Sounds and shakes

Philippines after a large earthquake

In January, the world experienced the loudest bang of the century – and that of the previous century as well. The sound wave of Hunga Tonga was heard across the Pacific ocean in Alaska. The air pressure wave traveled around the world – and again. And again. The ocean wave caused a tsunami across the Pacific, with devastation on nearby islands and damage in Japan and South America. And all this from a volcano we had never heard about.

There is a common denominator in these three effects. This volcano made waves – and it was very very good at it. We are more used to associate waves with earthquakes. Like the sounds of Hunga Tonga, their waves traverse the Earth and are detected everywhere. The whole world rings after a major shake. Hunga Tonga gave us a reason to delve into the archives, and find what we had written about waves, to learn from ourselves. This post is based on one we ran in 2014, in the heady days of the months before Holuhraun. We let Carl speak, with some updates.

This post is about waves, how they happen, how those waves travelling, and how they are seen. In a way it is not about earthquakes or volcanoes at all, and not even really about sound, instead it is about the strange and wonderful world of waves. A field I have spent 20 years studying and researching.

One thing I have noticed is that even though sound waves are all around us all the time, and even though they rule our daily life in the most fundamental ways, very few really know about them and they are rarely if ever studied in schools. I think this is a pity, because out of the humble little sound wave you can derive everything in the universe.  And I really mean everything.

But let us not venture out into quantum physics or plucky string theory; instead let us keep to our mutual shared interest of earthquakes and volcanoes. But, as with everything else we need to start at the beginning.

What is sound?

Representation of a spherical pressure wave from a point source. This could be a drum, a stone dropped in a lake, or a small earthquake. Image by Thierry Dugnolle, Wikimedia Commons

According to physics, sound is a vibration that propagates as a mechanical wave, while moving through a medium such as a gas (air), a fluid (water) or a solid (rock). It is one of many types of waves. They all have in common that they leave nothing behind. Once the wave has passed, the vibration stops. The net effect of a wave will always be a zero displacement. At sea, after a wave has passed, the surface goes back to how it was before the wave. A bird floating on the water will still be in the same place. The wave passes but the water stays behind. Think Mexican wave: the wave moves, the people remain, sitting still again.

To detect a wave we often need specialised equipment. For sound, may it be a violin or an earthquake rumble, it can be our ear, sensitive but imperfect. And it is also good to remember that the sound we hear is interpreted by our brains and may not always be as accurate as we tend to believe, and to complicate things even more, our ears are not that great. For recording we use the equipment of a studio or a seismograph. But, now I am getting ahead of myself again.

Back to the thing with wave propagation and media

There is a difference between waves moving in gases such as air and fluids like water, as in comparison to a solid. Mechanical waves within air and water almost to a flaw move as longitudinal waves. I will get back to longitudinal wave and its estranged cousin the transverse wave.

As the sound source vibrates it creates vibration in the adjoining media (often the air or water). This in turn creates pressure against the individual atoms. The atoms are pushed in a direction away from the point of origin; this creates excess pressure ahead of it (the atoms there resist being pushed), and the atoms are forced back. For the poor atom the movement will thusbe following the direction of the waveform, forth and back. This is important since it means that the mechanical energy will be following a longer distance (and slower) than the straight road. So, one could see it as the sound is travelling along an undulating road from the starting point.

A side effect of this is separation of frequencies over distance since a low frequency travels along a bigger undulation compared to its brother the high frequency component. This is though almost never a problem since high frequencies do not travel as far as low frequency components. Ahem, once again getting ahead of things.

Waves and energy

Now, nature seems to abhor leaving things dangling with excess energy, and a displaced atom will want to go back home, and it will do so in a rather mystifying progression. Well, if you have been a child born in the time where there were swings you will know the solution to the mystery by the seat of your pants, literally.

The four base module waveforms that are possible. By combining these 4 building blocks you can through combinatoric synthesis produce any complex waveform. Notice that all 4 base wave forms follow the 0, 1, 0, -1, 0 progression. Image by Omegatron, Wikimedia commons.

If we look at a wave as a discrete function it will move from 0 to 1 and one would then assume it would be happy at being back home at 0. But that is not true since the atom would at the end of the movement backward be going at full speed (think about how a swing behaves and what would happen if the swing came to a crash halt at the bottom with you on it), no, instead the atom moves happily onwards from 0 to -1 and then back to 0 as resting place. Now if you sum up the energy states 0, 1, 0, -1 and 0 you get a big fat 0 net motion of the poor atom. Natural longitudinal waves always have a net 0 energy value on the local scale. They leave no energy behind. The energy in the mechanical wave moving in a direction from the source. Think of the bird sitting on the water as the wave comes past. For a brief while the bird on the water moves energetically up and down, but then the bird comes back to rest and its energy is passed on downstream. The wave carries movement and energy with it, but leaves the matter behind. This might actually be the most fundamental part of our understanding of the Universe: energy and matter do not need to travel together.

Now a solid can suffer from another type of wave, the transverse wave, but we will get back to that one later. What is true for the longitudinal wave is also true for the transverse wave, it just has an extra step that is quite profound, but I will let that dangle until later.

Antique chinese seismograph. It works in such a way that a sudden jolt will make a ball drop out of the mouth of a dragon into the mouth of the corresponding toad under it. This will then give the rough direction of the earthquake. The only drawback is that a ball will also drop on the other side too.

Now a last thing about the medium. The wave will form due to the properties of the origin (a drum, violin or an earthquake) and that will give the waveform, but after that it is the medium that Rules the Waves. Speed, longevity and a lot of other factors govern how the wave will conduct through the media and how it will be transformed due to diverse diffraction and filtering functions. But, that, my friends, is beyond today.

You may feel this is enough for today. This article is based on a series of lectures I used to give as an introductory course to wave propagation theory in physics. Rest assured, I will not hand out assignments and there will not be a test at the end. This is my field and I tend to think about it in the form of mathematical formulations and technical jibber-jabber. I do hope that you all in the end will feel that you have gained a new understanding about seismographs and how they detect distant sounds from earthquakes. And, if I really succeed well I might even give a glimpse of my deep rooted love of physics, the Universe and how waves can help you understand everything.

Ready? Let’s move on.

Leave your sineful ways behind

It has been suggested by another of the editors that people enjoy images of cats and that if I posted one such it would keep the interest up for this dry series. The cat in question did not like the Haiti earthquake. The cat in question has doubts about this.


In the first part I told a blatant lie. I thought the other editors would catch me, but alas not. The lie was put in on purpose so that I would have a point to start the next wavy part with. In short, I wrote that there are only 4 basic audio waveforms, and it was once believed to be true. But nowadays we know that all audio waveforms consist of the humble sine wave (or it’s cousin the cosine). So in a sense of it you have only ever heard one thing in all of your life.

Why now is that true? Well, let us just say that we can create all other waveforms from adding sine waves together according to specific “recipes”. I could either spend 3 pages on explaining this, or we just watch a brief video. After all, “what you hear is what you believe”. Video by Matt Mayfield from the Audio Kitchen.

In normal life you will basically only hear the sine wave, and the sine wave rules the longitudinal wave as we learned in part one of this series. As I mentioned last time the longitudinal wave travels as a mechanical sine wave and that it is the only possible way an audio wave can travel inside gas or fluid media. There are a couple of exceptions but we can leave those behind.

The sine wave has a close relative: it’s cousin the cosine. It is just like the sine, with one fundamental difference. A sine wave starts at rest, at zero displacement. It is a swing starting at the bottom. The cosine starts at maximum: it is a swing starting at the top. The sine and the cosine is in a way the same conundrum as the classical, “which came first, the hen or the egg?”

How does a sound wave start? It starts with something moving, for instance an explosion. This starts of the wave. Thus the sound wave in the air or the water starts out as I that seductress of wave physics, the cosine wave, with the initial excursion of the swing coming from the whatever caused the sound: a drum, a cat, a volcano. The cosine carries the sound of the earthquake.

Animation by Nashev, courtesy of Wikimedia Commons. Illustrating the sine and cosine wave’s fundamental relationship to the circle. The plotted ‘x’ is the cosine. The ‘y’ would have given the sine.

But in solid media there is another type of mechanical audio wave lurking in the shadows and it travels as something called a transverse wave.

Transverse and longitudinal waves

In a sound wave the atoms move forward and back in the direction in which the wave is moving. It alternates as a compression and a dilution while traveling in that direction. This is what sound does, and what makes the thingies in your ear move, wave, and produce electrical signals towards your brain which make you ‘hear’ the sound. These waves are called ‘longitudinal’.

A longitudinal wave. Source: Christophe Dang Ngoc Chan, on Wikipedia

But waves do not have to travel this way. The can also move things on the ways sideways (transverse) while traveling in another direction.

Transverse planar wave by Christophe Dang Ngoc Chang.

As people set up new sciences they tend to want to differentiate themselves from the parent discipline. They use different names and expressions. In physics it is a transverse wave, whilst in Geologese it is a seismic S (secondary) wave. But basically it is the same thing with a different name.

The two most often occurring versions of transverse waves are the planar transverse wave (mega-thrusts produce these for instance) and the rather beautiful spherical transverse wave. One does not need to be a genius to understand why these waves really go heavy on buildings, one functions as a jolly trampoline and the other will twist the house upwards and sideways before the house is unceremoniously dumped back on the ground.

What is happening in the last animation is that the circular motion of the cosine is creating an expanding spiraling wave; this means that the sound from the earthquake will be immediately separated into two distinctly different components with one wave travelling almost straight to the observer, and the second will be travelling a much longer way.

Spherical transverse wave by Christophe Dang Ngoc Chan

Think of it like this, you have one fireman named Mike Ross sliding down a fireman’s pole and another fireman named Mike Ross running down a spiral staircase, both Mikes are of course starting at the same time. The poling Mike Ross will come down before the transverse (spherical) spiral staircase Mike Ross even if they travel at the same speed. This is due to the spiral staircase being representative of a longer route to the finish line.

If you want to experiment on your own you can go outside and tie a rope to a tree, if you move your hand up and down you will see a planar transverse wave wandering down the rope, and if you move your hand in a circle you will see a spherical transverse wave move down the rope.

I hope that my entire audience has not fallen asleep completely. I also seriously hope nobody got seasick from all the moving animations in this article.


Now let’s move on to reality. An explosion or earthquake does not behave like a sine, a cosine, or any other regular wave. It is a bit shocking, really. In fact what it produces can be described as an instant, chaotic combination of waves of all different frequencies, slow and fast, large and small. It makes a mess. As the wave travels out, the high frequency components get dampened out. They suffer friction, loose energy and give up. At large distances, what remains is a much more regular affair which lacks the energetic chaos of youth and instead moves up and down with the assured slowness of experience. You can see the effect when winds blow into a channel of water. At the start, there are lots of small wavelets looking like a good start to seasickness. But soon it develops into a regular wave, inviting the viewer to a surfing experience.


We can see this behaviour after an earthquake. A seismograph near the earthquake dithers all over the place, certainly in no way sineful. But far away, the behaviour becomes much smoother. Here, as an example, is the measurement from the Alaskan earthquake of 2021, measured in far-away Iceland. Note the two different part of the waves. The first wave (P for primary) is irregular, while the stronger later wave (S for secondary) is much more sine-like.

The Alaska earthquake and the Iceland volcano. This is the faf low-frequency seismograph plot, which should be showing the eruption but instead shows the Alaskan waves passing. The irregular part at the start (red) is the P-wave. The nice looking one is the S wave, arriving 10 minutes later but remaining visible for several hours.

The S-wave is the transverse wave, traveling a bit slower (and thus arriving a bit later) because of the continuous diversions which also shake out all the high frequency jitter. You can see a bit a beat in the signal, as waves of slightly frequency interfere, but otherwise it is well behaved. The P-wave is the longitudinal wave, traveling through rock as compression and decompression, just like a sound wave. It is faster but does not manage to shake off its irregular beginning and is just as messy as when it started.

For comparison, here is a seismograph near a large earthquake. This is not Alaska, but Christchurch, New Zealand, 2011. You can see it looks nothing like the long-distance wave. It carries the youthful chaos, before it shows the underlying sine wave.

The Christchurch earthquake, 2011, measured nearby. Source:

Other examples

Can we see all this hand-waving physics in the real world? Yes! Here is a wave pattern in water where regular waves pass in different directions, canceling each other out in some places, amplifying in other places. It gives a watery square grid pattern, as if inviting us to a game. (If you see this unexpectedly it might be wise to stay out of the water.)

Source Sergei Eremenko, Soliton Nature.

For earthquakes, the P and S waves are discussed above. These travel through rock. But there are also surface waves which can do much of the damage close to the epicentre. They are slower than the P and S waves. There are two types, the Rayleigh waves which move up and down, and the Love waves which will throw you sideways. Such waves were reported from the Lisbon earthquake, where buildings were said to be waving back and forth.

Rayleigh waves and Love waves

It is very difficult to find good videos of this in real life. You need a stable camera with a fixed viewing angle. Somehow, people who record phone videos during an earthquake run all over the place and point chaotically at the chaos, while traffic cameras provide a fixed view but can’t stop shaking. But here are two examples, one of swimming pools during earthquakes and the other of a fairly stable webcam, which give an indication of how the surface moves. In the second example, note how the people are stumbling sideways, not up and down.

Gravity waves are sometimes seen in clouds. The movement is up and down, driven by a disagreement between gravity and air pressure and caused by sudden vertical motions (e.g. an eruption). (Ocean waves are also gravity waves.) Clouds can form during the ‘up’ part of the wave, and dissolve again in the ‘down’ part, so you get cloud lines delineating the wave, in a circular pattern around the explosion site.

Gravity waves during the La Palma eruption of 2021. They were also seen around Hunga Tonga

Waves in liquids are of course well known. They require low viscosity, otherwise they damp out too quickly. Hawai’i is known for its low viscosity lava, and waves have been seen in it. Don’t expect oceanic waves! They are ripples – but ripples in beauty.

Waves in the Pu’u’o’o eruption, 2016

The final example is the already famous Hunga Tonga explosion of 2022, the VEI 5.8 which behaved like Krakatau 1883. The air pressure wave traveled around the world three times, the first time this happened in more than a century. Here is a video of its progress.

With that, the physics lecture is over and you may now wake up. If there is one bottom line, it is that waves happen everywhere. From starling murmurations to traffic jams, from swimming pools to clouds, they are there to be seen wherever something disturbs the world. It is there for us to see and hear.

And if you ever happen to find yourself in a large earthquake, please keep you phone stable, and directed along a long straight road. You’ll be forever remembered.

CARL & albert

118 thoughts on “Sounds and shakes


    Here is a good video of the waves made in a lava lake last year. Kilauea on September 29 2021. I think the picture you found is of a pahoehoe toe, which I guess is also a wave but not a fluid wave 🙂

    Also a picture of the eruption around 10 minutes in. Was some really big fountains before the lake drowned them out, going on 200 meters high in these pictures.

  2. It’s not even that dry. It is basics, okay, but well explained. The cats are not seeming to fell comfortable though, no good picture.

    Siberian cat in natural habitat:

    And on the other side of the handshake up north: Maine Coon in natural habitat:

  3. Excellent Nepal video. Distant buildings were very indicative of the approaching wave.

    Additionally, from what I remember, you need to pass up to the 13th harmonic to get a nice clean square wave through a filter circuit. Many O’scopes provide a square wave on the front panel so you can adjust your probe impedance for a clean square wave. Out of adjustment and it yields rounded or overshot corners.

    Me being stupid… if you start plotting out Fibonacci ratios you can see this “ringing” feature in your trace down near 0112358 etc. (the “overshoot” is what makes the ringing feature. It means your probe circuit is close to a harmonic and is giving somewhat bogus traces on the scope.)

  4. Maybe it is a bit too sober. A little element of catastrophe wouldn’t hurt, like a rogue wave.
    “It happened at position 45° 54” South, 38° 58” West. A wave rose out of the swell, as steep as if Poseidon had blown it himself. The log book notes a “breaker (sea surge) 35 meters high”. Bursting in myriad drops, it slapped the steel hull of the »Bremen«.”

    Called tsunami, but supposed to be a rogue wave, orignial title: The Great Wave off Kanagawa by Hokusai, rogue waves supposed to be the product of piling up (constructive interference), Hokusai from wikim. commons:

    The movie from Nepal very interesting, and beautiful picture of Pu’u’o’o.

    • Non sequitur: My shower curtain is a blow-up of The Great Wave. Maybe that Calvin and Hobbes strip from above was lurking in my subconscious when I had it made.

    • This happens on the South East coast of South Africa, where wave trains from depressions passing to the South of The East coast combined with a strong South West wind traveling up the coast combine the various wave trains to a point where they come to a momentary point of harmony forming an exceptionally high wave with an extremely steep wave front caused by the Mosambique current moving in the opposite direction. It has been responsible for a number of ship sinking and bad structural damage to many ship’s. The waves only trouble ship’s traveling South East into the weather.

  5. Please could you change the cat picture? Animals in real distress is not a good look for a flippant reference. The way the cats are being held suggests they might be bushmeat, and the cat at the front is clearly in distress – apart from its facial expression, look at the way its back leg is hooked into the watch strap. It is struggling. As Denali pointed out above, there are plenty of free cat photos on Wikimedia Commons.

    • As requested. The image actually came with the original post. It has now been replaced with a more appropriate cat.

      • My dog who’s befriended with a cat says thank you with Droopy

        wikimedia commons. His friend is cute and just looking for mice.

  6. Great article, thank you! And I almost..almost…understood the Cosine Sine mathematics for the first time in my 53 years. In my school years maths teachers would explain each element, put them in an equation, and then a whole load of extra letters would appear that defied any explanation and were not explained by teacher or textbook. After which I was beaten and thrown out of the class room. Shame you could not be my maths teacher, Carl. 🙂
    This interesting article reminds me of the roiling and splashing inside Fagradals giant vent, where lava waves would lash the cone walls.

  7. Argh mods please can you remove my email address!!!!?

    done – admin

  8. Thank you Albert for this great on-point tutorial!
    One thing that I’d like to see is the wave patterns developed from colliding waves of different frequencies.
    The beat frequencies (heterodyne) as well as the prime harmonics can create some interesting chaos in the resulting vibration pattern.
    My question is this:
    Hypothetically, if both a sudden volcanic explosion occurred at the same time as a nearby earthquake, each event would produce a distinctly different longitudinal wave at different frequencies. If the difference (or sum) of these two frequencies falls on or near a prime harmonic, would at the point of intersection between the waves produce a “pulse” of amplitude/shaking that could exceed the amplitude of either wave alone?
    On the other hand, if the two frequencies were close together, then the beat frequencies would be well away from any nearby harmonic, thus each wave would essentially pass through each other with little interference, so just a jumble of weakly interacting waves result.

    • Lest I forget to thank Carl!
      Apologies fer the quick trigger on the post button.

    • Note: By “close together”, that is to say the two frequencies are not identical. If they were the same frequency, then a first harmonic (resonance) would result…a worst case scenario as far as shaking is concerned.

    • Hunga Tonga did the experiment for us! Sadly we weren’t paying attention. The atmospheric wave which went around the world did so in both directions. Somewhere on Earth they passed each other, and you would expect interesting wave patterns. Because of wind, the two directions will have slightly different velocities. If only we had had a meteo station at the right location

      • Thanks Albert fer the example.
        If the leading edge of each wave was in the “same” direction (up/down), then the phasing at the moment the two waves collide would be constructive as far as momentary amplitude (2x) is concerned, thus forming a standing wave….which should have been evident in surface observations or even from space.
        A loose analogy may also explain the sonic boom’s/pressure wave heard across the Pacific at disparate distances after Hunga Tonga, where two sets of waves were generated…one that reflected off the upper atmosphere and returned to Earth where it then phased with waves moving along/through the surface. If so, then the audible harmonic would be limited in location to only where the two waves phased, and largely inaudible elsewhere except nearest the event epicenter. That’s why Alaska and California heard the boom, while Hawaii did not.

        However, this is not the same as the other side of the planet where vestiges of the exact same wave met, with each travelling through different atmospheric conditions to get to the common point.
        My bet is as you said…the frequency of each wave was altered differently as they transversed the planet, so most likely there was no discernable interference between the two when they met.
        This may also explain how the pressure wave was able to continue to travel nearly (greater?) the same distance as it is to the moon. If by comparison the waves were exactly of the same frequency and phase, then destructive interference should have dissipated/impeded the wave, which obviously did not happen.

        • Destructive interference does not actually cancel the wave. It only acts in one place, and both waves travel through unscathed and emerge on the other side with their original strength. Otherwise energy would be lost and that is not allowed in physics. Same for constructive interference. It leaves both waves to continue at their original strength.

          • Thanks for correcting my mis-understanding!
            I can see now where my logic broke down.
            My thinking was (in part) based on my observations of how ocean waves interact when a wave hits a seawall, then gets reflected ocean-ward. The reflected wave proceeds towards the ocean until it collides with the next incoming wave.
            Where the two meet/collide, there is a large wave that gets generated.
            As a result, both the incoming and outgoing horizontal wave’s intensities and velocities are greatly reduced as a lot of energy is robbed from the wave to building up the standing wave’s height…i.e. horizontal wave energy is converted to lift. The energy needed to lift the water is then returned to the system as the standing wave collapses, but since the primary waves have already passed through, the relatively slow collapse of the standing wave creates just a flattened surge of water. So, all energy is still accounted for, just that it’s spread out over a wider area.

  9. Given the laws of fluid dynamics is in play, weather also follows many/all of the same laws as far as wave propagation is concerned.
    Here’s a blip from climatologist Dr. Daniel Swain over at Weather West (a blog devoted to weather, et al, focusing on California).
    “Plenty of evidence that human-caused climate change from greenhouse gas accumulation is capable of profoundly altering the planetary wave patterns via waveguides, and thus large-scale resonance”:

  10. Where did you find the 5.8 figure for the Hunga Tonga VEI? I’ve been digging for information but haven’t found much.

    • It comes from a paper Hector dug out: We were happy to accept it as absolutely correct since our own estimates made here had arrived at a similar value! It is with some caution though since the evacuated hole has not actually been measured (and in any case is likely filled with ejecta that fell back). It is hard to assign a VEI value to underwater explosion. Do you count the evacuated water as well? I’ll see it as a VEI-equivalent.

      • Quite an insight into how variable volcanism is. Hunga Tonga is a young basaltic andesite volcano, probably if it ever became effusive it would be like Nishinoshima. By all accounts should be a safe volcano, and then in the span of a day underwent an ignimbrite eruption of a magnitude not seen in living memory.

        I think with my unprofessional opinion that there was a combination of Carl and Hector’s ideas. Ignimbrites probably are extraordinarily intense, but this reached the mesosphere, something that only one explosion we are aware of has ever done prior. I suspect Krakatau did too, but Pinatubo didnt. I dont think magma can truly detonate on its own volatile content, but add an infinite water supply…

    • Catastrophic is perhaps overstated, just a big eruption and I think Manam had a few of those last year as well.

  11. Wowvovovo!! woff!! wofff!! vovovo vow!
    Bark Bark.. Im back

    • What a coincidence:
      “In a world racked by war and desperate for good news, this story of impossible survival went viral. Shackleton overcame disaster, mutiny, and anything the Antarctic threw at him, while keeping his man (including a young stow-away) safe. A world at war badly needed such an image.”
      From Albert’s wonderful piece. Tom Crean needs mentioning. He was with them. He had also been on the ill-fated Scott expedition in the back-up team and walked alone 35 miles across the Ross Shelf to get help for Edward Evans.
      I can’t believe the state of the name, absolutely intact, the same goes for the steering wheel. Endurance, greatest name ever. What a story.

      • In a way good news, in another way, the ship that was used to find it had to search for 2 weeks (and hearing the story, it was not the first mission), has used a lot of fuel to get there through thick ice and looking at the conservation of the ship found, things that are deposit in that neighbourhood tend to stay there and influence the environment.. Personally I have the feeling that the (although limited) research performed in that area influences more the (local) environment relative to the pollution produced in other regions of this world…

        • They also did other research while looking for the ship. I love it that they found it and refuse to become a Calvinist.

    • He also has a video showing lightning during the precursory Jan 14 eruption which was apparently quite powerful already:

  12. Thanks, Albert, I just love it.

    Grytviken, South Georgia:

    Grave of Sir Ernest (died a few years later on another expedition):

    Endurance, iced in:

    All wik.commons. The discoverers of the wreck were also iced in, but today the technique is better, they got their ship free again.

  13. Will Grimsvotn erupt if we sacrifice someone? Do we have any volunteers? I volunteer Jesper

    • Hmmm ( cough )
      Not before I gets my Mega Flood Basalt eruption

      I hopes Mauna Loa goes crazy soon

      • Flood basalts are rare. I have the impression that they are getting smaller. Deccan traps and NAIP were not as big as Siberian or Ontong Java or CAMP. Debatable.
        The question is whether Iceland is a Flood basalt. It would be the third one in place as the NAIP had two periods.
        Basically you wish for a longer life with time lapses.

        • Iceland can’t really qualify as a flood basalt, not even close. It has been growing slowly for many millions of years. If Iceland did lava flows of thousands of cubic kilometers in volume then it would be a LIP.

          I really only started to get what LIPs are after studying Mars and Venus, which are 100 % LIP volcanism, and with well preserved landforms. We do not have anything like it on Earth right now. The most spectacular eruption I have seen so far was that of Syria Mons-Kasei Valles which started as non-stop overflowing that built a giant shield volcano, and then culminated in a flood that drowned one third of Mars in an ocean of lava in a matter of weeks/months?

          Of course not all LIPs have the same size, the last few LIPs on Earth, seem to have been relatively weak, but eventually our planet will do a big one again, of course that will happen too far into the future for us to worry, we have much more immediate problems. And if we want to see lava megafloods then we can simply go to Mars, they are hundreds of millions of years old, but some are as well preserved as recent Earth lava flows.

          • If defined that a LIP is just a lot of igneous rock in one place, then Iceland is a LIP. So is Hawaii, and probably also the large rhyolitic caldera complexes in New Zealand and the Andes.

            If it is to specifically refer to such a mega volcano as you say though then nothing is a LIP today, but also maybe alot of structures actually designated as LIPs are not properly deserving either. It seems to be another one of those things where the definition unintentionally (or not) excludes a currently forming event, as though LIPs are only a thing that has already been created and cant still be forming. Im sure there is at least something active right now that our definition would identify as a LIP if we saw it again deep in the future.

          • Yes, no real LIP right now, so what is it that causes them? And what is it that stops them?
            The closest I get to imagining them is Lanzarote. It stopped after six years. Imagine it hadn’t stopped, but gone on for one million years getting bigger.
            There must be a reason, maybe significantly more subduction than in the deep past plus production in spreading ridges, of course).

          • LIPs may last a million years but the most active phase will be a lot shorter. In the case of the Deccan, there were four or so fairly brief phases of high activity. Iceland is certainly not LIP. I see no evidence that LIPs are decreasing. They come in a range of sizes, where smaller ones are more common than larger ones. If you loo at recent events, you will miss the rare big ones. If you look at ancient events, you will miss the small ones which are eroded or buried. That gives the impression of a change over time from large to small, but this is not real. For oceanic LIPs, they last only some 200 million years after which they suffer erasion by subduction. Older ones only survive on land

  14. Concerning flood basalts I doubt it that they are responsable for extinctions.

    Reasoning: The Columbia River Flood Basalt isn’t associated with an extinction.
    I therefore rather think they might have contributed to extinctions if there was something else. With Chicxulub this is more than obvious. Popigai is supposed to have led to a small extinction, and there was no flood basalt at the time.

    Iceland – in case it can be seen as a SIP doesn’t seem to cause extintions, but if we died out, and a different albeit similar intelligence emerged they might start the same research. They might say: The Great Auk has died out because there was an Igneous Province or the Dodo died out because there were huge eruptions in Réunion and the African Rift.

    It was problematic when the continents all gathered in one place, and it certainly led to shelf rarefication and lower sea levels plus a change of currents. The Siberian Traps might have added to this the fossils being more numerous in Greenland.
    Basically life with volcanism is possible and fertile, unless there would be two 7’s in a row or one 8. The Siberian and also the Deccan Traps are assumed to have happened over a period of 1 million years. Most species are not even around that long.

    Most meteorite impacts have not been found (overgrown or under sediment), the same goes for sediments of old tsunamis.
    So, doubts be permitted seeing that volcanism has more good consequences (fertility) than bad ones and also seeing what is partying around black smokers.

    The other extreme is the folks in 3000 m depth on the Endurance. Coldish there.

    • Iceland is a poor analogue for a flood basalt event, it has the volume but not the scale. Hawaii also has the volume but again not the scale. Hawaii is larger in volume than the Columbia River basalts and formed in much less total time. But CRB volcano erupted a total of maybe less than 100 times at all, millennia apart and in increments of thousands of km3 per episode that ladted only a few years to a decade. Basically imagine all the lava erupted in Hawaii since the start of the Holocene, erupted in 10 years…

      Galapagos calderas are probably a better structural analogue, though the center of the volcano would also see abundant silicic volcanism. For CRB this was a volcano called the McDermitt caldera, and later the Owyhee-Humboldt caldera, first in an ongoing line of supervolcanoes going up to Yellowstone, which while deep asleep is not nearly as dead as Carl thinks, these places just operate on a different timescale.

      Siberian Traps would have been far more frequently active than CRB was, maybe operating on flows of that magnitude every few centuries as opposed to tens of millennia…

      • Yes. Collectors. Nobody in another civilization would ever get to that conclusion as it is crazy.

    • Exactly Hawaii and Iceland defentivly have the long term volumes, But they haves Not the speed or size of individual eruptions To be called true LIPs.

      Real catastrophic LIP eruptions can involve tens of thousands of km3 erupted in a few weeks along fissures that are many many 100 s of kilometers long .. its a sight from armageddon or biblical sagas of doom really. Nothing like that have happened during the recent evolutionary history of Homonid genus.

      Had just a single souch flow on that scale happened in the last 10 000 years it woud have influensed cultures and legends and religions all over the world, Thats the scale of catastrophic flood basalts .. althrough many LIP flows are smaller than tens of thousands of km3 per flow

      • Severe LIPS are insane events really.. knowing How long some Dykes are in CAMP and other provinces I knows one Intrusion complex that can be followed 4000 kilometers that are acossiated with the Pangea Pre Breakup

        • So, at least you seem to agree that they might have gotten smaller altogether. Deccan already was smaller than Sib. Traps and the Ontong Java Plateau. Without the impact the dinosaurs might have survived a bit longer, maybe not for much longer as species seem to pop up, radiate and then go.

    • Severe Flood Basalt LIP s are acossiated with extinctions because of the huge ammounts of gas they produce .. They pump the atmosphere full of CO2 and Sulfur Dioxide

      LIPS are short lived events, but acossiated with catastrophic global warming and overheated oceans that Leave a trace in the fossil record

      The scary thing is that Humans CO2 output is probaly larger than a LIP or most LIP s .. IF we dont stop burning fossil fuels soon .. the entire planets climate system will soon collapse

      But a really really really large asteorid Strike is probaly worse than a Severe LIP

      • And Columbia River Basalts where a very small LIP for comparsion

        • CRB basically was a normal volcano that got trapped. Supply to it was not as high as at Hawaii or Iceland, though maybe higher than Reunion. It was though apparently high enough to not be entirely rhyolitic as it is today. Maybe the simple answer is that it is just very rare for tholeiitic plume volcanism to actually erupt through a continent and that this is what happens when they do even if the supply is unremarkable. In which case there might not be any actual erupting plumes under a continent other than at Yellowstone. There are though two emerging plumes under Africa, when Afar first emerged it was a LIP, no reason to think the rest of the rift wont follow suit eventually. Virunga is quite obvious but the extensive (if somewhat old) volcanism in Kenya also merits attention, maybe we will go from 0 to 2 in short order…

          • Actually, given that there is a basaltic magma system under Yellowstone that is in the range of 15-20,000 km3, maybe the capability of the system has not changed just that now it is not possible for the crust adjacent to the caldera to rift, so no way to get major basaltic volcanism. It is likely that the whole Snake River plain is connected to the plume too, unlike an oceanic plume there is thick crust continuously intruded by abundant basalt over the millennia. The eruptions along the plain are also still tholeiite basalt and not alkaline like would be expected of a dying volcano as we see in Hawaii. It is even referenced quite extensively that the SRP province is underlain by a massive sill, which presumably must originate from the plume. So maybe Yellowstone, and not Hawaii ir Iceland, is actually the closest thing to a LIP volcano that is still alive, though not a close comparison.

          • Compare that to Mars and Venus: Volcanoes, but no mountain chains. Deccan Traps: Island then. Yellowstone’s rivers of lava would be stopped by mountain chains and then rather form a plateau. We might have more mountain chains anyway than back then when the lava ran and ran. We have mountain chains everywhere, old ones (eroded) and newer ones, so possibly a very different geographic situation. It’s not the same Earth any more.

      • Virunga is an emerging mantle plume .. and seems to be a rather powerful one
        Even its early very alkaline phase that we see now is very productive Despite its Alkalinity

        I wonder what the future holds ..

        • Virunga mantle plume? It’s a spreading ridge. There might have been a mantle plume once though.

          • There is definitely a plume involved, the area is raised up by 1 km and hosts one of the most powerful areas of volcanism on the planet. Nyiragongo is second only to Kilauea as the most powerful heat source detected from space, and that even includes the end of 2014 when Holuhraun was raging…
            Hawaii erupts plume basalt, Virunga though is still in the early stage, magma production is high but very deep, so is still alkaline. Basically Virunga is still in its ‘loihi stage’, when the tholeiite stage begins magma production will go up maybe even by several orders of magnitude, and that could very plausibly put it in flood basalt territory.

            So, it is a divergent boundary in the making but far from just a spreading ridge 🙂

          • It is also under the african superswell, whether there is a localised uplift as well (relatively speaking) I honestly couldn’t say for certain.

            I do think we will see a flood basalt event once the continental rifting becomes more advanced. There is a previous correlation.

      • Maybe. Maybe not. We reduced the sulfur too much. There is research about getting certain sulfuric acids into the stratosphere, and as everybody knows here a large eruption like Krakatau causes global cooling, and famines are thought to have suspects among volcanoes.
        CO2 is a life bringer too. There wouldn’t be any life without it.

    • Mars and Venus haves preserved flood basalt surfaces lava channels thousands of km long and tens of km wide sometimes a 100 .. and some are sheet Aa lava flows that are thousands of km wide flood sheets and a 6800 kilometers long lava channel system on Venus! Where each channel is as wide as Holuhraun

      Had Earth not had plate tectonics To vent its heat slowly over time .. it too woud produce souch catastrophic lava floods

      • If Earth hadn’t developped Plate Tectonics, we wouldn’t write here. Earth: 1. Tilt, 2. Plate Tectonics, 3. Water, 4. Magnetic Field, 5. Moon, 6. Habitable distance from Sun. Summary: Unique. Lucky guy. When there is a wave of enthusiasm because a new planet is found in a habitable zone and they say Red Dwarf I turn away.

      • Jesper, read up about the Stormberg Volcanics and the lava flows capping the Drakensberg mountains of South Africa and Lesotho. Those lavas formed the Gondwana land surface and covered most of Southern Africa extending far to the North.

  15. My idea is that we are seeing a 45 year old healthy patient (45=4.5 Ga). It has had measles (Rodinia) and Typhus (Pangaea) and survived and has a life expectancy between 80 and 90 years (8-9 Ga).
    When it assembled to super continents it would have had less subduction and spreading as a consequence and therefore developped bad rashes like the Siberian Traps or CAMP. It is in a good state and a unique life bringer with lots of species that come and go (we shouldn’t help the exitus though).

    It might be unique in the universe as it is unique in the Solar System. The main question is whether there was something like this before around one of the red dwarfs that were once brighter. The Universe is supposed to be four times as old as the Solar System.

  16. Did some quick research on the Columbia River basalts, seems it is very much a complicated structure. The mafic eruptions of flood basalt scale took place as recently as 6 million years ago, well after the Snake River calderas had started forming, though the majority of the lava was erupted over a 1.5 million year period from 17-15.5 million years ago. The first center at Steens Mountain was also very productive, no 1000 km3 flows as far as I can tell but it erupted on a scale to make Laki look minor at roughly century intervals…The slightly younger Imanha basalt was by contrast erupted in significantly bigger flows but tens of millennia apart. The major rhyolite calderas first show up at the peak of the flood lavas, as the plume began to interact with the craton.

    Seems maybe there could be a serious case to include the present day Snake River volcanism as a part of the Columbia River Basalt LIP, it is much less extreme in scale but there is no gap, it is direct continuous activity, plus the long succession of calderas. The heat focus is just now in an area of thicker crust so rifting is not so easy. It is a shame Yellowstone has its reputation, it is completely undeserved and there is near 0 risk of anything dangerous but at the same time it is also very certainly not dead. If one looks at the local topography it looks almost like a bow shock, the plume is shredding the continent apart in its wake, far from being snuffed under the craton.

      • Can see here how behind the active complex the crust is depressed while in front it is raised, the plume might not be as deep but is definitely there and pushing on the crust.

        I do feel like maybe the shape being as we see it now might be accidental, the east half reflecting post-CRB tectonics. Otherwise I think there would be massive dike swarms going north and south of the SRP calderas and that is not seen. Steens mountain was a frequent erupter but the other parts of the CRB were massive flows millennia apart, so local production was maybe not actually too different to that feeding Yellowstone, or the other calderas.

        I think I am going to make a map of all of this when I have time 🙂

    • Then it woud be hell on Earth If the Powerful Hawaiian plume was placed under a thick continent

      Souch a scenario Maybe is about to boil up in Africa soon 😛😈

      • Hawaii could be too narrow and hot, it might just blowtorch right through instead of building a massive magma chamber in the crust. But then Reunion seems to be the same and made the Deccan Traps so who knows. Either way the rate is sufficient just not the storage volume.

        Based on the last few examples, LIP volcanoes seem to show up about every 15-20 million years. Hawaii might have become one if not in the ocean. But on this track with the last true example being about 16 million years ago another one showing up soon would not be that surprising.
        If the CRB is typical in progression then the first stage is basically a hyperproductive but normal fissure volcano, Nyamuragira is already very active, the first sign could just be a change to tholeiite basalt and major increase in size of eruptions, going from <1 km3 up to 10-100 km3 volume events maybe at couple decade intervals. This could be somewhat imminent, within the next million years. Over time though the magma chamber grows so frequent eruptions transition to widely separated flows of massive scale. As the places grows these massive flows increase in frequency and silicic volcanoes form in the center of the complex. Peak of activity might see 1000+ km3 lava flows one or more times a millennium.

        It might be something worth mentioning that the Kenya bulge has got a rifting fissure volcano called Chyulu Hills, east of Kilimanjaro. It erupted in the 19th century. It is not of crazy scale but has transitioned from early nephelinites to transitional alkali basalts, it also is roughly circumferential to the bulge. This might be the beginning of the big unzip there…

        • Chad you may well be right about the CRB and Kenya. Do you have a map showing the outlines of the Kenya bulge? I’d like to trace the fissures and label each volcanic feature by magma type. Suspect they would be slightly different regardless with CRB being governed more by extensional forces than continental rifting.

          • No maps for a while until my computer is working again 🙁

            Probably would be different, but the LIP happens of a faster timescale than the rifting, so maybe difference would not be so marked. There would also have to be a point that the complex first starts and would not be a LIP, just a normal sized if excessively active volcano. Many LIPs have alkaline volcanics at the start, which turns tholeiitic when the plume can melt to the base of the crust and decompress in its entirety.

            Chyulu hills is actually circumferential to Kilimanjaro not the bulge as a whole, I looked at a map. It is actually slightly more radial to the bulge. But having what appears to be an accelerating basaltic center such a long way from the rift valley is itself a question mark, so maybe it is still the beginning of this whole thing regardless.

      • How powerful is the Virunga emerging mantle plume?
        Is it on power with Galapagos?

        African Superuplift coud very much hide its strenght as its under a thick craton or close to cratons

        • Not sure but it might be, it is able to push the crust up by 1 km.

          Im also thinking that Nyamuragira could transition much sooner than 1 million years, its entire volume is only about 500 km3, maybe less. Yet it is erupting at a rate of 1 km3 per decade in the 2000s, and has had a permanent lake since 2011 which would suggest considerable flow just not actively erupting most of it. Nyiragongo also has had a lake for years, as it almost always does. At 1 km3/decade Nyamuragira could be only 5000 years old, and yet everything I have ever been able to find says it is much older than that. So either those sources are right and magma supply has been dramatically accelerating or the volcano really is only 5000 years old and has never really stopped since. Either is a big sign magma production in very recent time has increased rather enormously. Nyiragongo also is a clue, it seems to be mostly a gas vent. Its net lava output is quite minor, but it degasses more SO2 than even Kilauea, might be the highest sustained rate of all volcanoes. It might be small on the surface but evidently it is directly connected to a massive volume of magma at depth.
          Crust is apparently under 25 km thick in this area, so only a bit more than Iceland under Vatnajokull, which is completely tholeiite. It is also much less than most of the rest of Africa which is going on 35 km. Might be on the verge of the next Deccan Traps here…

  17. Saturday astrophyscis fun

    Surface of the sun in Detail
    Looks superstrange really, boiling convection pot. The photosphere haves 1/100 th of Earths surface atmospheric density, so its conductive heating is rather very low as Chad says.
    The reason the photosphere is so bright Despite its low density, is that its hotter and deeper layers that shine through and you end up looking at alot of hot particles through depth

    But its the radiation heating by photons that makes things like rock and metals vaporize If it was put in the photosphere, still a planet woud take a very long time to be destroyed there by radiation heating as it only heats the surface of the unlucky imaginary planet placed there.

    Planets thrown into the Sun for fun
    If an unlucky planet say like Mars was simply carefuly placed in the photosphere ( Impossible in nature ) Then Mars woud quickly sink into the denser hotter solar interior, Down in the suns convection zone its much hotter and most important a much denser enviroment and that woud boil away Mars … transforming it into sillicate plasma and it woud merge and mix with the churing solar interior. Mars woud probaly sink deep enough until the solar interior is as Dense as Mars own density which Maybe as deep as the suns radiation zone, down there the temperatures and heating by high densities makes short work of Mars

    In real Life.. If Mars or any other experimental planet thrown in for fun .. it woud hit the sun at around 600 kilometers a second .. souch an impact alone woud generate enough kinetic energy that the planetary subject might be totaly destroyed and vaporized instantly by the sheer kinetic energy of hitting the suns surface at souch immense speeds, the Photosphere is only 400 km thick, under are hotter and much denser layers. A planetary impact with the sun happens at souch immense speeds that it woud be little diffrence between hitting a hard solid object like a terestrial impact. The Mars experiment impact woud cause a huge wave of rock vapour sillicate plasma To spread across the suns.. surface Increasing the suns brigthness alot as a hotter streak woud form as Mars vaporized materials thrown up by the impact settles on the photosphere, after a few months.. the mars materials that settled woud mix and disperse within the suns outer parts.

    I hopes I gets the physics right here
    I guess a Gas Giant thrown into the Sun .. woud behave much the same

    • I expect that the radiation would do more damage than the speed. The energy of the shock wave as the planet falls in will mostly go into the surrounding gas. The surface will get bombarded by 40 MW per square meter. It takes 1.2MJ to melt 1 kilogram of rock from 200C. So per second you could melt 30 kg in every square meter of surface, which makes 1 cm thickness. In practice this is a severe overestimate because the molten rock insulates and also itself radiates). But in theory you could melt 1 km thickness per day. You still need to vaporize it which takes more energy. Adding this takes the energy needed to remove 1 kg or rock to 5MJ, 5 times higher than just melting it. Now we are (very roughly) down to a rate of 1 km per week (about the average speed of a russian tank, it appears). At this rate, it will take 50 years for Mars to disappear if it mistakenly parked itself at the solar photosphere.

      • Something I have wondered for a long time is would an impact of a planet with a star be enough to initiate local fusion? Or even a high speed impact of two gas giants? Our solar systems outer planets as well as most we have found elsewhere are not very dense, but those approaching the fusion limit in the 50-60 J mass range are on average denser than any solid, and have extreme gravity. Seems whether to call objects like that planets or brown dwarfs depends on how they formed, brown dwarfs form like stars while some would form as planets and get supermassive. Same object really for this purpose.

        What I am talking about here is not the combined object exceeding the fusion limit and initiating the reaction at its core, but fusion happening at the actual point of impact. Could a collision between solid surface ice planets also do this? I understand the energy to initiate fusion is immense but these are planets colliding that we are talking about, or even planets hitting stars… Planets falling into stats have been observed to flare up or have a much bigger effect on the star than originally expected, as for V838 Monocerotis, which was caused by a planet impacting the star. Maybe local impact fusion is what causes this.

      • Deeper inside the Sun .. Mars woud dissolve into sillicate plasma even much faster..

        How fast woud it dissapear of it was placed into the suns center ?

    • Thanks for the input : )

      Two scenarios here

      Carefuly placing mars on the sun surface

      And the realistic .. letting it impact the suns surface

      Stars are really really really strange stuff for soure

      • ‘Carefuly placing mars on the sun surface’

        Those are some big tweezers.

          • Yes, those are the eruptions that the post is about. The Stormberg group describes rocks deposited over a longer period which includes this volcanics. A stormy time

            That is one of my favourite posts here

          • It’s a beautiful piece. I was wondering whether snakes had been around, the Puff Adder and Australian Death Adder having some resemblance; the same goes for the Cape Cobra and Indian Cobras. It is certainly possible as fossils might disappear with so much volcanism. The oldest fossils of snakes were found in England, 167 Ma:
            Generally that snake and the geelslang are not my favorites though. The dinosaur traces are great. And of course the rocks.

          • Denali the Death Adder is not a viperid, it is an elapid like all other venomous snakes here. Convergent evolution of the highest calibre.

            Pretty much every family of snakes that exists now is evolved post K-Pg, maybe in the late Cretaceous but no earlier, definitely not early Jurassic. Snakes are a lot like mammals in being a group that was restricted by dinosaurs until the Cenozoic.
            Snakes are thought to have had a common ancestor with mosasaurs within the Anguimorpha group of Squamata (also includes varanids and gila monsters) around 100 million years ago but because squamates have evolved legless forms many times independantly it is hard to tell what is a snake alot of the time… But in general Squamata was not diverse until the later Cretaceous, before that the Rhynchocephalians (tuatara) were in that niche.

          • Yeah well Chad, I was of course thinking of common ancestors, not the snakes of today.
            And the English fossils speak for snakes being older. Mososaur is today discussed as belonging to the pythons, not to all snakes, but that is also strongly contested. Some think python, some lizard.
            Basically, we don’t know enough as fossils are rare. It often doesn’t seem like it, but yet, fossils represent – I’ll look it up – I remember 1% of all species that have existed. Which means there is some guessing and construction. You know how many ancestors homo sapiens has had in the past 50 years. The knowledge is valid until else is found.
            If there were scorpions, I thought, there must have been snakes. And there were no snakes there in the Triassic and Jurassic until the fossil of a snake of that period is found, i.e. under Antarctic ice shields. At least a specimen with legs.
            Anyway, never mind, was just a thought, and before the British fossils were found nobody considered snakes that old.
            They are tasty sayeth the Chinese. Which means they might have been eaten up by some other species.

            Coast Garter Snake, pretty at least:

    • If I coud stand on the photospheres outer edge where its 1/1000 th of Earths atmospheric density at sealevel

      What woud I see? Bright everywhere?
      I doubt there woud be much of a horizon .. also the density of the solar atmosphere medium is very low

      Still woud be very hot and best To have liquid hydrogen cooled suit, also needs some bouyancy To keep me from being pulled down into the Suns depth

      Standing on a sunspot woud be just as bright

  18. Taal is throwing gas emissions like crazy and we still haven’t seen a major eruption. Phivolcs says the volcano has been deflating since October. which is either really good or really bad and I don’t have any recent insar data to work with. To fuel this degassing there must be a lot of shallow magma but what’s keeping this magma from erupting? Is this a large batch of ascending magma that hasn’t reached the surface or is it a smaller portion of magma that’s stuck?

    • Caldera collapse, slow drainage of magma into the rift made in 2020. This is not good as the collapse can (and with emissions like this probably is) make a ring dike. Hunga Tonga was able to induce collapse by erupting out the top but Taal is going invisible and taking it slow, like at Kilauea and Bardarbunga but much slower still, it hasnt begun to properly collapse yet. But eventually it will crack and drop, we will see a mag 4-5 quake, and it will go boom now a way to escape is there. Maybe it will be a firework show with Etna style fountains but it might just blow up like Hunga Tonga did.

      Ring dike is going to be in the small caldera on Volcano Island, not the big caldera, I should say. We arent going for a VEI 7, but could still be a solid 5 and probably a very powerful one at that.

  19. With the venomous snakes. Which came first: the poison or the hypodermic tooth? Unlikely they evolved in tandem as both are highly specialised.

    • Venom was first, varanids and gila monsters have it too and are not snakes. Possibly all Squamata ancestrally had it. Not all venomous snakes have hypodermic fangs either.

  20. Why is it so quiet here?

    Only 2 months ago was the biggest eruption since this place was founded, and probably in the lifetime of the majority of the audience, but it is so quiet there are comments from 2 days ago on the most recent 🙁

    • There’s nothing hot in the volcano news as of late, the Tonga eruption has already been well discussed and analyzed. Not to say that there is nothing more to be learned from the eruption but things have so far run it’s course in the short term. There is almost zero data concerning the new unrest at Davidof to the point that we have no idea what’s actually causing the quakes. Grimsvotn looks exactly the same as it did last year but less interesting as the glacial flood was a dud. Taal has some potential but Phivolcs haven’t given us anything comprehensive.enough for us to dive deep into. I don’t care about Hawaiian volcanoes but things look boring over there too. We have unrest but we don’t have any data to work with and for the volcanoes we have data for things look very neutral or slow.

      • Not sure I would say the eruption is yet well enough discussed, its official VEI is not even known yet, just a few numbers being thrown around. Most likely it will be a mid range 5 but then what if it is only a 4 or as high as a 6? Either is possible. Was only this week that it was discovered the eruption of Fukutuko Okanoba was actually a VEI 4, the biggest eruption last year and bigger than St Vincent, 0.35 km3. Was originally not even half way to a 4, off by a whole order of magnitude. Ocean volcanoes are quite mysterious even if in this case it was neither isolated or unobserved there is still alot that was missed.

        I understand why you find Hawaii boring being that you like explosive volcanism and rhyolite but why do you like Grimsvotn so much? It is basically the same magma as Hawaii, and much less productive. I think until someone actually finds tephra deposits from the Satsunarvatn eruptions in Iceland itself the VEI 7 claims should be taken with a massive bucket of salt. Would think Hekla is more your cup of tea, or Torfajokull.

        I would encourage you to look at the Pahala ash sequence. Kilauea was not always boring, it was like Taal on steroids in the Pleistocene. Meters thick ash 50 km from the volcano, 30,000 years of massive explosions sometimes alternating with flood lavas a lot bigger than it can erupt on land today.

        • Grimsvotn is one of the most active volcanoes in world, is firmly mafic, but throws cool explosion pretty often. Interestingly, the volcano has recovered from a lava flood pretty quickly. Hawaiian volcanoes are simple and boring at the moment and if they were cool 30,000 years ago that’s different. Taal has done feats like that before after all Manila is built over it’s iginimbrite

          • Sounds like you havent actually bothered to do much research on Hawaii, it is not really that simple at all, actually very complicated compared to most places.
            Grimsvotn has been rather hyped up on this site especially early on, actually it really doesnt erupt a lot of lava, both Hekla and Bardarbunga comfortably outperform it. Also not sure it stands out particularly for activity, given it has only erupted twice in 20 years, that is probably.

            I mean I could talk about how the volcano that did the biggest lava flow of the last 200 years now has a 300 meter deep lava lake less than 4 years later 😉

          • Hawaiian volcanoes are nowhere near close to even what I would consider “productive.”. It’s my opinion but I always compare current volcanoes, volcanic eruptions, and volcanic structures to the geological past. If you remember from my last article, I crapped all over the idea of considering Tambora a VEI 7 eruption. There are so many past eruptions that blow Hawaii out the water and into space, The recently discussed Columbia river basalts had over 500 km long lava flows. Hawaii is certainly no flood basalt and is not even in that ball park. Some systems have produced 10x the magma that Hawaiian volcanoes have in a quarter of the time frame. The volcanoes are impressive for us but not for the Earth
            These are the most harmless eruptions possible on some of lesser threatening volcanoes on the planet. Iceland and East African volcanoes have more variety, are more threatening, have more complicated setups, and are cooler. The only thing I find cool about Hawaii are the incredible landslides

        • Hawaiian volcanoes are the largest active and most productive volcanoes in the inner solar system!

          Their size is Impressive and the short time They reach the gigantic sizes

          In the last 5 million years Hawaii have produced an equal of Olympus Mons in size in volume that says something about the insane productivity of the Hawaiian Hotspot

          Big Islands
          350 000 km3 is not much older than neandethals are as a species.. lots of volume in short time

        • Grimsvötn is not close in productivity compared To Kilaūea

        • And Hawaii recovered from a 2018 Holuhraun sized drainout in just 2 years .. and is once again an unstoppable tap of liquid rock

      • That’s volcanoes for you. We have had an amazing 12 months, with Iceland, Hawai’i, La Palma and Tonga. But we could easily have a year without a significant eruption. Keep an eye on Merapi

        • Merapi does the most damage by erupting the least of any volcano. It probably erupts less than 1000 cubic meters / day, problem is that the landslides from collapsing lava flows and domes roughly head right toward populated areas (Yogyakarta metro, 4M inhabitants). It’s really not that explosive, actually basaltic andesite. Just the wrong location.

          • Not sure the volcano is in the wrong location, more whoever decided it was a good idea to live underneath it…

            I wonder if Merapi is one of those volcanoes with mixed magma. St Vincent is also listed as basaltic andesite but in reality the magma is dacite with mafic crystals, so overall of intermediate composition but felsic character. Merapi is much the same on appearance, basaltic andesite is not viscous enough to make domes like that. Even andesite is not that sticky.

      • Tallis Hawaii produce more magma and make larger volcanoes than any other place on the planet..

        Pretty much all other volcanic edifices are grains of salt compared to Hawaiis deep sea giants

        Its also Impressive the size of the immense Hawaiian edifices and the short time They grow that large

        I think Hawaii is un – rivaled on Earth

        • in terms of current active volcanoes?Yes. But in geological record? Nope.

  21. Albert thinks we might not have a significant eruption for a year. Oh, God.
    Maybe we’ll have an earthquake instead. No, better place bets. My bet for Mount Shasta. Reason? Hasn’t erupted in a while. Second reason: Would make a pretty piece for Carl or Albert. Third reason: None.
    Finally bored. You get there without volcanism.

    Mount Pretty with traces in the snow:

    • To help you with the boredom, a post has been scheduled for later today.

      In times of war, volcanoes take a back seat

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