Taal in water

Long time no sea… 😀  For those of you not familiar with me, I am one of the “dragons” that lurk behind the scenes.  My main claim to fame is that “I plot stuff.”  I also on occasion have written filler articles when needed.    This isn’t one of those articles… but since I am a bit behind the workload in contributions, this was sort of assigned to me.  My primary goal is to write this without scaring the crap out of people but still convey the seriousness of the threat.

First, some background.  Water is a pretty unique fluid.  There are some conditions that water can be in that change the way it behaves.  Normal boiling point for water is 100 deg C.   Above this temperature is turns to vapor.    If it is a pot on the stove, it boils as it does so.  But take water up to a pressure of  22.064 MPa  and it gets weird.  This is a critical point of water.  Above this pressure, no matter how much heat you add, water will not turn to vapor.  That is about twice the pressure found in a 1200 psi steam plant on board a ship (before they were outdated by technology and gas turbines became the go-to technology for main propulsion systems)  The beauty of a steam plant is that pretty much any fuel was suitable as long as it made fire.  Vodka, Diesel, Aviation fuel etc.  (At one time the ship I was on was burning decertified aviation fuel to keep from wasting it.)  But this is not about Naval weirdness.

Throughout its history, Taal has been known to have base surge as a phenomenon in its eruptive style.  This was noted by a former physicist who recognized a similarity to a base surge in atomic blasts.  In atomic testing,  one curious phenomenon noted that the surface blast wave appeared to be traveling faster than the speed of sound.  This should be physically impossible.  Eventually they determined that the air ahead of the blast front was being compressed and this artificially raised the speed of sound.  In a volcano, a similar process can be in play with enough energy.  But rather than radiative heating, compression heating is doing the trick.  This is the origin of a base surge and typically shows up with volcanoes in a water environment.  A “water volcano”  as noted in a very early Volcano Café article.

In a backchannel discussion  (yes, we dragons kick ideas around in our spare time) this article was brought out for review.

A large hydrothermal reservoir beneath Taal Volcano (Philippines) revealed by magnetotelluric observations and its implications to the volcanic activity  Alanis et al

From the abstract: “This {3km x 3km x 3km} high resistivity anomaly is hypothesized to be a large hydrothermal reservoir, consisting of the aggregate of interconnected cracks in rigid and dense host rocks, which are filled with hydrothermal fluids coming from a magma batch below the reservoir.”

Blink, blink…  whoa.  A region of pre-mixed hydrothermal fluids within the cracks and crevices of the host rock?  That is not very good at all.  That means that Taal does not need a flank failure to get water in contact with magma.  It could very well bring up that hydrothermal fluid in conjunction with an eruption.  All it needs to do is to drop below the critical pressure before that “hydrothermal fluid” flashes to steam.

For a conduit system open to the surface, that is anything shallower than about 2.18 km.  (assuming a water density of 1030 kg/m³). Under rock, it is roughly 1 km.

The boiling temperature changes with pressure. The critical point is for water that is 374 C or hotter. If the water is not quite as hot, then it first becomes normal liquid as the pressure drops, and boils when the pressure drops further. This will now happen closer to the surface.

The water turning to steam causes the explosions. If this happens a kilometer down it will probably not reach the surface: the overlaying rock contains it. If it is a hundred meter down, then the rock above will be ejected. At the extreme this can form a volcanic maar, a circular fairly shallow crater which can be anything from a few meters to over a kilometer in diameter.

With such a large water reservoir underneath Taal, a lot of hot water can circulate up. The phreatic explosion a week ago means that the circulating water is getting hotter, and it reached boiling temperature a little below the surface.

My point is, Taal can be VERY dangerous as evidenced by its past performance.  It is IMPERATIVE that any warnings issues by PHILVOCS is heeded.  This volcano, along with other systems in the Philippines is their focus of study.   They ARE the experts.

Informal Q&A from another Dragon: Why does the steam plume take on a darker color as it goes into a sort of phreatomagmatic phase then return back to just steam?

As noted in Alanis et al, the hydrothermal area above the shallow magma reservoir is made up of many small fractures and cracks with water entrained within them.  As the steam is being released, occasionally some of the rock near the pathways break loose and are pulverized if they can not withstand the pressure of the superheated steam passing by.  Superheated steam can easily erode pathways.  Presumably, as the water above 22.064 MPa (3200.1 psi), so it could be at any temperature, just the act of moving into a lower pressure region allows it to flash to steam…. at 3200 psi or less.  (Main Steam on 70’s and 80’s era USN vessels was 1200 psi.)

Additionally, water in contact with magmatic rock probably acts to cause the rock to undergo serpentinization. This is a metamorphic change in the rock where water is taken up into the crystal lattice of the rock and form new minerals.  Generally this new mineral form is weaker than the original rock.  (Talc, Chrysotile, etc…)  I don’t know if this has much bearing on the issue of Taal, but those alterations can act to lower the melting point of rock as happens at the melt region 110 km deep on the subducting slab that feeds the system.

Some discussion has been made about Taal having a more mafic nature to its magma supply.  Granted, the He ratios support this, but don’t assume that it’s just going to be a sedate mafic eruption.  Not very far away is Mindoro island.  If you don’t remember, SleeperFish, an article from some time back, pointed out that Mindoro is the far eastern end of the Palawan Continental Terrane.  My opinion only… Mindoro is probably the result of continental crust not wanting to subduct.  As a rule, oceanic crust, being denser (≈3100 kg/m³), easily subducts under continental crust (≈2700 kg/m³).  None the less, shards of continental material could very well be in the melt pool that feed Taal.

“It’s like an intersection between two trenches”

Not according to the prevailing information.  Taal does fall at the intersection of two volcanic lineaments, but not trenches.  Taal’s closest active neighbor along those lines is actually Pinatubo.  Honestly, Pinatubo seems to have a more pure oceanic crust feeding its melt zone down at the 110km contour.    An archive quake plot of the region is available in the SleeperFish article.  There you can see the Benioff zone indicated by 37 years of mag 4.5+ quakes. The subducted plate dangles almost straight down underneath Taal.


Alanis et al




241 thoughts on “Taal in water

  1. I think it should be investigated if the entire caldera of Taal is a maar crater, it has that look to it. To me based on historical data and the size of Volcano Island and the location in the caldera it seems not to be a volcano capable of actually erupting a VEI 7 volume, and when it is constructive and builds up the island the eruptions are largely effusive or at least fairly slow, as in the 1960s. Most maar craters are mafic, basalt also has the most thermal energy of all magmas so actually mafic maars should have the greatest potential for the biggest blasts. Masaya comes to mind…

    I think really there needs to be a detailed study of Taal, its obviously dangerous and apparently not well understood at all, but this is a very good insight to an aspect of volcanism most people dont think of 🙂

    • From the point of view of tectonics the situation is very complicated here.
      I just read that also Mayon produced some phreatic eruptions. Mayon is so incredibly beautiful.

    • I don’t think Lake Taal is a maar. But the Crater Lake might turn into a maar within a lake.
      Look at Tadlac Lake, Laguna Bay, Philippines.
      Then at Nyos Lake, Cameroon.
      They share a few common features: 1. Volcanoes dormant or extint. 2. Relatively low rim.
      And (which is amazing) overturns by CO2.
      Tadlac Lake is a maar in a large lake, fascinating. Nyos Lake though is a maar on the flank of an inactive volcano in the Oku Volcanic Chain.

      Your comment is interesting. I read a few pieces about maars. They mostly have low rims. I didn’t know that there are maars in lakes.

  2. Mindoro, sorry, is in the north-east of Palawan, not in the west.

    • You are correct. My bad.

      I will correct as soon as my chore assignments are completed for the day. (Wife will be pissed if I don’t, so that takes priority)

      Fiximated. Again, thank you for pointing out the error. 😀

      • Btw I think it’s great how you referred to Phivolcs as local people might get here.
        I once read a long night time discussion on VC with Carl and somebody who has worked on a ship für the American Navy. That might be you. High responsability I’d say. Most marines develop that.
        I think that responsabity has two distinct sides: 1. Not cause panic. 2. Do the right things at the right time.

        At the beginning of Covid a lot of panic was created with pictures from China and Bergamo. I consider that irresponsable. It can traumatize people for years, esp. old people and kids.

        I am a fan of Vassily Arkhipov. He prevented an Atomic war by making a decision which basically was in the range of disobedience. That is responsability.

  3. This was very informative and the article linked at the top was the one I read regarding the in-built hydrothermal system. What I wanted to know is – how much can this hydrothermal system withstand and still be intact, is water perennially going to make it’s way down there, or could it be blasted out by a sizeable eruption or heat increase?

    I imagine for instance, Yellowstone’s hydrothermal system has undergone some sizeable changes over time.

  4. Fingers crossed for Hubble


    Today, NASA began a switch to backup spacecraft hardware on Hubble in response to an ongoing problem with its payload computer. This will be a multi-day event. If successful, the next step will be for science instruments to be brought back into operation.


    They are switching to the alternative side of the Science Instrument Command and Data Handling (SI C&DH) unit on the assumption that the problem seems related to the power supply on the current active side.

    • While we keep our fingers crossed that the Hubble is going to reawaken from its ‘slumber’, NASA is busy prepping the new James Webb Space Telescope for launch in November 2021.

      If you want to find out what the new Webb telescope has to do with earth-bound volcanism in the Utah area (hint: beryllium), you can check out this article:


      and even watch a chipper video that shows the beryllium mining operations…

      (This entry is meant to distract anyone who is missing the webcams with their glowing and flowing lava.)

      • Beryllium salts are exceptionally toxic, processing must be a nightmare,
        Its atomic weight is only 9 and its melting point over 1200C so it is vastly superior to aluminium in strength, weight and ability to withstand high temperatures.

    • There is a good chance it will work. They have a good track record at such ‘repairs’ in other missions. But it is of course possible that the backup hardware is also damaged. It is 30 years old

  5. Thank you for more information on Taal! Let’s hope this volcano purges this Earth of all the filth occupying it.

    • That sounds a bit harsh unless if by filth you mean magnates and their huge corporations.

      • Well, I have a lot more people on my list, but rest assured those people are on my list

      • Who do you mean? If you want to find filth read about the murder of Peter R. de Vries.

      • No. I learned a lot from him about volcanoes. It’s banal. It’s a bad joke.

  6. Not long enough and not enough pictures………………………………….. 😉
    Seriously Thanks, Lurk. This is one of the more serious volcanoes due to the population
    surrounding it. The more we know about it, the better.
    Nice to see You, Lurk.

    • I purposely tried to not get verbose. It’s far too easy to hype the dangers of this thing because they are so profound.

      For any Taal locals stopping by, MABUHAY!

      Heed any warnings that INGV issues. It could save your life. All I can add is my standard warning about volcanoes. “Don’t be there” → specifically when they do their thing.

  7. Thank you GL.
    Tallis’s comments, information and warnings have racked up my interest in Taal, and it sure looks like a very big bucket of trouble. Even more so after reading this!

    • Not to forget Lughduniense’s excellent article, recently. Apologies for being so remiss.

    • “sure looks like a very big bucket of trouble”

      It can be, and has demonstrated so in the past. Don’t forget than Taal Lake used to be open to the sea, it was closed off following an eruption in it’s past.

      • I am wondering whether one of you, why not Albert who is brillant at this could add an explanation about the tectonics over there. There is certainly the broken off part of the Pacific plate called Philippine Sea Plate subducting under the Sunda plate which is supposed to be a broken off part of the Eurasian plate and which also seems to swallow the Indoaustralian plate.

        The islands of the Philippines are sitting on the Sunda plate, but the area is called Phillipine Mobile Belt. Then I see an orogeny mentioned in there. What is that?

  8. SO2 emissions at Taal have gone down by 95% since the high of 22,628 ton measurement, seismic activity has gone down a bit now too. I think another pulse is on it’s way since this current lull follows the trend from the past few months. What is being overlooked right now is that the entire Taal region is under inflation, using some insar data, the total area of inflation is over 1,256 km2. What worries me is that whatever kept the volcano from having a larger eruption in 2020 is failing now

  9. Going from bad to worse in Germany, up to 1300 missing/unaccounted for. Hopefully it’s just the breakdown in communication infrastructure for the most part.

    • That number comes from how many people are out of contact because of the failure of the mobile network in one area, and is not related to fatalities. The expected number of fatalities is well over 100 though – this is a real disaster. Weatherwise, I expect it is on the scale of a one-in-100-year event for Germany. There will be a big discussion now whether this is caused by global warming. That will take a lot of research to answer. It is tempting to jump on the ‘yes’ or ‘no’ bandwagon depending on your political persuasion (so sad that science has become a political enemy to some, and a political weapon to others). This kind of event has happened before and there is even a name for it in Germany (‘Zugstrasse’ weather system). But it is extreme and the question will be whether global warming has made this type of event more likely. Perhaps, perhaps not. The immediate cause is a meandering jet stream. I think it is the same meandering that caused the heat catastrophe in Canada, so the two events appear related. Whether global warming causes the meandering is still subject to discussion. There is a plausible argument that it does (related to the more rapid warming of the poles) but the evidence is not yet conclusive

      • The weak, meandering jet stream is a direct cause of global warming caused by the (relatively) extreme warm arctic, and the subsequent Omega weather pattern with very slow moving low pressure systems is an indirect cause of climate change.

        One key prediction made by climatologists is that extreme weather events become more frequent and precipitation and erosion will increase, so in my book this event IS caused by climate change.

        Who, apart from climate deniers, are disputing if human induced climate change is real? It is already having a direct, severe and increasing impact on society. What evidence do you need?

        • They spend all their time denying the evidence. And some people are quite happy to accept convenient rubbish. By the way, the term ‘climate change’ comes from this group. It tries to make it sound less threatening.

          But that is not the issue here. Does this weather event relate to global warming? Germany has had this kind of events in the past and will have in the future. They are rare but a known phenomenon. People should be aware that one in a century events are actually quite common, just not in living memory. Do these floods become more common? That we don’t know yet.

          The blocking pattern is the jet stream meander. Here some recent research work suggested it isn’t related to global warming. That is out of line with previous work but needs looking into.

          • Yes, that’s a balanced set of statements reflecting what we know.
            There are always records broken everywhere, in recent decades rainfall and high temperatures have been in the majority. One proves little, many suggests a problem. Whether any one is an effect of a cause cannot be known.
            If you look at some of the pictures its clear that like the UK newer builds in towns have been allowed on areas not built on before alongside the river (for obvious reasons). When the river floods it now has new buildings blocking its flow, and that drastically worsens flooding and damage.

          • I can tell you a bit from life experience. This time it might not be the notorious jet stream. The jet stream when it meanders is said to cause a firmly sitting weather zone, low or high, which doesn’t move.

            This was different, so far. I live in the Alps and also drive around there. There were snowfalls until the end of May, off and on. Then there were sunny days. After a short time there was a high air humidity, quite naturally from all the moisture of the ground. Very soon we had heavy thunder storms. Afterwards sunny days again, the same story starting over. All the humidity vaporizing and then thunder storm or heavy rain. An amazing lack of blossoms, many slugs 😉

            This has been going on for around six weeks now. The rivers are all full, full of spring snow and rain. It’s not sitting in there, it is, on the contrary, unstable and fed by the ground humidity. There was nearly no single day with dry heat. The nights are cold though.

            I would say it is basically fed by the situation in the Alps. There is still more snow on top than in other years.Skiing on glaciers is possible.

      • My view is that events like the European floods are within the ranges of weather that can be expected over time. Extremes happen – your once-in-a-hundred years events, etc. That’s the nature of weather and it is daft blaming one event on ‘global warming’ (as the UK Environment Agency is prone to doing to escape management failures, for instance).

        However, when these extreme events start following one after the other around the world in the space of two or three years, then I think we can agree we are seeing some of the changes expected from ‘global warming’ (or whatever fancy name it is given these days). And these changes have shown up quite clearly over the last five years, with this year being quite extraordinary.

        As things change over time, I expect we’ll see good years and bad. But I also expect the changes will intensify over time. Bad years will start outweighing the good.

        The slippery slope has started. 🙁

        • I’m not worried about climate instabilities. I’m worried that little is done for adaptation which would mean giving rivers more room i.e. It doesn’t matter what climate or wheather changes come from. It matters to adapt to them.
          I’m really worried though about the slow stealing of identity by digitalization and the wish to collect health data, also the pressure on people who do not wish to have a sparsely tested vaccination.
          I would not have kids at the moment. I share the worries of Edward Snowdon. A terrible world is looming and wheather will be the least of our problems.

          I am also worried that people are not allowed to say what they think, also scientists, if it doesn’t fit in an existing thinking pattern, that discussion is inhibited, in England, in America, in Europe. A time before Galilei and Copernicus is looming.

          And giving people a guilt feeling in the sense of a Stockholm syndrome is religious like the Catholic Church back then, when people were pressured to give money for St. Peter. If they didn’t they were threatened with hell. I am worried about politics.

          I think all out electric car driving won’t help clean the Kongo from yellow cake, heal civil war or drain the oceans from all that rubbish in there. And with our holy Corona lockdown we made them all a lot poorer over there in Africa or Bangladesh for that matter. I am thoroughly worried about politics.

          • Indeed.

            There is a reason why people ought to think twice about building on flood plains. The clue is in the name.

          • I agree there is no forum for average folks to comment on climate change and the effects. Here in the USA the government set up a flood insurance program along side some rules to leave food plains undeveloped. This was in the early 70’s after hurricane Agnes devastated the North Eastern states. My husband and I had just built a small home close to a river in NYS, so we were forced to buy flood insurance. The area around us was designayed flood plain and it was said no building should take place there as the land was lower in elevation than the houses that existed already. 10 years ago the town ignored those caveats against building and allowed the low area to be back filled higher than the existing housing and single family homes to be built on the flood plain ! Those homes do not have to pay for flood insurance because of height above flood plain while it increases my neighbors and myself of having devestating flooding if we have an event. It seems to me the government has figured out how to doge paying for catastrophic flooding events while not enforcing the rules they set for not developing flood plains. As a low income pwrson what recourse do I have to fight such unfair development ? Flood insurance is so expensive we could only afford to insure our lower level of home not the whole house, meanwhile the neighborhood on the back filled flood plain pay no insurance fees !

          • I am sorry to hear about your situation. The UK has a problem with development on flood plains, and insurance is private so flood insurance can be hard to get especially after an area has flooded once. The Netherlands has extensive areas around the major rivers set aside for winter flooding, but over time more and more houses have been build on it anyway, and once build the owners insist that the winter floods are kept out. Which affects other people. The situation is difficult enough already, but with rainfalls shifting and potentially increasing with global warming, it becomes important to redesign to flood defences. Add the increasing coastal flooding caused by sea level rise (expected to become significantly worse after 2030) and you need an effective government policy. One can hope.

        • Then in case you are wanderers you might know the area above Meran in the North where the Ötztal and Stubai Alps meet. They have a row of beautiful alpine lakes there, Spronser Seen. The ways up there were more or less closed until the middle of June, so people don’t end up like Ötzi, same thing with the near Timmelsjoch.
          And it is not the first year with this situation, two years ago it was similar. So, I am absolutely stunned that people study computer graphs and try to figure out the future, but cannot see what happens in the present tense.

      • There was the same kind of flood in the centre of the desastre zone, Ahrweiler, in 1910 and in 1804. The river Ahr bends there, and buildings are too close to the river.
        Besides there is probably too much ground sealed off like everywhere.
        What adds to such desastres is oldish canalisation.
        One funny thing: The church on the other side of the river is intact. That was the same situation in Tewkesbury a few years ago, church fine. So back then, they obviously knew where to build with probably a decent amount of respect for the forces of nature.

        • If you look at ‘legacy’ maps, a surprising number of really old villages clustered near churches carry the reassuring Medieval ‘dry-foot’ suffix, ‘On The Hill’..

      • Whether global warming is the cause of the floods I would leave to the scientists because we have had a great solar minimum for a dozen years or so. Just because everyone says the same thing doesn’t mean it’s true.

        • I am not sure I get your point. Are you equating the single solar cycle 24 (the last 12 years), which was a fairly weak maximum, with a great solar minimum, i.e. a near absence of solar cycles over a century? These same 12 years also contained 8 of the 10 hottest years on record, and in fact constitute the entire top 8. I am very cautious about assigning one weather event to global warming, but people who 10 years ago predicted a very cold decade because of relatively weak solar activity have kept very quiet since. Science is validated against its predictions. Climate models predicted the temperature rise of global warming and the data is following the predictions closely. It also predicted heavier rainfall in various places. It did not predict a major flood in the west of Germany, nor did it assign a higher likelihood to it. So there is reason to be cautious here. But climate predictions based on solar cycles have always failed this test.

          • That’s a precise and balanced comment as usual. Concerning the years with the highest temperatures I’m sceptical as 2018 an 2019 don’t fit for the Alps.
            What I’m sceptical about is the method of measuring, and I would not trust anybody in say Kongo or also the Malediwes.
            I can trust my own eyes and also memory better it seems. And concerning that torrential rain why should I trust a government which ignores warnings from the UK and weather services?
            The warmest years in my memory were definitely 1976 and 1994, and I was in Germany, the Netherlands, France and the UK in both years and know that the temperature went up into the higher thirties for two months and all the lawns were burnt.
            A method is okay when it’s in reliable hands.
            But exhaust measurements are taken uphill and in front of traffic lights, and the ocean temperature is measured at the surface, so I am very sceptical, not believing anything any more. I just watch it. The media you can ignore.
            What I believe though is that scepticism is a very important human quality which in the end freed us from the dictate of the Catholic Church.

    • How is that for service. Commenters here request a change of scenery, and immediately there is repointing and repositioning. Great! Now, how about that request to turn the eruption back on ..

      • Stable doors and bolted horses come to mind, thinking about the other Meradalir camera that was moved away, and the original Geldingadalir camera moved from viewing the cone to watching people walking a path…
        I’m such a spoiled brat sometimes; the webcam coverage has been unprecidented, even with the gaps due to concentrating on the potential for collateral damage.

    • It’s frozen, and no, I don’t think it can be rewound; and the close-up mbl.is camera seems to have been moved to Meradalir. The overview camera isn’t working, and the RUV Langihryggur webcam seems to be pointing at the Theatre Hill overspill gap… Just as well the vent is in hiatus at the moment.

  10. Thanks Lurking for interesting explanation of the Taal system. There must be a constantly shifting energy balance between heat injected and heat loss due to water movement. Probably an enormous energy storage! Would it be possible to estimate the heat loss by measuring the surface temperatur of the lake and ground?

  11. Last month of earthquakes at Kilauea. It is looking a lot more like last November now, the conduits are clearly defined and the quake rate is a lot higher than it was before the eruption ended.

    I do wonder if the reason there are not a lot of quakes along the ERZ past Mauna Ulu is not because of lack of activity but actually because the area is all magma, from the many decades of intrusions and filling, and the 30 years of eruptions, that have all happened there since 1960. The shallow volcanic rift at least at the upper part is probably in contact with the deep rift which is why it doesnt evolve or cool down, but the magma conduit is probably a part of the shallow system and might not connect to deep rift material. This could result in a slightly easier time cooling, hence quakes appearing when pressure increases, and would also explain the lack of eruptions in the area. I expect this situation of a defined lateral magma conduit so close to the summit like that is quite temprorary, a fleeting event in geological time, possibly only for the last 500 years.

  12. Reading comments on the cameras, I see an MBL camera is back on Borgafjell looking at the south-bound exit of Natthaggi valley. That’s a strange thing to do when the output from the vent has been pouring north into Meradalir the last couple of weeks.

    The RUV Langihryggur cam appears to have been moved further south and is currently looking over the gap into Geldingadalur. Perhaps it’s an attempt to prevent local Gurning contests 🙂

    The Visir cam close to the vent is stuck, presumably broken with the final image visible. Shame – engineers need to wade through the lava and fix it!

    The new Meradalir camera is handy – that should be interesting!

    And the volcano…asleep again? I suppose it is getting old and tired now.

  13. What is the digger driver at on the RUV cam? They don’t seem to be doing any picking up or dropping judging from the movement of the bucket. Maybe tamping something down but to what end? Making an emergency vehicle track? If any Cafe’ers are on the ground there would you mind going over and asking them?

  14. Odd, generally I would expect a low resistivity anomaly from hydrothermal fluids. Water generally lowers resisitivity, especially if saturated with ions. Ok I looked at the abstract. 10 Ohm meters is EXTREMELY conductive, and 100 Ohm*m is also VERY conductive – NOT high resistivity at all, that would be 10K Ohm*m or more. This is in line with what I would expect from an active hydrothermal system. In prospecting for copper porphyries, MT gives a high resistivity for the host granites, but much lower for the mineralized portion (the former hydrothermal system). Magma also gives lower resistivity than normal.
    To be honest I would expect there would be mineral deposit(s) being formed at depths. A lot of porphyry copper and some VMS deposits are associated with ancient calderas.

  15. The RUV.is people woke up at 17:22:12 pm, and move the camera field of view to center it on the active cone, although their camera showed lava splashing in the cone no later than 17:12 pm. The FAF seimosgraph shows lots of action, something happened at 14:40 pm and then rising action is seen, and it appears tumultuous now (but the sensitivity of the seismo has been turned up). See https://www.youtube.com/watch?v=BA-9QzIcr3c and

  16. Meradalir looks quite apocryphal right now! (7:30pm UK time).

  17. First I checked this: https://www.unhcr.org/th/en/28643-resilience-shines-through-despite-volcano-disrupting-lives.html
    Then I saw this: https://www.unhcr.org/th/en/27439-nearly-6000-people-flee-brutal-attacks-on-displacement-sites-in-eastern-dr-congo.html

    It seems quite difficult to help that country. The UNHCR doesn’t rake enough money in. People don’t know where it ends up.
    In the first piece people say their houses were looted. This seems to be the most difficult country on earth.

    I am sort of waiting for Jesper’s piece. And what is Carl doing?

  18. Why is there a gurning idiot on the webcam blocking the lava now that it’s back! I have a wax doll here and I’m going to use it.

  19. The new Meradadalir fixed webcam isn’t high enough to see the lava flowing across the surface, but it’s showing nicely on the stills camera, as well as the tooth, raised above the Fagradalsfjall hill on the horizon. There’s two good flows resurfacing the solid top of the lava lake.

    • True, a higher vantage point would be nicer; but the low altitude has the advantage of far less fog! Overall still an excellent camera. Just now there was a big professional looking drone flying around close to it; I hope we get to see its footage somewhere soon…

      Also, it would be great if the paning cam could pan around the edges of the Meradalir field regularly, just so we can see the rise (or no rise).

    • The perched lava lake next to the cone has now started to bubble, like an artesian well, and I see spatter shooting up, indicating fresh gas being injected from underneath this pool. Just started now around 21:17 pm. I am curious to see where this leads. https://www.youtube.com/watch?v=lrO-5-rt5Tw

  20. Thanks for writing about Taal. I have been watching it this week.

    It is still emitting a lot of S02 and steam. Also the earthquakes have slowed down, but are still ongoing and they are going on underneath the larger lake, particularly in the northwest.

    I am linking to this bulletin in Tagalog because it has information not contained in the English-only bulletin, and it has pictures:


    1. the current Taal Crater lake pH is 1.58. That is not “mildly acidic”, it is “very acidic”.

    Reference: https://www.aqion.de/site/ph-of-common-acids

    2. The current Taal Crater lake temperature is 71.8 C, and it has been that way at least two weeks.

    3. note the earthquake map. As it relates to the 3km ^3 high-resistance area, the earthquakes are going on in a much larger area.

    • I wonder how much magma is trying to escape, The NW side is the area that is inflating the quickest.

  21. Hi guys! think that a new pulse session is about to start…

    • You’re going to have to be more specific, Etna, Taal, or the tourist eruption

      • None of above..Geldingdalir Iceland….pulsating behaviour of eruption. Sorry about elusive comment, too tired….

    • It could be my pulse. It’s been a bit slow of late due to the pills I take… 🙂

    • You’re going to have to be more specific, Etna, Taal, or the tourist eruption?

  22. Nice little EQ swarm under Yellowstone Lake. Waiting for someone in the media to start a panic.

  23. The active cone is switching modes into pulsing now, but torrents of lava are pouring into Meradalir valley, via two very bright lava channels, almost like lava rapids. Timestamp around 22:30 pm.

  24. It is saying on RUV that the last couple of weeks the effusion rate has been not a lot higher than it was back in March, back to 6 m3/s. It seems though this is what is actually causing the episodic effusion, a big open conduit that needs to be pushed out before degassing can happen. I noticed the fountaining is not during peak effusion but usually after lava stops erupting at all, exactly like a geyser really.

    Will be interesting to see if a drop in pressure results in greater decompression melting and another increase in effusion, or if a shallow magma chamber forms and allows for more lengthy intervals with larger volumes of lava.

    • It is starting to look like a lava ocean now, in Meradalir. I wonder if the pulsing starts because the gas cannot escape up the channel or conduit, as it comes out of solution, so it gets into a geyser like action, and that is why we see the pulses. I did notice this time that the pulses are very low frequency, about 30 mins each

      • I have been wondering that, when the a’a flows going down the hill flow into the valley they advance over the surface but then suddenly the flow front turns into the smooth pahoehoe but still moving at the same speed. It is as though the lava flow collapses the crust under it and triggers foundering but the a’a surface cant sink due to its porosity.

        I am actually quite surprised the lava there hasnt already started behaving like a lava lake. The lava lake at Kilauea Iki began to founder and resurface that way when it was around 15 meters deep and way lower than the vent, and Kilauea Iki in 1959 was a lot bigger than Meradalir. I dont know how thick the lava is now but after weeks of continuous flows it must be getting into at least several tens of meters by now. Maybe foundering just requires a nucleation sight that is easy to get in a spattering lake, or where there is an open channel, but a tube will simply result in a very thick pahoehoe flow with normal surface, at least up until something triggers it to founder.

      • pulsing is not 30 mins, I misread the chart, it is about 15 mins long around 2:27 am.

    • Judging from the flows, the effusion rate is down significantly since the continuous eruption changed to a pulsing one. Yes, one possiblity for what is happening is that the top layer becomes degassed and just sits there, until the gas pressure below has build up enough to push it out. Say that the high effusion rate lasted 6 hours, at 10 m3/s. That erupted rather more than the content of the conduit, which is perhaps 2 meters radius and 1 kilometer deep. But if we assume that the lava lake at the top is 100 by 50 meters wide and 50 meters deep, than that gives about the right amount. So i think it is the lava lake itself that is causing the interruption. The gas rich lava rises most and flows out, while less gas-rich lava sinks a bit and stays behind. Over time it builds up a plug. Once it gets heavy enough it blocks the exit from the conduit and now the pulsing phase starts where it gets pushed out periodically. Finally it gets too heavy even for that, and now the eruption stops for one or more days, the time it takes for the conduit to start degassing

  25. I decided to map the area covered along the new channel to Meradalir. A few tiny islands are not shown. In the attached image, the red-striped area is what has been buried. The two small islands have greatly shrunk and the northern half of the big island is mostly covered. Soon only the Visir camera hill will be left, which will take quite a while to bury. https://imgur.com/a/BaZILoy

  26. Is there any asteorids that orbit .. close enough to the Sun to melt during perhelion?
    Souch asteroids woud have a smooth glassy surface without impact craters

    Lava Asteroids melted by the suns heat must exist .. souch woud have close approaches of just a few solar diameters from the sun.. and too small to be seen from Earth

    Chad knows .. alot great natural knowledge
    Whats your opinion? I Ask it here to get quicker answers

    • Sadely No Vulcanoids have ever been found

      But asteorid Icarus do get very close to the sun perhaps close enough to glow red ( But one needs to get quite close to the sun to get a surface temperatures of 1200 C )

      Parker Solar Probe wil face over
      1300 C on its heatshield a few solar diameters from the sun

    • Even comets can survive very close approaches to the sun. They are called kamikaze comets.

      • If they enters the photosphere then its another story.. 600 km a second .. flattened and then they explode in an X ray airburst over a ”Hell Sea”

        I doubt we have not seen a solar collision yet with comet or asteorid

        At these speeds the photosphere is like hitting a brick wall

        • Would be just like a gigantic meteorite, even though the Sun is hot the surface temperature is basically nothing compared to an impact of that magnitude, all gravitational energy, and the Sun has a lot of that when something is falling into it. Basically all the gravitational energy of something accelerating at 20 g over 1 lightyear, that is a comet hitting the Sun. Really it wouldnt matter if the sun was 1 K it would be a colossal impact.

          Question, is such a powerful impact enough to trigger localised fusion? Or if two gas giants collide and their mass is below star limit but the impact is head on could that trigger fusion during impact at least for a brief time? Objects in LEO have many times their weight in TNT as kinetic energy, and stuff hitting the Sun is way way faster than that, like at least an order of magnitude faster. Kinetic energy of something hitting the Sun must create a leading plasma shock in the solar atmosphere that is upwards of 1 million degrees. Maybe that is a small part of the cause of the extreme corona temperature.

          • Shall we put some numbers in? As a rough guess, we can assume that an infalling body comes to a halt when it has swept an amount of material equal to its own mass. Using the density profile of the sun, and assuming Mars, this happens when it has penetrated around 30% of the Sun’s radius, so still far outside the core. If we assume it fell in at 1000 km/s (that is generous), that would add about 0.001% to the average temperature of the Sun. To get fusion, you need a temperature of 10^8 K while the Sun only has 5 10^6K on average. If all the energy was deposited in one place, you could induce fusion in a mass that is (accidentally) about half the mass of Mars itself. (Mars itself cannot undergo nuclear fusion, of course, as it contains little or no hydrogen.) But in practice the energy is distributed over a larger region, carried away by the shocks. This reduces the temperature. The conclusion is that it will not induce fusion, but the numbers are such that it might reach it in a small part of the shock wave.

            An eagle eyed reader may spot that the Sun does not reach the temperature of 10^8 K anywhere, not even in the core. That is correct. The Sun is far too cool for fusion. The only reason there is any fusion is that there is so much gas, that even at such cool temperatures a tiny fraction of the hydrogen manages to collide in just the right way. If we really were to build a fusion reactor that replicates conditions in the sun (as some newspapers suggest), it would be an utter failure and produce no energy

        • Imagine an object an galaxtic Comet Thats gotten a gravitational slingshot ( without being destroyed ) by passing very close to a black hole 🕳

          Souch an Comet coud get up to a signifikant ammount of lightspeed ..

          If it hit a planet.. it will melt and vaporize large parts of the unlucky planet

          Even body impacts at souch speeds are disasterous

          • Chixlulub at these speeds woud probaly melt the entire earth

            If that was the case

            An extragalatic comet woud be insanely fast too

            But these two are very unlikley scenarios

      • Inside the suns mantle the plasma gets so Dense that you cannot sink into it

        Mars If it was placed inside there woud never sink to the suns center .. it woud stop sinking when the sourrounding solar plasma exceeds its own density

        It woud be like placing a little chocolate ball in a huge fire

        Stars are really insanely extreme objects … including our sun

        • I think you like it hot, from the hottest lava on earth, Nyiragongo which fascinated you a lot to the sun.

          • Kilaūea in Hawaii is the hottest lava on Earth.. some lavas in chain of craters road probaly erupted at almost 1400 C according to geochemical studies.

            Iki 1959 is the hottest live on video with 1280 C

            Hawaii Hotspot deeper down under big Island maybe 1650 C

      • Things that do fall into the suns photosphere are accelerated to 600 kilometers a second.. thats certainly ALOT of kinetic energy

        And to mention What woud happen If a protoplanet Collider with a neutron star
        Hits the surface in near lightspeed almost

  27. Apologies if this has been posted already but I’ve only just come across it. It shows the extent of the lava fields nice and slowly so it’s easy to work out where what is.

  28. Maybe not unexpected, but still very cool to see: The lava now runs on top of the old lava on Meradalir and creates new layers in the northwestern half of the valley. This pushes down onto that side of the still not solidified lava field, leading to an inflation in the eastern half (Like squeezing the toothpaste tube on one end). In the new overview camera this is very obvious if you compare e.g. 23:00 local on Friday to 9AM local on Saturday: https://www.youtube.com/watch?v=DaKtY__R6q4

    Especially spectacular on that cam: You can watch a new lava layer flow in overnight covering about half the distance through Meradalir, comes to a stop around 5 AM local, and then it slowly sinks down and “disappears into the lake” between 5 AM and 8 AM local.
    Meanwhile, the level close to the camera rises, by 0.5m or more (hard to judge without some object for scale) with almost no forward movement.
    A super-fast timelapse would be cool, don’t know how to do that myself.

    If this continues to be the main process of transport into eastern Meradalir, then I guess the “lake” level could be squeezed up quite a bit higher than the actual outflow elevations, before an actual flow of liquid lava out of the valley occurs (increasing the effective volume of Meradalir). Because the lava at the outflow end will be stagnant and cool continuously until actual flow sets in, which will then bring in more fresh, hotter and more liquid lava.

    That growth process also will look quite spectacular at the outflow point, with tha lava building up slowly, hopefully it will be documented in some way.

  29. I guess I am bored and just checked the weather forecast for the region – today is the only day with a half-decent chance of maybe being able to make another photogrammetry flight. I hope they have the aircraft ready… Unfortunately, up to now on the cameras it does not look that good though, cloud-wise.
    Hopefully the radar satellite company people are still on it, and that they make the data available.

  30. At 14:16 local on the Meradalir Zoom Camera; https://www.youtube.com/watch?v=DaKtY__R6q4
    the outer wall of one of the intermediate lava lakes that have formed recently collapses in a VERY spectacular fashion, leading to a massive lava-fall down the slope. It covers one of the remaining lava-free islands in seconds.
    Morale of the story: Never hang out on a slope below a lava lake! 🙂

    (Unfortunately, I do not know how to preserve this by recording the event out of youtobe and re-uploading there, so at some point you won’t be able to rewind to 14:16 in that stream. Maybe someone knows how to do that.)

  31. As it seems, the Fagradalsfjall volcano is going into another creative break:

    Maybe to remind us that there are other volcanos out there as well…

  32. Well, it is very foggy, but the mbl.is Meradalir webcams show an orange glow and occasional glimpses of flowing lava on July 18 00:00 and beyond (Iceland time according to the webcams).

    Looks like we have some activity even though the seismometers show only little / background activity.

  33. Taal is still emitting a lot of SO2 and steam, and earthquakes have not stopped. 99 yesterday, 86 today.

    Quote from today’s bulletin:

    “In the past 24-hour period, the Taal Volcano Network recorded eighty-six (86) volcanic earthquakes, including eighty-four (84) volcanic tremor events having durations of one (1) to thirty-four (34) minutes, one (1) low-frequency volcanic earthquake, one (1) hybrid earthquake and low-level background tremor that has persisted since 07 July 2021. High levels of volcanic sulfur dioxide or SO2 gas emissions and steam-rich plumes that rose two thousand one hundred (2,100) meters before drifting northeast was generated from the Taal Main Crater. Sulfur dioxide (SO2) emission averaged 5,466 tonnes/day on 17 July 2021. Based on ground deformation parameters from electronic tilt, continuous GPS and InSAR monitoring, Taal Volcano Island has begun deflating in April 2021 while the Taal region continues to undergo very slow extension since 2020.”

    Link to English version: https://www.phivolcs.dost.gov.ph/index.php/volcano-hazard/volcano-bulletin2/taal-volcano/12480-taal-volcano-bulletin-18-july-2021-8-00-am

    Link to Tagalog version with graphs: https://www.phivolcs.dost.gov.ph/index.php/volcano-hazard/volcano-bulletin2/taal-volcano/12482-bulkang-taal-buod-ng-24-oras-na-pagmamanman-18-hulyo-2021-alas-5-ng-umaga

      • That’s the problem with caldera systems. They can do things that would be alarming at a smaller volcano (a meter of inflation here, earthquake swarms there, geysers, gargantuan amounts of SO2, acid lakes) and then…

        not erupt.

        But if they do, watch out.

        • True. It’s difficult locally. From far away it’s suspense. I am amazed how well they handle it in the Philippines and also Java (Kelud).
          Better than in Germany. They should have evacuated some areas in Ahr, Erft and Rur areas. It turns out they had enough warnings, early from the Met Office.

  34. Green Iceland Vid drone flight over Meradalir lava rivers 07/16/2021

    • The rare combination of a fluid lava, high effusion rate and a steep slope, probably some of the fastest lava flows on video. Most other places in Iceland are too flat, and Hawaii has no steep slopes in close proximity to vents except at Kilaueas summit right now, its really frightening how fast this lava moves. Now take that lava and make it 100x the effusion rate from a 10 km crack in the ground, that is what will happen some time this century at Krysuvik. Like a miniature Deccan Traps…

      • I do not understand this, as this basically is Krýsuvík: The volcanic system of Krýsuvík has no central volcano but “a 50 km long, composite fissure swarm, i.e. a mixture of volcanic and tectonic fissures and faults, of which 30 km are volcanic fissures.
        The Krýsuvík volcanic system has a tendency to effusive basaltic fissure eruptions; before the 2021 eruption of Fagradalsfjall, the last eruption took place in the 14th century.

        • Fagradalsfjall is not really part of Krysuvik, it is a different character of eruption and the lava doesnt suggest lateral feed. The fissures around Trolladyngja mountain are much higher intensity, basically the entire eruption in a day or two with a couple of vents hanging on for maybe a few weeks. Not like now with a persistent and large cone, a new mountain in its iwn right, which has been at it for months now.

          The whole western rift system of Iceland I think is not well understood, it is assumed to be like the rifts around Vatnajokull with large central volcanoes feeding long dikes down rifts but that really doesnt seem to be the case. Lava shields dont form at the end of long dikes, and all the eruptions above 1 km3 in size along all of that rift are shields, no big rifting fissures.

      • I was out at the Timanfaya National Park on Lanzarote a couple of years ago. After reading the first hand narrative of the eruption there, I can imagine what it was like over the long haul if anything like this. Its quite an impressive landscape.

  35. Fresh out pour now at 01:50 am, and lots of very hot lava fanning out again traveling down the hillsides into Meradalir.

  36. Big flow into Meradalir right now (July 18th at 1:50 AM Iceland time). Looks like Mordor opened up the flood gates at Mount Doom…

    However, the fog is obscuring the view of the cone. Not sure what’s going on up there. Is it episodic again?

    • The FAF highpass seismo trace is showing activity again, so we’re on for the next few hours.

        • Thanks for pointing this out, the active cone is not going to become predictable. I guess it has more lessons to teach us.

  37. I apologize if this one has been posted already. This is what GutnTog captured yesterday in Meradalir. I’ve never seen anything like it.

    • RE:”I’ve never seen anything like it….!!”

      That ‘dork’ who climbed the cone several weeks ago would have ‘bought the farm’ under this.

  38. Is there a way to auto-register for comments on this site to be sent to e-mail.
    The only way I’ve found so far is to actually comment and then request for follow up e-mails.


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