Sapphire!

/ 03/08/2024

A sapphire (and diamond) ring, from Germany

Henrik taught us about what he called gemmology – the knowledge of gemstones, which he said was considered to be part of the geosciences and specifically a branch of mineralogy. It is also a subject closely related to volcanology. Many gemstones form deep underground, and rely on volcanoes to bring them to the surface and to our attention. Diamonds are a good example. They form in the mantle under tremendous pressure, and collect at the bottom of the deep cratons, the old thick cores of continents. There they sit, 150 or 200 km deep. But every now and then (quite rarely, sadly, it has not happened in living memory) a kimberlite eruption occurs. Those eruptions start that deep, move up to the surface on a wave of CO2 gas in a matter of days or even hours, and deliver their hoard of diamonds.

Most kimberlite eruptions fail in one of two ways. They may be too hot, and the diamonds perish on the way leaving us only their diamond-shaped carbon ashes. Or they may not make it all the way to the surface and leave a conduit underground, filled with diamonds (or with their ashes of the failed both ways). Erosion may later reveal these hidden treasures, and suddenly someone somewhere finds a diamond lying on the ground. People flock to these regions. This happened at the original Kimberley site – the location after which the kimberlite eruptions were named, and which is now only a deep hole in the ground. The Boer war was started about ownership of the Kimberley diamond mine. The ‘Boers’ (‘farmers’) had it and the English wanted it. Diamonds are hard won and can come with a deadly legacy. We still talk about ‘blood diamonds’ – although for some reason Kimberly itself is excluded from this term.

Once diamonds have been brought to the surface, they may not stay there. Rivers can move mountains – moving diamonds is peanuts, and the diamonds may end up well away from their source. Kimberley diamonds are now mainly mined on the Atlantic beaches, appropriately called the Skeleton Coast. But without volcanoes, they would not be there to be found, and many wedding rings and other jewelry would look very different. Your marriage may have a volcanic heritage.

There are other jewels. One of these is known as sapphire. Sapphire is a precious, deep-blue (although other colours exist) gemstone. The precious stones are not to be confused with the semi-precious ones: the only gemstones officially known as ‘precious’ are emerald (green), sapphire (blue), ruby (red) and diamond. (For some reason the Ring of Power was overlooked for this list, but then it did deceive.) The name ‘sapphire’ is apparently from a Greek-Persian origin. It may come from a word for lapis lazuli, the soft blue stone that was used in old paintings for the ultramarine used for painting deep-blue garments – if the painter could afford it! Lapis azuli is not in fact related to sapphire: it is a combination of different minerals.

Lapis azuli was so useful for paints because it is soft. Sapphire is not: it is only one step below diamond on the hardness scale. That scale is used to identify which mineral can scratch another mineral. It runs from 1 to 10. Diamond, a 10, can scratch sapphire since it is harder, but sapphire (9) will scratch almost any other natural material. (It is in fact the mineral which defines the ‘9’ class.) Obsidian was the volcanic tool of choice in the stone age, being able to cut through animal tissue with ease. But even this hardest volcanic material is only a ‘5’. (Don’t be fooled by the hardness: a hard mineral can still be brittle, and scratch resistant is not the same as chip resistant. A chip of the old block is still a chip.)

Looking at lists of material hardness, sapphire does not actually show up. That is because it is a variation of another mineral: corundum. Corundum is an aluminium-oxide (known as aluminum-oxide west of the Atlantic, thanks to the most spelling-prone dictionary in history, Websters). (An easier name is alumina). It exists in various forms: powders, fibres, cream or crystals. The first two are white and can be quite poisonous. The cream is a bit of a misnomer: I added it because corundum is a common ingredient of sunscreen. The crystal form of corundum is transparent in itself (as the word ‘crystal’ implies) and is poisonous mainly for your wallet. It is also hard: the name “corundum” probably is Sanskrit in origin, “kurunvinda”, meaning hard stone.

Corundum has a very high melting temperature, just over 2000 C. It is one of the minerals that can be found in space: it can form in the hot gas ejected by a star. In my night-time job, it is one of the things we study with JWST. (Don’t expect anything spectacular: these are mini-crystals less than a micrometer in size. We also find micro-diamonds in space – but we don’t advertise that. Anyway, buyer collects.)

The crystal form of corundum is rarely as transparent as the word implies. It can have quite a range of colours (or none). It comes as colourless, white, gray, blue, blue-green, green, violet, purple, orange, yellow, yellow-green, brown, golden amber, peachy pink, pink, black, and varieties of red. They are (artificially) divided into two categories. The red ones are called ruby, and anything else is called sapphire. (There is a bit of overlap around the colour pink with some would call a ruby and others a sapphire, depending mostly on whether you are the owner or the buyer.) Sapphires are known as blue gems, but that is not the case by definition!

Not all that glitters is gold (as Shakespeare states in the Merchant of Venice, followed by that shattering line ‘Gilded tombs do worms enfold‘). Henrik informed us that the famous Black Prince Ruby which at one time was mounted in the Tudor Crown and nowadays sits in Britain’s Imperial State Crown is not a ruby but a spinel. Spinel also contains aluminium and oxygen, but in addition contains magnesium which corundum does not – and spinel is not ‘precious’. It’s melting temperature is even higher than that of corundum, at 2300 C. Again, spinel is known in space and it has even been found in the worldwide iridium layer from the Chixulub impact. If you would like to test Henrik’s assertion, just do a scratch test on the Black Prince Ruby. Spinel is only hardness 8, so can be scratched by a sapphire. You can find the jewel in the Tower of London. You will probably spend the rest of your life there, but I am sure that is a sacrifice worth making in the name of Ruby Rebellion. (And that would make a good title for the next Doctor Who episode.) And it is not just Britain: the Cote de Bretagne Ruby of the French Crown Jewels is also a spinel. Whoever knew.

The Imperial Crown with the Black Prince ‘Ruby’ (red). The St. Edward’s Sapphire (blue) is a real sapphire – but the ruby is not a ruby

Why the range of colours? Corundum in itself is colourless. The colours come from impurities, where traces of other elements got themselves stuck inside the crystal structure. This is called ‘allochromatic’, where the colour comes from elements which are not a unusal part of the main crystal. (The opposite is called ‘idiochromatic’ and is the case for instance in lapis lazuli, which also contains aluminium and oxygen but combined with sulphur and either sodium or calcium; the intense blue colour comes from the sulphur which is included by default.) Rubies get their red colour from chromium which displaces some of the aluminium. Blue sapphires contain some titanium and iron. The iron or titanium changes the crystal structure such that it absorbs yellow. Seen under sunlight, the light that comes out now lacks the yellow, and it is this lack which causes the colour. If only iron is present, the sapphire appears green, or even green-yellow. Add the right amount of titanium, and it appears blue. The best gem-quality blue, requiring an ideal balance between iron and titanium is found in sapphire deposits from Kashmir. But be aware that sapphires are often treated in a heat bath to change their colour: before surrendering your fortune at the used-sapphire dealership, do make sure it has been independently tested so that you know what you buy. (Rubies are more resistant to heat-treatment.)

Sapphires can have actual uses beyond jewelry. Apple in particular is known for having used sapphire for the camera lenses in iphones. Expensive watches (remember those?) may have sapphire face coverings. Those sapphires are not coloured but are transparent (naturally) and are synthetic. No, you can’t take your iphone to the used-sapphire dealership to trade in the camera cover.

Growing sapphire

Sapphires are found in various locations across the world. Well known are Sri Lanka, Kashmir, Thailand, Myanmar, Australia and in the US, Montana. From this list, a volcanic connection is not obvious! None of these are in the top list for eruption tourism. But of course, almost any place on earth has a volcanic heritage if you go back far enough, just like any US president can seemingly trace their origin back to Ireland. Diamonds, where we know volcanoes have a crucial role, too are found in regions which nowadays are not particularly volcanic.

What do sapphires need in order to form? The recipe is simple: high pressure, high temperature, and aluminium. Aluminium can be found in sediments, as aluminium is not very solvable in water and has a tendency to end up in the muck at the bottom. The pressure and temperature are more of a problem: if you just take a rock, creating corundum (sapphire of ruby) within it may need a pressure and temperature only found below 30 km of depth. But add a bit fluid and chemistry can give a helping hand and allow them to form less deep, especially if a bit of heat remains available.

Mountains

Basically, you just pressure and heat applied to sedimentary layers. Mountain ranges sound like a good case, where the collision between two continents sweeps up the sediments of the ocean that was in between, and the mountains provide the depth and pressure. This is called the metamorphic deposits, where sapphires were formed by heat and pressure underneath mountains, at a depth of 10s of kilometers. Indeed, several of the main sapphire sites are related to the collision of India with Eurasia, with ages of roughly 40 million years. This has given us a sapphire belt running from Afghanistan to Vietnam, which includes the famous Kashmir sapphires.

It is not the only such sapphire belt. Another belt runs from Sri Lanka and southern India to Madagascar and Mozambique. If this seems a bit discontinuous (they are an ocean apart), it wasn’t in the past. Before the world fell apart (I remember it well), this was one continent, Gondwana, and all these sapphire (and ruby) deposits were adjacent. The sapphires here are dated to between 500 and 600 million years ago. This was the time when the east and west parts of Gondwana came together, in a collision which build mountains and made jewels.

Source: Giuliani et al., 2014; https://www.gia.edu/gems-gemology/winter-2019-geology-of-corundum-and-emerald-gem-deposits

There is a third such metamorphic region, but its origin is less clear because of its age. It is a rather shorter belt, is almost 3 billion years old and is located in southwest Greenland.

These metamorphic deposits are a major source of the world’s corundum. The mineral can form in this environment in three different ways. The first is directly in the metamorphic rock, purely through the pressure and temperatures on the original rock, similar to how slate forms out of mudstone. The second way is when the rock interacts with a fluid. For instance, the silica-poor rock may meet a rising fluid containing aluminium. ‘Fluid’ does not necessarily mean water and it may not even be a melt: solids too can flow under the right conditions. Granite intrusions do, and these are common below mountainous regions. The silica in the granite is absorbed by the rock, leaving the granite with a silica-poor composition that is perfect for the formation of corundum when it meets the aluminium-containing sediment layers. This ‘fluid method’ gives rise to thin layers of corundum, because the interaction happens only over small regions. The third way involves partial melting of the rock. Because silica melts at lower temperatures, it melts first, and the remaining rock becomes silica-poor and aluminium rich. It is now ready to form corundum. All three ways have contributed to the belts of metamorphic corundum.

Volcanoes

But there is another group of sapphires, not related to the three known belts of metamorphic deposits. These are found in many different places, along the Pacific from Tasmania and eastern Australia to eastern Russia, in France, Cameroon, and elsewhere. (Not in Canada: Canada has a Ruby mine near Ottawa, but this is a misnomer as it actually mined garnet.) This comes from the second route, a more volcanic one, and these are called the magmatic deposits.

The various sites have one thing in common: they are associated with magma, and specifically with a type called alkali-basalt. Basalt is poor in silica. Silica (SiO2) is important in continental crust, whilst basalt is sourced from the mantle.

Alkali-basalt is first of all a basalt: low silica, roughly in the range 40-50% of the mass of the rock. This makes the lava quite dark. (The silica fraction determines the colour of the lava: the higher the number the whiter the solidified lava.) The alkali part of the name means that it is relatively rich in sodium or potassium. This corresponds to the grey area of the basalt box in the picture. This is quite a common type which can be found in a variety of places, especially continental rifts and oceanic island arcs, but not in mid-oceanic rifts. It comes from relatively deep in the mantle, 150-200 km.

Alkali-basalts are associated with sapphires in Australia, China, Africa and Europe. Rubies are much rarer in these places. The sapphires have a range of colours from blue to yellow, but rarely pink or red (which would make it a ruby). These sapphires include more iron. Metamorphic corundum, on the other hand, tends to be poorer in iron.

The known deposits of magmatic sapphires date from the time after the dinosaurs: all the known older deposits are from ancient mountain belts.

A spiral time diagram of ruby (red) and sapphire (blue) deposits. Source: https://www.mdpi.com/2075-163X/10/7/597

But the sapphires cannot easily form in the magma itself. Instead, they are thought to be inclusions which are carried up with the magma. The origin of these inclusions themselves are still a matter of debate. One possibility is that a hot plume melts small amounts of the lithosphere, and that the corundum forms there. Other options are based around pre-existing sapphires, which are later carried up by the magma, much like the diamonds are already present at the bottom of the cratons before any volcanism occurs to carry them to the surface.

Transport

So we need not only make the sapphires, but also worry about the transport to the surface. In the case of mountains, this happens by removal of the overlying rock, i.e., erosion. After all, erosion, like faith, can move mountains. Mountains erode fast especially when still rising. Tens of kilometers of rock may disappear, enough to make the corundum appear.

Magmatic deposits take the hard route and bring it to the surface by hitching a ride with magma that is making the journey for you. If neither route is available, then the buried treasures remain hidden in the deep. As you read this, a royal (in potentia) sapphire might be sitting right below you. Better start digging!

The place where the gems first appear on the surface is called the primary location. They rarely stay put there for long. Water may move them from the original place to somewhere else. This is the secondary location, or the placer. If rivers are involved, then this secondary place may be far away on the flood plain. They may also just end up at the bottom of the slope, much closer to the primary location.

Source: https://www.gia.edu/gems-gemology/winter-2019-geology-of-corundum-and-emerald-gem-deposits

The Eifel

This brings me to the recent paper on this topic, involving sapphires in a thoroughly volcanic location. The paper was written by Sebastian Schmidt and others, and it appeared in May this year. It presented a study of some of the youngest natural sapphires known, in the heart of western Europe.

Europe has a surprising number of volcanic fields, separate from the well-known volcanics of Italy and Greece. They range from the Massif Central in France with its beautiful Puy’s and the field in the Western Carpathian Mountains between Poland and Slovakia to the domes and maars of the Eifel in Germany.

The Eifel region has been volcanically active over the past half a million years, including the VEI-6 eruption of the Laacher See. For a description of the region, see Gijs’ report in sleeping in our back garden the past present and future of the eifel volcanism part/. There are two main areas, the western and the eastern Eifel volcanic fields. They produce similar lava but magma in the western field is stored deeper (low crust, upper mantle) and erupts faster than the magma of the eastern field (mid crust, long storage time of 50,000 years). The Laacher See, source of a major eruption 12,000 years ago (and no, it is not the cause of the Younger Dryas), is in the eastern field.

Sapphires have been found in the volcanic deposits and in river sediment in the region. Don’t expect jewelry: they are not gem-quality and you may need a microscope to see them as they are less than 1mm in size. But they clearly are associated with the volcanism. And they exist across the region, including in the pyroclastics from the Laacher See eruption. We know in many cases even which eruption erupted the sapphires. And very important to scientists: these sapphires don’t have jewelry value, so it is possible (affordable, to be precise) to do the kind of analysis that scientists like, i.e., taking them apart and see what they are made of. It is called destructive analysis and it is not something we would be doing with the Black Prince Ruby. (Not for want of wanting, to be honest.) But to find out exactly which elements (and their isotopes) are in a gemstone, for instance to obtain its age from decay products of radioactivity, you’ll need to get its insides out. You can’t have your gem and date it. A date for a gem may not end well.

A number of sapphires were dated using uranium decay. All came from river beds in the eastern region, and cannot be traced to a particular eruption but the main eruption in this region is that of the Laacher see. Nine dates were obtained: all but one came out at around 60,000 years since they formed. The exception was clearly much older, and was dated to 25 million years, the sole grown-up in the crowd. The younger grains are about 50,000 years older than the Laacher eruption. However, they are clearly related to the volcanism here, and the age is about what would be expected from the age of the Laacher See eruption plus the storage time of magma in the magma reservoir. This is a clear argument for a volcanic origin of the sapphires. But they were not formed in the explosion itself: they were sitting around the magma chamber.

How about the single older grain? Is this the exception that makes or that breaks the rule? The river from which this grain was obtained contains some erosion from the ‘Siebengebirge’, a group of ‘seven hills’ (there are actually rather more) just just east of the Rhine which are quite a beautiful sight. These hills are volcanic, but they come from an earlier phase of volcanism which indeed occurred around 25 million years ago. So the grown-up also appears volcanic, just from an unintended volcano.

The scientists wanted to know more, so they kept crushing sapphires. Mass spectroscopy was used to identify the elements in the sapphires. (In fact, crushing is not enough for this. You need to ‘plasmafy’ them: turn the jewels into an ionized plasma.) (Please do ask permission from the owner first and do check they are not expecting their precious to ever be returned to them.)

Source: edited from https://link.springer.com/article/10.1007/s00410-024-02136-x#Sec11. These are sapphires in the volcanic ejecta. The different groups come from the different volcanoes in the region, each with slightly different iron abundance.

The results may seem a bit surprising for volcanic sapphires. The plot shows the amount of iron in the gems, versus the ratio between gallium and magnesium. Magmatic sapphires should be a bit higher in iron, but lower in magnesium. The iron abundance roughly fits, but the Ga/Mg ratio is what would be expected from metamorphic sediment – not magma. Gallium is lower in metamorphic rocks than in alkaline magma,and here the gallium is low. The sapphires formed in the magma, but apparently not from the magma! How is that possible? And why the large range in iron, which would indicate some involvement of the magma?

Other diagnostic diagrams can be made, and they all arrive at the same conclusion. The sapphires of the Eifel tend to the ‘metamorphic’ type, but some (especially those lower in the isotope 18O) are at the borderline between metamorphic and magmatic.

Digging for sapphires

What is the solution? Clearly, ‘magmatic’ sapphires still can have a range of origins. Sapphires found within volcanic rocks can be hitchhikers, picked up by the magma from the crust on the way. If the sapphires formed in the magma, it is likely to be from a syenite, which is a silica-poor magma formed from low degrees of melting: as this magma sits in the crust, the corundum would in time solidify (precipitate) as the magma cooled. If the sapphires formed in the continental crust, it will be a metamorphic (heated) rock (such as marble). Since in the Eifel, the age of the sapphires agree with that of the volcanism, the trigger must have been the same heat pulse that caused the volcanism. The same happened, apparently, in the nearby Siebengebirge, but much longer ago. But that doesn’t answer the question regarding how they formed.

The 18O fraction gives more information. Low 18O indicates an origin in the upper mantle or lower crust, while higher 18O indicates they formed in shallower crust. For this region, 18O values below 6 ‰ indicate an origin from crystallizing magma, while value above 10 ‰ represent the crust. Both are present here, and the sapphires with low 18O have composition of other elements which is closer (but not identical) to magmatic. On the other hand, although the sapphires occur in the pyroclastic flow, they are limited to inside solid ejected material, and are not found in the tephra which came from the liquid magma. Even though the Laacher See ejected various zones of its magma chamber with compositions ranging from relatively pure to quite evolved, none of those zones contained sapphires.

The easiest way to explain this dichotomy is if the sapphires formed on the edges of a cooling magma chamber. The lack of sapphires in the tephra suggest that they were not present in the liquid magma, so they must have been in the magma that had already solidified. If the magma chamber had partly melted a bit of the surrounding crust, then the interaction region would contain some magma with a bit of molten crust mixed in, but also some deriving only from a partial melt of that crust. If that crust is sedimentary with a bit of aluminium, the conditions would be there for the formation of our precious (albeit minute) stones, with some coming from the crust (high 18O) and some from the magma (low 18O). The intermediate values would come from sapphires that formed where the magma and molten crust mixed. Indeed, a few grains are known where the core of the grain has a composition consistent with crust, but the rim has a composition closer to that of a magma/crust mix. Clearly, this rim was added later, when the sapphire was within the magma. The fact that the difference between core and rim survived, without the 18O migrating between the core and rim, requires that the grain was kept at temperatures of no more than 700 C, i.e. in the cooler margins of the magma chamber.

The conclusion of the team is summarized in the following picture. The numbers refer to the 18O fractions in the various locations.

One study does not resolve major scientific controversies. But it is a brick in the wall, or at least a gem in the collection. In this location in the Eifel, the sapphires came not from the deep mantle, but formed in the crust in locations where the magma heated the local crust. Just like cultures can become much richer when interacting with (and challenged by) other cultures, so the magma picked up treasures and formed new ones. Precious stones formed by fire.

Albert Zijlstra, August 2024

The Hendrik original

Sebastian Schmidt et al: Petrologically controlled oxygen isotopic classification of cogenetic magmatic and metamorphic sapphire from Quaternary volcanic fields in the Eifel, Germany. Contributions to Mineralogy and Petrology, 195, 55 (2024). https://link.springer.com/article/10.1007/s00410-024-02136-x

A classification of gem corundum deposits aimed towards gem exploration.
https://www.sciencedirect.com/science/article/abs/pii/S0169136808000280

https://www.gia.edu/gems-gemology/winter-2019-geology-of-corundum-and-emerald-gem-deposits#part-i:-ruby-and-sapphire

Ruby Deposits: A Review and Geological Classification. https://www.mdpi.com/2075-163X/10/7/597

Berlin’s sapphire – the blurb says “the building is a sturdy, multi-sided thing, gleaming as it emerges from the cityscape. The colour of the ceramic covering even evokes the azure blue that corundum gives the precious stone itself.” But it is not volcanic.

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372 thoughts on “Sapphire!”

  1. First off: the password saving is not triggered correctly by wordpress. I rarely comment here and I have to request a password reset every time. I’m using Firefox on Arch Linux. I think I permanently fixed it now, but who’s to say…

    Second: This is the lull before the storm. I’m expecting an eruption any hour now, and I have my webcams down. 🙂

    • We haven’t had a Reykjanes eruption on a Tuesday and Friday. So be sure to watch closely those days! 🙂

  2. Gems, aside from volcanoes, always fascinated me as a child.

    When visiting my grandmother in northern Sweden during summers I used to dig for tourmalines amongst the tailings of an old interwar-WW2 mine. The mine also happens to have a mineral named after it. Kudos if you manage to guess it.

    • LoL Im not looking foreward at all towards the Nordic winters here it stinks really. Its true that Scandinavian winters that are marine moderated are relativly mild compared to eastern siberia and antartica that are deep continetal winters but, still talking about minus 15 to 28 for months months in northen scandinavia and because we are so much farther up than other cold cities, winters lasts much longer up here than in cities like edmonton and chicago. Winters in northen Europe also haves another disadvantage over winters in Canada: we have alot of marine humidity so cloud formation is excessive compared to Canada and Siberia that have dry sunny winters, continteal areas have sunny winters, while marine ones gets more clouds. Many parts of Scandinavia haves grey skies and low clouds for months in winter, it gets gloomy and depressing for the mind, most other persons wants bright and sunny winter weather. I remeber one winter with over 80 overcastdays of high stratus clouds or sheets of cirrostratus clouds, with little direct sunlight. That happens when marine humidty freezes into cloud sheets when it flows over polar air. My brain is not working so well, after three decades in this gloomy winter climate, that saied snow helps to bright up things even if its cloudy

      • ?crop=focalpoint&domain=matthewwilliams-ellis.imgix.net&fit=crop&fm=pjpg&fp-x=0.5&fp-y=0.5&h=1919&ixlib=php-3.3.1&q=82&w=2560&s=1940be5b3a794952614bae5902accdfb

        ?crop=focalpoint&domain=matthewwilliams-ellis.imgix.net&fit=crop&fm=pjpg&fp-x=0.5&fp-y=0.5&h=1919&ixlib=php-3.3.1&q=82&w=2560&s=24e106a8813699beb9ffd4c23c584fce

      • I guess most VC users woud tire quickly of souch light conditions

      • ?crop=focalpoint&domain=matthewwilliams-ellis.imgix.net&fit=crop&fm=pjpg&fp-x=0.5&fp-y=0.5&h=1320&ixlib=php-3.3.1&q=82&w=1920&s=2bbbe75e536953e50506e9df79c7992c

        The endless winter wastelands in Northen Scandinavia fascinates me… near the great mines too, miles miles miles of silent winter forest with shrunken heavy snow laden spruces really like something from a christmas saga but in real life, I have spend alot of years in souch conditions harsh but very beautyful, tourists travel from all over the world to see these winter landscapes and the nothern ligths

  3. I grew up near the sapphire deposit in Montana, I actually have a canister full of little gems I mined (placer deposit) myself. The biggest one is about 5mm across and you can see the hexagonal shape of the crystal it formed. The sapphires in Montana run on the clear/yellowish side, and when heat treated turn the familiar blue

  4. I grew up in Montana, and when I lived in Lewistown, our grocery store employees (I was one) drove up near Utica, to pan the sapphires from the small ice-cold creeks there in the late spring, early summer afternoon. The water was so cold that your hands and arms grew numb in less than 10 minutes and that more or less stopped the panning.

    I did find a pale red ruby, but most of the small stones found were pale green to straw in color. There is an interesting article about the Yogo Gulch dike https://www.gia.edu/gems-gemology/summer-2018-gemological-characterization-of-sapphires-from-yogo-gulch-montana. Figure 6 shows the volcanic dike and Figure 7 is an actual picture from the Vortex mine, the dike there is only 30 cm or about a foot wide. Fig 8 is a picture of a beautiful sapphire crystal embedded in a zenolith which the magma carried upwards. Finally Fig 17 shows that Yogo sapphires are chemically distinct from all other sapphires.

    Interestingly enough the authors of the article classify Yogo sapphires as igneous sapphires despite the metamorphic origin of the foundation minerals.

    • I have included a satellite photo from Google, the dike has been mined out since 1905 or so and it is the long trench like feature extending from mid-left to about 20 deg right hand side. I highlighted the Gadsen house with the geo marker. My memory was jgged a bit, around 1967 or so we drove up Pigeye Road and panned in sections of the Judith River in June. See

  6. Now it has been over a week it is easier to see what parts of Kilaueas ERZ are active now. The connector area is as expected but now theres a dense blob that is well east of Mauna Ulu, into the ERZ proper. The gap is possibly an area where there is active stored magma, probably formed under Mauna Ulu. This area did have pit craters before 1969 and it is likely a major caldera collapse will create another one here in the nearish future.

    Recovery after a caldera collapse is usually something that takes centuries or millennia but here we get to see it all in under a decade 🙂

    duplicate image removed – admin

    • These images look identical. Is there some subtle before-and-after difference? It might have been best to highlight it if so, as I can’t seem to find it just by eyeballing them both.

      • They are identical, its just one image I posted with two URLs in case one didnt display. Its the last week of Kilaueas earthquakes up to a few hours ago.

    • Seems the supply rate is still unchanged after the recent intrusion too. About 1 microradian a day, slightly less. So probably a supply of magma of between 0.5 and 1 million m3 a day to the source detected by UWE tiltmeter. The fact the ERZ stations all show uplift that continues makes me think the blockage us either gone or is failing, so the summit supply is not the full story…

      At this rate too the pressure will recover in about a week, which might be the breaking point of the ERZ. An eruption isnt guaranteed immediately but something will probably happen soon.

      I guess we have a bet for the next Sundhnjukur eruption or Kilauea doing something. As has been the case all year so far… but now things are getting more serious, in both locations. Grindavik might be only a name in a week, and Kilauea preparing the ERZ so soon after 2018 is surely not what the locals in Leilani want to see. Although another Pu’u O’o or even the original being reactivated in a not destructive location would be welcome I expect.

    • KERZ station between Mauna Ulu and Pu’u O’o has finally seen a uplift:

      ?fileTS=1722784836

      • This station is probably above a magma body that is responsible for creating Makaopuhi and Napau, and probably extending now further down the ERZ under Pu’u O’o, so I expect we will see uplift there soon too.

        If this is the case it is different to what I expected. I thought that magma getting past the bend would result in sudden major deflation of the summit and similar uplift along pretty much all of the middle ERZ from Mauna Ulu to east of Pu’u O’o. But the speed of uplift at the stations now makes me think the apparent deflation along the ERZ since 2020 might just be because of land movement and not magma drainage.
        If the bend opens up properly things might move very fast.

        • Yes, it looks like rapid inflation is taking place in Napau and Makaopuhi, downrift of Mauna Ulu. The uplift probably approaches 1 cm/day near the center so it’s quite substantial. We have also seen the first earthquakes around Napau. It looks like things are heading down the East Rift Zone of Kilauea. We might very well get a middle rift fissure eruption, or even Pu’u’o’o 2.0 at this rate. Things are evolving. When we started to get ERZ connector earthquakes at the start of the year I did think the ERZ was starting to awaken. Still, I wasn’t sure how far down it would go, yet now that Makaopuhi-Napau is inflating anywhere in the Middle East Rift Zone, as far down as Heiheiahulu is within reach of Makaopuhi-Napau dikes, although anywhere along the Chain of Craters is a possibility too. The summit has stopped inflating, SWRZ seismicity has died out, the East Rift Zone is definitely back and most magma seems to be now heading downrift of Mauna Ulu.

          • I wonder what the realistic chance is that Pu’u O’o itself actually reactivates. It is after all a very deep crater, filled with rubble but probably at least as deep as the start of the lower ERZ and within range of the magma now. It wouldnt be a resumption of the original but it could be an easy guide for a new vent.

            At least, it could fill with lava again even in an eruption centered elsewhere.

            I still think the area between Pu’u O’o and Heiheiahulu is the most likely place to get another shield. Its a balance between gravity favoring lower elevation and distance from the summit favoring higher elevation. Pu’u O’o was maybe pretty close to balanced, but the supply rate now seems to be higher which should shift that point east.
            Actually on that point when Mauna Ulu was active the supply rate was a little lower too and the shield was closer to the summit. 1969-1975 was 0.25-0.3 km3 and inflation so maybe 0.5 km3 tops, a little under 0.1 km3 a year. Pu’u O’o average was 0.125 km3 a year. Now the supply is probably way over 0.2 km3 a year and certainly higher than before 2018. I will have to look if maybe there is a consistent ratio of supply rates and vent distance from the summit.

            So this might have some testable evidence, although it isnt working in a vacuum and the other variables are relevant still.

          • The map of 18th century eruption shows that eruptions there didn’t reach the ocean. I think it’s possible that the Napau/Pu’u O’o region does small or moderate eruptions that don’t reach the ocean.

            1961 the region did a pure fissure eruption for two days. It was the first MERZ eruption of 20th. I have the impression that the Napau/Pu’u O’o region is the dominant actor or “central volcano” of MERZ. It did the largest and longest eruptions both of 20th and of 18th century. Maybe this is a reason why it will erupt first again before any other locations on MERZ awake.

          • Possibly so, but the style of eruption was not really similar to any that have happened there recently. Particularly the probable 1779 eruption, which was a major lava flood eruption, like a Mauna Loa eruption, and a lot bigver in volume than anything in the area since. Probably not unlike some of the lower ERZ eruptions even. A similar eruption now actually might reach the ocean, as Pu’u O’o presents a high point that might confine the fissure to a shorter length and thus more lava in an area. A flow in 1986 flowed down the south flank faster than you can run so its just as well no one can live there now…

            Im also not sure the time was quite so comparable in general. Heiheiahulu was a lot bigger than Mauna Ulu but still 1/3 the size of Pu’u O’o and was the only shield. The total volume of the 18th century activity excluding 1790 might be only about 2.5 km3 at most, although that probably jumps up by over double to explain the deep caldera. Still, that is less than the 7 km3 erupted since 1950, that seems still yet to be the final value too.

            Its pretty likely that the first eruptions to resume in the area will be smaller but get bigger, perhaps rapidly so. They could also occur as long fissures as happens at Svartsengi or in the 18th century, or occur from a limited area or a new persistent vent. Im inclined to the latter but early on both scenarios begin as the former.

          • Were the eruptions during the 18th century (f.e. 1779) comparable to the first three Pu’u O’o yeras 1983-1986 with tall lava fountains and thick A’a lava flows? Can the Pu’u O’o area do a pure 1983-1986 eruption without the 1986-2018 period?

          • Heiheiahulu was, probably for longer than 3 years too. That is another factor I want to look at, because historically eruptions with episodic fountains have gotten longer lived with wider spaced more voluminous episodes the further from the summit. Kilauea Iki had fountains hours to days apart and lasted only a month. Mauna Ulu had tall fountains for about 6 months and typically a couple weeks apart but variable. Pu’u O’o lasted 3 years usually over a month apart pretty consistently. I think Heiheiahulu might have been over 5 years, maybe even close to 10, of episodic eruption before it became a tube fed shield.

            Apart from that though all the other eruptions were fissure eruptions, sometimes forming cones in the late stage. So similar to in the 1960s but the scale was much larger abd the eruptions were probably not so frequent unless eash fissure was a repeated rift, which is really hard to determine if it wasnt observed, though isnt unlikely.

          • The two questions regarding Pu’o’Oo’o is why it continued for so long, and why it ended. The first one is probably related to a relatively large magma reservoir nearby, which kept it going during time of magma drought. That would have been set up in the early days. The presence of a fairly reliable conduit to Kilauea must also have played a part. Why it ended has two aspects. One is that it was declining for at least a decade. There were still spurts, but ocean entry was becoming rare and the fact that Kilauea was developing its own open conduit at the time shows that magma did not find it as easy to flow out. Perhaps the conduit had been narrowing. Why it ended may also have two answers. One was the big earthquake that released a lot of stress. The new conduit that by-passed Pu’u’o’o was given a big advantage by that. The second part was that the conduit to Pu’u’o’o probably solidified at this time, somewhere along the path. That can happen fairly quickly if it is narrow enough, so when it was starved of magma for weeks or months, it was a goner. There may still be a magma reservoir near it, but it is not pressured enough to do anything, is not getting new input, and is itself getting stale. I don’t see Pu’u’o’o easily recovering from this.

          • I didnt see it at the time (nor did HVO I think) but the slow activity after 2012 was because some magma was bypassing Pu’u O’o even back then and going downrift. The 2018 dike started on its own further down the rift. The lack of ocean entry was also, realistically, more because lava flowed northeast and not down the south flank, the lava in 2014 and 2016 up to the start of 2018 was quite strong and the last Kamokuna ocean entry was one of the longest lived of the whole eruption, going for nearly 1.5 years I think. It was rare for an entry to last over a year without moving.

            One think that I remember but which might have been forgotten, but immediately after the 2018 eruption died down, Pu’u O’o had a brief byrst of SO2 over 1000 tons a day, before it died. I think the conduit was still open and viable up to then, by that point 3 months after lava was last active. If the 2018 eruption hadnt been so big or uf the earthquake hadnt opened up the rift to let the summit drain rapidly, Pu’u O’o might have actually survived the event. Although that doesnt mean it can resume now.

          • By 2018 there was clearly a bypass in place or in the works. Earlier, the fact that the lava level was rising in Kilauea (every since the 2008 explosion there) shows that magma had difficulty leaving as fast as it got in. A higher pressure was needed to keep the conduit to Pu’u’o’o open. That may have been what started to open the bypass. Once that bypass broke through, the pressure at Kilauea decreased and the Pu’u’o’o connection slammed shut. All speculation, of course, but it seems to make sence

          • There was magma making it down to the JOKA station for years before 2018. Its getting hard to see with age but it is there.

            Uplift at Halemaumau, and high lake levels, mostly happened after 2015, when the first time it overflowed. Although this is only 6 months away from leaving the instruments. That might have been when the supply from depth increased to the post 2018 observed level. MgO content of the magma also dropped a little and stabilized at about 6.5% with only the early and late magmas of 2018 having a big deviation, and this is also the composition of the post-2018 lava. Although post 2018 lava isnt degassed.

            I guess those last 3 years were characterized by extra magma redistributing itself in the ERZ instead of increasing the output at Pu’u O’o, we know it made its way out eventually though…

            One thing of note, the long term average of the hotspot is 0.21 km3 a year for a few million years now, minor variation. But Kilauea today seems to be about this by itself, while the recovery of Mauna Loa in 2023 suggests it was getting fed at about half that for a while and not affecting Kilauea. Kilauea could well be even higher now, which is probably in part decompression melting but if the supply increased a few years before 2018 its a wonder why. The pahala quakes did start becoming obvious not long after, in 2016 is when I remember someone here first pointed them out. The 2018 decompression will go away but if Pahala connected 10 years ago and is as big as it looks then this could well be the new norm for Kilauea.

            Actually, in this scenario, Pahala could keep Kilauea in high activity while Mauna Lia has its turn. Does make me think about something Hector brought up about radiocarbon dates around 2500 years ago? showing major resurfacing of both. And 1500-1800 being lower rates at both than before or after (still high though). Maybe magma supply has been hindered for centuries and the buildup is getting out. I think Laki and Eldgja were the same, but more catastrophic.

            Ill have to try and compile all of this into something, not just a comment the size of an article. Its mostly just my thoughts though not backed with any sources. So not sure it fits modern VC article standards… 🙂

          • Seems that all of the middle ERZ stations saw a subsidence of about 20cm in the past few years that the ERZ was quiet. But uplift that we see is getting over half a centimeter a day at KERZ, maybe even as much as 1 cm a day in places nearby. So the area could well be refilled within a month from now. This does match with the extremely rapid uplift of the south caldera and SWRZ seen from September last year to July.

            At half a cm a day if this is sustained until the end of the year that is about 75cm of uplift. Its obviously a big presumption this will happen but that level would bring most of these stations back to their 2018 level. The summit in most areas is already recovered, the only options left are resumed eruptions likely in a long lived and voluminous manner, or magma going even further downrift and just delaying the former to a more dangerous location.

          • Inflation also appears to be resumed and ongoing at the summit and upper SWRZ. And more quakes are happening even east of Napau now. At this rate magma will be down at JOKA station in a few weeks too.

            Im confident to bet on another Pu’u O’o type eruption at some point in the next year now.

          • Anyone taking the bet? The winner gets to publish a VC post free of charge.

          • Just because, ill say January 3 2025. What would have been the 42nd year of Pu’u O’o if it was ongoing 🙂

            Being less specific, any time from November 2024 to June 2025.

          • Pu’u O’o area (including several craters/cones from Napau until the most NE craters) acts like an independent central volcano for Middle East rift zone. It is more independent from the summit than the Mauna Ulu (Aloi/Alae Craters) area.

            My impression of current GPS stations points towards the area between Napau and Pu’u O’o. Pu’u O’o stations are moving north and east. KERZ station (Napau) is moving south and west. Maybe the western border of Pu’u O’o lava shield is the place for next eruption. March 1965 was an eruption in this area. Google Maps shows the location. 2001 Volcano Watch looked back at the 1965 eruption: https://www.usgs.gov/news/volcano-watch-important-almost-forgotten-eruption-kilauea
            During only ten days of eruption an impressive lava lake was created in Makaopuhi crater. Here you can read in depth about the 1965 eruption: https://www.researchgate.net/publication/248784781_March_1965_Eruption_of_Kilauea_Volcano_and_the_Formation_of_Makaopuhi_Lava_Lake

          • I was geographically a bit confused by several vents 1965. The black 1965 lava on the western border of Pu’u O’o lava shield wasn’t part of Makaopuhi crater, but was a subordinated event during the 1965 eruption. Makaopuhi is between Mauna Ulu and Napau. There was the predominant March 1965 eruption.

          • March 1965 eruption was a long fissure eruption, probably looking like the recent Svartsengi eruptions but the fissure was twice as long. The westernmost vent was in Makaopuhi, and kept erupting longer. I think there was another vent at the other eastern end that went for about a day after the curtain of fire, but it got buried in the 1980s. HVO used it as an observation point at Pu’u O’o for a while.

            That eruption was the 3rd and largest of 4 eruptions along that same fissure. It started in 1961, but only erupted further east. Then erupted over a long stretch in 1963 but didnt flow too far. 1965 did manage to flow further although that us now buried. There was another eruption later in 1968, which is notable because it stopped and then resumed a few weeks later, maybe a sign that things were changing as Mauna Ulu formed only months later.

            The lava of 1965 also apparently was over 1200 C in Makaopuhi, even that far from the summit Kilauea shows its ultra hot interior.

  7. Etna making more super – fountains insane stuff watch the webcams

    • Yes, it does a fast intense lava fountain show, while everyone is looking at Hawaii and Iceland …

  8. Sapphires come in pink, yellow, blue, green, purple and pinkish-orange (rare and sought after).

    Burmese rubies are fluorescent. Is this because they are younger?

    • All rubies have a bit of fluorescence. It comes from incorporating a chromium in the crystal. Myanmar’s rubies have it very strong and a bright red (although so far red that people’s eyes may differ in sensitivity to the colour). Other rubies have it less and may appear more orange.

  9. Thanks Albert for a very fine essay! I like sapphires much more than diamonds. Sadly both gemstones are now fairly easily synthesized so the mystique and fascination in them are fading.

    As a kid we used to go fossicking for sapphires at Nullamanna and Oban – both in northwestern NSW, Australia. As well as the various colours you mention there are also what we called “party coloured” sapphires, with blue, yellow and green stripes and patterns. Interesting geochemistry! And as well as that there are “star sapphires”, which instead of being transparent are opaque. They are commonly cut into cabochons, which then display a bright hexagonal star reflection.

    A small segue: fairly nearby to Nullamanna and Oban is Copeton, which has the hardest natural diamonds in the world. They have a natural nitrogen doping of the carbon crystal structure.

    And finally here is the biggest sapphire I ever found. It was 8 carats raw – a crystal with the tip missing. I remember when it turned up in the sieve – almost glowing in the sunlight. That was fifty years ago. My old dad got it cut and some other ones with it mounted for me.

    • Born in Inverell, close to the Copeton diamond fields. Interesting articles available on deformed diamonds from that area. Take a look in Google earth and tell me if you can see what looks like an impact crater ( a big one ), I to used to go over old spoil piles for. The sapphire mines near Glen Innes. Found quite a few some 50 years ago now

      • ARW – Yes the Oban River and Mitchell River, creeks really, are SE of Glen Innes roughly on an imaginary equilateral triangle with Guyra. It was a nice place to camp and fossick. In the sieves we’d also get lots of beautiful river-rounded smoky quartz and topazes. Those topaz must’ve been bounced around for a very long time since they are only one notch below sapphires on the Mohs Scale.

        Our family had a fun arrangement with a farmer in Nullamanna – we lived on the coast so he’d come and fish with my dad, taking back home many snapper and flathead, and we’d in our holidays go and dig sapphires from the creek on his property (which had been industrially mined, but there were many crevices to scoop out that the machines couldn’t get to economically.)

  10. Great post.
    I’m not sure aluminium oxide is ever poisonous although fibres are probably best not ingested.
    Beryl, beryllium oxide, is of course VERY toxic, which is probably why they are not much used these days.
    I had need of a bearing some decades ago, for a corrosion-resistant rotating chimney pot that had failed. The sintered brass sleeve was good, I replace the (corroded) steel bar with stainless, complete with stainless ball bearing as the vertical pivot. Sadly stainless is horribly hard, more so when work hardened, and I racked my brains to source a corrosion resistant but very much harder contra-bearing. Then I discovered I could buy a 8mm diam sapphire disk 1mm thick for only a few £GB. This solved the problem. Synthetic sapphire (clear) is surprisingly cheap.

    • Yes, I believe that the danger in the aluminium oxide is in breathing in the fibres. That puts it in the same category as asbestos.

    • Generally speaking anything that isnt 20% O2 in an inert medium is poisonous. Asbestos and silica dust are dangerous because they cant dissolve in tissue and be removed, Al2O3 is not really any different, amorphous it will dissolve in acid and base but not really as crystals and I doubt that is useful in the lungs anyway. I think that inert or insoluble dust should be considered a respiratory hazard as a rule, but unfirtunately the rules only get made very specifically per chemical, not collectively. I know silica dust is also a carcinogen but that might just be a result of a foreign body causing unusual reaction.

      Really anything solid in dust form should be considered toxic. Far as I know it is the biggest reason diesel engines are being phased out, they have very high particulate emissions. And it is one of the most important hazards in manufacturing. It also might be one of the biggest risks of smoking.

      • I think you overdo the threats. Humans and the ancestors have been inhaling dusts, both silicic and aluministic (!) for hundreds of years. We have means of removing dust from our lungs which is why smokers lungs go from black to pink in a few years of giving up smoking. Some things are carcinogenic, this may be physical or chemical but not all fibres inhaled will result in death in the future. Excessively high levels of anything airborne will be hazardous for a multitude of reasons but this is no reason to panic needlessly over trace amounts. I am amused by the near panic people have about european urbam air pollution and nearly everyone thinks its been going up for decades, when in fact the reality is solidly the reverse. Much the same for traces of SO2 or NH4 which are not really a problem although high levels kost certainly are.

        • I think for most of history the jobs exposing people to these things had high mortality and low social status so we never really saw how bad it was or cared really… or understood what it was doing.

          • To be honest in most of history ignorance ensured that other than slaves (mostly) everyone had a chance to be exposed to something that was not good for you. From warfare to hygiene to toxins. Massive rapid population growth powers big inequalities and a strata of society that will do any work for food as in victorian england and parts of the world today. Drastic population drops, like the plagues and black death in england power social equality (serfdom ~ceased in the UK). THe german salt mines (bronze age?) had wealthy graves but with skeletons showing extreme damage due to working in the mines, men and women both, but they were wealthy!

        • It is though a real thing that I describe. That our lungs and biochemistry cant remove silicate dust from them. Asbestos is particularly bad because the fibers are so fine and sharp but it isnt a poisonous chemical.

          I think recent data suggests carbon nanotubes and graphene are similar. Engine particulate is mostly going to be carbon allotropes like this, maybe not so neatly strhctured. If we used a low carbon chain fuel in diesel engines like diethyl ether this might be avoided but at this point the investmebts are better in other areas. Diesel needs electric to unlock its true potential. Although EVs are non negociably better in urban environments. I do understand that the UK has a few uncommon complications on this trend…

          • The removal is physical (which is why fibres can be tricky) then microcillae take them to the mouth. I think asbestos probably has to do with the crystal structure as its hugely worse than similar glass fibres for example.Its very hard to disentangle the real evidence, often extrapolated from hugely polluted Indian/Chinese cities with a lot more going on than air pollution. My gripe is continually blaming air pollution when its clearly not the cause of asthma etc but a wider increase in immune dysfunction in first world society simply wastes resources fixing the wrong problem. Why we have a huge increase in immune dysfunction diseases is the problem, we do not look at causes but effects.

          • Asthma is genetic but it is caused to act by inhaling particulate matter. It can also be caused by inhaling some gasses like SO2, probably the reason being that it is acidic in solution and is irritating.

          • If asthma was genetic then it would present at a constant level over the centuries. In my youth (London 1950’s) asthma was quite unusual. Not so today. For info
            .webp
            and incidence

            Yes, its “obvious” that air pollution causes asthma, except the evidence is to the contrary. Best use resources finding the real cause. Not miasma but germs (analogy).

          • The NHS lists the following substances as known causes of asthma. These are work related

            spray paint
            flour and grain dust
            solder fumes
            latex
            wood dust

            And in some cases pets!

          • Albert,
            it seems to me there is a basic problem.I and my children have been exposed to grain dust, pets and to a lesser degree wood dust (note some wood dusts are very toxic and carcinogenic, particularly tropical hardwoods) vastly more than the general population. This will be true of people who work in farming (and third world ditto) yet this group are notable for having significantly lower asthma rates than the general public.
            Which makes no sense UNLESS the cause of asthma (ie whether you become sensitised to whatever) is different from the triggers of asthma (that is to say environments that trigger symptoms of asthma in previously sensitised individuals). To fix the problem we need to sort out the former, not worry about the latter (so much).
            Asthma is really due to a faulty immune system, but so are very many ‘modern’ diseases such as MS, some arthritis diseases and in fact a host of similar hard-to-treat diseases.
            To me there is enough evidence that exposure to adequate bacteria and parasites in youth is protective. That curve follows increasing levels of hygiene in an increasingly hygienic world. Remember a “peck” is about the size of a small vath …..

          • It is a difficult one. Reports state that some jobs come with higher risk of asthma, including wood workers but it is not clear whether it included agricultural workers. (One place mentioned chicken farms but i am not sure whether there was data behind it.) Some exposure early on may help against asthma and too much exposure may trigger it. Life expectancy was much less in the past, and there were reasons for that.

          • I dont want to be that guy but since the 50s the number of vehicles has increased significantly. I also dont know personally but family in the UK have told me the majority of road vehicles are diesel powered, and until the 21st century typically without a DPF. Idling diesel engines are not and cant be made to have clean combustion, they are designed to run at very high load at peak torque, which rarely happens in a vehicle but does happen in a generator. Diesel needs electric to realise its true potential. But too late I guess. Family has told me that only EVs are allowed to drive in urban London now.

            Only other thing I can think of is it is somehow related to longer term effects of TEL in fuel or the former heavy use of coal. But I know a lot of people personally with asthma and we never had a local coal industry so im not confident in that.

            Ignoring burning stuff, perhaps asthma is related to microplastics somehow. But thats not based on anything just putting it out there.

          • The green curves show that, although stuff that’s been around for thousands of years (pets, wheat dust, etc.) might have been causing a low baseline level of it, most of it is now being caused by something that is a) new, b) increased in the developed world from the mid-fifties until 1990 or so and then began to decline slightly, and c) began to appear in the developing world later (1980s or so) and only really began to ramp up very recently.

            Two candidates immediately leap to mind: vehicle pollution, which fits the decline in the developed world post-1990 when the developed world began to widely adopt emissions limits and technologies like catalytic converters, and chemical industry associated pollution, including spills, fumes, and microplastics. Based on the post-1990 decline I’m leaning toward vehicle emissions as the likely culprit. That also fits the steep rise recently in the developing world, where motorscooters with two-cylinder engines saw massive uptake in the past decade or two. Those are nightmarish for toxic pollution (and GHG emissions). AFAIK plastics and many other non-vehicle-emissions chemical pollutants are still on the rise worldwide, so the post-1990 decline doesn’t jibe well with that, unless it’s instead from shifting much of the industrial polluting activity to the developing world during globalization. In that case, that shift could explain the spike in the developing world, but the decline in the developed world is then oddly small.

            I still lean toward vehicles as the likely culprit. If so, the levels should drop steeply in the developed world soon now that EVs seem to be taking over there.

          • How well would it fit the trend for obesity, just to mention another candidate?

          • Albert,
            we need to distinguish between “the general public” and groups who (histotically these days) had excessively high workplace exposure to dust (in general). Woodworkers, poultry farmers miners etc are occupational and need environmental protection. The levels were also very high indeed. I am talking about general increase in immune dysfunction diseases. Here I fear we blame the triggers, not the real cause of the increase. We blame the obvious miasma, not the unknown infection because its “obvious” (which to be fair, it is: just wrong).

    • Synthetic sapphire (clear) is surprisingly cheap.

      Just don’t ask Dr. Nichols where he got the formula. 🙂

      • Al2O3 and 2000 C for a long time 🙂

        Hardest part is probably a suitable crucible, with electricity it is surprisingly easy to get that temperature. I think crucibles for making silicon and sapphire single crystals are made of iridium, which is probably the most inert solid element.

        It also is the only solid element that is apparently inert to elemental fluorine at room temperature, the stuff is basically indestructible.

        • Yes, interesting:
          https://metalstek.com/refractory-metals/tungsten/tungsten-crucibles/
          Description

          Tungsten crucibles and other parts can be used for sapphire crystal growth and rare-earth melting due to their high-temperature resistance, low pollution, and other excellent characteristics. Tungsten’s melting point is 3422°C (6192°F), making it perfect as a crucible.

          The tungsten crucibles manufactured through the chemical vapor deposition (CVD) process exhibit notable characteristics, including a high density reaching up to 98.5% of theoretical density, exceptional purity at 99.9999%, and a distinctive microstructure characterized by columnar or multilayer columnar crystals.

          • Tungsten is good as a crucible but only if the thing being melted wont react with it. Chemistry gets really weird at high temperatures. An example is that you can reduce NaOH to elemental Na using Fe at 1000 C, because Fe oxides are solids and Na is a gas at that temperature. And making F2 without electricity is also possible.

            As a side, I have melted tungsten, its actually disturbingly easy with a welding machine… or just shorting a car battery through it. You can theoretically do it with an oxy fuel torch but in practice it doesnt work without confining it, even when the rod starts glowing bright enough to outshine the workshop lights… I have seen videos of arc foundaries and they run at a power of about 0.2 GW to melt 30 tons in 40 minutes.

            Which means Kilauea in the 2010s could replace 6 steel furnaces 🙂

          • Almost everyone over the age of about thirty has probably melted tungsten. If you’ve ever had an incandescent bulb burn out when you switched it on, you’ve melted tungsten. 🙂

          • I am under 30 although I have still done that too, heat lights in bathrooms are still incandescents and likely will be as long as they are a thing, and one of mine is blown.
            Incandescent lights are 100% efficient they just make most of their light outside the visible range… 🙂

  11. I’m thinking about the crystal structure of Diamonds. Carbon atoms are able to create four atomic bonds. This allows them to build elementary crystals with only Carbon atoms. Otherwise crystals often have ionic bonding as f.e. Aluminium oxide in Sapphires. Al2O3. Two Aluminium ions (each 3+) ally with three Oxygen ions (each 2-). Aluminium belongs to the Boron Group.
    Carbon, Silicium and Germanium belong to the Carbon group. The Quartz is to silica, what diamonds are to carbon. Quartz only has a hardness (Mohs) of 7.

    • Irrelevant comment:
      It would be bice to make semiconductors out of diamond. Carbon is cheap and I believe its not that hard to grow diamond films on an appropriate substrate. The bandgap of diamond is MUCH higher than silicon so devices would work well at very high temperatures allowing high output small devices. I believe the devices are inherently faster too.
      BUT
      current methods rely on manipulating silicon and (insulating) silicon dioxide layers to make multilevel devices, but sadly CO2 would not work well for obvious reasons. Carbon nitride might work but I think there are “technical difficulties”.

      • Would be expensive wavers! Graphene has been proposed, when combined with another material. The other material creates the band gap, graphene the electron mobility.

        • Graphene would be good, but a good easy to ,make molecularly contiguous insulating layer is still a problem for complex devices. The insulating layer has to be able to survive multiple thermal cycles etc etc and that’s hard. In essence, we are lucky that silicon and SiO2 are so mechanically compatible. A lucky fluke of nature.

        • Yes diamond devices have been made for a decade (probably more, I underestimate time at my age). Diodes are fine, no insulating layer needed. Transistors (bipolar) can be made too, but only one layer thick. Modern devices can have lots of layers and complex three dimensional wiring, that’s where the problem lies compared to silicon.
          Its annoying ….

    • Actually CO2 is to carbon what quartz (SiO2) is to silicon. Elemental silicon in the familiar metallic form has the same structure as diamond, tetrahedrons of atoms. Silicon carbide (SiC) does too, alternating the elements. They are of course not the same size so have different properties, although SiC is a lot more like diamond than elemental Si.

      I do find it interesting how CO and CO2 are gasses, but SiO2 is a high melting point solid. Its an interesting question why CO2 doesnt polymerize, I think dry ice is still molecules not a polymer.

      • Yes, indeed, quartz is an oxid of Silicon. Rhyolite contains quartz

  12. There actually are sapphires in Canada, there are in the nepheline syenites of the Grenville belt in Ontario and Quebec, I collected some black star sapphire near Bancroft, there is some blue low grade material near the York river in the same area. As well, I have some large corundum crystals with sapphire centres from a secret locality in Quebec that I got from the owner of the claim before he passed.

      • Never did get the location, he was pretty cagey about it. The crystals were large frosty white barrels up to about 15cm in length, about 5cm in diameter, but the gemmy blue part was in the centre. The host contained white mica, which allowed the crystals to be extracted largely undamaged. The black ones I collected in Bancroft are EXTREMELY difficult to separate from the host syenite, and my maul and chisels were badly damaged getting manageable chunks of the syenite pegmatite from the outcrop. Corundum cuts hardened steel like butter. I can see why most of the famous localities are alluvial.
        Did you know there was a relatively recent discovery of watermelon sapphires in Brasil? Two different chromium oxidation states are responsible for the colour. Not sure if any facet grade has been recovered though, though I have seen cabs.

  13. Etna had the most violent paroxysm of its Voragine crater in the current series today. Video and pictures suggest lava fountain heights of up to 1500m. Also quite explosive, ash up to 11 km. Tremor started rising already Yesterday evening, then started rising sharply about 5 am. I was glued to the webcams the whole time. Insane.

  14. I’m guessing it’s Sunset in Iceland but the cams looks pretty wild right now

  16. A great use for sapphires is in playing vinyl records.

    What Are the Different Types of Record Player Needles? (16 May)

    The material from which record player needles are made will determine the sound quality and durability. Some needles are made from sapphire, and others are made of diamond. The needles also can be made of steel or a combination of sapphire and diamond. Diamond-tipped record player needles have the longest life, and steel and sapphire ones can wear out relatively quickly.

    Sapphire needles are ideal for playing 78s. Some sapphire needles feature two tips, which provides as much as 100 hours of use.

    So there you go, sapphire may be very hard but simple vinyl plastic can fairly rapidly wear it down. I had a turntable with a sapphire needle when I was a poor university student. But during my education some nice person invented the CD, so when I graduated I gave my turntable and record collection to one of my housemates. I then bought a CD player with some of my brand new salary in my first job. Vinyl LPs have made a come back of course so I guess someone still makes sapphire styli for them.

  17. The following 4 GPS stations in Iceland show a significant 4-7 cm. drop in elevation around July 15 or so.
    Does anyone know what happened around that time? Did a graben deepen?

    AUSV_4hrap.png
    AUSV-GRIV_8hrap.png
    AUSV-GRVV_8hrap.png
    AUSV-GEVK_8hrap.png

    See https://strokkur.raunvis.hi.is/gps/8h

    • I see a sharp drop by about 50 cm in AUSV but the others have blank spots around middle of July. Perhaps data that was skewed. Could be bad weather, including solar flares.

      But AUSV … either some car bumped into the sensor, or it was indeed subsidence. It’s definitely in the eastern graben area.

    • The common denominator is AUSV. The three last plots are differences between two stations, where AUSV is included in all of them. Maybe they did some work on that station and mounted the antenna back at a different elevation. Maybe a bolt came loose and the mount slipped down a pole. Once, a station monitoring the Grímsvötn lake level had a dramatic drop and everyone thought for a moment that a jökulhlaup had started. It turned out that the mounting pole was drilled in the ice and spring thaw had caused the pole to sink down in the ice.

    • Inflation of the area has decreased recently, as also IMO’s Icelandic update describes. This may force the magmatic pressure to move towards an eruption. They expect that the magmatic pressure will exceed the geophysical limits of the area during this week, so that an eruption is very probable.

  19. Seems to be a fair amount of activity between Katla, Eyjafjallajökull and Tindafjallajokull. Mix of deep, medium and shallow quakes. More on the caldera rim of Katla too. Definitely restless at the moment.

    • Note that very few of the quakes are verified and that most of them have very low quality score. Most of this activity is probably noise.

  20. Professor Shawn Willsey of the College of Southern Idaho around the 8 min 54 sec mark in his video https://www.youtube.com/watch?v=Gh_OMNV_DpE discusses an interesting Excel spreadsheet chart sent to him by Bruce Garner on when the next fissure eruption in the Svartsengi Iceland region might occur. Bruce’s data suggests the last week of August. Bruce is using the count of earthquakes per day to get a suggested fissure eruption date. Bruce also does a height analysis too versus the inflation rate of the magma as a predictive indicator. I find Bruce’s data analysis intriguing.

    • Another 2-3 weeks then, when we are already at the trigger of last eruption, which was the biggest and most intense yet. And also had the most fluid lava…

      If the eruption is north of the wall I think Grindavik will be spared but lava is reaching the ocean this time, it will be cut off. If a fissure opens within the wall though then it could be game over.

      It is interesting that the volume of the fissure stage stays about the same, but it gets more intense now every time, and it also has now lead to parts of the fissure staying open for longer instead of shutting after pressure drops. Its likely the same cone or a nearby vent will stay open again, and maybe also the other fuming spot that began to form a cone too.

    • IMO’s new Icelandic update expects that the magmatic pressure will exceed the upper limit to do an eruption during this week. They differ between two scenarios:
      1. Between Stóri-Skógfell and Sundhnúkur (most frequent location since December): Short warning time (Hekla style). 1,5-3 hours until lava floods Grindavikvegur.

      2. South of Sundhnukur, either on Hagafell or south of Hagafell (January eruption): Longer warning time, but it’s uncertain how much. Lava would need less than 1,5 hours to reach the southern roads west/east of Grindavik and block escape routes. Ocean entry after 1,5-3 hours. Grindavik may get significant deformation (with faults) and a lava flood.

      I’d expect that also scenario 1 will lead to an ocean entry. The last eruption already had the direction towards Nesvegur (west of Grindavik) and the volcano is likely going to repeat this again.

      • Basically the same scenarios and equivalent timescale to what they have been saying for the last couple of weeks or so.

  21. HVO finally stating uplift and magma buildup is occurring near Makaopuhi where the earthquake cluster is, though if you look at the GPS stations further east it appears magma is getting to Napau, a few earthquakes have also happened there. Also the south flank is slipping south of Napau but not further east.
    Might just be a coincidence but Napau is where the January 1983 fissure started.

    • Not coincidence I think. Pu’u O’o was interesting though, the dike started at Napau or maybe slightly west of it, but apparently made contact with magma along most of its base, so was a bit more independent than the 60s eruptions in the same place. Magma was there following 1975. More or less the same thing applies today I expect.

      That we get a fissure opening is inevitable, very likely wuthin a year. Once that happens though is the question of if it dies completely or parts of it stay weakly active. If the latter, then we have a new shield 🙂

      Between Makaopuhi and Pu’u O’o would be ideal, locationwise, but with Halemaumau being only 950 meters elevation it wouldnt take as long to make a shield ir cone that tall, which could lead to another pressure rise and repeat of 2018 faster. A shield east of Pu’u O’o would be probably safe from doing that quickly, but does also necessarily imply the whole rift up to there is storing magma, so when it does fail it could be big… As well as a shield there would be close to inhabited areas.

      This still isnt likely to be a problem for a long time but we might get an answer soon enough.

    • 1965 was a ten days eruption at/around Makaopuhi: https://www.researchgate.net/publication/248784781_March_1965_Eruption_of_Kilauea_Volcano_and_the_Formation_of_Makaopuhi_Lava_Lake
      “The eruption was preceded by inflation of the Kilauea summit and was accompanied by collapse of the summit.” “all eruptions on the east rift zone since 1961 have been accompanied by sharp collapse of the summi”
      Should we take into account that the summit does a collapse or major deflation again before the next possible MERZ eruption?

      • Not a literal collapse, just a big drop on the tiltmeter. The elevation difference between the ERZ at Napau and the floor of Halemaumau is about 170-200 meters, compared to about 300 meters before 2018. Part of why I think the next shield will be east of Pu’u O’o where it is a similar difference. But that doesnt rule out eruptions elsewhere.

  22. I don’t know if this is meaningful or not. But on the Husafell thermal webcam https://www.livefromiceland.is/webcams/vi_husafellt the point spot measured by the thermal camera was measuring regularly about 42c up until last week. It’s been measuring 65c for the last few days ( when no obscured by cloud and rain of course).

    Could this be a signal that magma is closer to the surface?

    And a question I’ve wondered for the last couple of eruptions. Could fresh magma be coming out of the fissures from previous eruptions at a very low rate under the old lava, as the pressure starts to mount, but at a rate that does not receive the pressure. And then an eruption only occurs when the pressure gets high enough to burst through a weak point? Is this a possibility that we have no way of verifying?

    • Eolienne:
      This is a very hard question to answer. I went to the thermal camera this afternoon and checked, sure enough there was a spot on the right hand side marked by a tiny x which was around 65 deg C. I just now came back and checked about 4-5 hours later, and found that the spot has moved, not longer on the right, but a new spot on the left measuring 66-67 degs C, so there has been about a 1.5 to 2 deg Celsius increase or so. I don’t have the answer, but find it interesting to notice a slight increase and a new location.

      • Fun if it turns out to be a vehicle tailpipe or something.

      • It is 19:33 pm Iceland time, on Wed 7-Aug-24 at least 17 hours later than my last post above, and the spot to the left is the same spot, but now running 69-71 deg C. It is right at evening time, so direct sun isn’t heating this spot.

        • I believe the camera is looking at the lava field and as such it seems logical that the temperature is unlikely to be much affected (much) by the sun, although if clouds / rain obscure the spot the temperature will reduce.

          The spot measured has been fairly consistent and is focussed on what looks like a hotspot. Right now it’s 62c.

          It’s the 20c increase in the past week that interests me. One to keep watching as the expectation of an eruption increases!

          • Eolienne:

            The infra-red camera, as it is (in my opinion) is at best scientific entertainment, but really not set up to take trend-analysis. It has a “wow-gee-whiz” factor, but the auto-ranging feature of the camera really renders measurements very problematic.

            Additionally I have notice that air currents and fog dramatically affect the IR readings, so that while we can say fog (water vapor) absorbs IR, it is almost impossible to again get a general reading, in order to establish a trend.

            For all we know the heat from the lava flow might fluctuate, but how would we know?

            I would like to see S02 measurements being done daily over the whole area, that would be much more indicative of a pending fissure eruption. I did notice that increase of steam and other gases only seemed to occur 2 mins or less from the actual lava reaching the surface, on the fissure trace.

            Summary: IR camera provides entertainment, but not much else. I don’t mean to be harsh here, but automatic reguaging is really ruining any real scientific inquiry.

          • Hi Randall. In no way am I suggesting that my random looking at a webcam is scientific! And of course a lot of things can affect the temperature measured.

            It’s just intriguing. The 42c was something observed fairly regularly over a couple of weekend when it was it cloudy or wet. And the. It increased quite significantly. This could be movement in the lava field exposing a warmer patch that will take time to cool. Or it could be the lava field has warmed.

            What I’m going to try and watch it so see if the temperature goes up again in the next few weeks before the eruption.

            It’s not scientific, but it’s an interesting possibility. There must be some interest in the temperature, after all surely they’ve installed the thermal camera there for a reason, not just entertainment…

            It’s 51c this morning, and the crosshairs are not visible. That opens the question of has the camera moved. I’ll keep watching.

  24. Latest NASA experimental solar cycle prediction compared to 2019 panel prediction.

  25. https://browser.dataspace.copernicus.eu/?zoom=13&lat=-1.39285&lng=29.19888&themeId=DEFAULT-THEME&visualizationUrl=U2FsdGVkX1%2BJ1bOBxtB7T4LL4c0BZlE%2FenOsEMj3rXdo6LLIya3NEt%2FbCxX9%2F%2ByY7f6ZlbpiNii%2F6LjQ8JgwDFxlAwBWvectzce%2B3SqIEMNLCyoU5M3HH2g2qDZY4au2&datasetId=S2_L2A_CDAS&fromTime=2024-02-06T00%3A00%3A00.000Z&toTime=2024-08-06T23%3A59%3A59.999Z&layerId=6-SWIR&demSource3D=%22MAPZEN%22&cloudCoverage=30&dateMode=MOSAIC

    https://browser.dataspace.copernicus.eu/?zoom=12&lat=-1.44525&lng=29.2419&themeId=DEFAULT-THEME&visualizationUrl=U2FsdGVkX19BWBsHcykPGfzHpKlRWxp7MVWXCLirMUyrWEQryknn90g1F8RvTW3W6hgvnc7WR8ZQSEus0Zq3L9hET0Hlv2FU%2FO09etFM5wktK%2BMphcj%2BDx%2FZ7Meq5otx&datasetId=S2_L2A_CDAS&fromTime=2024-02-06T00%3A00%3A00.000Z&toTime=2024-08-06T23%3A59%3A59.999Z&layerId=1_TRUE_COLOR&demSource3D=%22MAPZEN%22&cloudCoverage=30&dateMode=MOSAIC

    Volcanic activity keeps going at Nyiramuragira: the whole caldera have filled up and is now overflowing its rims with pahoehoe flows, the lava tubes are feed by a lava lake kind of like the 2015 – 2018 pond at Puu Oo but presumable directly by buried lava tubes unlike the buried side fissure of 61G. There are two tube feed pahoehoe fields are forming now one is already well developed and already many kilometers long now, another one far smaller but flowing south. This is some real classic textboox shield building a shield volcano overflows its caldera and gentle lava flows down in alll directions. Looking at older past pahoehoe flows have before flowed all way down to Kivu lake and formed lava deltas, souch eruptions may last a few years before the supply lowers. The last time there was a large pahoehoe flows was in early 1900 s I think and managed to flow down to the Kivu lake, should the south flow become vigorous and long lived it coud perhaps threaten the farmers properties at the south flank. I guess if this keeps going we coud end up with a lava shied build inside the caldera, by thermal data it seems pretty vigorous, Nyiramuragira have gone into pahoehoe mode rather than doing fast fissure eruptions… the rifts haves to be closed up now to allow this

    • Its last flank eruption was very big, I remember reading 0.4 km3 and with nearly 500 meter lava fountains. Most eruptions there are probably under 1/4 as big though happened almost yearly before. The 2011 eruption was probably a terminating eruption resetting a cycle that might have begun a century ago when it last had a lava lake at the summit the way it does now.

      Its still surprising to me how little seems to be recorded of Nyiragongo and Nyamuragira. Even only considering written history it is hard to find much over 50 years old and written history is a lot loner than that. Not to mention people have probably lived near the two volcanoes for longer than there have been volcanoes in that location…

      • I suspect the lack of research means they are deeply, deeply underestimated. Nyiragongo and Nyamuragira are absolute monsters, perhaps the closest thing Kilaeua+Mona Loa have to a rival and still very much in the up-and-coming phase. To put it in gymnastics terms, Hawaii is the Simon Biles of volcanos at present, Virunga the Rebeca Andrande, the closest there is to a real rival (I guess Iceland too if you lump it all together, but no Icelandic volcano individually comes close to these monsters). Nyamuragira has a few hundred km^2 of still very visible on satellite flows. In rainforest country! Remember the https://www.volcanocafe.org/the-heat-is-on/ article! Combined they nearly matched Kilauea’s heat flux for 2000-2020! Not exactly a slow stretch for Kilauea!

        • Nyiragongo is important in terms of heat venting, but Nyamuragira is clearly the big deal from a production point of view. What would a black swan event look like for it?

          • Nyamuragira doesn’t have a big caldera nor is there anything else to suggest a large magma storage, so the volume of eruptions is limited. Overall, I don’t think Nyamuragira does much variation in its activity, it either produces summit overflows or rift eruptions that radiate from the summit. In the past, it was also able to do Etna-like paroxysms, I think it was Zach Trent who brought up a photo of a subplinian eruption of Nyamuragira from 1907.

            It can be one of the most productive volcanoes in the world when it does fissure eruptions in rapid succession, perhaps only second to Hawaii. That said last fissure eruption was in 2011 and since then it has had some overflowing episodes at probably supply rates, but mostly has seen just passive lava lake activity, so I doubt it has been as productive as it was in 1977-2011 lately. In the 1977-2011 period, it had a productivity of 0.04 km3/year, identical to Etna during the same time, and somewhat superior to Piton de la Fournaise, but only 1/3 of Kilauea’s.

          • It can claim to be the most productive basanite volcano in the world. As Nyiragongo can claim to be the most productive nephelinite volcano in the world.

        • Hawaii and Virunga are sitting directly above the high points of the two LLSVPs. This is not a coincidence.

          Best case scenario: Nyamuragira does some spectacular shield-building for a while, then turns over and goes back to sleep.

          Middling case: Nyamuragira sends a Holuhraun-to-Eldgja-sized flow that melts Goma and sets off a limnic eruption in Kivu. Nothing caught within several tens of kilometers survives, except (ironically) up on the slopes of Nyiragongo.

          Worst case: the Virungan Traps finish the job humanity started and it’s exeunt the Cenozoic Era. Starts out looking like the middling case, except it simply keeps going for year after year, and actually ramps up until some individual flows occur that cover thousands of square km at a go. The gas pollution has worldwide consequences, most of them dire — the whole world’s breadbaskets get to experience what Iceland endured with its agriculture during the Skaftar Fires, while acid rain devastates what forests are left, climate warming kicks into even higher gear, and all the coral reefs die. Finally, after a century or two, it lets up … only to do it again after a few thousand years, and then again, and again, until a couple of million years have passed.

          But the Virungan Traps probably won’t start for a few hundred thousand more years yet.

          Probably.

          • Might still be another million years to get a Traps volcano, but a volcano that is basically a land Mauna Loa and with Laki capability on a semi frequent basjs is a likely future path for Nyamuragira. Although it might take 100k more years to get in that territory.

            All of that changes completely if it turns out magma generation is much higher than the volcano supply rate and a big lower crustal chamber already exists, then a black swan actually could be a Laki sized eruption. But I dont know if that would be preceded by any obvious precursor at the normal location, I guess just sudden extreme seismicity, maybe increased activity in the lava lakes immediately before it surfaces.

            But I do agree that Virunga is probably what a Traps province looks like before it initiates, even if many potential cases never get that far. And the last flood basalt in the traditional sense was 16 million years ago, with average of 15 million between it wouldnt exactly be unusual to expect something to be in the making now.


  26. Tremors on the rise on the fissures… eruption coming?

      • If I had to guess, maybe a few days, maybe even hours, but the word might be “soon”. Based on the muti-view from Live from Iceland on YouTube, the earthquakes are still around 5-9 kilometers down.

        • The depth of the quakes is not really a factor here. The reservoir is located in a depth roughly around 5 km and already full, so the quakes are mainly caused by inflation of this reservoir and not by rising magma (the conduit is already open).

          As soon as the critical pressure is reached, magma will shoot into the pre-existing dyke and erupt within 1-2 hrs (or even faster).

        • The earthquake depth is of no importance here. You won’t see a sequence of progressively more shallow quakes. The thing to look out for is a very dense swarm with new quakes every minute. Once that happens, an eruption will most likely start within 30 minutes.

          There’s no doubt that we are getting close. It could start later today, but it could also be another two weeks from now (which is what happened last time).

        • Direction is relevant. Are the earthquakes trending SW at all? If yes, with a depth of 5km an intrusion may be migrating in the direction of Gríndavík.

          • Such intrusions generate swarms with a much higher intensity than what we see now. We have witnessed what that looks like numerous times, both in Iceland and Hawaii. It would also clearly show up as ground deformation in GPS and InSAR data. Currently, the quakes tell the tale of increasing tension in the area. Something is about to break, the question is only when.

    • Several of the previous eruptions have been preceded by persistent earthquakes over the same spot a minute or so apart, like a pulse, usually half an hour or less before the onset of eruption. So that’s probably the best indicator.

    • Looks like the majority of the quakes is closer to Grindavik this time, let us hope that it has no relevance.

      • With high volume and output rate on first day, the risk for Grindavik is very high independently from the location of next fissure.

        Only a very NE migration of fissure towards the northern slopes of Fagradalsfjall would help Grindavik.

  27. Good look at the quakes at Kilauea now. There is a few clusters, with a gap at Makaopuhi and near Napau. Likely a magma chamber in both of these, as well as near to Mauna Ulu. Its unclear if a similar gap exists under Pu’u O’o, but it is likely, we will probably know in a few weeks when ir if quakes start showing up to its east…

    Lots of potential spots to erupt out that way now.

    • Been a few intetesting quakes at Kilauea this past few hours.

      Only SDH station looks exactly like this though, which is interesting.
      Its also interesting how the quakes appear to follow the outer caldera fault, its unlikely to be able to erupt here but this area has been a persistent seismic area now for a few weeks. Looks like more magma going east.

      • Actually looking over it all, SDH is the only station that shows the longer signals. So it seems to be very local, maybe a small pit opening above a crack.

        I guess it also could be magma, but while prsssure is increasing here it isnt higher than before, so doesnt seem a good explaination.

      • The earthquakes appear on the “triple point area” between upper ERZ and Koa’e fault zone. Maybe the very active fault zone is going to move somehow. 1965 there was a vertical movement of 2.4 meters, but movements up to 15 meters are considered possible. https://en.wikipedia.org/wiki/Koa%27e_Fault_Zone

        UWE is inflating, but next deflation may lead to next exciting developments in ERZ.

        • More the point where the ERZ connector goes past the outer caldera fault. The triple point of the ERZ is actually at the bend, Mauna Ulu original fissure was partly in the Koa’e area at the west end although Mauna Ulu itself is a bit east of this triple point. Pauahi seems to be above the point that magma gets stuck here, so maybe not a coincidence that high pressure in Mauna Ulu caused eruptions here, or that the first place to see magma pressure in the ERZ is here too.

          Im interested in Koko’olau crater. Its an actual cone not a pit crater, and seems to be categorized as either being very old (over 1000 years) or as being very young maybe 18th century even. I chose the former on my map as the USGS whole island map does, but it is very hard to actually tell… But if it is 18th century that would infer the caldera was possibly filled nearly to its overflow, even higher than before 2018, to allow an eruption at this altitude. Of course that is still only speculation.

  30. What chemical elements can be found in uncombined form in magma/lava and volcanic gas?
    Sometimes volcanoes produce pure Sulfur as f.e. Mauna Loa’s Sulfur Cone. The diamonds Albert mentions in this article are another example of native elementary minerals. Examples for pure volcanic gasses are Hydrogen, Helium and other noble gasses (f.e. Radon).

  31. Jewels are best worthless objects on the planet next to humans

  32. Interesting viewing on the Iceland webcams at the moment. A lot of steam coming from the previous fissure all along it. It doesn’t even seem to be that cold at around 10c.

    Thermal husafell webam measuring 67c up from 62c as a the very not scientific but interesting thing to watch!

  34. Can anyone identify this submarine volcano? The NASA Firms/Lance satellite has detected a hot spot today Aug 8th 2024 at 05:55:00 am UTC The overlay map shows a submarine volcano almost exactly underneath the hot spot. . The next red spot south is a lava lake or pond in the Tofua volcano which seems to be long-lasting.

  35. Pu’u O’o is starting to feel effects from the recent activity.

    • HVO also has an interferogram of the middle ERZ now too, confirming uplift centered on Napau crater.

      Admin: Image removed because of large size

      Presumably, as the summit refills it will start pushing more magma this way.

      • HVO states: “These observations indicate that magma is accumulating beneath the ground in the area of Makaopuhi Crater and Napau Crater, a well-known magma storage region on Kīlauea’s remote middle East Rift Zone.
        … a magma pathway between the UERZ and upper MERZ has been reestablished and that new magma is being supplied to the storage region near Makaopuhi Crater following the July 22-25 intrusion.” https://www.usgs.gov/observatories/hvo/news/kilauea-information-statement-middle-east-rift-zone-inflation

        After 2018 I didn’t expect an active middle or lower ERZ so soon. The expansion of seismic/deformation activity towards the east has been a bit surprising. But all signs point toward a possible longterm big activity somewhere (including MERZ) that may begin with a fissure eruption between Makaopuhi and Napau like 1961. 1961 the eruption only lasted for two days, but was discontinuously 21 km long. Do we witness the onset of a 60 year MERZ Fires series?

    • Interesting, the tilting is consistent with the Napau uplift, though it must have expanded or moved closer to Pu’u’o’o to affect it, so maybe it’s happening slightly downrift of Napau now.

      • That was one of my ideas, that the sudden appearence of a tilt excursion at Pu’u O’o is from the magma moving slowly down the ERZ. Pu’u O’o is about 13 km from Pauahi, and the recent intrusion was over 15 days ago. So magma moving at roughly 1 km a day or at least the pressure wave is.

        At that rate, we can expect to see JOKA station show a similar tilt reading at the end of August, its a prediction then. Although if the summit refills then magma might get pushed into the ERZ faster.

        If magma does get down to JOKA then it is pretty unlikely for there to be voluminous activity west of Pu’u O’o, although its likely for further eruptions at the summit and both upper rift zones to occur at least up until a shield begins.

        • This year we have seen a lot of magma inflow in whole Kilauea summit, SWRZ, upper and middle ERZ. It looks like a loaded volcano which can do a big variety of eruptions over time. The 1960s showed variable activity from the summit over upper ERZ, pre-Mauna Ulu area (Aloi/Alae) towards pre-Pu’u O’o area (Napau).

          A period of variable locations of minor eruptions may preced the “boss eruptions”.

  36. It looks like a fourth day of construction work near Grindavik, judging from the tremor an drumplots.

  37. New problem with the camera feeds. ALL of them now crash frequently to a Youtube message that just says “something went wrong”. It’s been doing this for two days now.

    How do I get things back to how they were three days ago, in time not to miss the start of the next eruption and without messing up anything else?

    • That seems to be a common problem when running the youtube app on a mobile device, at least judging from the search results when searching for “youtube something went wrong”.

      Any way, it’s not related to the operation of the webcams. There could be many reasons for the problem. Is your app up to date? Have you tried rebooting your device? Are you accessing youtube through a vpn connection? In that case there could be an interruption in the vpn service. Some users have had to restore the network settings on their phones. Others have had to uninstall and reinstall the youtube app. It’s impossible to guess what is causing the problem for you. I hope you manage to get it fixed before the next eruption starts.

      • Why on Earth would I be using mobile, squinting at it through a tiny keyhole, on an app that will bombard me with unblockable ads? 🙂

        This is Firefox on desktop. I’ve found the problem; apparently I now have to whitelist scripts from “jnn-pa.googleapis.com”, whatever that is. Their web site player widget grew a new script dependency for some reason.

    • It would be bad for southern Japan, but Iwo jima (Ioto) is much too far to be affected. The chance of a large quake this week is not high but higher than it was before, enough for Japan to issue a very rare warning. Perhaps copying Iceland in building dams ariound the nuclear reactors?

      • Aso and Aira/Sakurajima are much closer to this particular subduction zone than Iwo Jima.

        What would such a quake do to the real VEI8 monsters of Japan?
        There have been many great earthquakes in that region in historical times, and the volcanoes don’t erupt as often (I think, haven’t actually looked it up).

        • A large earthquake can trigger a volcano that was already close to go. It wouldn’t cause eruption in a dormant volcano. Darwin noted how the Concepcion earthquake he experienced (M8 or close to this) was followed by eruptions in four volcanoes. However, note that land slides are very common with earthquakes and the clouds of dust can look like eruptions. Smoke does not always require volcanic fire

    • To be fair if a megathrust earthquake happens in Japan especially the southern half an eruption at an island 1000 km away is pretty minor no matter the size.

      Not that a possible VEI 7 is a trivial thing but if there was any location to have such an eruption out in the middle of the ocean is probably the best. Yes water exaggerates the explosion but not THAT much. If Ioto blows up even at the worst case unlikely 1 gigaton blast the only thing that will get near inhabited areas is the tsunami, which is probably the most taken seriously disaster of them all, and a much better understood hazard.

      Maybe a controversial or unpopular but I think Iwo Jima is probably the safest VEI 7 we can hope to experience.

      • I am going to have to wholeheartedly disagree with that statement. While it is correct that the tsunami is the only substantial direct hazard from a hypothetical large eruption from Iwo-Jima. It would all depend on the size and scope of the tsunami. long-distance volcanic tsunamis are not respected as they were not taken seriously before Hunga Tonga with some even dismissing their existence altogether.
        There are 3 progenitors of a volcanic tsunami. Landslide, Explosion, or PDC entering the sea from above. If the main progenitor is a large explosion then I could see everything being relatively safe. However, the energy that pyroclastic column collapse and a high-velocity landslide are a full order of magnitude, maybe 2, above what volcanic explosions are capable of. If the Tsunami is big enough, it won’t really matter that it is the only direct hazard.
        Volcanoes in the Aleutians and Kamchatka are the best bet, far from people and critical infrastructure with limited tsunami risks

        • Would counter that the fact we have actually seen a similar eruption with all the effects, means all those hypotheticals arent anymore. Its also not necessarily true an eruption at Iwo Jima will actually be bigger than HTHH in 2022, more volume doesnt necessarily mean a linear increase in explosion. Its pretty likely actually that HTHH was about as powerful as a volcano can be, higher VEI might just be the same thing but it lasts a few hours or days instead of 40 minutes. Which is more of a deflagration than a detonation for analogy.

          I mean, HTHH actually proved that an ultraplinian eruption is a real thing, and that was despite probably being a high 5. None of the VEI 6s of the 20th century were anywhere close despite bigger volumes. It also does bring up Tambora, it was the most voluminous eruption of recent time but I have some doubts its instantaneous power was as high as HTHH, or Krakatoa.

          It is all down to eruption intensity. Its why Kilauea was treated as a tourist attraction but then bumped to US #1 most dangerous volcano. Its why Mauna Loa has the worlds most powerful effusive eruptions, despite none being more than 4% the volume of Laki. Its why St Helens really should be elevated far above being the baseline to compare VEI 6+ eruptions to…
          Eruption intensity is absolutely everything. It is especially the case for hazards associated with oceanic volcanoes. Iwo Jima might erupt big but not really violent, and make no tsunami, where it would be harmless.

          One thing that is concerning, the last eruption made lava balloons, so the magma is relatively fluid. Its not crazy liquid like Hawaii, but enough to degas relatively freely and blow into a bubble, its not a crystal mush, more like a molten glass. More fluid magma means higher eruption rates if it all goes down. HTHH was a basaltic andesite fluid volcano and we know the story there, while nearby Home Reef and Lateiki are dacitic and have both recently (still ongoing) extruded lava domes into the ocean making new islands completely silently. Iwo Jima is inbetween, its recent eruptions are mostly effusive but not silently so. It seems to be a lot like Nishinoshima in magma consistency although not composition.

          • What makes it likely that Hunga Tonga intensity is the peak of volcanic explosivity or intensity? Eruptions like Novarupta, Krakatoa, and Tambora happened so long ago that is downright impossible to compare these 3 to HTHH. Estimations of HTHH were based on detailed data we have atmospheric signals from the eruption. Data that we don’t have for the other 3. Hunga Tonga seems to be king but it may only seem that because we just don’t have a grasp on exactly how intense these past eruptions are.

            Instantaneous explosivity is only one metric of measuring intensity, sustained high ejection rates is another. Haetpe smashes Hunga Tonga to pieces as it releases 4 times as much material as the total HTHH eruption mass in just 5 minutes. It may not have been one big explosion but one wicked portion of high ejection rates.

            Eruption size does have a strong correlation with intensity although it is not absolute and it is also not absolute that intensity will always beat size. The St Helens eruption despite beating Pinatubo in explosivity, destroyed a similar-sized area through pyroclastic flows while Pinatubo had far worse ashfall and lahars. So Pinatubo is still a bit superior to St. Helens in terms of damage potential. A magma chamber primed for VEI 7 will have more pressure, heat, and magma to work with than a chamber of inferior size so it will be easier for VEI 7s to have violent eruptions.

            If Iwo-Jima were to go Caldera, everything would have perfectly lined up for it not to produce a violent eruption. There would have to be no interactions with seawater, no magma mixing, no plug development, and for it to erupt through a relatively weak vent.1 of these are impossible and the other 2 are extremely unlikely. Iwo-Jima is already plugged, it is surrounded by water and has Basaltic Trachyandesite, Trachycite, and Trachydacite. Ryholite and Basalt are likely to be present as well. So the volcano has a huge variety of magma types ready to mix. All causes of highly explosive eruptions could happen at once with this volcano.
            It may not seem like this volcano is plugged but the block has forced a cone-sheet-like intrusion which is causing the current eruptions. I was GOING to write an article about it! But there is genuinely no useful information beyond that.

          • Krakatau I have seen was probably similar to HTHH but longer. Tambora was long enough ago that it isnt clear so that is a good point. Although, I doubt a completely magmatic eruption, even an ignimbrite, would be as explosive as a volcano that has water interaction, HTHH was an ignimbrite and a maar combined into one. Tambora was very likely not, still a big bang but not a nuclear-like instant detonation.

            Novarupta though, it seems was a ‘gentle giant’. Not literally, but the flows stayed in a valley and didnt really go that far all things considered. The eruption was over a few days and not a ring fault ignimbrite like the others. It was still a huge eruption of immense power but you probably could have been pretty close and actually watched it, not at all so with a lot of the others.

            I also think that we shouldnt be absolutely certain of some of the extremes with unobserved eruptions. Hatepe could have been mosty in 5 minutes but we didnt see it and further analysis could give different numbers. HTHH has absolute values.
            In any case it doesnt change that no eruption possible at Iwo Jima is ever going to get more than 5% of the way to the mainland, so the only direct impact will be a tsunami, something that probably nowhere else in the world is taken so seriously. Volcanic tsunamis have much longer reach than expected, probably becahse the only example until recently was in a continental shallow sea not the deep ocean. But still, its nothing compared to 1000+ km of the seafloor lifting up by 15 meters or nore in a few minutes. Iwo Jima isnt going to throw a 20 meter wave at the whole west Pacific coast, likely not more than 2 meters at the highest and nuch less on areas that have shallow shelf seas to break the waves. I think that is something that famous old article from the olden days if VC should have been more cautious on stating.

            Im not trying to trivialize what might turn out to be the biggest eruption for the next 200 years. But I feel like we have all been looking at it like we are counting down to judgement day, when the reality is this is literally about the only place an eruption that big can happen without a huge body count. An opportunity to watch a potential Tambora sized event with the only direct impact being a tsunami smaller than the seawalls of most cities it will see, sounds about as safe as it can be.

          • It is factually incorrect that earthquake tsunamis are inherently superior to volcanic tsunamis. The HTHH tsunami had exactly the same energy as the Tohoku tsunami around 717 kilotons. A medium-sized eruption with high intensity rivals the near pinnacle of earthquakes when it comes to tsunami genesis. Keep in mind that the HTHH tsunami was a blast-generated tsunami, a substantially less energetic event than a PDC column collapse or high-velocity landslide. It is rash and dangerous to arbitrarily decide that HTHH was close to the peak of volcanic tsunamis when the eruption was not even close to the peak of eruption volume and has an unknown albeit high ranking in intensity. The HTHH tsunamis were caused by specific explosions not exceeding 11 megatons.

            A column collapse from a VEI 7 could have energy around 269 megatons of energy and be culpable of producing a tsunami with 13 megatons of energy assuming optimal conditions. A high-velocity landslide worth 150 cubic km3 would be worth around 4 gigatons and could generate a tsunami with 200 megatons of energy. 18x and 279x times the energy of the Tohuku tsunami. With an unreliable sample size for long-distance volcanic tsunamis, we can’t just say our only good example is the peak. The potential is there and Iwo-Jima is not a “safe volcano”.

            In my opinion, I feel as if there isn’t enough attention directed towards this volcano. The volcano has a chamber of unknown size or depth under an intrusion of unknown size which helps feed an extremely shallow sill of unknown size. What could be the greatest and most violent eruption that modern human civilization could ever witness is getting less attention than volcanoes whose impacts are local at the most, I

          • The Hunga-Tonga tsunami in the Tonga islands was induced by pyroclastic density currents that engulfed the entire seafloor tens of km in every direction around the volcano, displacing a volume of seawater. These PDCs cut the internet cable, and likely came to only 10 km from the nearest coasts of Tongatapu and some of the other islands. Outside Tonga there was little damage, only in Moce, Fiji, 380 km away, was there some destruction. In Samoa, 800 km away, and similar locations, closer to Hunga Tonga than mainland Japan is to Ioto, there was no damage at all from the tsunami, as far as Wikipedia goes. In the rest of the planet it was mostly related to the pressure wave, which was similar to Krakatau´s, and bathymetry locally amplified the waves but was mostly a harmless event.

          • Most studies point to the tsunami being directly caused by the explosions and not PDCs
            https://www.science.org/doi/10.1126/sciadv.adf5493
            Even subscribing to the notion that the HTHH tsunami being caused by PDCs, a higher-end VEI 6 or a low-end VEI 7 would be 10x worse and give a Total tsunami energy of around 7.17 megatons. Far surpassing that of any earthquake-driven tsunami barring maybe Valdivia There is no reason to assume that a VEI 7 would be just marginally more dangerous than an extremely low-end VEI 6. As I have already shown, a column collapse PDC or high-velocity landslide, on a bad but still realistic scenario for an Iwo-Jima eruption is on a completely different order of magnitude of energy than the HTHH eruption did and what earthquakes are capable of.

          • Megatons isnt a unit of energy its a unit of mass, it gets used in energy only to refer to a mass of TNT exploding with the same yield as the explosion being released. But setting off 10 million tons of TNT would make a much more powerful bang than a volcanic explosion would, because TNT has a density of 1.7t/m3 and it basically turns into a gas with the same density and a temperature equivalent to the chemical energy density in heat. So a mix of CO2/H2O/N2 that is at a few thousand C and has a density that is higher than any of them are naturally at ambient in any form, wanting to expand… going from 1.7 tons/m3 to 1.7 kg/m3 is a ratio of 1700:1 so TNT exploding is similar to steam but there is a lot more stored energy so it expands a lot faster. Nuclear does all that but with a million times the energy release in the same area, so fast it is basically turning the bomb core into a piece of a star unconfined by gravity…

            Its also, surprisingly, pretty hard to find a yield for HTHH, an eruption we observed exactly. But the most recent number I saw in a search was “between 9 and 37 megatons” so call it about 25 midway. So we cant really be confident in older eruption numbers at all I think. But we can look at wave runup at equivalent distances nearby and HTHH actually isnt less than its two famous 19th century rivals. So I dont really think the megaton yield is very relevant other than to give an energy release number and a comparison to other explosions, it doesnt necessarily scale to effects caused.

            It also is a factor that to actually dump the yield into a wave that will go a long way there has to be sideways force, PDCs either flowing down a slope into the ocean (Tambora) or down submarine flanks. Column collapse into the ocean vertically isnt going to be that efficient. It also still doesnt really change the fact that a landslide tsunami is a point source, where a thrust fault tsunami is a long line. Its going to be really hard to get a dangerous wave height on the continents, especially as a lot of east Asia has wide areas of very shallow sea that would break the waves way out to sea and depending on distance could completely stop it before the coast.

            Iwo Jima also definjtely isnt unknown risk either, just about every video on it by GeologyHub has a popular comment about it blowing up. Just like how now every eruption at Kilauea has people asking if it is safe to go. HTHH was a big change of view, if anything I think most people now have too high expectations of Iwo Jima than underestimating it. As before if there was anywhere in the world to test such an event its hard to find a better place than the middle of the ocean.

          • TNT equivalency is a valid unit for measuring energy as long as whoever uses it remembers it’s not a unit of power Using joules makes no difference in this case. Iwo Jima has a nice and broad slope for PDCs as well and there is some models that point to column collapse tsunamis being the principal cause for Krakatoa’s big tsunami. Tambora and Krakatoa are completely different from HTHH in location. These volcanoes were much farther from the deep sea than Hunga Tonga and their tsunamis were likely not blast-generated. These 3 eruptions are not very comparable to each other beyond intensity.

            I don’t think the shallow areas of sea are relevant to a large tsunami in the water regardless if it’s from a point source. Especially if it failed to stop the HTHH tsunami. Nothing will change the fact that Iwo-Jima is capable of producing a more energetic tsunami than HTHH regardless of what method is used. Why would the hypothetical Iwo-Jima tsunami be as weak as the HTHH with far more energy? That doesn’t make sense.

            I never said that Iwo-Jima was an unknown risk, just the fact there no information on critical details on the size of the magma chamber, sill, or intrusion. Too many unknowns about a known risk. If this is the closest volcano in the world to producing VEI 7, scared comments on YouTube videos, and consistent discussion on volcano blogs are not an overreaction at all. Completely ignoring the Tsunami hazard, the climate impact is more than enough to get concerned about on its own.

          • A point source has a radial decay, but a long line will have parts that are parallel and potentially even focussed, Hawaii had 6 meter waves in 1946 and 1960 from earthquakes in Alaska and Chile, I have seen the markers in person. It also seems that HTHH was mostly a landslide tsunami up close, PDCs going underwater as far as 80 km and parts of the upper clopes actually eroded away. But the waves werent especially long lived, the distant waves were pressure waves from the blast, and didnt do much damage.

            If Iwo Jima does have a directed eruption that could make a colossal wave that way, and that would be a big oroblem if it did so westwards. But decay would probably render it relatively small if it was a radial distribution equally, not harmless but far from record breaking.

            Im really not trying to downplay the risk for no reason, Iwo Jima has the top place on the NDV series because it was considered the most likely place to have an eruption that could have a million body count. But that just doesnt seem at all realistic when the only part of the hazard that will actually do the dirty work is probably the most taken-seriously of all natural disasters. Lots of people do stupid things near volcanoes but very very few people take any chances with floods, be it from the ocean or the land. And especially after 2004. Iwo Jima could be the biggest eruption of the century but it isnt coming close to that, no eruption ever has, and that was only 1/5 of the NDV criterion… Everyone in the Pacific basin gets an instant tsunami warning within a minute of any large event.

      • No studies that I am aware of state that the HTHH tsunami had a landslide component and there is no evidence that definitively says the long-distance impacts of the tsunami were only the result of the pressure wave. Especially considering that the tsunami had just as much energy as the 2011 tsunami.

        If you want to talk about radial decay from a point source, you have to use a function and some detailed mathematics to model the tsunami with specific details on the point source which we don’t have. There is no historical event or formula that I am aware of that disproves a long distance tsunami from a point sources

        • 2011 tsunami actually is a perfect example of why Iwo Jima wouldnt be a million count event… Despite being a 9.0 quake the waves were pretty small in Hawaii, where other Pacific tsunamis have been devastating. 1000 km away from the epicenter on maps it was usually about 1/10 the peak height offshore. And that is with a linear generation so certain directions have longer reach. That isnt insignificant but its not beyond the scale.

          Its also kind of confusing why you state Krakatau and a hypothetical similar Iwo Jima eruption would have landslide generated waves when that isnt actually conclusive (and in one case hypothetical) but say HTHH had an explosion generated wave when we have direct observations of it in the act and good evidence that it was landslide related through bathymetry…? The intensity of the eruption does also matter, Iwo Jima might have a 10x bigger eruption but if it isnt also at least 10x faster then the power to make waves is no greater. The fluidity of the magma is important in that, more fluid magma has higher flow rate in the same space. HTHH has fluid magma so could well be at the high end of intensity for given volume. Tambora has a lot of evidence for being very similar too. Iwo Jima is not especially viscous for being a trachytic volcano but the lava isnt what I would call fluid. Unless it is gas rich it might have a hard time erupting faster than HTHH even if it goes 100%. The recent eruptions dont appear to be particularly explosive, degassing and some fragmentation on top of a lava flow that is mostly submerged.

          • I never said that the Krakatoa tsunami was landslide generated, I just stated that it’s a possibility for this volcano. If you point me to a study that says that the HTHH tsunami was landslide-generated. I’ll give it a read, The 2011 Tsunami had the same energy as the HTHH tsunami. The volcanic eruptions can go far larger than HTHH while maintaining similar levels of intensity.

            None of these arguments truly debunk or invalidate the possibility of stronger volcanic tsunamis. Why would an Iwo-Jima eruption have to be 10 times faster than HTHH to make stronger waves? What basis does that have? An Asteroid 10 km wide will always produce a bigger explosion than a 1 km asteroid at the same speed. It is not just about speed for tsunami genesis it’s about energy and displacement and speed is an important factor but only because it factors into the 2 cores. Why would a 1e+14 kg of material (either through a landslide or PDC) moving at the speed of sound be incapable of displacing and inject less energy than the same event of inferior mass while moving at the same speed? That doesn’t make any sense.

            The Haetepe Eruption was almost completely felsic and was an undeniably violent eruption with the most intense PDCs known from a non-VEI 7 eruption. All magma is capable of producing intense and gentle eruptions. The current eruptions and their surface-level behavior have nothing to do with the intensity of a future explosion. For years, HTHH produced unremarkable eruptions up until it didn’t. The magma that’s erupting now is degassed and not representative of the magma that would erupt in a VEI 7.

          • I think you are severely understating Hunga Tonga. The tsunami killed people 10,000 km away. It did massive damage within 100 km, and we were very lucky there that the direction of the main tsunami missed the populated islands. In Hawai’i, the areas worst affected by tsunamis (bays) are directed away from HT so that is not a good comparison. The waves in Japan were 2 meters high, I believe. It is 8000 km away, which is about the distance where the tsunami reaches minimum. Now imagine an eruption 5-10 times larger and 7 times closer. No, Hunga Tonga showed us the danger of HT-like eruptions rather than their harmlessness.

            Kuwae may have caused massive tsunamis in Australia, but that was doubted by many. The doubt whether it was at all possible should have been removed by Hunga Tonga.

          • Im not sure if you two are both trying to argue tangents to what I am talking about but I think you are missing the point I was originally making, which is that an eruption of Iwo Jima isnt going to single handedly count us down to the apocalypse, im not trying to present a calculated thesis on the probability just a casual realistic look, not the worst case scenario.
            If it does erupt, no matter how big or fast or whatever, its only important part is the tsunami, which isnt to be underestimated but it is a singular hazard, the volcano itself may as well be ignored. Provided that the waves are reacted to appropriately the eruption could be a historical biggest yet with no fatalities, which is a completely reasonable expectation as it being a megadisaster.
            The disaster of 2004 made it certain no event like that would ever be so bad again in living memory, and as a result the potentially very similar 2011 quake was relatively much less severe, very damaging but far fewer lives lost.

            It also, really, does need to be considered fairly that Iwo Jima might not do a VEI 7, or an extremely violent eruption. Those are just assumptions, at the moment realistically Iwo Jima is hardly even interacting with the ocean, something that HTHH was a lot more obvious with in erupting. And in the case of Hatepe, the TVZ volcanoes are very felsic with very high water content in the magma itself, they are extremely explosive even by world standards, not the norm. The way Iwo Jima is erupting now doesnt give the impression of a volcano that is a pressure cooker on the brink but it is leaking out. That doesnt mean it wont all go up but it does matter for how fast and powerful.

            Im just looking at this myself and drawing my own conclusions. Sometimes the scientific method is too specific and doesnt make logical sense. To me Iwo Jima is clearly a big risk but everyone here seems to be taking that extreme end as the given and running with that from there. The worst case scenario is, realistically, the same as a mag 9 quake tsunami but you get an hours warning of the wave instead of a few minutes, and no quake damage associated. We have already seen worse, and as far as potential VEI 7s go you can put them in a lot more destructive locations very easily.

          • I don’t think we’re missing what you’re saying correct me if I am wrong but you’re saying that
            1. Iwo-Jima is not going to produce a strong enough long-distance tsunami to damage threaten Japan or China.
            2. The volcano is in a safe location for an eruption.
            3. Current eruption doesn’t support a future violent eruption
            4. A lot of people here use the extreme scenario concerning the future of Iwo-Jima
            To those points, I’ll say.
            1. There is no evidence or model that proves Iwo-Jima or any other volcano are incapable of producing a powerful long-distance tsunami.
            2. With the point above this means that this volcano isn’t in a definite safe place.
            3. The current eruption behavior does not speak to the condition of the whole volcano. Caldera-forming eruptions often start small and weak.
            4. A lot of us here use a higher-end VEI 6 to a low-end VEI 7. This is definitely not an extreme scenario. A higher-end VEI 7 to VEI 8 is technically possible since we don’t know how big or pressurized the shallow chamber is. Unlikely as it is it is not an impossibility.

            The impacts of an Iwo-Jima tsunami depends on how big it is and how seriously the people take it. I’ve seen people ignore or downplay these types of warnings. Japan in 2011 was the most prepared country for quakes and tsunamis but they still ignored warnings, ignored the data pointing for higher walls and got the most damaging natural disaster as a result. Just because 2004 happened and awoke people to the threat of tsunamis doesn’t mean that the right decisions in the case of most future tsunamis

          • Generally yes, but not exactly.

            I think that a tsunami hitting the west Pacific coastlines wouldnt be worse than an earthquake tsunami in size. And unlike one of those, it would give at least an hour or more of warning if the eruption is seen, and there is no local earthquake damage to compromize structures. Im a bit sceptical a tsunami is going to do much to modern megastructures, especially if a wave is broken far offshore and hits slowly, which of course is very situational.

            I do think that anywhere that entirely negates all but one of the numerous hazards of a VEI 7 is a reasonably safe place to do one, yes…

            The eruptions of Hunga Tonga before 2022 were nearly always surtseyan and quite powerful, it never entered an effusive stage. There was obviously water interaction but the magma was pretty volatile alone too. The eruptions of Iwo Jima have a mostly effusive character, with some magmatic explosive activity and seemingly very little water interaction. Doesnt mean it wont blow up but theres probably a higher threshold to reach to do that. It would make sense, given Iwo Jima has a larger caldera and wider intervals, it would be harder to trigger. Kilauea began runaway collapsing with 5% drained, so for a VEI 7 you would need a VEI 5 as a trigger most likely with the same rough ratio. Doesnt appear to be very close to that as yet.

            Im going on the assumption most people arent idiots who will ignore a warning. I know it is an unpopular opinion here for some reason, but people like to say a lot of things but will act differently in reality. I guess, that is something none of us know for sure and cant until it happens.

            I think a VEI 8 is impossible here. Would need to have a 10x10x10 area of melt ready to go up. Magma seems to like to spread out before getting deeper, VEI 8 calderas are always really wide for depth. But a 2x10x10 area is entirely reasonable with the way magma chambers seem to form and that could get a VEI 7 that is bigger than Tambora. But a VEI 6 is generally a more likely option in the face of uncertainty.

          • It isn’t guaranteed that the HTHH eruption was principally caused by water.
            https://www.livescience.com/planet-earth/volcanos/record-shattering-tonga-volcanic-eruption-wasnt-triggered-by-what-we-thought-new-study-suggests

            You can’t just say that VEI 8 is impossible here when you have no metric for the size of a magma chamber. The area of the chamber could be the same area as the volcano, at around 1,200 km2, we could easily get 12,000 km3. For 800 km2, 8,000km3 or 400 km2, 4,000 km3. We can throw as many arbitrary numbers as we want but it won’t change the fact that we don’t know how big it is. Extremely unlikely? Yes.

            I am saying from my experiences with hurricanes, floods, and tornadoes. That people don’t warnings seriously unless they can see what’s coming. Every time a city floods, there is a bunch of idiots who will drive in fast-moving water and need to be rescued keep in mind that my city is notorious for the country’s deadliest and worst floods. When a hurricane hits, people are surprised to see damage. “Can’t believe this is happening!” When a Tornado warning is issued people will automatically assume it’s weak up until they can see it’s strong.
            Tsunami warnings are common and from the perspective of an average person who would be in the crosshairs of an Iwo-Jima tsunami. They won’t know how dangerous it is up until it hits. There is no model for any tsunami scenario for Iwo-Jima so these people won’t even know what to expect. Sending a warning is just one part of warning people, you have to give them a good view of what you can expect.

          • This is not a VEI-8 volcano. Those events happen in very different environments and a VEI-8 is not a very large VEI-7: they are a very different style of eruption. See https://www.volcanocafe.org/super-eruptions-and-hyper-eruptions/ and https://www.volcanocafe.org/power-of-the-past-25-super-eruptions/ .

            Krakatau was VEI-6. HT was 5.8 to 6.0. But Iwojima has had massive eruptions in the past with thick deposits and it has created a significant caldera. I would think it could erupt quite a bit larger than HT or even Krakatau. The comparison is Kuwae 1458, which is a possible VEI-7 but we don’t know too much about it. It has been associated with a 30-meter (run-up) tsunami in Australia and with the collapse of Pacific trade around 1500.

            In fact, we have ignored the potential of these type of eruptions. For HT, the energy was much higher than it would be for a land-based volcano of the same eruption volume. That already is a warning sign. It is very unlikely that HT is the largest that such eruptions can get.

            In the end, the large inflation lasting over centuries is the reason Iwojima drew attention. HT has now added urgency.

          • Albert, Hunga Tonga tsunami was not that powerful. There are many islands close to Hunga Tonga where as far as I’ve seen the tsunami had no impact at all. Niuatoputapu has coastal settlements and is only 500 km away from Hunga Tonga and there was no damage as far as I’ve been able to learn. Tokelau and Tuvalu have several populated atolls, with settlements at the edge of the atolls and at sea level ~1300 km from Hunga Tonga and in the direction to get the worst hit possible due to bathymetry of the Lau Basin, and again no mentions to any tsunami damage as far as I can find.

            Hunga Tonga was not a point source tsunami, at all. Submarine pyroclastic density currents make tsunamis as any submarine landslide would. And these currents came to 10 km or so* of some of the coasts of Tonga, so the tsunami generation mechanism were right in front of it, and same as with Krakatau or Tambora were locally devastating. Substantial tsunamis in the far coasts of the Pacific were mostly due to a meteotsunami. Due to Hunga Tonga there was even a 50 cm tsunami in a harbour here in Spain, in the Mediterranean, a particular harbour that is susceptible to pressure changes in the atmosphere and that has been known to produce tsunamis with the passage of strong thunderstorms (Ciutadella de Menorca). So the atmospheric pressure waves made tsunamis along their way, across the globe, mostly too small to cause damage.

            *Edit: Looking at bathymetry better, pyroclastic density currents reached up to 17 km away from Tongatapu coasts where tsunami had 19 m run-up, 23 km from Nomuka Iki Island where run-up was 20 m, and ~35km from Tofua where run-up was 20 m. But in Neiafu at 260 km the tsunami was smaller than the tide, as happened in Samoa, so the tsunami due to pyroclastic density currents was relatively local. Only in Moce, Fiji (250 km away) was there some damage, probably amplified by the U shape of the atoll with Moce at the end of the U, and run-up must have been less than 10 meters.

          • The disparated appearance of the tsunami in different places has been commented on in papers. The underwater flows may have contributed but the tsunamis were reported to have arrived within 20 minutes while those flows took twice as long: the flows did cause damage but were not the sole cause of the tsunamis. A megathrust is worse because it extends over a long line. This means that the wave height decreases less fast than that of a point tsunami.

            https://www.nature.com/articles/d41586-023-01272-x

          • In comparison the run-ups of the 2004 Sumatra earthquake tsunami reached up to 51 meters in nearby Sumatran coasts, 20 m in Thailand, 10 m in India, and as far 5000 km away (in Somalia) there were 10 meter run-ups:

            https://sos.noaa.gov/catalog/datasets/tsunami-wave-run-ups-indian-ocean-2004/

            So megathrust tsunamis are A LOT worse, because of how quickly energy is released and how much of it goes into ocean waves. Hunga Tonga was about as intense as eruptions get in normal calderas, to get a substantially bigger tsunami an eruption of Taupo intensity or better yet Mangakino intensity would be needed, I think. Maybe Ioto can be a bit more intense than Hunga Tonga but I don’t see any obvious reason why, most ignimbrites are quite similar with pyroclastic flows reaching 30-40 km over relatively flat ground around the volcano center, an intensity like that of Oruanui or Hatepe is for very very large rhyolite calderas.

        • I will concede that Iwo-Jima doesn’t have the traditional markings of a VEI 8 volcano and I wasn’t trying to say that Iwo-Jima is going to pop off like that but that it’s technically not impossible.

        • Hector, Why would a VEI 7 need to be more intense than a low-end VEI 6 to produce a bigger tsunami? Where’s the precedent, models, or formula that proves this? The HTHH tsunami took place in a geologically complex area and the environment limited run-up heights in certain locations and areas. It has not been definitely proven that the tsunami was generated by PDCs. Simulations with the pressure wave tsunami don’t line up with the run-up heights along the coasts of the pacific. Studies in fact segregate the 2.
          https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JC020926?af=R

          • The following article finds the Lamb (the global atmospheric wave) of Krakatau and Hunga Tonga to be comparable, and also mentions the arrival time of tsunamis consistent with coupling with the atmospheric waves.:

            https://www.science.org/doi/10.1126/science.abo7063

            Blue is Krakatau, black is Hunga Tonga, amplitude of the Lamb wave is practically identical despite Krakatau being 4-5 times bigger than Hunga Tonga in terms of volume. So at least the meteotsunami won’t clearly correlate with eruption size:

            That s because the total volume is not released at once, you can only put energy into the amplitude of a wave within a certain timeframe, be it a Lamb wave or a tsunami, and eruptions likely last longer than this timeframe. It’s to be presumed that Hunga Tonga released as much energy per unit of time as Krakatau.

            The distance reached by a pyroclastic density current is related to eruption rates, for example Hatepe and Oruanui eruptions of Taupo have the same PDC distance (some 80 km) despite Oruanui being 50 times more voluminous, but of course the mechanism is similar, composition the same, caldera geometry and as such ring dike opening the same. So same conduit same magma is a similar eruption rate just that the reservoir was a lot more filled up with magma before Oruanui so it went 50 times longer.

            That’s the way I see it, I may be wrong, and certainly I’m not the one who decides whether the coasts of Japan and China should prepare for evacuation or not, so I can express my opinion with no responsibility, and that is that I doubt caldera eruption tsunamis can get much worse than what Hunga Tonga did unless you deal with a giant rhyolite caldera like Kikai or Taupo, or whatever strambotic experiment of the TVZ Mangakino was. I should also say that a Hunga Tonga scale tsunami could still have devastating effects in the Ogasawara Islands, home to 2000 people, and only 200-300 km distant from Ioto,

          • It is true that intensity would be the crucial variable for meteotsunamis, I can’t argue with that. I will say that the Haetpe Ignimbrite was formed through plinian column collapse and Oruuani Iginimbrite seem to be straight from the vent. So I don’t think these situations are comparable. There is no model or data that proves or disproves the existence of strong long-distance volcanic tsunamis my point is just that it is rash to dismiss their existence considering the energy of that high-speed landslides and Column Collapse Pyroclastic flows.
            I doubt Japan gives a damn about Iwo-Jima since there is no information about the volcano’s internal system or warning plan for Ogasawara islands

          • Landslides may be a different matter given that the can involve a much larger displaced volume of water in a very short timeframe where it can go into a massive wave, in Hawaii there are suspected tsunami deposits that would have been produced by hundreds of meters tall run-ups, of course this is an extreme. That said landslide tsunamis should be pretty straightforward to model, surely that has been done many times.

          • The models for Krakatau 2018 ( a landslide tsunami) were pretty accurate, and that was years before it even happened. It makes a difference whether it is in shallow or deep water, whether the slide is slow or fast, and whether it enters the water or is full submerged from the start. But in all cases, the main parameter is the volume of water that is being displaced. A megathrust is also very similar to a landslide: the tsunami is started by the vertical ground movement, not by the shaking. I think that a flank collapse played a role in the Krakatau 1883 events. For submarine eruptions, the volume of vaporised water does the same, but it matters what fraction of this volume goes straight into the atmosphere and what fraction displaces water. (It also excavates rock, of course, but the volume of rock may be similar to the volume of water vapour that excavates it.) If the explosion is magmatic, then that volume should be added to the tsunami.

    • Hope it pops soon otherwise will be looking at a pretty significant eruption for the area.

      • The authorities seem to think so. I just checked RÚV, they had this a couple days ago:

        Magma under Svartsengi nears upper limit, but uncertainty is great (7 Aug)

        Benedikt Ófeigsson, an expert in the field of earth’s crustal movements at the Icelandic Met Office, says that the magma gathering under Svartsengi reaches the upper limit of what is believed to be needed to trigger a new magma flow, or eruption, by the end of next week.

        So stay tuned!

    • Thanks Andy for the AfarTV cam link, it’s a PTZ cam, nice!

      (Also thanks, everyone, for the info on Iwo Jima.)

      • Your simple question probably just sparked the biggest volcano debate of the year! Thank you.

  40. Pu’u’o’o is now having some earthquakes, and the deformation in the tiltmeter is quite fast. Magma is definitely moving under Pu’u’o’o. Will it keep going downrift? Next comes the MERZ, which is a massive storage with plenty of room to fill. Problem is it can also supply intrusions toward populated areas of the Lower East Rift Zone.

    • If we look at eruption history 1961 the 21 km long eruption fissure went from Napau beyond (downrift) Pu’u O’o. On page 33 of the following report you can see a sketch of this fissure: https://pubs.usgs.gov/pp/0474d/report.pdf
      It’s possible that the first eruption of a MERZ Fires Series begins with a short lasting, but long line of fissures with lava fountains.
      Again the 1st episode of Pu’u O’o built a long line of lava fountain fissures. The line of fissures went from Napau to Kalalua. This map shows the position of the first fissure eruption:

      So it’s probably that again magma will intrude into the whole (and low) MERZ beyond Pu’u O’o’s shield, before the next long fissure eruption is going to happen.

      • I agree that we will probably see magma and inflation all along the middle ERZ down to where JOKA station is. But if magma is under Pu’u O’o now it is moving east about 1 km a day, so it isnt going to be all that long before this scenario actually occurs. And based on how fast some areas have uplifted, the last 3 years of subsidence of the ERZ seems to be just related to lack of magma input, not magma going back to the summit like was hypothesized in 2020. I dont think there is much space to fill. If a shield was to form near Heiheiahulu then it doesnt require the ERZ to recover to pre-2018. Pu’u O’o started before Kilauea had recovered from deflation in the 1975 quake, and 2018 was still way lower than that again too. Move east and it seems to be increasingly more magma supply rate not magma pressure that is the important factor.

        https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcT6xqBFtE-S5zGRuLFyPjZN-Xq8cQJasoE_xCcPxS_63P7QaC-KDEaNimJx&s=10

        We arent ready yet for a shield to form west of Pu’u O’o, but I think we are east of Pu’u O’o. Question is if the supply rate is high enough to keep magma flowing that far. I think it is, based on magma getting past Pu’u O’o before 2018 and inflation and sill intrusions near Heiheiahulu as recent as 2020. We will know more certainly in a few weeks I think. After that, it depends on rate of uplift, but if JOKA goes up as fast as the stations at Makaopuhi and Napau, or the summit before late July, then we are looking at a year max before it erupts. Thats my prediction.

        • Kilauea whole tilt record at Halemaumau up to late 2023. So this actually doesnt show any of the crazy uplift that has happened in the last year. The present point might well be twice as high as the end of the line on the picture which would put it near the 2018 point, if the tiltmeter shows similar scale as the GPS does. Just today though it also looks like it might have finally reached its maximum, with deflation now occurring, and the ERZ is now in charge again.

        • In my opinion Kilauea has a big variety of options how it can erupt on MERZ during 21s century. We can’t know what it will do. But the beginning of the series is probably a “Curtain of Fires” eruption like 1961, that ends before a central vent can appear.

          • Will almost certainly have one or more long fissures first but I think that within a few years there will be a preferred location. It took only 8 years in the 60s, with probably half the supply rate of now or less. But the first intrusion probably will give an idea where a shield will probably form. An intrusion from Napau might happen pretty soon but if magma can still freely go east then it might take a while for something to break. But still, my guess is a dike somewhere before new years, probably with at least a bit erupting somewhere.

          • During 18th century the majority of MERZ lava flows occured in the same area as 1983-2018 Pu’u O’o, but with shorter ways and fewer square kilometers. This area is the heart/center of MERZ, where usually the majority of eruptions happen.
            So we can be nearly certain that also during next decades the majority of MERZ activity will be in the greater Pu’u O’o area (from Napau to Kalalua). But extent and duration of eruptions is uncertain.

            September 1961 to 1967 the summit did no eruptions. During this time the lower MERZ (Napau to Kalalua) was predominantly active with three eruptions. Activity there has apparently a negative effect on the summit. After 1967 (summit eruption) the main activity moved towards Mauna Ulu area, and at the same time the summit got more activity. Active periods of Mauna Ulu support activity in the summit region, including parts of upper SWRZ 1971 and 1974.

          • I think that having the tall shield of Pu’u O’o there now will make it more complicated, it will either force eruptions to be in the immediate area of Napau or to happen further east. There are few eruptions directly on the flanks of Kanenuiohamo that is a 1000 year old shield, eruptions happen next to it and vents directly on it are small. Pu’u O’o is at least as big and is wider too. If a long fissure opens up it probably will cut through Pu’u O’o but I would be surprised if an eruption can center there unless it goes right through the crater but even then it is unclear. East of Pu’u O’o it is around 400 meters lower than the summit lake, if magma gets that far passively it will be hard to not favor this area I think, the next few weeks will be important.

          • On the google map with physical geography (altitudes) the shield doesn’t look very high. How tall is the shield approximately? The liquid lava allowed a fast transport towards the coast and to cover a giant area (144 square kilometers) that could nearly cover the whole principality of Liechtenstein. If we distribute the 4.4 cubic kilometers evenly on the whole area, we get an average thickness of 3.1 cm or 0.031m. Maybe a height of 200m on the shield’s peak is realistic.

            How much aged magma is still there from the 1983-2018 eruption? During the collapse 2018 some went gone, but the Pahala eruption 2018 showed, that sometimes there remain pockets of “forgotten” magma in small chambers. Maybe this and subvolcanic rock (usually harder than lava basalt) will influence the opening of a fissure eruption. But it will be interesting to see how a long crack with fire and steam opens through the Pu’u O’o shield. 1084 the “Curtain of Fire” eruption of Mauna Loa split the 1949 spatter cone in the caldera: https://www.usgs.gov/media/images/mauna-loas-summit-shows-cinder-cone-and-lava-flows-w

    • GPS station R931 (eastern border of Pu’u O’o shield):

      ?fileTS=1723245219

    • Looks not all that different to before, the densest concentration is the same and the long lived cones are at the center of the line just a bit south of there. I dont think the eruption will be inherently biased southwards, the danger is that each sequential eruption seems to be more intense, which brings both bigger and faster lava flows but also faster dike propagation and possibly longer fissures.
      I doubt any eruption is going to center anywhere nearer to Grindavik than the last two already have, that seems to be the central point. But all it takes is a fissure to open inside the wall with high eruption rate and it could be all over, and that is a real possibility now…

      • Chad:
        If you look at the map, there is a butterfly pattern of the stress fields, centered near the highway about 135 degs to Mount Torbjorn. This would indicate a possible more southern fissure eruption location. We also see a lot of quakes just north (NNE) of the current fissure cones, but I am taking that at indicating possible re-emergence of the new fissure near the past two occurances. I agree that a high flow rate fissure inside the berms means all human efforts have been in vain. We’re stuck right now and have to wait on Mother Nature to do her thing.

  42. The NASA/Firms satellite does a good job of keeping up with small volcanic eruptions on islands. Yesterday there was a brief offshore eruption to the west of San Benedicto Island, then today Heard Island, near Antartica had a brief eruption.

  43. Again I’m only going off vafri quake, but is ljosufjoll having an eruption? Massive earthquake swarm there past 2 1/2 hours. For those that are a bit baffled, it’s the eastern end of the Snaefellesjokull peninsula rift area, just west of Prestahnukur.

    • Andy:
      I would say that no volcanic eruption is occurring. The IMO office is pretty much on top of things and they’d issue a bulletin on this fairly promptly. This most likely is tectonic but perhaps in release to some magmatic pressure underneath.

      • I think it is most likely a magmatic intrusion which is pretty interesting as there hasn’t been an eruption there in a thousand years. Quite intense swarm.

        I’m not on social media or anything but can’t see anything online about it yet so will wait and see.

        • Ljósufjöll has slowly been showing signs of awakening in the last few years. This is the most intense swarm I have seen so far and it certainly looks magmatic. This is not to say an eruption is imminent. It could take decades of unrest before it finally pops, or, since this is Iceland, it might throw a curveball and erupt tomorrow, but I don’t find that very likely.

        • Last eruption there was in the early part of the last Reykjanes cycle though, which might not be completely coincidental. Reykjanes is after all literally where the MAR is, it would be logical to assume stuff happening there has a big impact on other places. I think it has maybe been underestimated a bit in that regard.

          If it does erupt then its going to be pretty visually spectacular. Eruptions here have very fluid lava like Reykjanes, but it is more alkaline and more volatiles, most vents are cinder cones, like the cones at Bifrost, or Eldborg which looks extremely similar to Fagradalsfjall 1 as does the 900s eruption flows. And the actual spot active now is under a mountain, so fluid lava flowing down a steep slope, which is always nice to watch 🙂

          Also logically, if it does go, then we will very likely have two volcanoes go together and both visible from Reykjavik.

    • During the Medieval Reykjanes Fires an eruption occured at Ljosfjöll. Not very big, maybe in size like Fagradalsfjall 2021.
      Activity on the Reykjanes Peninsula may be accompanied by increased activity at neighbouring systems. But – from human perspective – this activity will happen very much randomly. We don’t know whether Ljosfjoll, Langjökull or Hengill will erupt.

      The worst case (and rarest case) of Ljosfjöll is a Ryolith eruption. During glaciation there was a subglacial Ryolith eruption. “The most recent eruption of this type occurred during the late Pleistocene (>11,500 years ago). Frequency of this scenario is estimated as once every 100,000 years. Duration of eruption is unknown.” https://icelandicvolcanos.is/#

  44. What the hell? Between 13:00 and 16:00 (Iceland time) the number of comments here went down from 208 to 207.

  46. Noting the debate about how bad a VEI7 at Ioto would be: seems to me the real danger with a VEI7 is what it does to the atmosphere and the climate, rather than the explosion, tsunami or other near term effects. Most of the fatalities from Tambora were due to crop failure and famine.

    Though it might improve the weather, the way things are going of late.

    • That’s true but it’s really not worth debating at the moment. Volcanic climate impacts are already hotly debated and there is so much uncertainty about aerosol microphysics, potential boosts and debuffs from ACC, background climate factors, and more. That it’s just pointless to argue. It all depends on which one of the published opinions or hypotheses makes sense to you. We won’t know the SO2 load until it happens. It could have 2 million tons or 200 million tons of SO2.

      • The mechanisms are debated, but one of the clues they use to unravel mystery eruptions, along with tree rings and ice cores, are historical reports of volcanic haze and weather disruptions.
        It happened with both Tambora and Samalas. It is an issue with VEI7 eruption if not always with VEI6. Same with other events that show up by the same methodology (tree rings, ice core sulfates, historical accounts of strange weather, crop failures) for which a volcano has not yet been identified.

        I suppose there could be a VEI7 that doesn’t affect the weather, but would it really be a VEI (explosive) 7 or just a giant effusive eruption? It is also possible some of the not-yet-identified mystery eruptions weren’t that big.

    • I think we are still getting a live view of the effects of a powerful eruption near sea level. It seems that the amount of water vapor in the stratosphere is the most important factor unless the magma is very high in another volatile. Iwo Jima is a more alkaline volcano with trachyandesite and trachyte, which can sometimes fit the latter (Tambora was trachyandesite) but I dont think it is a rule so much. Even at that, HTHH and probably also Krakatau show that most of the ash doesnt get high and might not even really leave the ocean, the blast is mostly water. So its possible such eruptions scrub themselves of potential SO2, but throw up immense volumes of water. HTHH was a caldera formation combined with a maar. It actually does fit a bit of the mechanism in Hectors old Big Basalt Blasts series. I think this also could apply to some other very violent eruptions, like Taupo which is a deep lake.

      I think there are still too many variables to be able to properly predict affects but maybe subaerial high altitude eruptions have a general cooling effect based around SO2 and maybe suspended ash, while shallow submarine eruptions could have net warming from H2O.

      • The most recent models indicate that HT caused a small cooling worldwide, not warming. Krakatau produced a fair amount of sulphate in the stratosphere: the coloured skies were seen for years afterwards. It also led to a small cooling, significantly more than HT did. The two eruptions were different. The atmospheric energy was comparable between the two, but the ash volume ejected into the atmosphere was different. Krakatau’s tsunami was confined in a narrow sea but did affect the African shores of the Indian Ocean. It also hit Sri Lanka. The 2004 tsunami was of course much worse in that respect: Hector is right to point out that comparison. Such a tsunami requires a M9 earthquake but those are still more frequent than a VEI-7 volcanic event. How much of the Krakatau and HT tsunamis were meteo rather than volcanic (or landslide)? It is hard to tell. Arrival times suggest both played a role. In the worst case the two are in resonance and amplify each other.

        I do not buy the argument the HT was the worst a volcanic tsunami can be. We have had two comparable events in 150 years. That is hardly enough to know! Assuming that the worst recent event is the worst that can happen is exactly why we lost the Fukushima reactor. A pebble bed found across northern New Zealand 32 meters above sea level has been dated to approximately the (presumed) Kuwae eruption of 1453. That is unproven: it may have been ‘just’ a megathrust nearer to New Zealand, but it needs investigating. And may I point out Santorini?

        Most volcanic arcs are on land (Japan, Indonesia, Americas). But there are exceptions (Kuril, Tonga, Greece, Caribbean) and those volcanoes are severely understudied.

        Climate impacts of a major eruption are also a danger. We have not seen this since Tambora. Quite a few cultures or even empires disappeared at the same time as a major eruption. We can’t continue to rely on luck, whether for tsunamis or climatic eruptions. Both should be taken seriously – but also realistically.

        • Also in terms of the tsunami, I’m not sure how relevant a lot of the Hunga Tonga results are. Looking at some of the heights relatively close to further away, pretty clear coral reefs had to have done a lot to break the height of the tsunami. Without them Tonga, etc would have been hit much harder.

    • Climate effects would only be shortterm weather effects like Pinatubo 1992. One or two years with cooler climate, then it’s over. Peanuts compared to Greenhouse Effect. A VEI 8 (super eruption) might be different and last for some years with “volcanic winters”, but would end relatively soon as well.

      A different aspect are weather effects. Volcanic Plinian eruptions put particles (tephra) into the atmosphere that facilitate the formation of clouds … and rain. Has this effect been examined? But also this effect would be a shortterm and regional phenomen.

      • Intense Short-term effects are nothing to scoff at. A few years of intense enough cooling is enough to cause massive famine.

  48. The last 2 or 3 days I have noticed that significant degassing is occurring on the latest fissure flow field. This might need attention. I wish that there was someway to measure the SO2 output over the whole field as I believe that this might be an predictor of the next fissure eruption. See

    • That is at the margin of the latest lava tongue that went towards Fiskidalsfjall. It’s far away from the actual fissure and is probably just the easiest path for gasses to escape from the already erupted lava.

      • Heavy degassing now in multiple areas. middle of the rift too but seems to be mostly the southern areas. I don’t know why but Randall is correct that last time the same thing happened and very close to the time of the eruption.

        • Could it be from hhe increasing number of quakes? A bit like shaking a bottle of coke, relasing the gas?
          I think we’re a matter of hours or days away. It’s gone quiet at the moment.

        • With all respect, I think that’s just down to confirmation bias. We know that an eruption is about to happen any time, so we pay extra attention to details that we believe to be important, ignoring the fact that the amount of steaming goes up and down all the time due to weather.

          Go have a look at these timelapse videos. Notice how there has been heavy steaming the entire time, with some variations due to weather.

          https://livefromiceland.is/timelapses/fagradalsfjall/2024/07/25/

          • With all respect, I was talking about degassing, the blue haze, not the white steaming which increases with rain.

          • The blue tint is there also in the timelapse videos and it also shifts with shifting lighting and weather. Once magma is close enough to the surface to make any difference, it will erupt in minutes, not days.

          • I’m not suggesting that degassing is anything to do with the impending eruption. I was suggesting it could be due to the quakes shaking things about.

          • Didn’t say that either. The reply was meant for Alice, but you managed to sneak in a reply as I was typing.

            I doubt that the microquakes will affect the degassing at all. I think it’s all about the amount of rain in recent days, dew point, lighting conditions and wind speeds.

          • Yes, I totally agree. That’s why I mentioned wind speed 😉

          • Thank you for your comments, Tomas. I trust you agree with me that if we had someway to monitor the total SO2 output over the whole field, this might, and again I say might possibly indicate the nearness of the next fissure eruption. I did carefully watch several hours of the videos of the steaming fumeroles, taking into account the humidity and temperature which greatly affected the visual situation. I also noticed that the sudden increase in steaming occurred less than 1.5 minutes before the lava broke to the surface. Basically your comments are correct. I tried to be carefully to be open here and I was aware of confirmation bias.. as it so easily sneaks in.

          • No, I don’t think the SO2 output of the lava field is a good indicator for the next eruption.

            The way this thing builds up is not by accumulating magma that slowly gets closer to the surface in one of the fissures. Instead, it accumulates in the sill under Svartsengi until the pressure is high enough to set things in motion. When that happens, magma immediately starts rising from 5km depth through the feeder near Sylingarfell. In about one hour it reaches the surface and starts erupting. During that time, there are earthquakes every minute and rapid deformation that can be seen in real time GPS measurements.

          • Gas may play a role in this. Once a small opening exists, gas can come out which reduces the pressure at the top of the magma column. More gas forms in the magma and a stream of bubbles moves up, pushing the magma with it. This may be why these eruptions begins with vigorous fountaining. So I would not be surprised to see gas emanating from the spot in the minutes before the start of the eruption.

          • Yes, that seems likely, but that’s in the minutes before an eruption, when we already have earthquakes and rapid deformation as a clear sign that it’s about to start, so it would add little extra warning time.

        • I noticed some more Vatnajökull earthquakes last days, maybe a life sign of Grimsvötn. GPS showed some minor movement recently, but there has to follow more to let it be significant.

    • Often eruptions of Svartsengi and Fagradalsfjall were preceded by minutes of degassing/steaming, but the Curtain of Fire followed very quickly and expanded explosively. As long as this doesn’t happen, the degassing/steaming is normal. The old, cooling lava and weather effects can lead to changing steam and gas behaviour. The dew point and air humidity can f.e. determine the visibility of steam and gas.

      • Exactly! Here’s how it looked at the start of the last eruption (8x speedup):

        https://www.youtube.com/watch?v=bXN4m8dvbdc

        The steam we see in the beginning is the same that has been there all the time and the same that we can see currently. Then a thin line of new steam appears, and just 30s later the lava fountains start. Here’s another view at normal speed and a wider angle. No extra steaming can be observed.

        https://www.youtube.com/watch?v=N3QXxqTHnIU

        That opening sequence sure was impressive.

        • This eruption started with lava and steam simultaneously. I remember the eruption August 3rd 2022 at Fagradalsfjall, where steam/gas was visible a few moments before the lava fountain followed. I can’t find a video about this moment. Lots of movies about the erupting volcano, but none about the start.

    • To be honest im not convinced SO2 or any degassing otherwise is a reliable indicator for basaltic eruptions. Only example I can think of otherwise is if an open conduit and lava lake form, but dikes dont give any visible sign until within a few seconds. Doesnt matter where, we have seen it now many times in both Iceland and Hawaii and in both cases there is absolutely no early degassing until immediately before lava erupts. Most likely, if you were standing over such a crack in that moment, you would probably be able to look down it at a very rapidly rising magma surface… 🙂

      But yeah, seriously, after now at least 10 very well observed basaltic fissure eruptions in just the last 4 years (!) ranging from a leaky crack to persistent spatter cone to a lava geyser all the way up to a continuous 15+ km long curtain of fire, and they were all absolutely undetectable visually until seconds before the floodgates of hell opened. Dont forget Kilaueas summit has almost as many instruments in a 10 km wide area as all of Iceland combined and it still caught HVO with their pants down in 2020, a full shift from alert green to red, only time I have ever seen that from USGS.

      I dont know why this is in doubt anymore, basaltic fissure eruptions are stealthy, extremely so. Watch the quakes.

      • Chad:
        Your points are well taken. I think it is important to pay attention to everything, when it comes to doing science.

    • The Hagafell webcam shows some Sulfur deposits on the lava field that may indicate Fumaroles along the fissure zone:

    • “strictly prohibited to access”

      Yet they went there, even set foot on the island. I mean I’m thankful for the closeup at 1:08+ but oh boy I would not even consider approaching the island, let alone boating near the coastline and even stepping foot on it. 😮

      • They could have sent a drone, as mentioned in one of the comments.

    • Oooooh … Extreme Pursuit. Didn’t notice before. Now that explains everything. That guy is both educated AND insane. 😀

    • Quakes next to Grindavik, but not along the rift. I remember these quakes in this location before the last eruption, although there have been quakes here otherwise anyway so it isnt very reliable. But it probably is pressure increasing, I think this week will be the one.

      • This area is under a lot of stress. Crustal bending from the inflating sill directly north and it’s in the trigger quake zone from the dyke to the NE. There were lots of shallow quakes in this area also before the last eruption, but I don’t think the active part of the dyke stretches this far south.

        All eruptions have started with intense swarms near 63.881N 22.389W. I don’t expect the next one to be any different. There’s a small area void of quakes just south of this point. It splits the earthquake trace of the dyke in two segments and I suspect that’s where the feeder from the sill is located.

        • It ties in with vectors from the relative inflation too, just south of Sylingarfell, suggesting the same general site for the feeder.
          I think pressure is building more widely too, across Reykjanes, which also fits with earlier episodes.

        • Yes I meant to say these are stress quakes, not on the dike itself.

    • This may (in bad case) indicate an intrusion towards the SW like the January eruption. But it still doesn’t has to erupt there. The sill intruded there in November without an eruption. Is it expanding now due to rising magmatic pressure?

        • On that same note, I have studied the start of the last eruption and saw an abrupt rise in venting, sometimes in areas that haven’t seen any venting at all. The venting would get intense enough that it ‘outpaces’ the rest, minutes before an eruption. I think once an intense swarm starts, we should start looking for that.
          https://youtu.be/N3QXxqTHnIU?si=E2zoU-xuQ9tqkcRf

      • Ljosufjoll with another heavy (albeit deep) quake.

        Sundhnukar doesn’t look on the verge just yet, not really a high density of quakes over the past day or two, this is still in build up stage. Maybe 5/6 days away.

      • How did the earthquake swarm during the hours before the last eruption look like?

        • I’ve checked May 29th on https://skjalftalisa.vedur.is/#/page/map
          The first 0.x earthquakes began around 10:25 with three quakes between 10:00 and 10:30.
          10:30 to 11:00 the number of earthquakes increased to 30
          11:00 to 11:30 they counted 38
          11:30 to 12:00 40
          12:00 to 12:30 41
          12:30 to 13:00 53 (12:46 the eruption began)
          13:00 to 13:30 32

          With the first quakes around 10:25 to 12:46 it took 140 minutes from first innocent signs to the eruption. The warning before the eruption was published 11:40. Were the earthquakes between 10:30 and 11:00 enough to be cautious? How do/did they distinguish between a pre-eruptive swarm and a normal one?

          • Pretty sure they use real-time GPS data along with the earthquakes to tell when there’s an intrusion happening.

          • I was looking for those tremor charts for a while, then I recalled you can get them by clicking a Seismomenter (not enabled by default) on vafri.is.

            GRV has these bumps in the past days … construction?

          • Yes, on some webcams you can see that they are working on raising the berm between Hagafell and Sylingarfell.

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