Volcano who ?

In memory to the 22

Today, May 22, 2022, it is five years ago. On May 23 2017, we woke up to the dramatic news of a suicide bomber in our home town. It killed 22 people including children. The target was an Ariane Grande concert. The artist later came back for a free concert, in memory of those killed. She is still deeply appreciated here, showing courage against terror which no doubt deeply affected her as well. Later today I will take part in a small act of remembrance of the day hate came to my city. Today is also the day England’s football season ends, with the winner still to be decided. Perhaps Liverpool, our for-ever adversary, has the best song for the occasion: You’ll never walk alone.

Hatred grows from a dislike for what is unlike. It may be the colour of someone’s skin, ethnic background, gender (or lack thereof), or (as in the case of Ukraine) independence. The smallest difference can suffice. By not accepting someone’s right to be different from us, we sow a seed that in extreme cases can lead to terror, even against children: Homo homini lupus.

Humanity is under constant attack. Often it is self inflicted: global warming can only be blamed on all of us. And it is not always foreseen. My city is proud of its history: it split the atom (we still have the bench where this happened), and it invented the computer. Both have been used for better, but also for worse. The first provides both energy and medical treatments, but we also have the scars from nuclear accidents, and we now live in fear of Russia’s nuclear weapons. The internet has revolutionized our lives. But it has become become a vehicle for adverts, commerce, emotions and politics, rather than for facts. Could we have foreseen the misuse of Facebook and Twitter? It used to be said that a lie could go around the world before the truth got its boots on. It is so much worse now. Hatred is fertilized by false facts. Perhaps VC tries in its small way to help spread at least volcanic truths.

Other attacks have natural causes: viruses, earthquakes, tsunamis and even eruptions will always be with us. That does not mean we are blameless. Our growing population puts more and more people in the path of danger, and sometimes our planning falls in the realm of wishful thinking. But where there are dangers, there are protectors. They range from the staff at your local hospital to the people manning (and often unrecognized, womening) (which my computer claims is a word that does not exist!) the volcano observatories. The bigger the danger, the more important the protectors. I salute the people who work tirelessly to keep us safe. They can get things wrong – volcanoes are unpredictable – but they have saved countless lives.

The greatest of those protectors first became known in 1963 when the BBC dedicated a program to it. It aired with a bit of delay (about one minute), caused by the fact that earlier that day president Kennedy had been assassinated. The program followed two teachers who are worried that one of the children appears to live in a junkyard. They follow her, and find that her home is an old phone box. Going inside, the worried teachers have a shock: not only is the box quite comfortable, it is also much more spacious than it should be. It is bigger on the inside than outside. The child’s grandfather shows up, and kidnaps the two teachers. This begins a series of adventures across space and time with the box, the enthralled humans and the grandfather – The Doctor.

The first series had four episodes. The next series of episodes introduced the most famous of humanities’ enemies: the Daleks. As one of the producers said, after the airing of the Dalek she heard children playing ‘exterminate’ and knew she was on to a winner. Ever since, the Doctor, in many different incarnations, has been defending the hapless human race against the space invaders. Space opera – with a bit of science, mostly about solving all technical problems by ‘reversing the polarity’ (do not try this at home!), and being vague about various details of physics: “time is a strict progression from cause to effect, but actually from a non-linear, non-subjective viewpoint, it’s more like a big ball of wibbly-wobbly, timey-wimey stuff”. And it shows: one of the companions mentions in passing “Oh, the moon landing’s brilliant. We went four times”. Those human companions now join by choice, not by abduction. The threats to humanity are always severe, but at times come from humanity itself, such as when the last human at the end of the Universe tries to sabotage the spectacle. Especially future human worlds are subject to our failures. Visits to the past more often emphasize alien threats. It is almost 60 years since the first episode, and Doctor Who has turned into a phenomenon, with a very human touch. The episode about Vincent van Gogh required a help line for the emotions reactions it caused.

This, however is beside the point for VC. What we need to know is, does the Doctor ever fight volcanoes? How do they rank on the spectrum of humanities’ adversaries? After all, any alien with bad intentions towards Earth should explore the potential of a flood basalt, or Large Igneous Province.

The first time a volcano played a role in Doctor Who, was in 1966, as a touristic diversion. It was in fact not on TV but in a Doctor Who comic, in which the Doctor visited a Pacific island, witnessed an eruption, and met a mermaid and king Neptune (the latter parts should not be expected as a normal part of volcano tourism. Just to avoid disappointment).

The science of volcanoes was briefly explored by the fourth Doctor, Tom Baker, who marvelled at seeing the Earth’s crust forming. The companion, Sarah Jane Smith, was appalled by it. Not everyone is impressed by volcanoes! And that is fine – everyone has a right to be different. Even if I find it difficult to understand! This happened not on TV, but was part of a BBC audio program for a schools study module on geography.

The Doctor is more of a VC fan. He watched two famous eruptions in person. When Krakatoa exploded in 1883, the Doctor was there. This is not shown in the series, but the Doctor talks about his experience, and especially the noise (‘Inferno’, 1970). A drawing showing the Doctor in front of the eruption later was found on a beach on Sumatra. (We have requested a post on this from the Doctor but have not had a response. The email may not have arrived in timey wimey.)

Apparently the Doctor never visited Tombora, a curious oversight since it means we still don’t know what the mountain looked like before the explosion obliterated it. The Year without Summer does occur: the Doctor visits Lord Byron and Mary and Percy Shelley in Geneva. As appropriate for the year, he arrives soked due to the incessant rain. But the Doctor proposes that the poor weather is not due to volcanic ash, but has some other cause. A lone time-traveling cyberman soon shows up. But the mystery of Tambora is never solved.

There is of course Vesuvius, How could a time-traveling volcaholic with a travel box not visit it? But the Doctor arrives unintentionally, actually wanting to visit Rome. They arrive the day before the eruption, and discover an alien race called ‘pyroviles’ inhabits the volcano (making them the original volcaholics). But now there is a surprise: the eruption of Vesuvius is triggered by the Doctor, in order to destroy the pyroviles. Earth is saved by a volcano (and a water pistol, apparently a very effective weapon against volcaholics).

1813 painting by Pierre Henri de Valenciennes. But did he know that the eruption was set off by the Doctor?

Some volcanic eruptions are slightly unexpected. In ‘The Enemy of the World’ (1967), the adversary Salamander sets off dormant volcanoes in Hungary. This may be a surprise to VC readers. And the surprise would be compete with an eruption in southern England (Bedfordshire, of all places). This happened in a very early episode in 1964, still in the presence of the Doctor’s grandchild. The ever-popular Daleks have invaded, and are working from a mine. It turns they have mined to the edge of the Earth’s core, and intend to replace it with a propulsion engine under their control. The final penetration will be done with an explosive. The Doctor causes it to explode before it reached that deep, and the explosion sets off a volcanic eruption in England.

There are a few volcanic eruption on planets other than Earth. They sometimes play a role in the story, but the only active role is on the planet Dulkis, where volcanoes are used by the adversaries to turn a panet into starship fuel.

So by and large, our ultimate protector has a mixed involvement with volcanoes. the Doctor at times uses volcanoes to destroy the enemy, and has some touristic interest in them. The opposition may live in volcanoes, but tends not to make them erupt.

The message is clear. Volcanoes are our allies. They belong to us, not to our adversaries. The world’s protector does not protect against eruptions. It is up to us to live with them.

In the end, nature is not against us. Volcanoes are unpredictable and dangerous, but they are not our enemies. And may be one day, we will learn to use them.

The Doctor is said to live in the Whoniverse. Perhaps the Volcaniverse has been overlooked.

Albert, May 2022

See https://tardis.fandom.com/wiki/Volcano

70 thoughts on “Volcano who ?

  1. Thanks Albert;
    A sobering and poignant reminder of the multitude of frailties living in today’s world.
    Understanding the threats from both within and without is our/my only defense.

    • Thanks Albert, it is a very fascinating article. It gives a lot of insight into the eruption. Note however that we are talking of the flanks, the caldera has not been surveyed by this team:

      “The RV Tangaroa did not survey directly over Hunga-Tonga’s opening, or caldera.

      This will be left to a robot boat developed by the UK company Sea-Kit International. The 12m uncrewed surface vessel, called Maxlimer, is currently in Singapore en route to Tongatapu, the main island in the Tongan archipelago.”

      So we will have to wait for the Maxlimer to get a definite DRE estimate. 2-3 km3 is what has been stripped away from the upper flanks of the volcano, likely by the erosive power of pyroclastic density currents. Pyroclastic density currents erode near the source and then redeposit the material further away, here we are talking of submarine PDCs which might have even greater erosive potential.

      They speak of 6-7 km3 of material that has been deposited in their area, most of this must have been ejecta from the eruption, some it could be the 2-3 km3 eroded from the upper flanks of the mountain. There is a lot of volume not being surveyed here though, PDCs will have likely reached outside their small survey area, and also there will have been material lofted into the atmosphere, or carried far away in ocean currents, all this not being included in their estimate.

    • Another possible hint about the size of the Honga Tonga eruption…Shane Cronin’s crew has done a preliminary map of the top of Honga Tonga. There is a new caldera about 4 km in diameter and about 850 meters deep. The maximum water depth in the older caldera was about 150 meters. It therefore appears that caldera collapse on January 15 was as much as 700 meters ! It is not clear to me yet that the new mapping can constrain the volume of the Jan 15 caldera collapse yet, but a cylinder 4km in diameter and 700 m in height would have a volume of 8.8 km^3. An inverted cone of 4 km diameter and 700 m depth would have volume of 2.9 km^3. If the actual caldera shape is halfway between a cylinder and inverted cone in shape it would have a volume of about 5.9 km^3. If the caldera collapse replaced crystal poor liquid andesite with a density of 2,500 kg/m^3, the eruption could have had a mass of about 15 * 10^12 kg. This would be a magnitude of 6.2 and could be a VEI of 6.

      By comparison, the survey already completed suggests a volume of about 7 km^3 of new deposits off the summit of Honga Tonga. If the density of new deposits is something like 1000 – 1500 kg/m^3, the mass of deposits could be about 7 – 10 * 10^12 kg. That would be a magnitude of 5.8 – 6.0. The question arises about whether to include the 2-3 km^3 eroded from the upper flanks of Honga Tonga in this total, but it also must be considered that some of the Jan 15 erupted products may be present as intracaldera fill and thus not included in the quoted 7 km^3.

      It seems likely that the volume of caldera collapse on Jan 15 was probably the largest on earth since either Katmai in 1912 or Krakatoa in 1883. Perhaps the great explosion of Jan 15 could reflect the vent dynamics during caldera collapse, which could have allowed extreme eruptions rates not been seen on earth since Krakatoa in 1883. Based on the rate of growth of the giant umbrella cloud the eruption rates may have been of the order of 2 – 4 * 10^9 kg/s during the first hour or so, (and perhaps much greater in pulses over much shorter timescales of minutes or less).

      • From the images, the diameter of the crater is 2.5 km, not 4 km. The 4km refer to the outer boundary of the rim, not the inner edge. That explains the numbers, because a 4km crater would be solidly in VEI-6 territory. The reported numbers are lower than that, although still high VEI 5


        • Actually, the outer rim is more like 5 km east – west, and 6 km north – south. According to a map from Shane Chronin the interior ~270 meter isobath extends at least 3.7 km north south, from as far north as a line drawn between the NW end of the remaining part of Hunga Tonga and the NE end of Hunga Ha’apai southward to those two reefs in the southern part of the caldera. If so, the inner rim is at least that dimension in the north south direction. The east – west distance between the SE end of Hunga Tonga and the SW end of Hunga Ha’apai (based on their pre Jan 15 outlines) was about 3.8 km. The inner rim looks like it extends at least that far in the east – west direction. If this is the case the Jan 15 caldera does have a diameter of about 4 km, which is the size that I have seen quoted.

          At exactly 4 km diameter, if the average subsidence is even 1/2 of the 700 m or so maximum subsidence, the volume of the Jan 15 caldera would be ~4.4 km^3. If the average subsidence is 2/3 the max, the volume would be ~ 5.9 km^3. The 2/3 value would be halfway between the value for a cylindrical shape and an inverted cone shape.

          • An update here….I found a presentation done by Shane Cronin to the government of Tonga about the eruption. In this presentation he presents a new map of the Jan 15 caldera and even provides a preliminary estimate of the caldera volume of 6.5 km^3 based on the difference from the 2015 survey. Not including any caldera fill, a caldera collapse of 6.5 km^3 compensating for andesitic magma with a density of 2500 kg/m^3 would indicate an eruption of ~16 * 10^12 Kg mass. If this is correct the eruption would have a magnitude of 6.2 and a VEI of 6. In fact Shane Cronin gives the eruption a VEI of 6 in his presentation.

            The estimated volume of caldera collapse is exactly equal to what I though was the estimated volume of new deposits on the sea floor away from the top of Hunga Tonga on it’s lower slopes, ring plain and beyond. If the volume quoted was new loose deposits, the mass of the eruption would be less than that estimated from the caldera collapse as the material deposited would have a density of perhaps 1000 – 1500 kg/m^3 which would be much less than the density of dense andesite stored several km below the surface in the crust.

            Is it possible that the quoted volume of 6.5 km^3 that I have seen from several sources in general science news reporting actually comes from Shane Cronin’s independent estimate of caldera volume and not from the differencing of the sea floor done in the wider survey away from the summit area of Hunga Tonga ? That would explain the perfect match between what I had thought were two different volume determinations.

          • The DRE volume is then greater than Pinatubo, which was 5.4 km^3. We can now say Hunga Tonga is the biggest explosive eruption since Katmai in 1912. It is also probably the first ignimbrite-forming eruption since Katmai and its Valley of Ten Thousand Smokes.

          • Seems like ignimbrite eruptions happen really fast. Probably they occur when a ring dike fully encloses the center of the future caldera and it is left unsupported. Then the middle falls down and the whole magma chamber gets ejected in short order. More fluid magmas would be able to erupt faster through a given space so maybe the most violent eruptions are not with rhyolite but much more mafic magma, rhyolite is just easier to accumulate in an enormous volume without erupting compared to basalt.
            Basalt with a high water content might be the peak of it all. Etna during major paroxysms erupts lava that is as hot as the stuff found in Iceland and Hawaii, it is probably similar viscosity and yet this is when it goes borderline plinian like in 2015-2016 or last year. It is at about the point that such eruptions actually cause deflation as opposed to being a sign of overpressure as summit eruptions at more effusive basaltic volcanoes are.

        • Just wanted to say you did an absolutely phenomenal job estimating the size of this eruption, mere days after the event and without much in the way of hard data.

          Very impressive Albert.

  2. Long term upward trend of the Kilauea GPS has been reversed this week. Caldera has contracted by about a cm, though the tilt has not changed significantly. The lava lake has become very active though and has risen by over 5 meters this week where the measurement is taken.

    Looks like an open conduit has formed completely now.

  3. Inflation north of Grindavik is continuing at a steady rate, now 4-5 cm. It seems have paused or stopped at Eldvorp.

    • From the Frettir page by IMO (https://www.vedur.is/um-vi/frettir/talsverd-skjalftavirkni-a-reykjanesskaganum), google translated.

      “”Considerable seismic activity on the Reykjanes peninsula
      New data clearly shows the rise that is taking place

      Updated 23.05 at 12:25

      New satellite images have been received from the Sentintel-1interferogram from April 27 to May 21, 2022. It shows that the earthquake has been around 40-45 mm since the latest earthquake.

      Latest information showing the rise that has occurred from April 27-21. May. (Image processing: Meteorological Office, Vincent Drouin)

      About 400 earthquakes were measured with the Meteorological Office’s automatic location system in the past 24 hours. Today 23 May at At 07:15 a magnitude 3.5 earthquake was measured about 3 km northeast of Þorbjörn. He was seen on the Reykjanes peninsula and in the capital area. Last night, May 22 at 23:13, a magnitude 3.0 earthquake shook the area.

      Latest information showing the rise that has occurred from April 27-21. May. (Image processing: Meteorological Office, Vincent Drouin)””

      • The inflation is happening just north of the Reykjanes fault, I think.

  4. A large pyrocumulus cloud has formed above Etna. It’s largely of meteorological origin but nonetheless looks pretty cool.

    • I have also found this video of one of the big explosions of Stromboli in 2019. I don’t I had seen this view of the explosion before. There was quite a lot of magma under the crater that for some reason suddenly depressurized and blew up. The danger of Stromboli is having so much magma under the crater like a large roofed-over lava lake. Quite impressive:


      • Very cool, thank you for sharing!

        Do you have any thoughts on Vulcano lately Hector? Was looking over its list of eruptions and it does seem to have had quite a long repose time, last erupting in 1890. I recall the alert has been elevated on it for a while now.

        • The last news in Volcano Discovery are from December 2021. They mention the increasing CO2 emissions and uplift of the northern Fossa crater area. My thoughts? Some magma must have been flowing into the conduit of La Fossa crater. But I don’t know how much it would take to make it erupt. If pressure keeps increasing or degassing is intense enough, a pathway for magma could be opened. I wouldn’t feel too confortable going anywhere near La Fossa. Then again it might just go back to sleep.

        • 3 days ago I saw a report of discolored water off Vucano. A large amount of sulfur rich water emerged from some new hydrothermal vents in the harbor.

      • Really shows how a lava fountain and a plinian eruption are the same sort of thing. If this was viewed at night it would look like a lava fountain but as we see it in the day it is dark and ashy, though still incandescent. Interesting the side of the mountain moved before the eruption.

        • I can see that too. Every eruption is just magma coming out of the ground. Basalt explodes when it erupts. Even a 50 meter lava fountain can be considered to be explosive, the lava is after all being blasted into bits of spatter. It is a matter of eruption rate, as the eruption rate rises you go from a lava fountain, to a subplinian eruption, then to a plinian eruption, and finally to ignimbrite (I’d call them krakataoan) eruptions. Normally silicic magmas have far higher eruption rates because they use substantially wider conduits, larger conduits are required to transport a melt that is more viscous. However in rare circumstances basalt can go plinian, or even make ignimbrites. In fact Hunga Tonga is in the fluid side of things, with 58 % SiO2 and low crystal content, it is closer to Hawaii than to Taupo. And yet Hunga Tonga beats every other eruption in over a century in terms of explosive power, so viscosity isn’t everything.

          • Hunga Tonga I imagine would visually have looked a lot like Stromboli or Etna if it ever made it properly above water before January. I guess it is unlikely we will ever know now though…

            Also makes you wonder of Kilauea and Sierra Negra, with their fluid magma but large and very shallow storage. Before I would have thought it impossible to get a real ignimbrite more just an extreme curtain of fire if they ever did what Hunga Tonga did, now not so sure. In saying that both have collapsed without that happening many times in the Holocene, probably hundreds of times each, but it is a bit more scary how much of a near miss 2018 might have been now.

          • I am thinking that Honga Tonga might have erupted a somewhat scoriaceous and spatter rich ignimbrite on Jan 15 if it had not been for the shallow water. Most of the 2008-2009 and 2014-2015 Honga Tonga andesite was quite water rich (about 4.8 % wt) in the melt, and with a minimal cargo of phenocrysts to dilute the water content based on the “whole – rock” magma. The water content of these Honga Tonga andesites is comparable to many silicic magmas. Although we may never know for sure, my guess is that the Jan 15 eruption sort of looked like a super super SUPER – sized version of the powerful surtseyan activity filmed the day before.

          • Regarding the sheer ‘boom-iness’ of Hunga Tonga, I’m still convinced from an earlier article that a major driver of the explosions was explosive decompression of one or more supercritical water reservoirs. I do not see how shallow water interaction with erupting magma can lead to the gigantic detonations that were observed, since there’s constraints on how rapidly energy can be transferred from rock to water to vapor. Those same constraints don’t exist if the water is already supercritical and is suddenly provided an exit.

      • A basaltic plinian woud be constant souch too .. instead of a burp

        Stromboli 2019 was a rare basaltic vulcanian style blast.. 🙂

  5. Considering the various fascinating discussions on VC on the interplay between climate change and Black Swan-like events such as volcanic eruptions, asteroids, continental breakups, etc;—(I excluded Human Beings from this list because there are other more descriptive words than “Black Swans” to describe us), just had to pass on this link to a pre-print abstract of a possible intergalactic event I had not heard of, (nor even considered). https://arxiv.org/abs/2202.01813v2
    According to Prof’s. Merav Opher and Abraham Loeb at Cornell, about two million years ago, Earth encountered a “Cold Cloud” of gas and dust, and in the process, the Suns’ heliosphere shrunk/compacted to less than 1 AU, thus exposing the Earth to neutral hydrogen ~3000/cm3…with possibly catastrophic impacts on climate and maybe even human evolution on Earth.
    As for some of the hard data, this from the abstract:
    “There is overwhelming geological evidence from 60Fe and 244Pu isotopes that Earth was in direct contact with the ISM (InterStellar Medium) 2 million years ago, and the local ISM is home to several nearby cold clouds”.
    Just wish I had access to the rest of the paper to see what other corroborating evidence they are providing….but it’s a fascinating subject nonetheless.

    • A small correction to the authorship::
      Merav Opher is with Brown University, not Cornell.

      • OMG…I must be having a senior moment of epic proportions this morning.
        Opher is from Boston University, and Abraham Loeb is from Harvard.
        Is there anyway for a dragon to help clear up my mess?
        Would hate for this thread of temporary insanity to perpetuate into eternity.

  6. Here is a corrected version of my erroneous post above.
    If a dragon can just kindly delete all the above comments, I would appreciate it

    Considering the various fascinating discussions on VC on the interplay between climate change and Black Swan-like events such as volcanic eruptions, asteroids, continental breakups, etc;—(I excluded Human Beings from this list because there are other more descriptive words than “Black Swans” to describe us), just had to pass on this link to a pre-print abstract of a possible intergalactic event I had not heard of, (nor even considered). https://arxiv.org/abs/2202.01813v2
    According to Prof’s. Merav Opher (Boston University) and Abraham Loeb (Harvard), about two million years ago, Earth encountered a “Cold Cloud” of gas and dust, and in the process, the Suns’ heliosphere shrunk/compacted to less than 1 AU, thus exposing the Earth to neutral hydrogen ~3000/cm3…with possibly catastrophic impacts on climate and maybe even human evolution on Earth.
    As for some of the hard data, this from the abstract:
    “There is overwhelming geological evidence from 60Fe and 244Pu isotopes that Earth was in direct contact with the ISM (InterStellar Medium) 2 million years ago, and the local ISM is home to several nearby cold clouds”.
    Just wish I had access to the rest of the paper to see what other corroborating evidence they are providing….but it’s a fascinating subject nonetheless.

    • This paper is silly. It is well known that the heliosphere on occasion will be pushed back to within the Earth’s orbit. For instance, there are papers by Ian Crawford on this. Clearly that has not caused major problems before.

      • Thanks Albert for the lead!
        As I said, this is a fascinating subject for me, and any opportunity to learn more is greatly appreciated. But, after doing some further research, I wouldn’t classify the Opher/Loeb paper as “silly”.
        In this paper titled “The lunar surface as a recorder of astrophysical processes”, the authors (including Crawford) make reference to an abundance of 60Fe in ocean core sediment and in samples returned by three Apollo missions that are roughly consistent with the same ~2Mya timeframe as the Opher/Loeb paper…it’s just that the explanations for the deposits are different. The Crawford paper re-iterates the relatively well known/publicized theory that a “nearby” supernova could be directly responsible for the radioactive deposits, while Opher/Loeb are arguing it could have been an interstellar cold cloud encounter with possible SN debris embedded in the cloud?
        From the Crawford paper:
        “As reviewed elsewhere [51], another component of interstellar material that might be identified on the lunar surface would be ejecta from nearby SN explosions. There has been a long-standing recognition that SN occurring within a few tens of parsecs, and perhaps as distant as 100 parsecs, may deposit debris enriched in radioactive elements within the Solar System (e.g. [76–79]), and evidence for two such events, in the age ranges of approximately 2 and approximately 8 Myr, has been reported from 60Fe deposition in ocean sediments [80–82]. Cook et al. [83] argued that the lunar surface has some advantages as a collector of SN ejecta as the much slower rate of surface re-working would allow it to accumulate in more concentrated layers than on Earth, and in 2016 this group [84] identified 60Fe enhancements in Apollo 12, 15 and 16 soil samples (collected from depths a few centimetres or less) consistent with the approximately 2 Myr old SN event recognized in Earth ocean sediments”.

        • There is no doubt that some grains from supernovae can reach us, and there have bene a smattering of supernovae in the past 10 million years. There is also no doubt that on occasion, interstellar clouds have compressed the heliosphere to within the orbit of the Earth. Both were well known. It is rather unlikely that the two have any relation. Nor is it likely that interstellar dust clouds change the Earth’s climate. The idea that cosmic rays affect is climate is ‘controversial’, and lacks a mechanism, and the cloud itself is far too low density to have any effect. Loeb is becoming known as a sensationalist. In my professional opinion, this paper (not refereed) is best ignored

    • Thanks, Craig. Interesting pre-print, I hadn’t heard about this hypothesis.

      FYI, the arxiv platform is open access, i.e. you can download the full pre-print for free as a PDF on the right hand side of the page!

      Since this pre-print focusses on the heliosphere and its contraction only, I wonder how good the 60Fe and 244Pu data are to support such a hypothesis. Will have to do some more reading, I guess…

      • Thanks!
        I retried to download the .pdf and it worked this time …no idea why the download failed earlier…it was not one of my better mornings on several accounts!

  7. Thank you, Dr Albert for your thought-provoking post.

    Back in 1963, I was one of those scared kids who watched The Doctor and his companions be imprisoned by the Daleks. How would they escape?

    Some scant seven years later I was doing a Gap Year as an aide at a home for handicapped kids. I needed to borrow a bicycle to go to the local village on afternoon.
    “There’s one in the garage,” said Colwyn. The garage was dark, closed shutters on the windows. I flipped on the switch and a 40W bulb dimly illuminated a mess of old toys, clothes and junk. Scanning for the bike, my heart went bump and then pounded in my throat. There, 15 feet away, staring at me with that single lens, was a real, live Dalek!

    For the original series, the BBC had 3 or 4 Daleks with motors that could be driven around by operators during the shoot. It had another 9 or so without motors that could be rolled into place before the shoot to give the massed effect. As the TV series progressed, the earliest versions were replaced by new and improved props. Some of the originals were given to children’s homes and one ended up at the place I later worked. After the initial excitement, it was relegated with the other junk to the garage where it scared the heck out of me.

    No idea what happened to it. Imagine if I had the forethought to say to the Principal, “Mr Richardson, if nobody wants that old Dalek, can I buy it from you for £5?” An original Dalek prop from the first series with known provenance ought to be worth a bit.

  8. Still lots of persistent quakes around just inland of Grindavik, near the Sundhnukur fissures. Everyone is expecting the same big quake swarm as Fagradalsfjall had last year but is that really as likely? Fagradalsfjall had been basically inactive since the beginning if the Holocene, erupting about 8000 years ago but that was not on the trend of the rift last year. Also there was no heat flow or geothermal gradient, and it is a sizable mountain for its location. So basically a piece of hard crust that was broken.
    Svartsengi is really almost the opposite, very active in the Holocene and with huge heat flow, there are parts that are hot even at the surface let alone deeper down. The crust is probably much more plastic. Of course a full blown dike might be very seismic but that might form in under an hour so not really a good warning.

    Would expect the same thing to apply at Krysuvik, which is very similar in a lot of ways to Svartsengi. Brennisteinsfjoll and Blafjoll systems might be like Fagradalsfjall but then they have also both got substantial Holocene volume so perhaps not. Hengill is kind of like Krysuvik but with an actual mountain, probably is hot underground despite the lack of frequent eruptions. That might only apply to the actual mountain of Hengill though, not the whole fissure swarm. Hengill doesnt usually erupt anyway so probably not a real risk.

    Either way it looks like last year might have given us a real extreme high end of what to expect as a precursor and it might not take nearly so much to set off future eruptions.

      • This image is absolutely amazing. This is exactly what I’ve been wanting to see. That I’ve been able to find, there seems to be precious little in the way of footage or images of the actual eruption column.

        Really, I’ve been staring at this image for about fifteen minutes now trying to comprehend the scale of this thing.

        Any idea how far away this image was taken / which island it’s from?

        • I expect it was taken somewhere in the first 20-30 minutes of eruption. Before the ash formed that lower umbrella that extended through the stratosphere and doesn’t seem present in the photo. It may have been taken from Tongatapu, it’s where most people live, although I don’t know for sure. The height of the umbrella edge might be something like 30-35 km above the ground, something to take into account.

          • It also looks like the eruption column is about that width, something like 30 km wide. Due to the pyroclastic flows mixing with hot air and rising up into multiple updrafts, all of it merging into one massive plume.

        • The Image of the eruption column was taken from a NW facing beach about 1,250 m SW of the NW tip of Tungatapu Island (the main island).

          The location is at 21 degrees 4 minutes 10 seconds South and
          175 degrees 20 minutes 4 seconds West.

          The centre of the Jan 15 caldera is about 57 km away from this location on a bearing of about 355 degrees true.

    • Will have to add it to the list of giant coignimbrite clouds caught on camera:

      Saint Helens in 1980:

      Lamington 1951:

      Bezymianny 1956:

  9. The attempt for the surface has started, if the depths are correct. Still some ways to go

    • There have been several stacks like that. Eventually one will be successful. Have IMO / local volcanologists said where they think the magma is now?

      • Earthquakes restarted this morning underneath Hagafell, Thorbjorn, 2 km from Grindavik. They are now between 1 and 2 km deep.

        • They are also smaller now. Are they are clear of the crust and in a sedimentary layer?

          Did the same happen with Geldingadalir? Although I recall there was a shallow aseismic patch pre the eruption, itself.

  10. Water Ice and titanium are good radiation insulators. An IO perserverance woud be fun with its computer brain encased in titanium and water Ice.

    But that rover woud be destroyed by volcanic eruptions If not placed in correct place. the average geothermal heat flux on Io is 4 W/m^2, whereas even in Iceland where geothermal power is a competitive power option on Earth, it is only 0.1-0.2 W/m^2

    Still I wants an IO rover .. sent to Pele Patera, I do love IO almost more than any other volcanoes .. and I daydream all the time hiking IO s volcanoes, Earths current eruptions are tiny .. compared to IO s wast eruptions lava lava flows .. one Ionian lava lake is almost 300 km wide .. : O

    • This is off topic but Jesper have you read The Expanse novels or seen the show that just concluded in the winter? I’m absolutely positive you would absolutely love it.

  11. Because there has been some discussion of Hunga Tonga Hunga Ha’apai as of recent 🙂


    I think we might need a whole new category, the hyperplinian eruption. 87 km is only a few km short of the Karman line… It is really quite something to behold that this happened only a few months ago and with relatively little damage.

    • I’d suggest a new eruption type too, although I would call it krakatoan, or maybe change the definition of ultraplinian to the following.

      The eruption must be a pyroclastic fountain that continuously feeds a massive pyroclastic currents extending radially around the volcano, the process known as boiling over. The stratigraphy must consist of pumiceous pyroclastic flow deposits reaching >30 km from the vent, or scoriaceous pyroclastic flow deposits reaching >15 km from the vent. Theoretically krakatoan eruptions will occur when a magma chamber blows up though a ring dike. It will be preceded by a trigger that causes the caldera to collapse, which most commonly will be a plinian event, and will also be heralded by the initiation of caldera collapse and intrusion of a ring dike in the caldera fault, all in rapid succession.

      • Curious as to what happens if a ring dike forms at a volcano with gas poor magma in large volume. Would seem to me that a large fast effusive eruption might result. Kilauea probably does this as it has huge fountain deposits overlying the 1790 ash, the lava presumably was trapped in the caldera as the befinning of the lava lake that was present fo much of the 19th century. If such a ring dike were to form at Sierra Negra with its VEI 6 sized shallow magma chamber it might be rather biblical. Same perhaps at Bardarbunga or Askja.

        • I’ve been wondering about that too and I’m not sure what the correct answer might be. There is Krafla’s case, the Halarauour eruption. In this eruption gas-poor fluid tholeiite basalts got erupted as pyroclastic density currents which then welded into an ignimbrite resembling a lava flow. But the Haralarauour eruption started with rhyolite, basalt came up only towards the end when the bottom of the magma chamber erupted.

          So there is no case as far as I know of a volcano that only has gas poor tholeiite basalt doing an ignimbrite. Kilauea, when caldera collapsing, has always erupted in the way I described in Big basalt blasts, with big explosions of lithics generating surges. Fernandina also went up this way in 1968. So I don’t know if it’s possible for such volcanoes to go krakatoan or not.

          Ultrapotasic basaltic magmas can however make large ignimbrites. Colli Albani for example did the Pozzolane Rosse ignimbrite which erupted foidites with only 44% SiO2, making a 30-35 km3 scoria flow. This ignimbrite must have been very fluid, possibly somewhere in between the fluidity of Nyiragongo and post-1631 Vesuvius. Of course foidites are very gas rich, with abundant carbon and water, many times more than tholeiites. The other three Roman calderas Vicco, Sabatini and Vulsini have also done low silicia scoriaceous ignimbrites I think.

          What happens with foidite magmas is that they barely increase in silica as they evolve, because they had so little silica to begin with then olivine takes up almost as much silica as there is in the melt. So ultrapotassic volcanoes can have magma stored in magma chambers for a long time and still erupt very fluid, but explosive lavas. Only when they get very evolved do they suddenly take a turn towards silicic compositions, I’ve seen it many times. This is the TAS diagram of Colli Albani, the arrow shows how it evolves. I know from looking at many TAS that the evolution always starts in a particular part of the basanite field even though not very obvious here:

          • Here is Fogo’s TAS diagram, the evolution trend is like Colli Albani only a little less potassic. Shows how ultra potassic volcanoes increase their silica very slowly as they evolve. Even when at its most evolved Fogo still has the same silica content as Kilauea. Ultrapotassic calderas are rare though I can only think of the Italian calderas right now.

          • As far as mafic magmas erupting as ignimbrites, the other candidate might be calc-alkaline but very water rich arc basalts. Arc basalts can have way more water content then tholeiitic ones. There certainly are arc calderas that erupt relatively mafic ignimbrites, especially when the arc is set in relatively thin mafic oceanic like crust. Many of the examples though are probably not true basalts but rather basaltic andesite.

            As for Italian volcanoes, it is kind of interesting that Vesuvius has been getting more alkaline with time. The first large felsic eruptions of Vesuvius (such as the “basal” pumice were just into the trachyte field in the TAS diagrams. Since then, the liquid lines of descent have rotated anticlockwise on the alkalies/silica TAS over into the phonolite-tephrite fields.

        • Trying to imagine what such an ignimbrite would look like. It probably wouldnt look like a lava flow but I cant imagine that it looks like a pyroclastic flow as we usually think either, which is more of a fluidized powder. I guess it might actually look like a lava flow but with a greatly exaggerated velocity, like how a tall wave looks when it breaks and keeps moving. There are descriptions of more typical pyroclastic flows at Vesuvius in the same eruption as lava that was erupted effusively, so perhaps even these fluid lavas can be fragmented. It is though equally possible those flows were collapses of the mostpy solid welded spatter at the top of the cone as happens at Etna and Fuego, rather than direct eruption products. Vesuvius also has some phonolite which would be expected to behave like this too.

          Something to consider too, that if the Pozzolane Rosse eruption was more of an ‘extreme lava flow’ than a dusty ash flow, it is bigger than even Thjorsahraun. If it does look like a frothy wave breaker but made of lava and moving at 100 km/hr that is surely one if the most hellish things that can be made a reality. The landscape must have looked apocalyptic afterwards, 456ka was in the depths of a glacial so the area was probably a cold steppe or perhaps even a tundra, then a vast expanse of black rock.

  12. Very shallow earthquakes north of Grindavik today… only a few hundred meters and checked.

    • If it is magma it might mean the eruption will not be a lava flood as feared, so at least not a dangerous flow. But then we dont know how eruptions begin here, maybe the big curtain of fire is a late stage that is preceded by more sedate eruptions along a weak line that ultimately rifts completely at the end to give a curtain of fire.

      Or maybe we are about to see the floodgates of hell open right before our eyes.

      • This area tends to do small eruptions. Large flows do occur but are rare. But it could be in an awkward location and Grindavik should have evacuation plans ready

  13. Remember this? This is the Fagradalsfjall lava field. The Sentinel image is four days old. The outflow channel of the cone is still hot, after 9 months. (Don’t worry, it is not new activity. This spot has been visible ever since the eruption ended, and is slowly fading a bit.) The much fainter spot is from the centre of the cone. The hot spot is at the end point of the outflow channel

    • And I am now waiting for Páll Einarsson to pop up stating that I am wrong, and then I will make a bet about a beer, Páll loses as per usual, and I will never get the beer from him.
      For reference, it is 3 – 0 in beers now.
      And counting…

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