobody, a Ph.D. candidate at the University of Kansas, and he said that he had found the site with no institutional backing and no collaborators. I thought that he was likely exaggerating, or that he might even be crazy. (Paleontology has more than its share of unusual people.) But I was intrigued enough to get on a plane to North Dakota to see for myself.”
      https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died

      • Wow, the exact moment. Really was a true apocalypse.

        Also actual feathers from Dakotaraptor, guess there is absolutely no more argument to be made on featherless raptors, this one was the size of a lion, not a chicken, no small beast at all…

        • Yes, impressive. That’s why he decided to call it Tanis.

      • I was quite skeptical about the initial reports of the Tanis site, because (as others said) it seemed to good to be true, plus the 3 meter problem was well known (lack of sites just before the KT boundary). However, I was delighted that I was wrong.

        Since the linked article came out in 2019, there’s been a new find reported at Tanis; an impaled turtle.

        What really opened my eyes though was the preserved impression of dinosaur skin; that, in conjunction with the tektites, is the strongest evidence ever found of a dinosaur alive (or very recently so at the KT boundary.

        My guess is that most dinosaur species alive at the time went extinct within days or months of the KT impact. So far as I know, only one branch of the dinosaurians survived the KT impact, a branch of therapods. Those were the ancestors of birds.

        • Was not just that, only birds with freshwater aquatic habits made it, seabirds and terrestrial birds were wiped. Possible exception were penguins, but late Cretaceous penguins were not really so special all things considered, generic seabird more or less.

          There is though, a controversial fossil of a non-neornithine bird from the early Paleocene, Qinornis, so possibly there were a few lingering survivors of several groups. Obviously no megafauna, but very small non-avian dinosaurs were often time really different from birds only by our technicality. There is also a reliable fossil of an early Paleocene ammonite, 5 million years after the KPg boundary, and repeated though not proven claims of even quite large dinosaurs fossils ever so rarely found in layers dated from the early Paleocene. It is though also possible (probable?) those are reburied fossils, as is usually presented.
          Seems that there is always a second hit to a mass extinction, the survivors go crazy and then a lot of them go extinct very suddenly. Lystrosaurus might be the bext example, Coelophysis could be another.

          • I recall seeing one analysis that postulated that the surviving avians were ones with beaks, thus allowing them to scavenge seeds, etc. Quinoris looks to have had a beak, maybe. I hadn’t heard of this fossil until your comment, so thank you!

            I think you’re right, the ecosystem radically and permanently changed after the KT impact, even after foliage recovered.

            I’ve been trying to figure out how many avian species survived the KT event, to become the ancestors of modern birds. It looks to me like the fossil record is very sparse regarding avian ancestors, so this may be unknowable, but it seems to me that the diversity of avians very soon after the KT event means its unlikely that Avians are all descended from one KT-surviving species. The ratites and galloanserae seem especially unlikely to have branched off after the KT event.

          • The split between Paleognathae and Neognathae was during the Cretaceous, at the very least. Seems also there are mesozoic fossils of penguins and ducks too, penguins are actually relatively derived so possibly most bird lineages already existed just were largely indistinguishable among the vast array of other birds.

            Same thing seems to have been the case with mammals though too, most major groups of mammals have a late Cretaceous origin, only to diversify later.

          • @ Denaliwatch;
            I wasn’t aware of either of those, so thank you very much! The “wonderchicken” especially is IMHO an extremely important find, assuming the dating of it as pre-KT-impact is certain (as the article seems to indicate that it is – though I’d sure like to know their methodology). To me, this looks like proof that multiple branches of the Avians survived the KT impact.

            @ Chad;
            Mammalian survival is intriguing to me; most mammal species didn’t survive the KT event and after effects, though a lot did. All that did survive were quite small, and may have been burrowers. The thing is, a lot of dinosaurs were also small, and some of those small ones were burrowers. Yet, they did not survive, but the mammals did. Why would a rat-sized mammal species, and a rat-sized ground bird, survive, when a similar sized dinosaur did not? My only guess used to be that it was diet; perhaps dinosaurs couldn’t eat fungus. But, I was wrong; there’s now evidence that Alaskan dinosaurs ingested decaying wood (a big indicator of eating fungus). I’m guessing that fungus would be a prime food source after the KT impact because of all the dead biomass.

            Could it be temperature? Perhaps the small ground-dwelling dinos were not equipped with feathers or fur, so could not survive the post-KT months of no sun and cold? But, what about cold-climate dinos? Alaska (most of it, anyway) was as at least as far north as it is now, and even in that climate would have had freezing temps in winter. Those dinos thus must have been cold-tolerant (and able to survive the months with no sun).

            Or… is it possible that some small non-avian dinos did survive, only to be out-competed by the resurgent (and some species rapidly increasing in physical size) mammals, who were better able to quickly exploit the ecosystem changes (such as all large predators being extinct), so the few surviving non-avian small dinos went extinct within a 100k years or so?

            My guess is that the answer is multi-faceted; more than one thing. I just have no clue what those things might be. 🙂

  4. For readers here who haven’t seen it it is worth reading the whole piece.
    Besides a precise dating for the day many of the dinosaurs died – if not most – by finding tektites it shows some other important details:
    1. Feathers
    2. Seiches
    3. The way scientists when not equipped with a great name yet are treated by institutions. One of the shocking details is how the then young man’s bone collection disappeared because he had no written proof of ownership. That must have scarred him.
    4. The way scientists treat each other (the Bone War).
    5. The permanent ridiculizing which can destroy some people.
    6. The unhealthy practise of private auctions of fossils, a part of history that should belong to everyone. An example of a top auction of a T-Rex.

    So, it is a very complete well-written piece, in itsself a piece of history.

  5. You really shouldn’t use nuclear bombs as a comparison for explosions. It is important to remember that “megaton TNT equivalent” is a measure of energy (about 4 giga Joules), not of power. The power of an explosion is the energy released per unit of time. Nuclear explosions are very quick compared to anything humans have an intuition for. Thus, for the same energy, i.e. the same amounts of equivalent TNT, a nuclear explosion can have thousand or ten thousand times more power than for instance a chemical or steam explosion. Since it is the power of a nuclear explosion that makes an impression, this comparison tends to lead to a false impression.

    • Here I disagree to quote some extent. First, we use MT TNT energy equivalent as an energy scale. It has per se nothing to do with a nuclear blast. I mean, it is called “TNT equivalent”, a classical chemical explosive! 1 MT TNT energy equivalent is simply 4.2 PJ. When we say the pressure wave energy was 50 or 60MT TNT, you can just multiply that number by 4.2*10^15 and be happy with Joules. Nothing nuclear at all. It just gives more handsome numbers and sounds flashy.

      Why references to nuclear explosions entered the discussion is because they are the only way that humans have ever created comparable pressure waves. No one says it is a simple 1:1. No one. But it is also not quite as skewed as you make it sound. The fission and fusion processes are very rapid, yes. But what happens then? A lot of the energy is initially emitted as soft X-rays, which penetrate the atmosphere to order meters / tens of meters. Heating of the atmosphere forms a fireball, which in turn is then overtaken by the shock front. From then on timescales are way detached from the nuclear timescales, and allow indeed for comparison. Actually many methods for gauging nuclear blasts were at some point calibrated using “classical” explosions. If that would not at all work, that would have made no sense.

      Bottom line: a nuclear airburst in the lower atmosphere will deposit about 40% of the total yield in the pressure wave. That is a very substantial fraction, and it is not at all clear that volcanoes are in any respect more efficient in making pressure waves (see Helens, 24MT TNT total, 7MT TNT pressure wave, this is less than 40%). Admittedly, very high yield fusion bombs will suffer more drastically from thermal losses, but still, a 58MT TNT nuclear test producing a pressure wave substantially less intense than the one we just observed is telling more than nothing about scaling.

    • I think the point is the word “explosion”. That is an amount of energy in a very short period of time, concentrating (as Dominik points out) on the air pressure wave. As such its a very apt comparison. Admittedly its an implied power rather than energy, but since there is no other commonly used value for a large discharge of energy in a short time period, to use petawatts (or more likely and even more extreme unit) is probably unhelpful.
      I wonder if you could suggest your alternative measure?

  6. Very interesting article, Carl! I always liked the short glimpse (1/2 year) I had into thermodynamics during year of my graduation 🙂 Sadly didn’t go into supercritical fluids though.

    What do you all think are the telltale signs that this detonation wasn’t a *true* nuclear (test) explosion? Place would have been pretty much ideal (disguised by random volcano) 😀
    I think there would have been at least some radioactivity detection by now..?

    Sorry for my question, had discussion with my dad but I didn’t have too much facts against his view, or I didn’t feel safe in my facts =(

      • He wouldn’t be surprised if it was a test perfectly disguised as a (unexpectedly) weird volcanic explosion, kinda like underwater test of Tsar 2.0…
        All the news etc. could be faked, measurement of the pressure wave already shows more than original Tsar bomba.
        But ya, obviously borders conspiracy theories ==> so won’t talk more.

      • The first one that did not upload is Bikini, the second one Castle Bravo.

      • Stupid how much they tested 😀
        Thanks for the reminder. Appears to look a lot more symmetric and clean than what has happened a week ago…

      • There where acually sovjet plans on the table of build Nukes with yeilds thousands of times bigger than Tsar Bomba .. to be able to wipe out entire countries

        But these plans where very quickly scrapped after the Tsar Test.. Tsar was to have 100 megatons as original design, but was scaled down

        A real ”Worlds Ending Nuke”
        Woud have to be assembled on a giant ship, souch non arieal based nuke explosions have No limit of their size.
        Then that ship dressed in civilian paints coud be brought to the country that To be destroyed .. There you can dwarf the Tsar Bomba as the ship is blown up

        Or better make a whole umanned submarine of the ten thousand megaton giant nuke .. and the nuclear device coud just swim unseen to distant shores.
        Giant Nukes built and disgusied as submarines woud be a scary sight

        • History and movies, not politics:
          Read this, this gave a lot of people something to think about:
          https://en.wikipedia.org/wiki/Vasily_Arkhipov

          K19 was made into a rather depressing movie by Kathryn Bigelow: K19, The Widowmaker. Most of them survived. B59 was made into a phantastic real Hollywood-style movie in a different setting with a fictional story in the Pacific Ocean called: Crimson Tide.

          I saw most of the submarine movies. The dangerous thing was that they got an order, and then they staid dived. To not be heard by other subs they were not allowed any communication. So they had to make decisions without headquartes.

          Red Octobre is fictional too (possibly). Very good. They cruise around near Iceland first.
          Then there is an old one with Captain Ahab, sort of (Clark Gable). Second World War, Pacific side, Japan: Run silent, run deep.

          The real danger was submarine. I thoroughly recommend them when bored. Fascinating stuff.

          • 😉
            I prefer happy endings.

            I like it more when they sail into Maine (Red Octobre) or Hawai’i (Crimson Tide). It is extremely sad to save a boat and then be attacked in a harbour.

          • In between I saw “Midway”. Then I read about this guy:

            https://en.wikipedia.org/wiki/Isoroku_Yamamoto

            and read this:
            He also opposed war against the United States, partly because of his studies at Harvard University (1919-1921).
            He travelled around too, seems to have loved the United States.

            I spent two or three days thinking about fate and Greek tragedy.
            He died over Bougainville. What a waste that war was, a total waste. A guy who loves the United States has to attack the United States – what a terrible fate – and is then killed by some guys who he would have been friends with in peaceful times.
            That is why we were lucky so far and should be happy. Some younger people are not aware of it any more.

        • The ideal tsar bomba at tens of thousands of megatons woud be as a mobile nuke built as a submarine. That mega nuke coud unseen swim into city habours and really blow up entire countries, A solution for mega nukes that too large to be fit on ICBM s

          • Could? No. They know what the opponent has. But then there is also “The Wolf’s Call”. That one is very depressing.

          • Just as an idea, Nukes that does not have to be flown into space, can be built as large as you want, a giant thermonuclear device with a yeild of a an asteorid impact can be bult as a giant unmanned submarine, just put a propulsion system on it and bouynacy system. Souch a doomsday machine coud be sneaked into many habours, tens of thousands of megatons is maybe possible with souch a marine stealth nuke

          • Jesper

            I have to believe that nobody would be so crazy to do that. In order to stay alive I have to believe in some reason and humanity. And some services maybe to be on the safe side.

          • Thats true… what I say is that its possible, and that model is the best way to create nukes too large to be ICBMS… souch hidden mobile marine nukes coud be as large as you wants, with devices 100 s of meters long maybe possible

            But indeed no one will build these… as you say
            I hopes my comments does not inspire any crooks or malificus states 😉 🙂

            But yes you are correct

          • I just dreamed of a thermonuclear device as long as Oasis of The Seas
            Souch devices woud perhaps be too large to make into stealth submarines, needs alot bouyancy. They woud have to be built as giant container ships kilometer long… now we are getting into scary stuff

            My sligthly smaller ( still huge ) devices coud be used as stealth submarines

    • A nuclear explosion would have released a lot of radioactivity.
      So wasn’t a thermonuclear bomb test.

      Unless this would have been the test of a pure fusion bomb.
      Which would be in line with the size of the explosion (near or above that of the Tsar bomb size, which was the largest nuke ever detonated).

      But even then one would hear reports of neutron radiation.
      I am quite confident that this wasn’t such a test.
      But I cannot say it with 100% certainty.

      It’s difficult to keep these things secret.

      However Israel and South Africa probably tested a thermonuclear bomb in secret, back in 1979, somewhere between South Africa and Antartica. Which wasn’t a secret after all, as it was detected by satellites back then. What happened was that the US pretended it didn’t know about it. This is now documented as the Vela incident. Nowadays it would be much harder to keep such events a secret.

      People like always to speculate wild conspiracies.
      I think it’s very easy to see how this eruption happened. In fact we were due to a VEI6 anytime early this century. Volcanic activity does happen.

      However there is indeed a significant amount of tension between the western world and Russia, and also with China, at the moment.

      • We should I think realise that it is absolutely certain that this was not a weapons test. There were ongoing volcanic eruptions at precisely that site. No one tests a weapon on top of an active volcano.

        That aside, even if someone could come up with a credible design for a pure fusion bomb, what happened very clearly was not a nuclear blast. No double flash, and development of the umbrella cloud clearly shows several stages. This is not something humans caused.

        For the record, I also think it is far from certain the the Vela event was a nuclear test. It does however at least have a double flash signature.

    • Besides, Microwave, these things were planned. The population was evacuated before. It wasn’t a good idea though as radiation was high for a long time, and nobody was able to return. So, one day they got compensation. Some fishermen on a Japanes boat were covered with debris and suffered severe burns, all in the piece. Therefore, considering details, I would throw the idea out of your head.

    • Hello!

      The simple answer is that we have a large array of nuclear test signals to compare with, and the signal is extremely distinct and looks very different compared to the signal for an eruption or a volcanic explosion.

      Even the extremely rapid explosive sequence of Hunga Nomore was very slow compared to a nuclear detonation. We are talking about hundreths of a second for a nuclear detonation, versus several seconds on Hunga Nomore.

      Furthermore, there was no double-flash detected by orbital bhangmeters (yep, that is actually a thing), and no gamma rays, X-rays and no neutron burst.

      Also, the size pretty much tells everything.
      Nobody is building that big nuclear bombs in this day and age. It is “better” to build several small ones compared to one very large nuclear bomb.
      Let me put this into as brutal a way as possible. The Tsar Bomba was the biggest case of nuclear cock-whanging ever performed. It was the nuclear version of surgically enhancing a male member into the size of a blue whale dick. It looks impressive, but there is no way in heck you can use it together with your wife…

      • “Nobody builds…these days”. There were some rogue minds back then. It all started well before WWI.
        Don’t know, Carl, whether this is interesting, I got hooked to the passage:
        We consider it likely that a substantial exsolved volatile phase is present in the shallow plumbing system comprising a large proportion of the co-eruptive gas flux and dominating the inter-eruptive passive emissions. This volatile-rich phase could exert a strong influence on eruptive style: a permeability drop in the upper conduit impeding gas escape is an important mechanism for triggering explosive eruptions ……”
        See yourself:
        https://www.frontiersin.org/articles/10.3389/feart.2019.00009/full

        • Denaliwatch, this is something different I think from what Carl meant.

          Thing is, very large bombs had some limited with the comparatively stone age technology of the 1950s and 1960s. Bomber crews were more or less able to reliably hit a sufficiently large city from 10km altitude. Weapon yields in the MT TNT range sort of guaranteed at least some effect, even if the target was missed by kilometers (at least for “soft” targets). This has changed dramatically. Today it is possible to softly land orbital rockets on a small boat on an ocean. This has made nuclear weapons borderline useless, as precision always wins against power of the blast. 1/r^(2+x) is a very convincing argument. And at the very least it means that modern delivery systems will carry several smaller warheads instead of a single powerful one. To attack several targets at one, or to blanket an area without loosing a majority of the energy: as I said above, very large fusion explosions have huge losses in the form of all thermal radiation that goes upwards. To space, which does not care and stays at 3K no matter what. Even in the 1960s that weapons test was simply a symptom of acute testosterone poisoning. Today, most politicians take to twitter in that case.

          • Dominik really nailed it here.

            Also, we know who has hurled the largest blue whale twitter over-compensation (beep)…

          • That is NOT what makes nukes not used today. The vastly improved CEP of delivery systems certainly means that the same results can be achieved with a hugely reduced device yield today compared to previous eras. What that means is that modern nukes are high tens to low hundreds of kilotons rather than megatons. More efficient use of fissile material making devices of that kind of yield.

            What makes nukes not used today is Hiroshima and Nagasaki. People had two live-fire demonstrations of just what a nuke can do. That has been sobering enough (so far) to stop people using them. Once the nukes start flying it’s over for the power(s) on the receiving end of the weapons. Larger nations would likely survive, but they would be so smacked around that they would be easy prey for others not involved in the exchange. That’s one reason the Soviets decided that everyone should get attacked, so that all were at the same, low, horrendous baseline and no one would be able to come along and conquer the Soviets because everyone would be so busy recovering from doses of instant sunshine.

            If there is ever a direct war between two nuclear powers then all bets are off. We are all in deep, deep trouble. Hence why Ukraine at the moment is so serious and so potentially problematic.

            Pray no one ever forgets the lessons of Hiroshima and Nagasaki.

    • Thank you for your qualified answers.
      I also think that it would be pretty difficult to keep that secret.
      Thank you for your word suggestions too. Will read up onto a few words.

  7. That’s why NASA is more than important, one of the reasons:
    Stong competitor of CAMP concerning the end-Triassic mass extiction:
    https://earthobservatory.nasa.gov/images/1993/manicouagan-impact-structure-quebec
    about Québec crater 212 Ma

    Possible near-death event for the radiating mammal:
    https://earthobservatory.nasa.gov/images/148403/russias-crater-of-diamonds
    about Popigai in North Siberia 36 Ma

    This one is no suspect for a mass extinction, but would have caused havoc:
    https://skyandtelescope.org/astronomy-news/new-location-proposed-for-australasian-strewn-field-source-crater/
    https://www.pnas.org/content/117/3/1346

    About a meteorite whose impact crater is now suspected under volcanic rocks, Bolaven Volcanic Field, Southern Laos.

    We wouldn’t want either of them.

  8. Dear Microwave,

    In case you want to discuss this further with your father or learn more about the history of the atomic bomb from a moral perspective I’d like to give you some material:
    Some of the physicists – I myself know of Einstein and Szilárd – sincerely had regrets and second thoughts about the science that they had helped to be brought forward. This was also put into a very readable play by Swiss author Friedrich Dürrenmatt: “The Physicists”.
    A reader (amazon): “Nice to read the English translation – very close to the originial text in German (at least what I remember of it). It’s a beautiful play about responsibility in science …..

    The Manhattan Project had been set up against Germany, and Einstein and Szilard had considered it urgent:
    https://www.atomicheritage.org/history/einstein-szilard-letter-1939#:~:text=The%20Einstein%2DSzilard%20letter%20to,the%20world's%20first%20atomic%20bomb.

    In March 1945 then it was clear that Germany would lose the war, but Japan was a problem. So Einstein to the White House:
    https://www.atomicarchive.com/resources/documents/manhattan-project/einstein-letter.html
    And Szilárd in July 1945 (The war in Europe was terminated, Roosevelt had died, Truman was Potus:
    https://biology.indiana.edu/documents/historical-materials/gest_pdfs/hgSzilard.pdf

    To no avail. Truman decided with his Generals to go on to finish the war in Japan and excused himself by stating that the bomb had saved the lives of hundred thousands of soldiers on both sides.
    Good discussion stuff.

    It went on with the Cold War. Einstein wrote a manifesto with the philosopher and mathematician Bertrand Russell:
    https://en.wikipedia.org/wiki/Russell%E2%80%93Einstein_Manifesto

    Albert Einstein besides being a genius was a 1A human charactre and Leo Szilárd as well.

    • These things, btw, gave rise to considerable anti-Americanism in the fifties and even more in the sixties. I didn’t become a part of it, as without D-Day and a perspective my father wouldn’t have fled when he was called to the army, and I’m aware of the fact that even more Jews and more soldiers would have died, and I myself probably wouldn’t exist. So, I can say that I was thankful that the US invaded Germany and finished that guy riding Europe into an abyss. And I went one day to visit all those graves near Arromanches with all their tiny crosses for young men from the US, the UK, Canada and even Australia. And I must say that I had to shed some tears.

      • That is a very interesting article. I suppose we are expected to read it up to the end including the footnote.
        Btw, found a paper the other day which scaled the millenium eruption down to a VEI 6.
        Beautiful volcano and lake.

        • Great song. I believe, aside from those caves thet annoy the Chinese rightly at what they call Changbai-San, there must be lots of those caves in the setting in the Pacific Ocean with or without any tests.
          Why that?
          As you see in the structures that were once in the depth of the oceans and have been exposed after sinking sea levels long after the Cretacious, so probably in the Holocene, lots of caves, in Algarve, in England, in Brittany, France, everywhere.
          It seems that also water and erosion can do what the NK guy did.
          I didn’t travel much as a child and had to travel with Enid Blyton who seems to have had good knowledge of all those caves, the same knowledge that pirates used to have.
          My own kids discovered some and it was always tiresome to keep them from exploring them.

      • Pretty example: Mull volcanic Field, an assumed 60 Ma old, with Fingal’s Cave.

    • You might want to look up operation ketsugo and the anticipated cost in lives to force Japan to surrender conventionally. Imperial High command was truly and utterly nuts, willing to sacrifice potentially millions for a better spot at the negotiation table.

  9. Wheeeww thanks for the polite resonance to all of you, despite of a very difficult and bad subject!
    Will try to read some of your suggestions.

    And will reason to him when we meet again tomorrow.I s
    This nuclear bomb sh** is spectacular but endangering people/environment with it is absolutely gruesome.
    However, I would never judge the US for having used it against Japan. It must have been more like a very unfortunate accident in my eyes, a human mistake because all were so exhausted in the end of WWII, and likely could not think clearly enough.

    • Thank God I can sneak out of an answer here, the Master’s Voice:
      “Footnote: This article is skirting the boundaries of the rules of Volcanocafé since we try to stay away from politics. But, I felt that this time there was no way to stay away from it due to the location of the volcano at hand. I would though like to implore people to keep the comments as un-political as possible…”

  10. Since everyone has been talking about politics and nukes, I am quite curious about this:
    Is there anything of the natural order that could rival our nuclear weapons? (Besides asteroid impacts, those are the winners).
    I’ve heard there is something called a Verneshot eruption – an eruption so explosive it sends out debris into sub-orbit or even to the moon. Of course, this is all hypothetical, but I an quite curious.

    • Would be interesting to know.
      Solar storm EMP maybe?

      On the exploding (detonating) side of things, something like Taupo Hatepe on steroids?

        • Those old cratons when connected in Pangaea were three huge masses, and there were Large Igneous Province between them at some point. These facts might have led to some thoughts of this kind, but I wonder what the physicists think about it. The other one in Africa is a lot smaller. I think they have a new pic on wikipedia of Ol Donyo Lengai, an active beauty that never got close to that kind of thing.

          • Luckily, it is only a hypothesis (and also thankful that Ol Doinyo Lengai never blew up like that), but seriously, how much would it take for a true quote on quote “Verneshot eruption” to happen?

          • Let’s phrase it this way. If you wanted to shoot a bullet at as high a speed as possible, would you build the barrel out of brittle stone?

          • The bullet would just go in some sort of random direction because the stone would shatter immediately. Instead, it would just be a massive explosion of bits of stone, with the bullet probably going in the not-so-intended target. A true Verneshot eruption would more rather look like a large ball-type explosion (hard to explain the shape) or it looks like a nuke put a few hundred meters underground. That is why the original Verneshot eruption is only a hypothesis because it’ll never work.

          • I think we can safely rule out the Verne shot.
            If a full on big kimberlitic eruption can’t do it…

          • Is a kimberlitic supervolcano possible? Never really thought about that before.

          • Well, I kinda knew about it but I wouldn’t think it’s possible.

          • The heat, the dust, the flies and sound of distant drums. The same creek verily, where everyone in the safari truck, stripped off clothes and shame, to take the waters, once they had been declared bilharzia free.

    • Zach, what do you mean by “rivalling”? In a potential to disrupt civilisation, or ecosystems, on Earth? Civilisation-wise, surely the next Carrington event (high X-class solar flare with massive coronal mass ejection onto a trajectory towards the Earth’s magnetosphere) will be a bad day. On a much grander scale, nearby supernova or even gamma-ray burst. But strictly Earthbound? M>9.5 Earthquake, if you can find a fault long enough that is willing to rupture? Other than that, I can not think of much to rival volcanoes, if impact events are excluded. And surely not in the explosive department.

      As we have discussed here, while a nuclear explosion initially is much more rapid, farther away timescales anyhow get longer, and for the pressure wave, as we have seen, our nukes do not even rival the power of water and magma.

      Sending stuff to suborbital trajectories is however exceedingly hard if one has to work on seconds++ timescales initially, and with a source as extended as a volcano. If not to say not feasible. Even the 55km discussed now are high HIGH. Nuclear mushroom clouds can rise as high, but the fireball is very hot and light. Not much stuff to drag up from an airburst.

  11. Just read up on Tsar Bomba in Wikipedia.
    Seems that is certainly some different story.
    Hunga ??? = nuclear test? ==> Highly improbable at best!

    • Already discussed above.
      Almost certainly no.

      But Ukraine and Taiwan are reasons for concern. I think we will see war in 2022 and we will miss the good old lockdown days! Covid is nothing compared to what might be happening.

      We are getting near the most dangerous time since the Cuban missile crisis.

  12. Here are are two images of the surviving part of the western island, taken Jan 19 and 18 but Planet labs. They show different parts in between the clouds. The third image was take Jan 2. The lines indicate the part that I think survived. It is notable that the current coast is long the old cliff. The benches that were originally below those are gone. Either they were to weak to survive the catastrophe, or the island has gone down a bit

  13. Still incredibe How a Kimberlite gets through a 300 kilometers thick Craton core, Igwisi Hills are the youngest holocene true Craton volcanoes.. insane stuff really and How does partial melting begin 330 kilometers down, perhaps a mantle plume? Kimberlites erupts as cool, ultra gas rich explosions, perhaps resembling kelut 2014 But lasting just hours

    Igwisi Hills that true craton holocene volcanism seems To have been quite fluid, But still erupted violently. The Igwisi hills are formed by three lava filled tuff cones formed in the middle of the Tanzania craton, they are perhaps not alkaline enough To be classifyed as true kimberlites, But Craton volcanism anyway

    Co2 rocket gun gas like dyke propagation is the main theory how it gets through a Craton interior

    • Technically, cratons don’t really have the thickest crust on Earth. That title belongs to the Himalayas at 70 km in thickness, compared to the 30-60 km thick craton, however, cratons do have the thickest lithospheres, which would reach 300 km thick. Just pointing that one out, but still impressive for kimberlite to reach through 45 km of crust.

    • The Kimberlites are born in the astenosphere 300 kilometers below right? They haves to rise through the litosphere from their partial melting zones

      • Whoops, disregard my comment. I was thinking about the Moho and realized the athenosphere is not part of the lithosphere. My mistake. Apologies to Jesper. He was right all along.

  14. Couple of interesting articles I found that could be of interest.

    Electrostatic levitation – the plume (the centre of which did reach the mesosphere). https://pubs.geoscienceworld.org/gsa/geology/article-standard/46/10/835/547176/Electrostatic-levitation-of-volcanic-ash-into-the

    A relief agency doing groundwork in Tonga has reported 5-10cm on the ground (60km away from the main blast)
    https://reliefweb.int/disaster/vo-2022-000005-ton

    Fascinating pictures in this article of the ash cloud from the ISS.

    • An average of 5-10cm at that distance means a minimum of 1km3 of tephra, almost certainly much higher, and it could approach 10 km3. It is not clear where so much ash could have come from. I expect that the average is less but wind may have caused it to pile up in places

      • Albert,

        This is wholly unscientific, but I’m just curious as it pertains to this ongoing debate about the size of Hunga Tonga.

        I’m seeing / reading about a good number of reports of what you would expect sunsets to look like after a large eruption, for example here:

        https://spaceweathergallery.com/indiv_upload.php?upload_id=181786

        That’s from Germany, obviously in the northern hemisphere which seems strange given the assumed size of the eruption (mid 5, for argument’s sake) to have crossed hemispheres. Do these atmospheric effects normally come into play at VEI 5 level outside of the vicinity of the eruption? I always assumed they were too small and haven’t read much about atmospheric effects at that magnitude. I know Puyehue was only a borderline 5 but were such effects observed in South America afterward?

        Is it more likely that this sort of thing is just unrelated pretty sunsets? Again, unscientific but the ash cloud itself looked massive on satellite imagery as it dispersed and began traveling.

        Very perplexing eruption on all fronts, even if what I’m asking is quite literally nothing, there’s so many intriguing facets to this riddle.

        Thanks for your articles on this Albert (and you, Carl).

        • Can confirm, sunsets all around the southern hemisphere were fantastic after Puyehue erupted, no major climate impacts but VEI 5 eruptions can definitely have long distance effects.

          Not sure about what happened after Grimsvotn that same year, maybe the coarser basaltic ash was not able to stay in the atmosphere.

          • Grimsvötn was to coarse, but Eyafjallajökull did do some really weird sunsets.
            One evening at the beginning we had a sunset that looked more like Sahara after a duststorm than northern Sweden.
            The same dustladden air together with a deep red that slowly grew until it covered most of the sky.

          • We have had very different and beautiful sunrises (and moon) in the last days when view had been possible. Incredible colours.

            With the historical cold and snow in Greece now (+50 cm in several central areas) it is impossible to tell though. Luckily it hit to the west of us and another system to the east of us with problems in Istanbul for instance, so very little snow here. But 0C and 100-110 km/h windgusts here during the storm last night 400 m. asl. feels colder than where we live in western-Norway. And took down a plate-covered steel Pergola form an old house behind ours.

            The newsreports are just mindblowing. Both greek and turkish. Like here from the northern suburbs of Athens now;

            https://www.newsit.gr/ellada/kakokairia-neos-kyklos-pyknis-xionoptosis-sta-voreia-proastia/3454285/

      • Where was it that the estimate was 5-10 cm ?. Different direction and distance than Nukualofa where it was 2 cm ?

    • I would think that the ash will become soil in a relatively short time. Plants are surprisingly resilient and unless the ash is actually toxic, should soon be bound by new roots.

    • I have seen that circulating on twitter.

      Another thing that is bugging me about the eruption is the Sulphur Dioxide plume. I don’t know what NASA satellites put up, but sentinel 5, carries just one instrument – Tropomi. It’s focus is the troposphere not the stratosphere. It is there to measure emissions – question remains. Is the SO2 cloud that is fed to Windy.com, by Copernicus, just the tropospheric SO2? Given the winds in the Indian Ocean, it seems to follow that.
      Is there any data from the stratosphere? Surely, given the power of the eruption, up to 55km, I would expect that to be the case.

      Incidentally, following the Copernicus feed over the last week or so, I have noticed a distinct yellowisation of the map, that seems beyond the realms of standard deviation.

      Is it possible for gasses and tephra to be carried by the shockwave?

      • A shockwave, as the name implies, is just a wave that passes through whatever medium is in its way. There’s no forward movement in the medium except briefly forward and backward or up and down.

        • I think we need to consider everything measured from this incident before saying “no, it is not the case”. The shockwave is only one ingredient.

          “Atmospheric waves from the explosion shot across the globe in less than 24 hours. The waves even shifted local air pressure: In Seattle, the wave briefly lifted the city’s fog, said the local National Weather Service office.

          The colossal detonation sent many types of waves through Earth’s atmosphere: infrasound waves, Lamb waves, acoustic-gravity waves, and signals from tsunamis across the Pacific Ocean.”

          From a link I posted earlier: https://eos.org/articles/the-surprising-reach-of-tongas-giant-atmospheric-waves

          We have not fully observed something like this before, and we do not have a full 24h worldwide coverage from every location of the planet simultaniously by satellites or ground-stations measuring everything relevant. So some will (from the event) still be modelling based on data from elsewhere in the timeframe of the event. Or from earlier/later passes made by the satellites.

          We do not know the full process behind post-atmospheric disturbance (or particles, or dust, or tiny aerosols (fill in)) now changing sunsets and sunrises in the NH. We do not know if relatively huge amounts of tiny tiny aerosols or extremely fine grained dust spread out from those recorded events. From atmospheric waves,infrasound waves, Lamb waves and acoustic-gravity waves. I am not saying it did. I am saying we do not know. Yet. Heck. Scientists are puzzled.

          I am thinking that as long as arrogance from “what we do know – the old regime of one generation before acceptance” does not stand in the way, the scientific method and curiosity of scientists will be able to give us new understandings from the event. And to throw out ideas and explore them is a basic core for new understanding.

          What else to find – if any – from this event, is up to the data, observations, chemistry, physics, mathematics aso. to give us answers from. The first step is to imagine (from former understaning and knowledge) what to look for. And where. And how.

          Just the fact that the atmospheric waves have travelled at least 10 (!) times around the globe is amazing.

          https://twitter.com/diegoaliaga2/status/1485469621327069185

  15. Ambrym has erupted again, at least the first time officially since the end of 2018. ArcGIS map though most definitely shows a small active lava lake in 2020, so maybe just no one bothered to check…

    Still, shows it is really quite a force of nature, to erupt so fast after a major magma drain. I wonder if we are heading into a period of high activity there, characterised by larger summit eruptions of Etnean type and frequent large flank eruptions, like it was doing in the early 20th century.

    • Chad, it’s something to think about. 120 years ago (1902), contemporaneous vulcanologists were wondering the same thing when Pelee (Martinique), Soufriere St. Vincent, and Santa Maria (Guatemala) all erupted violently during the same year and in the same geographical region (the Caribbean). Were they connected in any way, or was it just coincidental?

      • Who wouldn’t think about such coincidences – there is one precise difference though: Guatemalaen volcanoes erupt all the time, the volcanoes on the Lesser Antilles erupt much less frequently. Maybe they didn’t realize back then.

        • It’s all connected in a way. It is a swimming connected system. There is nearly the same amount of subduction as production, and the subduction is in different places. That’s why the globe doesn’t grow which was also an idea for some time.
          There’s considerable surprize in it. While everybody is staring to the location of the last eruption suddenly another guy pops up and says hello. That’s what we had here. Waiting for Iceland there was suddenly a surprize one day and eight hours (Auckland, NZ) away by plane from Reykjavik, two stops though, both in the United States I guess.

        • In regards of the Guatemalan volcanoes.

          Not really, and yes, and at the same time…
          The volcanoes that we see happily puffing away today: Santa Maria (Santiaguito), Fuego and Pacaya, are all doing so after quite a bit of dormancy (for being Guatemalan volcanoes).
          Santa Maria had been dormant for at least 500 years when it blew in 1902.
          Fuego, it is not until 2004 that the volcano starts to evolve into the Stromboli of the Central Americas. Before that it had intermissions that lasted for decades between eruptions.
          Pacaya is the most active of the volcanoes in the last 500 years, but even that is known to take decadal long naps.

          Anyway, as long as Pacaya and Fuego are happily puffing away it means that the Volcán de Amatítlán is well vented and we are safe from a big one there.

          The one that is giving me a headache is obviously Volcán de Atítlán. It has not eruptede since 1853. And the lack of eruption is slowly tilting the entire caldera lake, something that has been going on for at least 1000 years. There is an entire Mayan city down under the water due to this tilting.

          My point is, constantly erupting volcanoes comes with their sort of problems. But volcanoes that should be erupting, and is not, is when there is problem brewing somewhere ahead.
          The problem of Fuego and Pacaya is not that they are erupting, sometimes with tragic consequences, the real risk with them (especially Fuego), is that sooner or later they will suffer from a flank collapse, and they will go galumphing off for the coast (levelling my little beach house).

          Lake Atítlán, you have not lived until you have visited this place. It is one of the most beautiful places on Earth, and as a volcanoholic you also get the thrill of looking at a true beast in slumber…

          • one of the most beautiful places….
            This is clearly visible on photographs. In Europe the Bay of Naples and the surroundings including Amalfi’s coast should come close to this.

      • Voolcanology was deep into looking for patterns back then. Pelee and Santa Maria both erupted in 1929, too.

        Jaggar spent a lot of time and used up a lot of credibility in trying to find a pattern of Kilauea eruptions based solely on the data points of the 1790 and 1924 eruptions. He posited a 132-year pattern superimposed on 11 12-year subpatterns. Sure, Jaggar was *creative*, but this sure smacks of doing something…*anything* in order to keep the grants and subsidies coming. Wasn’t the first scientist to do this and certainly not the last…

        • Trying to see periodicities in insufficient data is still a common issue in science. It is always done by overfitting, and it should always be checked using predictions. For instance the claims for long periods in the solar cycle variations. The current solar cycle is running at twice the intensity predicted from various long-period models (nothing definitive yet as it could easily calm down again). These predictions may take a long time to test, but it is necessary

          • I say let us stick with the smoothed number. Spikes and calmer periods are common. Fully understandig the effects of (if any) from weak solar cycles also takes so much more parameters to be taken into consideration than the sunspot-number. TCI-comparishment, Neutron-count comparishment, Flux-data, aso. We just do not know as of yet. Dismissed say some, but how can you dismiss something with too little knowledge.

            Paleo-climatological volcanoes might (might) have the effect of longer-term cooling when the energy-budget is otherwise in a state of equlibrium. Maybe with increased volcanic activity for a prolonged period as onset. Cooling climate for a long time(iceages of diff. lenghts). Depending on when the energyinput encreases (or other unknown factors happen) the T starts to rise again.

            My thesis is that we might enter such a period going forward. Due to not yet fully understood effects upon volcanoes. Somehow related to secondary effects of the solar output. Could be magnetic, could be energetic of undiscovered type, could be secondary effect on weather/climate. Could also be wrong.

            Wo.several following climatic eruptions I think the time to cool a warming system could be a looong wait. Sometimes it has been historically. Sometimes with intra-changes, sometimes more stable.

            Was the Tonga-eruption one? I highly doubt it, but there is much from the eruption we still do not know. Are more volcanoes than before “readily primed” and are we seeing rare (historically) eruptions as of lately. Yes. And we know were in that solar cycle we are. But to say that is going to last – or if they are going back to sleep – is still very speculative to say anything about.

            Etna is now after new measurements reported to “be in charge of” 10% of global volcanic CO2-output.Really? Maybe that makes the whole total estimate larger? And maybe it should be measured for all active volcanoes?

            https://www.research-in-germany.org/news/2022/1/2022-01-20_Mount_Etna_s_exceptional_CO2_emissions_are_triggered_by_deep_carbon_dioxide_reservoirs.html

        • The best confirmed volcanic cycles are for Iceland.
          And even there red swans are cropping up everywhere.
          How many of the Icelandic cycles are real, and how many are over-fittings? We will have to wait and see.
          So far the plume pulse cycle and the Reykjanes rift cycle seem to be “a thing”.

          I do not like the black swan analogy, black swans are nowadays fairly common, and in the end all swans will be black at the going rate.

          • I was a bit literalist here, I mean that the white swans are going extinct due to a highly dominant mutation that is turning them black, it all started in Paris.

            Kim Young-un have ventured into culinary advice and claimed that black swans are more nutritious and tastes better… Ever the fashionista that one.
            This had me venture out into the realms of obscure swanology, and it turned out that there is an Asian swan that is indeed black.

            Wonder if there was a dapper Parisian swan that wanted some Asian tail?

          • Do not tell that to Kim Yong-un, if he is peckish he might invade. 🙂

          • Every swan I have ever seen in real life has been black 🙂

            Pretty sure white swans are only really found in the northern hemisphere, maybe only in the Atlantic area too.

          • Every swan seen is black. Extraordinary. A true black swan event

          • The black swan is just as normal as the mute swan (considered the white). Apx. 500 000 pop. of each. Of course other variants but with the analogy bl./wh., those are the numbers.

            So maybe this is a question of perception? Or even consensus judging from some comments?

            Have fun though. 😉

    • Smoke yesterday. Doesn’t seem to be anything special though.
      The earthquake of Mag 6 between South Georgia and Bristol Island though is interesting as it is about as far away from our setting as you can get travelling around the globe. The setting itsself is extraordinarily similar with a neat row of volcanoes, 12 of them submarine. The earthquake was somewhat north of Mount Michael and Mount Belinda though,

  16. Although I’m getting slightly and slowly better with petrochemistry this paper is beyond my horizon. I could imagine though that Héctor might be interested, possibly also Carl and Albert. It is about the LSC in comparison to the HEC and also about the question whether there is any connection to the OJV. Much chemistry. Very interesting paper.

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GC005288#:~:text=The%20Louisville%20Seamount%20Chain%20(LSC,%E2%80%B2S%3B%20Figure%201).

      • What I consider extremely interesting about this paper is the fact that this island chain has grown on crust of the same age, whereas the HEC has grown on crust of different ages.
        Second point is that they haven’t found any thoeliitic parts so far. There is a caveat though: They describe that everybody is extremely careful there when drilling to not cause a flank collapse/land slide and tsunami. The plume itsself might have died, but who knows. Earth is good for surprizes. Anyway, it’s easier with an active volcano like on Big Island. This might be pure history.
        I was looking for this wondering why the bend has a different angle and a different age.

  17. Carl,

    remember I asked you about physics, and you and Farmeroz and a few others were extremely helpful. I am putting physics at the end of a to-do list, not all of it though. It suddenly popped up in my memory that I had been good in one part of physics: Mechanics. Typically German in a way. And I was also good in Biochemistry and extremely interested. So I’m doing these things first. Petrochemistry shouldn’t be an enigma to me although organic chemistry and then biochemistry is – in a way – also mechanics.. If I’m fast enough I might get to the realm of higher physics before I die. I doubt it though, and it doesn’t matter as there are enough people here with a good knowledge of physics.

    • Organic chemistry is all in the understanding of the mechanisms of the functional groups. Don’t let the aliphatic or aromatic ‘chains’ distract you. It’s the front of the dog that bites while the tail is wagging.

    • I like inorganic chemistry much and of course electrochemistry.
      Destroying and ripping apart molecules to create new ones, which may be impossible or unfeasible to create otherwise 🙂

  18. And in other news… It is now 10 times around the globe and counting for the wave of Hunga Nomore.

    • Makes me wonder. Would all of these rounds have been detected back in 1883, or is it a matter of better instruments today? Vice versa, how many rounds would have been detected if Krakatau happened today?

      • I have seen seven mentioned for Krakatau. With statements from several saying this was measured accurately back then. Well. 1 hPa hasn’t changed so I gather that data then and now are correct. Not sure Carl sees it (at least saw it) the same way?

        The great difference beeing that it is easier to track that it actually is a wave after 10 passes today than in 1883. However seven passes is seven passes. It is fairly easy to see in todays data if they disappear in some of the stations with a factor of time or not. To calculate wether or not there could have been more unregistered passes in 1883, but with reports from a variety of stations back in 1883 (mentioned here in a former posting to former article) I suspect not.

        10 passes most lightly makes it more powerful in effect on atmospheric pressure release than Krakatau was.

        • I think it is quite simple. Sure, our ability to measure pressure waves has improved, but the Krakatau wave was 1.5mbar at 6000km distance, while the HTHH one now was 2.5mbar at 17 000km distance. It is about twice as strong.

          • Not quite because it does not go down linear with distance. Beyond 10,000 km the pressure increases again in strength, peaking at 20,000 km. But it was certainly comparable

    • One wonders about the damage a chicxulub (?sp) megablast could do globally. Not obe pressure wave but lots of them.

  19. Gerd Baumgarten of the Leibniz Institute of Atmospheric Physics confirms an outbreak of Noctilucent Clouds over Antarctica is occurring.
    What makes this observation notable, is the southern NC season started very late (mid-Dec.) and had been noticeably much weaker than normal…then rather suddenly, (i.e. not gradually as is usual) sparked to life in a big way shortly following the Hunga Tonga event.
    ATTM, it is not known if there is a causal tie between to two, but an injection of water vapor and potential condensation nuclei from Hunga Tonga into the upper mesosphere (suspected but not yet confirmed) could explain the NC outbreak.
    If the eruption is found to have triggered the NC’s, this would be strong corroborating evidence that supports the theory that NC’s originated (at least from a human observation standpoint) from the time of Krakatoa (although Albert has mentioned NC’s may have been seen prior to the eruption).
    Assuming that Hunga Tonga did spark a NC outbreak, as well as Krakatoa, then that gives two eruptions (at least) that could be tied to NC’s within the last 135+ yrs…so that would be suggestive that NC’s should have been produced on a relatively frequent basis. However, I cannot find any corroborating evidence for NC increases that were tied to Pinatubo, El Chicon, Novarupta, etc., despite their respective eruptions resulted in planetary cooling from aerosol formation, yet no/little NC formation. Curious.
    That leaves an intriguing possibility…which is only a Krakatoa-ian style eruption can produce enough vertical acceleration to propel water vapor high enough into the mesosphere to trigger NC’s?
    If so, then NC formation could be a powerful point of distinction between Krakatoa-ian eruptions and other types of explosive eruptions?

    • That is interesting, and, given that NLCs happen at the upper boundary of the mesosphere, it would obviously fit to the transport of water and condensation nuclei to mesospheric heights. But as you know, more commonly an extraterrestrial origin of this nuclei (micrometeorites) is discussed. Would maybe still profit from the water. There have also been events — most memorable to me the historic outbreak on 21.06.2019 over Europe — with no obvious trigger…

      • Dominek…
        There probably was a trigger(s), which were several SSW events in that basic timeframe (there is a lot of latency involved).
        It’s possible that lower level turbulence formed a pseudo-pressure wave that was able able to propagate into the mesosphere thus transporting some extra moisture (and other nuclei sources) that briefly enhanced condensation?
        Long time watchers of weather satellite loops know that you can occasionally see pressure/gravity waves visibly emanating outwards from points of intense convection…which coincidentally? looks very similar to what the Hunga Tonga pressure wave looked like.
        I’ll try to remember to post an example the next time I see a storm-related pressure wave-train showing up on satellite. It’s amazing how similar they looked (except in size and scope).

        • Thanks for the observations Craig Heden, I find these ideas very interesting. I have wondered if maybe the big pressure wave wasn’t generated by an explosion and was instead created by the rapid growth of the pyrocumulonimbus cloud. I remember seeing a barometer from Fiji and pressure went up for 30 minutes or so and then went down for a similar amount of time. Isn’t 30 minutes too long for an explosion? The explosions may have been responsible for some of the short pressure spikes seen in infrasound. However the big wave I wonder if it was created by an atmospheric process, the rapid growth of the pyrocumulonimbus cloud. Perhaps it could be compared to pressure waves generated by thunderstorm cumulonimbus clouds? Also, some of the interpretations on the Krakatau eruption may need to be revised in light of new data from this eruption.

          Plus there seems to have been a global meteotsunami resulting from the pressure wave. For example here in Spain a tsunami was recorded in the Balearic Islands (Mediterranean Sea) measuring 50 cm as a result of the pressure wave from Tonga. This event may have affected the entire planet and it will be very insightful to study it.

          • Agreed that the pressure waves from atmospheric disturbances closely resembled those coming from the Hunga Tonga series of explosions.
            When we look at these waves via satellite and surface observation, we tend to think in terms of 2-D visualization and forget that pressure waves travel in the Z-axis as long as there are enough gas molecules to sustain the wave…i.e. below heights where mean-free path is achieved (around 10-4 Torr or roughly 10-7 Atms/Bar)

          • Hector, I think any distinction between an explosion shock and expansion of the pyrocumulus is partly artificial. That a shock was generated is I think evident. We hear the typical “crack” in many videos. To initiate that shock, a huge gas volume needs to be rapidly expanded into the atmosphere (a basic phenomenon actually for atmospheric explosions), and that in turn unavoidably contributes to the pyrocumulus. As Carl has calculated, to arrive at the order of magnitude of the pressure wave we measured, one needs about 500km^3 of gas volume. Quite something, even if compared to the umbrella cloud.

          • If if was the growth of the cumulonimbus cloud then it would have taken tens of minutes to make the pressure wave. As opposed to an explosion that would be much shorter. The principles are the same but the exact mechanism matters.

          • Well, even the growth of a nuclear mushroom cloud takes minutes in total. A huge amount of gas is injected (or, in case of the nuke, heated), and that pushes away the atmosphere. But as said, we know a shock was formed, we heard the crack…

          • It is the size and speed of the initial birth of the expansion front that is important, not the end size in and of itself.
            As soon as the expansion front becomes subsonic the “cracky” phase is over.

          • Do note, the expansion front and the wavefront is not the same, the former produces the latter, but will be disconnected as soon as the former becomes subsonic.
            This is an important distinction in all detonations.

          • I see it may not be so different then. In any case thunderstorm generated pressure waves might be a fitting comparison to this eruption.

            Do we know if the booms that were heard correspond to the same wave seen in barometers around the world. There were many waves at different frequencies occurring. Some, in all likelihood, were the result of sudden discharges of volcanic gas or steam. The wave that was recorded in most barometers however must have been inaudible. As I mentioned earlier the wave period was several minutes long already in Fiji, relatively close to the eruption site. I have the picture in my computer, which I’m not with right now, I will try to see if I can find the imgbb link I uploaded to.

          • Here it is a Fiji barometer showing the pressure wave. There are waves occurring at many different frequencies. There is a wave with a period a little longer than half an hour, that is the one that was recorded in distal barometers too.

          • Nice! The slow oscillation is the pressure wave. It starts as a gravity wave from the shock of the explosion, and these travel with this approximate frequency, at the speed of sound. They are therefore large. You can see it in the visualizations of the pressure wave posted here by some: the wave is ‘thick’. The fast fluctuations are the shock wave itself. Some of it may even be inside the instrument itself, which will not be designed to measure instant changes. But mostly it is the ‘ringing’ in the atmosphere set up by the shock wave. The rest, the irregular fluctuations, can come from the structure of the atmosphere along the route

          • Sure there exist many timescales! All I am saying is that first, we know in total a huge gas volume was expanded, and second a powerful shock started (the crack that was heard even on Fiji). Now, need that shock explain 100% of the subsequent transcontinental pressure wave? Surely not! But to me, the pressure wave at distance does not look generally different from the ones recorded at earlier sudden events. As said, even in a nuclear blast (keep using that just because it starts instantly, compared to a volcano), there is a fast shock from the hydrodynamic front, but of course the mushroom cloud keeps growing for minutes, and keeps pushing aside air.

            As said, I am fully comfortable with not all the pressure wave being suddenly generated. It may even be satellite recordings show distinct events. But it is at the distance it was observed quite pronounced and sharp.

          • I think two different waves. The sharp cracks must be due to supersonic debris/gasses, the 30 min wave due to the eruption column. To be honest a supercritical expansion is to some extent self limiting because backpressure will inhibit expansion beneath. So to loose say 2000m in 30 mins is still ~60m/min or 1m/sec of the supercritical mass, then the time to ascend, really 30 mins for the whole shebang is pretty damn quick.

          • farmeroz, that sounds surely interesting! I mean, in a way it is unavoidable that the cloud from the eruption will contribute to the pressure wave, and of course that cloud over wide areas grew subsonically. But that is basically the case for any and all volcanic eruptions, I would dare say…

          • Phrasing it a bit differently: I think we agree that the Pinatubo-cloud was geometrically of similar size, and maybe even more massive. Very evidently, Pinatubo did not produce anything even close to the HTHH pressure wave…

        • This is also why I think many of the effects of this eruptions could be best studied from a meteorology standpoint.

          As to the causes of the eruption they are magmatic. Of course an eruption is the result of a magma intrusion reaching the surface so that certain factors like the eruption rate, timing of events and total volume will be determined by the intrusions leading up to this event. It is impossible though to know the exact circumstances leading to the eruption because the volcano was so poorly monitored. And

          • Even if it had been properly monitored it would be very difficult since we have no technology capable of detecting existing intrusions underground. For example the presence of sills or cone sheet intrusions, ring dikes, or the shape of the magma chamber are all unknown factors…

          • The eruption and its effects are the interaction of the magma intrusions with the atmosphere and the ocean…

          • “Even if it had been properly monitored it would be very difficult since we have no technology capable of detecting existing intrusions underground.”

            Yes, we actually do have both the equipment and the knowhow about how to do that.
            It can be either be done via a seismic array using distal earthquakes creating a tomographic image, this is useful when there is large amounts of magma available.
            For more detail specific images we utilize active measures across a seismic array. Ie, we detonate a charge and get depth images from refraction.
            And if that is giving positive results, we can always deploy drilling stratagmes to find even more detailed data.

            But, alas at Hunga Nomore the problem is the lack of an array, and also there is a problem with where to deploy an array. Logistically parts of the array would have to be emplaced on the ocean bed.

          • Very hard to keep the timing correct on detectors on the ocean bed. The floating arrays do it by regular surfacing to reset the clocks (I believe). These measure the sound waves produced in the water by the shaking of the sea floor. But they do not have the resolution to map the magna chamber of a single volcano.

          • There is a version that is deployable on a cable.
            Those have the precision to do what is needed, and also find any lurking submarines (it was the original use for that particular technology).

    • It is a sign of water in the mesosphere. They have become more common in recent years, for unclear reason. Could they be related to Hunga Tonga? The clouds occur in the lower mesosphere, normally stated to be around 80 km. But in summer in Antarctica the mesosphere is lower, around 50 km. That is within range of the Hunga Tonga plume. The mesosphere is susceptible to pressure waves and that is another way that Hunga Tonga could have affected it. Rossby waves are efficient way of transporting high altitude material from the tropics to the poles, so perhaps we are looking at a combination of water injection at 50km, followed by Rossby waves transporting it to Antarctica. Any reports of sudden stratospheric warming?

      • Yes. These are unbelieveable.
        Last or second last summer they were strong even in Mid-Europe. Very puzzling display it was back then!

  20. Kilauea now erupting from its Halema’uma’u vents again, the rootless lava lake is over 300 meters deep now I think and 1 kilometers wide

    • This is possible if the tsunami was caused by a landslide and the shockwave by the explosion if that happened afterwards.

      • Yes. There might have been a flank collapse and something became clogged. That is an excellent eye-witness, probably alert as she was trusted with all those kids.

    • Interesting. Perhaps due to sound traveling much faster through water than air? Most tsunami’s travel at typically only about 600mph….well below mach1.
      However, if the tsunami was a surface manifestation of a sub-surface pressure wave travelling mach1+, then I guess it could exceed the speed of sound?
      But otherwise, I have no direct knowledge of any water wave that could even approach, let alone exceed mach1 on it’s own.

    • It would take sound about 4 minutes to travel from Hunga Nomore to Tonga. Sound travels nearly 5 times as fast through water, so ocean shock wave could have arrived in under a minute and so already cause ocean disturbance a couple minutes before people would hear it.

  21. Bit random but could anyone please explain the term ‘mantle return-flow’?

    • A bit unusual term, but I will try to explain.

      A mantleplume will carry material upwards, and part of it is normally erupted, this would produce a low pressure zone at depth and a general lack of material.
      This is solved in the greater scheme of things by colder upper mantle material sinking downwards.
      People tend to forget that the mantle is a convective system, with the plumes being a part of it.

      • Thanks Carl, makes a lot of sense.
        I read it in the context of ‘return flow’ from the Pacific to the Atlantic/Indian oceans, and think I now understand what they mean with regards to all the subduction going on in the Pacific, and more crustal creation than subduction going on elsewhere.

        The way I read it in the article mantle was flowing through the Caribbean gap but getting trapped in there due to the Puerto Rico trench and developing subduction. The same is also true of the Scotia sea somewhat, but not so much through the Antarctic-Australia gap.

      • Maybe somewhat different: – Mass Balance and the Shrinkage of the Pacific –
        “Mantle return flow must transport material from areas of lithosphere consumption toward areas where new lithosphere is being generated. Despite rapid spreading at the East Pacific Rise, net lithosphere consumption is presently concentrated, in a general way,
        in the Pacific, while lithosphere production is dominant in the hemisphere surrounding Africa. One would therefore expect mantle return flow to proceed from the Pacific hemisphere to the African hemisphere.”
        Walter Alvarez, 1982

        A model though like many things

  22. Tuesday
    25.01.2022 18:50:45 64.559 -21.131 2.5 km 3.3 99.0 19.4 km SW of Húsafell

    • Interesting article, Carl. Thanks for re-re-posting the link.

      So far these quakes are all very close to each other, not arranged linearly.

      • No, they are creating another feature known as a vertical stack conduit. Basically a happy warm dyke swiming straight up.

        • Very kind of Iceland to offer up a variety of intrusion types in such a short period of time.

          • This is more common in central volcanoes as the conduit opens up. And that is bloody surprising at Skotmannsfell.

          • Decided Fagradalsfjall was a bit close, so is going to put Icelands Pu’u O’o in a bit more safe spot. I think given the slow progression it will likely be another slow eruption too beginning tiny, but after a few months becoming a big lava geyser, and no rift here to slow things down too just a neat hole, should be good for a few decades.

            So in case you cant go to Hawaii now there is option 2 🙂

        • I guess we will need to wat if it really does something, but it is quite incredible to have potentially two eruptions in two volcanoes that have not been active in the Holocene erupt within a year.

          Looking at Langjokull it seems to to be completely different to Vatnajokull. There are supposedly two central volcanoes but there are no big fast eruptions, only lava shields and slow fissures, so no large magma chambers. Seems eruptions here all happen slowly and last a really long time, and maybe there are no true central volcanoes anymore.
          Sort of like what has happened to Lanzarote, or on older Hawaiian islands or Yellowstone calderas, where the deep magma system is active but the shallow magma chambers are dead. Apparently all current systems under Langjokull are relatively young but it would seem to me extremely hard to verify this. Maybe the area is up to several million years old, the old central volcanoes only being represented by the tough rhyolite, while newer eruptions are more monogenetic and reusing the weakness.

          • In regards of the Holocene eruption from Prestahnukkur and Langjökull, they are highly contentious.
            Ok seems to have separate feeder according to earthquake data, and Skjaldbreidur is not proven to have been caused by them. Instead it is equally likely that it is dyke from Hengill, or a separate volcano altogether with it’s own discrete feeder tube.

          • I tend to imagine the shields being direct from the melt zone, with little amount of horizontal crust transport, because that leads to cooling and introduces more places to get blocked, not good for maintaining eruptions for decades.

            Not sure about Hengill being the source of Skjaldbreidur or any of the other vents north of Thingvellir either, given those are higher in elevation than the summit of Hengill and seem to be quite off the axis to where the rift from Hengill goes. The majority of vents north of Thingvellir seem to be on a separate rift, without a central volcano, between the mountains of Tindaskagi and Kalfstindar.
            Actually, looking on maps shields around Langjokull seem not usually to be on any rift zones at all, maybe why thye are able to get so big, they avoid the passive rifting that takes away most of the magma.

            If that is the case, Icelandic shields being rare cases of conduits that form outside of rifts, then this is looking very promising. It is in maybe the best place to be as well, close to Reykjavik but also not close enough to be dangerous, if Fagradalshraun gets any bigger it will start to cause problems.

            Skotmansskjaldur 🙂

          • I know it wasn’t your intention but there’s almost more Icelandic in your post than English xD

            I’m in for another tourist eruption^^

    • Langjökull eruptions last a long time, it have some of the larger pahoehoe fields, they can last decades and are mainly tube feed. Souch an eruption woud be a tourist show, But involve long hikes in an endless lava landscape, activity woud be seen as thousands of small fluid breakouts along a wide flow front, the lava tubes are fast flowing But hidden in a well developed pahoehoe flow field. Before thingvellir rifted and sank and flooded with water it tougt to have been covered by 30 km3 of pahoehoes.

      Infact Pahoehoe is the most common lava surface in Iceland, most of Northen Rift Zone north of Vatnajökull haves pahoehoe surfaces, as well as in Langjökull and Reykjanes, very common surface in Iceland among holocene lavas, Area alll along Askja, Krafla, and North of it haves extensive pahoehoe surfaces

      We are used to Iceland producing fast short lived Aa lava channel eruptions, But long lived pahoehoe type eruptions been common too, althrough most of the pahoehoes maybe just the result of the extensive decompression melting after the Ice Age relaxed 9000 years ago

      Historical Iceland eruptions been much shorter lived, as faster Aa channelized eruptions in Iceland. Surtsey was the last one To produce a real pahoehoe shield althrough small. Fagradalshraun had excellent fluid lava, but never vent into constant non stop effusion really

      • For those who are not familiar with strange Hawaiian denominations.
        Aa is the same as the more easily understood Illulava (Illuhraun), which in turn translates as Evil lava or Bad lava due to how hard it is to walk on top of.

        Pahoehoe is Helluhraun, or Poured Lava.

        If it is especially ropy lava you obviously have Kaðalhraun.

        Lately we have though mostly gotten Óvænthraun (unexpected lava).

        Icelandic terminology is so much better. 🙂

        (I can hear Jesper going “meh” all the way to my office)

        • So we have lava from evil, lava from hell, and lava from the oven. That clears it up..

          • And we also have the all important Dutch lava:
            Sundhraun = Channel lava…

            (Okay, I will grab my coat)

          • Remember admiral Johansson. Don’t mess with Dutch lava – it shoots back

        • Concerning Dutch lava and coats I had problems sleeping last night, and when people can’t sleep they have strange thoughts, and in the middle of the night I was suddenly asking myself what would happen if Kilauea collapsed.
          Is that possible at all?
          Thinking about all those flat islands in the west that must have collapsed first and then been eroded.

          • Question is not really if, question is more when, and most pregnantly how…

            I favour the slow slip model with the flank slowly dropping down stepwise as larger earthquakes hit. This happened during the last eruption when the entire bottom of the flank went sideways half a meter at the bottom.

          • Thank you. Further concerning Dutch tephra, not lava though: Maria Laach-Maastricht: A little over 100 km for birds.
            😉

          • Will not happen for many millennia, probably not until the volcano is as big as Mauna Loa is now. Hawaiian volcanoes also mostly collapse only well after they become more inactive. Techanically speaking, the most likely volcanoes to collapse are probably going to be either Haleakala or Mauna Kea, though in practice Mauna Loa might collapse along its southwest sector again, as it has done twice before.

            Hilina faults are not at all a risk of collapse, the faults are not pointing the right way, and dont extend deep enough. Small slides though do happen there quite often as at any other cliffs though.
            In future (actually, maybe this century the way things seem to be going) lava will eventually overflow these cliffs again. Parts were covered around 1000 years ago in the early stages of the Observatory shield eruptions, and also about 2500 years ago. Some parts though are very old, the only part of Kilauea to preserve Pleistocene ground surface.

      • Yes Helluhraun and that acually is the most common lava surface in Iceland

        Even if faster Illuhraun or also called apalhraun in Iceland for Aa is the historical norm

        Fagradalshraun produced nice near very vent fluid pahoehoe But did not go into constant effusion, thats why the lava never reached the ocean, despite being so close to the Atlantic ocean

        The faster eruption rates of Fagradalshraun strongly favoured Aa formation some kilometer away from the vent althrough most of Fagradalshraun is capped by a pahoehoe layer of ”fast sheet pahoehoe”

        • Fagradalsfjall would be Óvænthraun in the form of helluhraun with some kaðalhraun.

          Hunga Nomore is obviously Óvænthraunspringur 🙂

          • Hahaha Lol’d IRL xD
            What the?? 😀

            Ok got it now, need to read the comments on lava types^^

          • Illuhraun and Helluhraun are the correct terminology, the others is more my suggestions due to all the unexpected explosive lavas we seem to see.

          • Now obviously Iber will pop in and exclaim that Hunga Nomore is Koltvísýringshraun.

      • Im curious when we will get the next decades long pahoehoe eruption in Iceland, althrough even if souch eruptions are not generaly the norm in souch a geological setting

        But Iceland can do very long lived monogentic shield eruptions perhaps a few 100 s of years in extreme cases, souch are equal To the very large previous shields on Kilaūeas summit and upper ERZ.

        • Those are rare, about one every 1500 years or so.

          The only likely one for that would be Skotmannsfell currently.

      • Hmmmm every 1500 years or so, But they are very long lived too and produce alot of volume over long time, that may explain why most of Icelands holocene lava surfaces are pahoehoe

        Older Pahoehoe is easy to see in Google Earth in Iceland the inflated Tumulus mounds can be seen everywhere in holocene Iceland lava flows, they are everywhere

        Historical Iceland flows since colonization been of the faster Aa flow type thats the norm in my lifetime in Iceland

    • Thank you for that article.
      Must have been both, pretty scary and spectacular, especially the lightning show 😮

  23. May I remind about the “Be nice!” rule.

    This little banner is put up due to someone who just tried to comment and got insta-bined due to breaking that rule, and on top of that… well I just got a headache now.
    Please leave out the cusswords, insults, and try again.

  24. Not to change the subject again, but is Langjökull getting ready to erupt? Quakes looking shallower.

    • It is Skotmannsfell going at it, and yeah… it is looking promising.
      I can though not say anything definite due to the lack of GPS stations around it.
      I posted a link up above to an article I wrote a few years ago about the volcano.

  25. A recent satellite SAR image from Capella Space of Hunga Tonga:

    • Looking at the water, if that inner structure inside the old caldera is the new caldera, it sort of implies that quite a sizeable volume was gouged out.
      If that is right a VEI-6 (volumetric) is definitely back in the potential cards.

      • Are those colours related to the turbidity of the water, or could they actually be related to bathemetry ? I wonder what happened to the south shoals and the 1988 vents.

    • So the previous caldera is still there. Not a surprise but it puts a limit on the rock part of the eruption.

    • This is what I think I see as the new nested caldera, that I just named Fluffy the Caldera.

      • The long “axis” of the left remaining island is about 1.5km or so?

      • Amazing picture. Why didn’t you take the blue line along that rim?

        • I followed what I believe to be the new caldera wall, and that does not seem to follow along the rim.

    • That would actually be larger than I would have probably guessed! Great find, the image! I may be mistaken, bit it seems the shallow reefs that would have to be to the lower right of the image center are also gone? We should put a scale to the image…

    • Having had a second look at this image.

      There is a chance that what we are seeing is the result of a flank collapse, ie that this is the result of all that material sliding outwards between the islands due to the side of the volcano in that direction having failed and galumphed downwards.

      I so look forward to new bathymetry 🙂

      • I’m not that sure that you can see under water with SAR image. Maybe it’s just circular changes of surface water texture ?

        • Obviously possible that this is surface texture only, but then begs the question of what is causing that texture.

          Do note that I am only speculating while we wait for bathymetric data.

        • Yes, it shows the waves, not the subsea surface. But waves form over shallow water so this still shows the places of shallow depth, and that follows the old caldera rim plus some internal structure that wasn’t there before. You have to be a bit careful in case of wave interference and that may play a role inside but not on the outer ring

      • There is a mass in the water in the south. You are thinking of That? A flank collapse would make a lot of sense. It would have caused the (rather small) tsunami, put a cork in the bottle neck wherever that might be, and then after a little while there was Champagne.

        • One point: this was not a small tsunami. Just because it wasn’t a giant 2004 or 2011 event does not mean it was minor. There was damage all around the Pacific, 10,000 km away, and at 50-100 km islands were wiped clean and at least two of Tonga’s islands have disappeared (both small and not occupied). The fact Tonga came out of it so well is credit to them and their preparation.

    • Ok, on this pic it becomes clear what you did and why. This might turn into one of the most interesting volcanoes in the world. Nobody living on it, no vegetation, not very much under the surface, so I guess it will be studied very well at some point.

    • Its quite hard to take a pic in odd colour settings with a modern camera because they all set the white level automagically.
      This can be fixed with photo software, and even overfixed.
      In my experience its really really hard to get a photo of a sunset looking they way your eyes saw it, even with later graphic adjustments.

      • Very true. Such deep pinks in the sunset can often be a result of aerosols in atmosphere. Common in desert regions. In a post-industrial, wet and relative rural Northwest Europe would seem to be more unusual than normal. It seems more than coincidence that these types of sunset are popping up across Europe since the eruption. Certainly something to keep an eye on over the coming weeks, does the unusual become the norm?

  26. Rare photo of Intra – crater activity of Nyiragongo in 1982. Defentivly very fluid lavas. and you can see that on the fountains How low the viscosities are for this ultra – alkaline lava, sillica is down at 36% Nyiragongos lavas maybe the least polymerized at any given temperatures because of their low sillica content

    But Hawaiian and Icelandic basalt lavas 50% sillica are very hot and can have the same low viscosity as Nyiragongo because of their sheer heat. Heat also breaks down the sillica chain polymerisation and is very efficent of that.

    And prehistoric Komatites at sometimes 50% sillica and 1650 C where as fluid as water because of their High temperatures breaks down all polymerisation

    Its difficult to know if Nyiragongo is the most fluid sillicate based lava, since viscosity depends on other things than sillicate content, temperatures is one that effects viscosity a lot.

    Nyiragongos lavas seems quite cool, and probaly is a good colder than Hawaiian and Icelandic basalt due to Nyiragongos origin with very small ammounts of partial melting, Nyiragongos haves a viscosity similar to near vent fagradalshraun because of its very low sillicon, yet at lower temperatures. But How fluid Nyiragongo is If difficult To know

    But Nyiragongo is defentivly one of the most fluid of all sillicate lavas

    • The research on Nyiragongos viscosity have yeilded inconqlusive results, althrough yes its is very very fluid. But probaly not more than a very hot normal basalt, but its more fluid than almost all other mafic lavas

      But in some Photos like these Nyiragongo does look more fluid than any other sillicate lava on Earth and the sillicate content is indeed very low 36%

      But Hawaii have produced similar Fountains in Halema’uma’u in 1960 s

      The 2002 and 1977 flank near vent did produce amazingly fluid deposits, but seen similar at Mauna Ulu and Photos of the 2008 – 2018 overlook lava lake lava splash on walls

      But Nyiragongo is the most fluid lava at any given temperatures I think If you haves other lavas in experiments at same temperatures

    • How fluid Nyiragongo is depends alot on its temperatures even if the sillica content is very very low, this photograph shows it to be dull orange so quite cool, perhaps not alot hotter than Mount Erebus but with much lower sillica

      But other photographs of Nyiragongo shows it sometimes to be yellow hot in Patrick Marcels youtube videos, lava spatter cools very quickly on the surface masking their true temperatures

      Even fagradalshraun and hawaii can be dull coloured in direct daylight and With combination of surface cooling on exposed spatter

      But Nyiragongo is almost certainly quite cool, since its a product of very small ammounts of partial melting

    • What you see in this photo are lava fountains that behaves like jets of water constantly spewing, they are not lava bubble bursts

      So yes Nyiragongo have low viscosity
      But not soure If its lower than fagradalshraun and Halema’uma’u

    • Carl .. you Agree too?

      Its difficult to say about Nyiragongos viscosity.. and exactly how fluid it really is But its low in viscosity

      Hawaii is just as low in Halema’uma’u I think

      Well I dont know really

      • Carl is trying out a novel thing called working today.
        I am back at the office after testing out the Omicron flavour of The Pestilence.
        It tasted Lilacs.

        • Welcome to the Omicron community. Nearly all people I know have had it now. In different countries. It will get us to the first piece you wrote about it, then sitting in the middle of Africa.

        • Have your antibodies checked please. Good for documentation and one day – who knows – maybe good for something.
          Your countrymen dealt best with it. Anders Tegnell is a couragious man, probably viking descent 🙂
          Worst: New Zealand.

          • There were three approaches. One was to let it run rampant, like you would do with flu. The second one was to go for full suppression. The third one was to buy time. I am not going to judge. Option 1 turned into an economic success but a humanitarian catastrophe. Option 2 worked well but required a competent government and a cooperating, obedient public. Option 3 was the lucky one, as vaccines were developed in record time – that was never guaranteed, but it is now running into the problem of a fairly rapid decline in immunity over time. I feel lucky: I got covid fairly late, benefited from the vaccines but still became badly ill. Three people I know died of it, two colleagues (one only a few offices away from mine) and one family member. We now need to find ways forward, and these will be different from the past. Positives is that the current version of covid is three times less lethal than the first one, and we have high degree of some immunity . Negatives is the rapid turnover in the virus (we have no idea how lethal the next variant will be), the increase in transmission as the world re-opens, and the vaccine hesitancy.

          • “Option 1 turned into an economic success but a humanitarian catastrophe”

            Not really, Albert. Altogether Sweden doesn’t have a higher mortality. At the beginning they did not take enough care of the care homes and changed it then. Their kids all went to school which is brillant. Altogether there is no human catastrophe anywhere. There’s a rise in suicide attempts among youngsters in my country though.

          • Sweden had significant constraints on the population, just largely voluntary. I would put them in the option 3 group. An example of option 1 was Brazil

          • Make it simple, Albert. Compare New York State and Florida, about the same population number. NYS: Hard lockdown in 2020, altogether more than twice as many deaths than Florida, light lockdown for about four weeks.

          • ?? New York State and Florida have the same population size. NYS has reported 65,000 covid deaths. Florida has reported 64,000 deaths. Tracking is different and numbers can’t easily be compared between US states. But I do not recognize your number of twice as many in new York State.

          • Let me clear up something here.
            We went with option 3, we did suppress it and we continued to suppress it when the rest stopped.
            We knew we could never stop it, but our goal was to not overwhelm our hospitals. Something we succeeded with.

            The Meme that we let it run rampant was never true (except in UK tabloids).
            Next item, we are far from the country with the highest death rate in Europe.

            Also a small point, the death rate with Omicron when vaccinated is almost zero. 99 percent of our mortality are among what we call Darwin Award cases, ie. the antiwaxxers.

          • You are completely right, Albert.
            I checked the 28th day deaths, didn’t look properly. Right now they are better off.
            But that doesn’t change the message: Florida, light lockdown, and New York, gruesome lockdown, have about the same number of total deaths.

            Sweden, light lockdown, has about the same number of deaths as other countries with a hard lockdown. And – I am not looking the pop-count up right now (estimate 60 m) – about the same number as Spain with a dire lockdown last year. Sweden, aside from that, has the oldest population of Europe, next is Switzerland, as far as I know. Same state for Switzerland, lower medium lockdown.

            Meaning: Fast spreading viruses can’t be locked out. With Ebola it would help or with something like SARS and MERS, slow spreaders, accordingly more serious disease.

            Second meaning: Sweden trusted their population concerning distance rules and responsability. It might be boring (Jesper), but is the best country in Europe and always was. When the Danish realized that the evil guy was going to invade their country back then they organized an overnight boat action taking all the Jews to Sweden. They survived there. The Danish are not bad either.

          • I recall a news interview with the Swedish Ambassador to the U.S. in mid 2020 in which she owned up to the fact that their lack of a lockdown hit the aged population hard in the percentages.

          • I am not judging the different approaches. First, you can’t compare a crowded city environment to a state consisting only of suburbs. Second, the epidemic hit at different times. We now know it is easier to control it in summer than in winter. Medical care is different: a lot of the actions were taken to safeguard the hospitals. Third, early on we did not know what was coming, and what worked or what didn’t. The early models on how the epidemic would proceed and how many people would die turned out to be remarkably accurate. But we did not know that either, and did not know which restrictions were most effective and which ones less so. (It may well differ per region.) We didn’t know the link to poverty. We didn’t even know that older people were particularly at risk. There will be studies later and from that we will learn how to handle the next such epidemic better. There are two uncertainties remaining. One is that of data: in many places (including some US states) we only have estimates because of a lack of recording. The other is that we do not yet know how long covid will develop: it could be anywhere between a slowish but full recovery to a substantial reduction in life expectancy. We don’t even know whether people with mild covid also have mild long covid or will have life-long problems which only surface when they reached 50. We have a lot to learn.

          • I agree, we have a lot to learn.
            But, as always I look foremost at the important question: Do we have enough to eat?
            Currently more people have starved to death due to Covid-shutdowns than have died from Covid itself.
            We in the western world do not see it, but the effects down-chain have been horrendous. We in the west just have to grump over rising food prices.

      • Omg You got the virus
        I heard Omicron is even more strange than corona

        • It is like a common cold, sometimes with a bit of temperature and neck pain. Some people (supposedly 1 in 10) lose their taste for up to half a year. No worries, Jesper. I had it myself and didn’t even realize – but I’m a typical doctor having nothing (suppressing things) – until another family member had it. I have antibodies high like Mount Everest. The labatory writes they might be partly due to the booster and partly natural. So I don’t know what it does to unvaccinated people. The people I know are all vaccinated and had something like a common cold. No worries. And spring will come soon.

          • Still unaffected despite travelling on tubes and trains.
            Which means I will go down with it really badly any time now.
            UK press is saying “Two-thirds of people recently infected with the Omicron variant say they had already had Covid previously. “.

          • Not necessarily. You might not have realized when you had it, Farmeroz.

        • One day we should write about volcanoes and viruses. We know volcanoes breed bacteria, or at least encourage them. https://www.volcanocafe.org/apocalypse/ How about viral diseases? Did Covid19 in reality evolve in the heat of Leilani? Hard to believe how all those conspiracists missed that one.

          • At the very least, Covid-19 is breeding armchair volcanologists 😉

          • Fox News did a segment on Fauci-gate Tuesday evening during Bret’s hour and a followup Wednesday night is scheduled.

          • That is crazy, it clearly evolved in the Galapagos, in the heat of the double eruptions of that year at Fernandina and Sierra Negra. That Leilani was simultaneous with both is just a coincidence, and one that worked to distract quite well.

            🙂

          • Ulawun should be under suspicion of creating covid: it had the largest boom of 2019. Every volcano produce a new variant, perhaps. Omicron clearly came from La Palma, and delta from Etna

          • The latest news is that Covid comes from the Norwegian ski-team.
            They found an infected pregnant woman who might have been case zero, somehow a Norwegian skier must have been involved.

            Any day one can blame the Norwegian ski-team is a good day.

          • @Albert:
            According to Dr Bruce Dahmer all life is originated from volcanoes.
            He makes a fairly compelling case.

          • Those Scandinavians (Carl) with their proxy wars. Sweden doesn’t have a Kristofferson, that’s right. But this year the hero Odermatt, Swiss.
            And guess – Dave Riding who won Kitzbuehel, very special.

          • I should though point out that the pregnant Norwegian is a real thing, she was carrying antibodies at the same time as the Chinese found live virus in patients.

            Back to joke mode: So, a norwegian skier must have taken the virus to China on one of his ski-trips 😉

          • The sequel is already out. Omicron II, coming to a place near you anytime soon! 😀

            The original was pretty ok, so let’s hope this one doesn’t turn in to a turkey. Wake me up for booster 9. Or something (joke, fully vac’ed). Here we strive with omikron two times a week, but our teacher is hiding her frustration well. 🙂

            But I do find it interresting to read Robert W Malone.

          • Denmark that Invented the O2 it was so scary that they decided to remove all of their corona measures and go on a complete binge.
            In other words, it seems to the same as the O1…

  27. Regarding the swarm west of Langjökull. Icelandic geologists don’t seem to think there’s ongoing magma accumulation or dyke formation. Just intra plate movements.

    https://www.ruv.is/frett/2022/01/24/sprungur-a-hreyfingu-en-engin-kvika

    There was a large earthquake in the area 1974 (M5.5) and groups of faults have been mapped nearby. A certain professor in geophysics pointed out in a discussion in an Icelandic Facebook group that instrumentation is poor in the area, so depth measurements are not precise and should not be trusted.

    Unless we start to see deformation signals (GPS, InSAR) consistent with magma movements, I’m going to trust our Icelandic geologist friends on this one, even though it would be fun with some more óvænthraun.

    In the same Facebook group, I also discovered this great earthquake map of Iceland:

    https://vafri.is/quake/

    If you click on an earthquake you get some detailed information, links to the closest GPS and seismometer, and a beach ball. Unfortunately it’s not the full moment tensor, only the best double couple solution. Good for planar tectonic faults, less good for complex geometries and/or volume changes. The M3.3 seems to have been a normal fault, and the ones that didn’t quite reach M3 were strike slip or oblique. I’m guessing echelon strike slip with pull apart basins.

    • In this case I do not agree with them.
      Also, there is no GPS-network there…

      • i am curious on what you think about Langjökull. ?

        • Technically it is not Langjökull.
          It is the old volcano of Skotmannsfell that seems to be reawakening.
          At least it seems to be forming a rather nice stack. This particular set of swarms have been going since at least 2017.

          • It becomes even more evident when you start in 2017 when the first intrusion was (there may have been previous intrusions, but that is when I saw the first one, observation bias and all…)

      • Carl, could you please explain a bit more why you believe that it is Skotmannsfell reawakening? You have my curiousity.

        • negate my question, looking at the Iceland webpage on IMO shows that definitely quakes are clustering in this location and slowly starting to add up.

  28. Confirmed lava on the surface at Ambrym again, after several days of vulcanian eruptions. Lava lakes are back.
    Currently only in Benbow, Marum is still ash, but seems likely both will be red hot soon.

    Considering Ambrym is a volcano that has historically erupted basically every year, after 4 years a bigger eruption might not be out of the question, like happened in the first half of the 20th century. 2018 was a major rift, but rifts that big happened around 5 times between 1910 and 1940, with eruption of 1914 being of almost flood basalt scale (along with what might be the scariest description of a lava flow I have ever read… :O ).

    • That is indeed interesting, Jesper! By necessity, a great deal of it is extrapolation based on theoretical modeling, but it looks soundly done.

      Super-Earths seem quite common in other star systems; our own is a bit of an anomaly. It’s a pity that’s so; if we had one in the outer solar system, we could learn much by studying it.

      I suspect that the greater heat (from decay, given all that mass) would make for a lot of volcanism.

      /Found you loitering in the Dungeons, hope the cookies was tasty. Admin

  29. Absolutely right, Carl, and that is another point:
    “the effects down-chain have been horrendous”

    • In the end, the magnitude-9.0 Tohoku earthquake and subsequent tsunami killed more than eighteen thousand people, devastated northeast Japan, triggered the meltdown at the Fukushima power plant,

      18,000 people!!!!!!!!!

    • Please don’t imply that something that engulfed entire islands was not a ‘real’ tsunami. It is not respectful for what those people went through.

      • I think many peoples impression of the Tonga Tsunami comes from the footage taken at the beach front in Nukualofa. I suspect that the tsunami there was greatly weakened by having to drag across more than 10 km of reefs and shallows. In other areas, like the NW end of Tongatapu, where there wasn’t a wide flat shallow shelf the tsunami was much worse.

        • No. Older people like me have seen bad things, storms in Germany and France, floods in the Netherlands and Germany, hurricane Katrina, other hurricanes, last one last year in the Midwest taking down a whole town (five-state-hurricane), typhoon in the Philippines, South-England under water, tsunami 2004 with pictures of the dead swimming in the water, tsunami in Japan 2011 with 18.000 deaths. That made me call it RELATIVELY small=moderate. Relatively includes that all desastres, moderate or large, are difficult for the people concerned.

  30. From an article today;

    “Kagoshima blast 30,000 years ago dumped ash in Tokyo”.

    Exepts;

    “A team at the National Institute of Advanced Industrial Science and Technology (AIST) made the finding with a simulation while re-examining huge eruptions in the distant past, which although rare, had devastating consequences for the environment.

    The team members spent two years or so looking at strata in and outside Kagoshima Prefecture. They also combed through past data to simulate the pyroclastic flow that reached the ocean 30,000 years ago.

    The so-called Ito pyroclastic flow was calculated as having spread out from the Aira caldera up to a radius of 100 kilometers. A 100-meter-high pyroclastic flow rained down on the area now occupied by Kagoshima city, which lies very close to the caldera.

    …The latest estimate of the total volume spewed out of the Aira caldera places the amount at between 800 billion and 900 billion cubic meters, about 1.5 times the previous estimate of 600 billion cubic meters.”

    https://www.asahi.com/ajw/articles/14532350

    • Wow, nearly a VEI 8, and just 2000 years before Oruanui. Also almost makes the cut of being an erupting supervolcano now too.

      • It is SO close. Actually, if the mass of material was at least 10^12 tons (a trillion tons) it would count as a supervolcano, but the average density of the deposits would have to be >1100 kg/m^3 if 900 billion cubic metres in volume, or >1250 kg/m^3 if 800 billion cubic meters in volume. That might be possible.

        I think I read recently that the last Aso 4 caldera eruption (~88 ka) might be larger than originally estimated. If so, we can add Aso 4 to the roster of Quaternary VEI 8′ s.

        • If that volume is in DRE then the eruption was certainly a VEI 8.

          • No, that volume was expressed in loose tephra. Without the average density of the deposits it is hard to know what the DRE is, but if the average density of the deposits is about 1000kg/m^3 and the density of the crystal poor rhyolite is about 2300kg/m^3, the DRE would be about 350-390 km^3.

          • It says ~400 km3 DRE, which is indeed about 1000 km3 bulk, so yeah I think it does just reach VEI-8. Not that the difference between a very-high-end-7 and an 8 really matters!

          • A quick estimate based on the ash thickness plot suggests the quoted volume is a factor 10 too high. I make it approximately 100 km3 of ash

          • That would make the eruption just as big or smaller than Tambora! This eruption produced a 20×20 km wide caldera, that alone is sign of massive eruption.

        • The area does seem to be somewhat similar to the Taupo volcanics, being that it is a rifting arc. First eruptions there were voluminous basaltic lava flows in the early Pleistocene or late Pliocene, and then as crust melted the calderas started showing up. Seems to be that silicic LIPs form when back arc rifting goes under continental crust, so it is more rift driven than just arc volcanism. Not always, the Andes are pretty well exactly the opposite, but apart from that most supervolcanoes are on rift zones or areas of extension.

          Managua seems to be presently at that early stage, given Masaya is a tholeiitic shield in a subduction zone on land, which is otherwise very rare but seems common in early products of silicic LIPs.

    • ‘some controversy’ understates it. The paper itself presents an idea but without any actual model or calculations. (It explicitly says that was ‘outside the scope’). If you want to make a case, you do need to do your home work. Until that is done, this will be ignored.

        • It is a model, and she (Hofmeister) herself says it needs testing and suggests Pluto for that. Pretty far away and expensive. Difficult to prove and find evidence.

          • Well, no real evidence for now, but probably would do some real field testing to prove this hypothesis in order for it to become a theory. Just simply posted it as a thought.

      • I’ve seen the same author (Hofmeister) weighing in on astrophysics. To put it as nicely as I can, some of her theories are profoundly unique, as well as utterly unsupported.

      • Well, looks like this theory is disproved, but how could anyone explain about odd coincidences where the Earth has a moon and that other rocky planets that do not have large moons don’t have plate tectonics or at least limited tectonics. Looks like Earth is the lucky one after all. (Not just about the Moon about the fact Earth has prolonged plate tectonics by itself for the longest time).

        • More both are byproducts of the same thing, the last big merger of two planets in the inner solar system. Earth is probably the hottest on the inside, and also spins the fastest. Mars is slightly slower spin but much smaller mass, Venus is slightly smaller mass but spin might as well be nonexistant…

          Moon is there I guess as an accidental byproduct of that collision, where enough material was ejected to form an orbital ring, and the reformed Earth was spun up fast enough to give that material a tidal kick and prevent it from coming back again.

          • This collision between the planet and Earth might’ve rejuvenated Earth itself (if it weren’t for that collision, Earth might’ve looked like a boring version of Venus…
            maybe).

        • Earth has the greatest mass of all the rocky planets, so more nuclear material to drive things.

          Jesper do have a point with his Massive Planet Fetish. 🙂

          • In our solar system yes Carl

            But There are even much bigger rocks around other stars 🙂

            I wants To visit a Big Super Earth and explore its geology

            Gravity wont be a problem. 10 Earth masses yeilds only 2X Earths surface gravity

            So 6 Earth masses barely any diffrence really 🙂

      • Earth is the most massive terestrial planet in our solar system, so it haves the most internal heating among the solid bodies, Earths mantle convection drives tectonics
        Earths center maybe as hot as 6200 to perhaps even 7000 C degrees C

        Most models puts the surface of the inner core at around 5500 to 5700 degrees C, the interior is well above boiling points, But keept solid and liquid by high pressures

        Its the heat left from Earths formation and radiogenic heating

        Super Earth class exoplanets that can be as massive as 10 Earth masses will have very much more internal heating than Earth do some larger example maybe able to reach up To 20 000 C or more in their centers! They maybe very good at liqufy themselves into magma oceans

        • Heard Venus may still be somewhat active with volcanoes, but not as much as Earth at the moment.

        • Venus is almost as large as Earth is so not strange at all

          But Venus gets rid of its internal heat in more catastrophic ways since it lacks venting tectonics

          Last eruption was in 2009 I think

          • Pretty much by periodically covering the surface with lava and then going real quiet for millions of years with a few exceptions.
            Couldn’t really imagine if those “catastrophic events” on Venus happened today.

          • Some interpretations based on crater counting of the planet’s surface indicate that the whole planet may have been resurfaced by eruptions 450 million years ago. This event is not just a flood of lava. No, it would have been volcanoes growing everywhere and making kilometric thicknesses of lava, together with giant dykes opening massive chasms in the surface, and sills intruding the crust and thickening it. A geologic cataclysm of planetary proportions. Of course it will be very difficult to confirm and unravel many details about this event.

          • Hmm…
            I quite wonder what that would look like from space?

          • The temperature and densuty of the atmosphere there make it nearly impossible to resolve heat signatures less than 1 km2 in area. For example that the lava lake at Kilauea is 0.7 km2, should it entirely flood over we might be able to see that if it were on Venus, but it would be very small and hardly visible. No way we would ever see any of the other continuously active volcanoes, even Nyiragongo and Kilauea before 2018 would not be visible. Basically to see anything clearly we would need to see a major flow, like Holuhraun, and those are rare enough that it isn’t surprising one has not occurred in the last 20 years we have good data.

            Likely Venus is not as frequently active but I find it hard to believe it has no currently erupting volcanoes, when our planet has around 60 at any time.

          • One thing that’s always puzzled me is why Venus has such a massively dense atmosphere. Venus has a very weak magnetic field, as does Mars. With Mars, the currently favored theory is that the atmosphere was stripped away by the solar wind once the mutagenic field became weak. Yet, Venus is vastly more impacted by the solar wind, and has a massively thick atmosphere (92 times that of Earth). Any ides why Venus’s atmosphere has not been reduced by the solar wind the way Mars’ has been claimed to be?