Magma rising

/ 18/04/2025

In 1864, three people set out on the journey of a life time. Starting at Snaefellsjokull, Hans, Axel and Otto descended into the crater, found openings to the depth and started on a journey to the centre of the Earth. At least, so Jules Verne told us in his book Voyage au centre de la Terre. They descend to over 60 km depth where they find a lost world, one that has inspired many stories. Even the Jurassic Park series can be traced back to Verne’s imagination. A climb back up of 60 km seems rather daunting, worthy of a book by itself. In the end, the party is carried back up to the surface pushed up by a fountain within a volcanic chimney, lucky for them a fountain of water rather than magma.

The book is among the earliest ‘science fiction‘ rather than ‘fantasy‘, in spite of the ‘fantastic’ content. Verne tends to stay close to physics as it was known at the time. Where the story deviates from that, Professor Otto carefully explains the difference and the possible reasons. But the journey back has been overlooked in the discussions of the physics of the ‘Verne-verse‘. What can cause the fluid to rise 60 km up, with enough force to carry three people?

And what if the fluid had been magma rather than water, as it should have been inside a volcano? There are obvious reasons why Verne avoided magma. (It would have been a very different story had Jesper written it.) But magma does exactly what Verne wanted. It does travel upward by that much, and manages to do so through solid rock. How does magma get around the laws of physics? Does it live inside its own ‘magma-verse‘? It is time for the definitive discussion of the physics of rising magma.

Fear not. This is not that discussion. But it is the bit of the story Verne never wrote. It is about the journey of magma from its formation to its closure. This is a story about pressure – and about a fight against gravity.

Physics for beginners

Physics knows four fundamental forces. These are named the strong force, the weak force (physics is not known for literary eloquency), the electromagnetic force and gravity. The first two you are unlikely to meet in real life as they only show up at the smallest scales, atomic nucleus or smaller, although the universe, Verne-verse or magma-verse could not exist without. The electromagnetic force is experienced occasionally by us, such as when using a compass or being hit by lightning (or both, if you are unlucky – a compass cannot be trusted after being hit by lightning. Ask Captain Ahab). But it is omnipresent: much of what this force does is hidden from view. And finally, gravity is everywhere; it is the force we experience most often. But it is not a ‘may the .. be with you’ kind of force. In physics, gravity always wins. As it is written, ‘the greatest of these is charity gravity’.

“Science, my boy, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.”
― Jules Verne, Journey to the Center of the Earth

Volcanoes seem to be impervious to gravity. While gravity pulls everything down, volcanoes go up. Liquid rock, not a substance known for its lightness of being, spouts out of a crater in total disregard of gravity. Volcanoes rise and grow, in the case of Mauna Loa to a staggering 9 km above the seafloor on which it sits. Normal mountains require plate collisions in order to make crumple zones, so that as much matter goes down as up. Below the Himalayas are the anti-Himalayas, the deep roots going the other way. (I now imagine an upside-down world where magma-beings walk among these inverted mountains. Where is Verne when you need him!) Volcanoes don’t need this. They do it all by themselves. How is that possible? How does magma manage gravity?

Beyond physics

There are many other forces which physics does not recognize as ‘fundamental’ but which still affect our lives. Pressure is an example. We know about the pressure of expectations and about peer pressure. Pressure in itself has no direction: it pushes equally from all directions and therefore has no other effect than making us feel ‘under pressure’. But the pressure may be different elsewhere. For instance, there may be a lot of people trying to get to the bar and get a drink, while there are fewer people further back. Now there is a force pushing you away from the bar – hopefully with a drink in hand. (Hint: if you see a beer called ‘magma’, go for it.) This is a general principle: if there is lower pressure in some direction nearby, we feel a force pushing us in that direction. This is very notable with the pressure of expectation: we easily move to a place where expectations are lower and feel reluctance to move to a more demanding environment. When there is no such direction, pressure can become unbearable.

Pressure is opposed by another force we are all familiar with: inertia, or resistance to change. It turns people into immovable objects. It can be good or bad. Some people thrive under pressure, some just cope, and some wilt. Each are kept in their place by inertia. But against gravity, such resistance seems futile: gravity is an irresistible force. Unless you are a mountain goat, that is: these are the only mammals known to be resistant to gravity. Everyone else should pay attention. As the UK found out, if you run the economy off a cliff, don’t expect an easy ride back up.

Back to physics

It is a quirk of physics that inertia goes with mass in the same way that the force of gravity does. No other force has this property. Because of this, even though the force of gravity on an object ten times as heavy is ten times as great, the effect is identical: the two objects move exactly in the same way. Hence, the famous experiment showing a bowling ball and a feather falling at exactly the same rate. Gravity is a funny beast.

If you want to do this experiment yourself but can’t get hold of a large vacuum chamber, try to find two bowling balls of the same size but different weights and drop them from a suitable height. A risk assessment should be undertaken first, and anyone in the way should be forcefully removed. The two balls will fall at the same rate.

But some things seem impervious to gravity, and manage to hold their own. The world around us manages it: neither the solid ground nor the liquid sea fall in on themselves. Why is that? The saving grace is that gravity is amazingly weak. If you stand rather close to another person in the queue for the bar, you may feel many forces between you, some repulsive, some (perhaps) attractive, but gravity is not one of them. Atoms are kept apart by electrical forces, and those forces are far stronger than gravity. So materials can withstand gravity even from something as large as the entire Earth. But with great difficulty, and with limits, as you will find out when trying to build a mountain higher than Everest.

Our atmosphere also manages to stay up against gravity. Air is easily compressible (try to squeeze a balloon filled with air and one filled with water), which raises the question, why doesn’t all air collect at the lowest point? It doesn’t happen because of air pressure. As the air falls down under gravity, it becomes denser and therefore has higher pressure. This is something we are all familiar with. Climbers on Everest (ok, not everyone may have done that) need extra oxygen. Even at a height of a few hundred meters, the air pressure is notably different. As mentioned above, a pressure difference creates a force towards the region of lower pressure. A stable situation forms where the force from the pressure difference exactly balances that of gravity. Hence the fact that we have a usable atmosphere, but that the air pressure declines when going up.

Finally, floating balances gravity. If your density is less than that of water (true for people), than being submerged causes an upward force: you end up floating on the surface with about 90% of your body submerged. Try the same thing with a brick and it won’t work so well. Ice has a lower density than liquid water, so it collects at the surface. Cold water sinks, as the density of water gets a bit higher when it cools -so the bottom of the ocean is very cold,

Now we are ready to attack the story of the magic physics of volcanoes.

Magmarising

The crust and the upper mantle of the Earth form the lifeblood of volcanoes. They contain three distinct regions. The upper mantle consists of a mixture of silicates (45%), iron oxides and magnesium oxides, with a density of 3300 kg m-3. This density increases with depth because of the weight above it! The crust above it has two different types. Oceanic crust is like the upper mantle but with a bit higher silicate fraction (50%) and a bit lower density (2900 kg m-3). The lower density is in part because it has less weight to carry. Continental crust has a higher silicate fraction (60%) and a lower density of 2600 kg m-3.

The crust and upper mantle can also be divided into the lithosphere and asthenosphere. The lithosphere is the rigid part of the crust, while the asthenosphere lies deeper and is more ductile (lower viscosity): the rocks can deform a bit. Below the asthenosphere lies a more rigid part of the upper mantle.

Deeper rock has higher density. So it won’t easily come to the surface: gravity stops it. Volcanoes, which are in the business of bringing rock up from the deep, seem to be fighting a losing battle. But there is a loophole, and volcanoes use it.

To melt or not to melt

A substance has a melting temperature: the temperature at which it ceases to be a solid. This melting temperature changes with pressure: at higher pressure, a higher temperature is needed for melting to occur. As we go deeper into the crust and mantle, both the temperature and pressure increase. A rock will melt if at some depth, the local temperature is above the melting temperature for that pressure.

The relation between depth and temperature is shown in the figure above. As an aside, note that the temperature in such plots is often given as the potential temperature: this is the temperature the rock would have without the pressure it is under. Pressure increases the density by making the rock contract (even rocks do this, a little, if the pressure is high enough). The contraction heats the rock a bit. You can try this with a bicycle pump: as you compress the air in the pump, the pump becomes warmer. In contrast, air escaping from a tyre feels cold. This is also the reason why sea-level air is warmer than that high in the mountains. If you would bring the rock to the surface without adding or removing heat, it would arrive slightly expanded and with its potential temperature. The potential temperature is used just to confuse you and I won’t mention it, or at least, will ignore this distinction.

After this diversion, back to the story. The figure has a black line and a dashed red line. The black line is the actual temperature, also called the geotherm. The dashed red line is the solidus: the temperature at which the rock begins to melt. The solidus temperature is different for each depth.

The red line becomes very close to the geothermal (the actual temperature) at a depth of some 150 km. The red line may be just above or just below it: it varies a bit in different places on Earth. In the first case you get slightly ductile rock; in the second case you get some melt. The close approach of the two lines is an accident of nature: it may be different on different planets. It is not an accident that this location is in the middle of the asthenosphere. The rocks in the asthenosphere are more ductile precisely because their temperature is close to the solidus.

Why is it called the solidus rather than the melting temperature? That is because there is a bit of funny magic physics about melting rock. Whilst water is either frozen or liquid, rock can be partially molten. If the solidus is at 1500 °C, then at 1550 °C the rock may be 20% molten, at 1600 °C 40%, at 1800 °C 60% and only at 2050 °C is it fully molten. The temperature at which it is fully liquid is called (hold it..) the liquidus.

Because the solidus and the actual temperature are so close together, you may only get a few per cent melt. If you want to do better, there are some ways to increase it.

The first way is to increase the temperature: insert a hot spot or even a plume, the local temperature goes up by perhaps 50 C, and the melt fraction increases to 20%. Bingo, job done.

The second way is to reduce the solidus temperature. This can be done by adding water to the rock. This happens above a subduction zone: the subduction brings wet rock down to the mantle, the water comes out and wets the mantle wedge above. That wedge now has a lower solidus. This occurs at a depth of around 150 km, where the temperature is already close to the solidus, so a small change can push the rock into the melt zone. Don’t expect too much: a small percentage of the rock may melt. It doesn’t work in the subducted slab itself because this slab is too cold.

How does this work in practice? Let’s first look at a typical piece of mantle, away from any rifts, hot spots, plumes or subduction. This gives the following profile for the geotherm and the solidus:

As shown by the heading in the figure, these images come from the Geological Society (“Serving science, profession and VC”). In this typical region away from plate boundaries, as indicated by the arrow on the left, the geotherm is well below the solidus, and therefore the rock is too cold to melt. There is no magma.

Now let’s look at other cases. At a mid-oceanic spreading rift, mantle material rises up. It is hot to begin with, and although it cools a little while rising, it stays hotter than rocks here would normally be. In the figure below, this situation is shown in is the second panel. The geotherm is now much steeper, and it stays above the solidus for a range of fairly shallow depths, here between 10 and 50 km. The reddish section shows where magma is generated. The melt fraction remains low, at typically 2%-4%.

The third panel shows a plume in action which brings up hot material up from the low mantle. But because the crust itself is not splitting apart, the plume hits a brick and can’t rise further. A plume head develops, much wider than the plume itself, where the warm material collects. Magma is now generated at depths of 100 to 150 km. This is the situation in Hawai’i. Iceland is a bit more complicated, as it is both a spreading rift and a (mild) hot spot. So it is intermediate between this and the previous case.

The fourth panel depicts a subduction zone. In the well-watered mantle wedge, the solidus has shifted to lower temperatures, creating a deep red-coloured region. Magma is now generated at depths of 100 to 200 km.

So now we have situations where some rock 150 km deep has partially melted. What happens next is that it finds a way to circumvent gravity. This is the Theory of Magma Quantum Gravity.

Falling up

The rock now contains a small fraction of liquid. Everything is under a very high pressure, having 150 km of rock weighing down on it. The rock with its extreme inertia just has to grin and bear it, but the liquid does not like pressure. It is both incompressible and deformable. Think squeezed sponge: the rock gets squeezed and the liquid is squeezed out of the pores. The liquid begins to form drops.

Molten rock droplets (proto-magma) have a bit lower density than the surrounding solid rock. The pressure now acts as an upward force, pushing the drops upward. This is rather difficult, as the solid mantle rock is in the way. The liquid drops are trying to move something with the inertia of a mountain 150 km tall. That is obviously not the way upward. It is worse than making your boss change their mind. The drops instead move from pore to pore, trying out how permeable the rock is. The fact that the rock is partially molten makes it a bit permeable, luckily. As one drop is squeezed out of a pore, another drop from below replaces it. Let the rise begin.

But not too fast. A typical melt velocity through the asthenosphere is 100 meter per year. To rise 100 kilometers, to the bottom of the rigid lithosphere, may take 1000 years. During that rise, it may have to content with a lower temperature and pressure, while trying to stay above the solidus. Luckily, solid rock is an excellent insulator and the rising melt brings its heat with it. The melt fraction may even increase, under the right conditions. But by and large, making magma is not so much like an air fryer and more like a slow cooker.

At some point, the ascent becomes more difficult. The rock above is now well below the temperature of the solidus, and becomes rigid and not particularly permeable. Force is needed to break through. It is time to catch breath, after the slow dash up. The melt may accumulate at this depth, forming liquid magma chambers, waiting for the right opportunity. The moho is a common location for such stalled magma. Over time, the liquid can cool a bit, causing the magma chambers to become a ‘mush’, a liquid with a lot of crystals where the liquid fraction may become as low as 10-20%. If it fails to break through, then the magma may even solidify here. In such cases, magma’s journey may end here, Otto didn’t make it back out of the Verne-verse and new crust is plastered onto the existing one.

“Is the Master out of his mind?’ she asked me.
I nodded.
‘And he’s taking you with him?’
I nodded again.
‘Where?’ she asked.
I pointed towards the centre of the earth.
‘Into the cellar?’ exclaimed the old servant.
‘No,’ I said, ‘farther down than that.”
― Jules Verne, Journey to the Center of the Earth

CO2 wind

To rise further is indeed difficult. The rock above still weighs more than a mountain and won’t just move aside: to rise requires breaking rock. Help is needed. Often, this help involves volatiles.

The volatiles in the magma include CO2, water and SO2. The most important of these is CO2. The volatiles account for a few percent by weight of the magma, and initially remain safely dissolved in the magma where they are not much use to anyone. But as the magma rises and pressure decreases, less volatiles are allowed in the liquid and the magma may become saturated. The magma behaves like a fizzy (carbonated) beer and CO2 especially can now form gas bubbles. When dissolved, CO2 is part of the liquid and has the density of the liquid – liquid rock. The gas bubbles have a lot lower density: adding the bubbles makes the magma much more buoyant. An added bonus of the CO2 dissolution is that this process generates heat and so the magma reheats a bit. Water does not do this.

The magma is now driven up against the will of gravity by the bubbles. It is blown by an underground wind of CO2.

This process of wind-driven magma ascent can happen even at great depth if enough CO2 is available. The main example of this is kimberlite, a kind of eruption we have never seen ourselves – but we can hope.

The formation of the mush can cause CO2 to reach saturation. As more of the melt crystallizes, the CO2 remains in the liquid and reaches higher and higher levels. The liquid becomes saturated, the gas comes out of the solution and forms bubbles against the confining cap rock. Boy, is that rock in trouble. The gas expands as it comes out of solution but there is no room for expansion. Pressure goes through the roof – literally in this case as the cap rock gives way. Initially, the gas also needs to break through the crystal mush but that is peanuts in comparison to the rock. The gas bubbles break a path through the rock and allow the magma to restart the ascend. The crystal mush may be carried with or may remain behind.

The wind often makes use of existing planes of weakness. Luckily, these are not uncommon. They may be inclined faults or there may be horizontal layers of different compositions. In the latter case, the magma forces the layers apart and forms a sill between them. Sills seem to be the most common type of magma chambers. Underneath volcanic regions, there may be a whole series of such sills at different depths waiting for their chance. The high pressure of the forming bubbles fractures the rock and causes microseismicity, and for the first time the rising magma is detected by our instruments. This is happening at the moment at Snaefellsnes, in a twist to Verne’s story.

The process can repeat multiple times, leading to the formation of magma sills at a number of depths. A magma batch may bypass intermediate sills and go straight to a less deep one. That happened, for instance, at Bardarbunga a few years before the 2014 eruption when magma rose from 22 km to to 7 km, bypassing the lower magma chambers between 8 and 12 km.

So, passing a bit of wind clears the way. (It may work in the crush for beer at the bar as well – I haven’t tried.) Some of the microseismicity we detect in various volcanic regions is from this process. Often it does not lead to an eruption. But sometimes it does, with a final push to the surface.

Anti-gravity: the final ascend

At the end of this process, the magma sits a few kilometer deep. So far we have had a successful intrusion with magma rising from 150 km to near the surface. But unless the last few kilometers are also succeeded, it counts as a failure. What to do? The CO2 wind has had it last breath and gravity refuses to go away.

As gas continues to come out of the magma (CO2, H2O, SO2), the magma develops froth and the frothy magma rises, creating a conduit if necessary. During the rise, more gas bubbles form and the density of the magma decreases fast. This accelerates the magma.

The conduit that forms (Otto’s chimney from the deep) has constant size with depth. The flow rate of the magma, in kg/sec, must be the same at all depths, otherwise more magma would enter than leave. or the opposite. As more bubbles form, the density keeps going down. The volume increases but the size of the conduit stays the same. The only way to keep the flow rate constant is by increasing the speed. At constant width of the chimney, the flow rate is equal to the density times the velocity. If the density goes down, the velocity must go up. And so it goes.

The gas bubbles become larger and congegrate into slugs. This happens within hundreds or even tens of meters of the surface. These drive the magma at ever higher speed. Because of this acceleration, when the magma reaches the surface, it comes out in a tall fountain, typically 10 to 100 meter high. The lava may come out of the conduit with speeds of 10 to 100 meters per second. It is a long way from the 100 meter per year at the start of the journey.

The tallest recorded fountains are over 2 km high! The height is determined by the gas content, the size of the opening and the spread angle. The height reduces if the magma becomes degassed. It also decreases if the conduit widens close to the surface. This happen, for instance, if the magma overflows the conduit. The magma fills the crater and forms a lava pond. In effect, this pond acts as a much wider part of the conduit. The flow speed slows down dramatically in the pond, and the fountains become smothered.

The process does more than produce fountains. The forces opposing gravity are so strong that magma is pushed far beyond sea level. It builds mountains, typically 2-3 km tall but in some cases (Hawai’i) much higher.

Source: Edmunds et al 2019, https://royalsocietypublishing.org/doi/10.1098/rsta.2018.0298

It matters whether the eruption is on oceanic or continental crust. Basaltic magma has a density that is a little lower than that of oceanic crust. It can erupt easier on the latter, especially for effusive eruptions. This is the case in Iceland, which in spite of appearances consists of oceanic crust. Gas content helps, and the eruption may be much faster when it has a high gas content. As gas content reduces the eruption becomes calmer and eruption rates become lower. This is the normal process in Iceland: a slow start if old magma needs to be pushed out, a fast phase of fresh, gassy magma and a tapering off as the gas reduces, until a sudden end when the density of the magma is insufficient to overcome gravity and inertia.

On continental crust, density is a much bigger problem. Basalt has a higher density so needs help. This can be a very high temperature (mantle plume), a high gas content or a thorough wetting. The latter reduces the solidus to a much lower temperature and allows basalt to remain liquid in the cool crust. If the magma consists of molten crust, then its density is also less and the problem goes away: silicic volcanoes have it much easier than basaltic ones.

Down ..

Once the magma has completed in journey and the three intrepid travelers are back on Earth, gravity again reigns supreme. When magma turns to lava, it can only flow downhill. But not necessarily all the way to the lowest point. Thermodynamics kicks in to help.

Lava exposed to the air loses the insulation of the solid rock, and is free to radiate its heat away. And so it does, and it quickly cools to levels where the surface of the lava solidifies. This slows down the flow dramatically. Eventually, the flow stalls and the lava turns back to solid rock.

The distance traveled can range anywhere from hundreds of meters for viscous, cooling lava to tens of kilometers for the hottest, lowest viscosity stuff. On Venus, they can run for thousands of kilometers, aided by the heat of the atmosphere which slows down the cooling dramatically. If the lava runs over long distances, then it builds mountains of wide shields. If it stops quickly, it builds steep cones. The more viscous the lava is, the steeper the cones it can built.

The most viscous stuff of all are the cinders, lava that solidifies in the air. Cinder cones can especially steep, and, speaking from experience, the loose stones are a nightmare to climb. Ashy falls are not as steep but still not easy to walk on: even the path up Vesuvius can be too hard for some. Frozen lava flows are less steep.

But in all cases, a mountain gets built. The beautiful cones of Mount Fuji or of Mount St Helens (it was much prettier before it blew up) are signs of defiance against gravity, of the power of inertia.

One of the many cinder cones near Flagstaff, Arizona

.. and out

But mountains don’t last. Gravity has a way of sneaking up on you. Gravity has powerful allies. One is weather, the power of falling rain and of blowing wind which can take down any mountain over time. It can go fast in the tropics and slow in deserts, but the outcome is the same. Coastal erosion can be particularly fast. Many of our landscapes were formed by the glaciers of the ice age: the world looked very different a million years ago, before the ice came. Erosion creates, but the creation comes out of destruction. Erosion increases entropy.

The other ally of gravity is the asthenosphere, that ductile layer underlying all volcanoes. As the volcano grows heavier, the asthenosphere slowly -very slowly- adjusts by flowing sideways. The mountain now begins to sink. Even Mauna Loa, giant of giants, is sinking by 4 cm per year, and is desperately trying to hold its own by expelling lava at the same rate. Eventually, gravity will win. The skeletal remains of older Mauna Loas litter the ocean floor between Hawai’i and Siberia, sunk to kilometers below sea level. Here they find their own ally: the ocean itself helps carry the weight and stops the rain from reaching the remnants. But even that doesn’t last: the ocean floor carries the mountains to a final fate in a subduction zone. Gravity will, in the end, return the magma to the mantle.

There is nothing more powerful than this attraction towards an abyss.”
― Jules Verne, Journey to the Center of the Earth

There is an exception to this. Continental crust does not subduct, and lava coming to the surface here can survive much longer. Still, erosion comes to us all and even in the driest regions, eventually the thickest lava shield will be gone. It can take a long time: it may go down by 1 cm per 1000 years, or 1 km per 100 million years. Siberia still has large fragments of the flood basalt that covered it 250 million years ago. But if you are looking for one of a billion years ago or older, you may have left it too late.

Explosions

But the surface is not the summit of the magma’s journey. It now may take to the air.

The eruptions described above are effusive: magma rises to the surface through an open conduit. But not all eruptions are like that. Sometimes, the battle against gravity is a high pressure event fought with explosives. These are the eruptions most likely to go above the cal of duty and affect the atmosphere.

We have mentioned how the liberated gas moves within the magma. But sometimes, the inertia of the magma becomes an impossible obstacle. This happens when the magma is cool and viscous. Gas comes out of the solution as the magma chamber slowly crystallizes, but the bubbles have nowhere to go. The pressure goes up and up but the gas find no escape from the magma. This typically happens in shallow magma chambers, and because the magma is viscous, it is most likely to happen under steep volcanoes.

Thus situation can lead to sudden, instant failure. It may start with an earthquake which creates a weakness in the mountain. This reduces the pressure a bit, but the lower pressure just causes more gas to come out of the solution, instead increasing the pressure further. The process can rapidly cascade into catastrophe. This is the main cause of the largest volcanic explosions. They are more common in evolved continental volcanoes where the magma is viscous, but can also occur in subduction volcanoes where the magma is saturated with water, or, unwisely, gains access to water, as happened in Hunga Tonga and Krakatoa.

Such explosions can throw out lava bombs to impressive distances. Reportedly, Hekla in 1947 ejected them as far as 30 km. This required an ejection speed of 500 m/s, reaching as high as 6 km – aircraft in danger! But mainly, these eruptions just blow mountains to smithereens.

Mount Tambora

So the battle against gravity ends with an explosive fight. But it is not wise for a volcano to blow up the mountain it itself painstakingly built. In the end, they themselves become gravity’s ally. The volcanic world is littered with mountains that are no longer there. Those volcanoes would make strong candidates for a Darwin award.

Up in the air

But this brings us to the final battle with gravity, where the magma uses the atmosphere as an ally. Lava fountains can reach 2 kilometers and lava bombs reach 6 kilometers height. But volcanic ejecta can do much better. Eruption plumes can reach the stratosphere and in the unique case of Hunga Tonga, the mesosphere. How do they do it?

The Raikoke eruption of 22 June 2019

We have seen that air pressure keeps the atmosphere up. Volcanoes have found a way to make it work for them. It uses not the explosive power of the eruption, but its heat.

The eruption heats the air, both by the explosion itself and from the hit interior it exposes. Hot air is overpressured, and therefore rises. As it rises, the hot air expands and cools, and this eventually brings it back into equilibrium. Up to that point, the hot air will continue to be hotter than the surrounding air and therefore continue to rise.

The rising air can reach high in the troposphere, and for larger eruption, even enter the stratosphere. The stratosphere has an inverted temperature profile: here the air temperature goes up again with altitude. This eventually suppresses the rising convective column, at height between 15 and 30 km. The rising column carries with it some tephra and lots of sulphur. These form sulphates, aerosols which turn the skies white and opaque, and once in the stratosphere, they stay there and are circulated around the world. We have seen this a little after Pinatubo but have little remembrance of the much larger events of 1815 or 1257. Those were dark times, and they could come again.

The sulphates don’t last forever in the air. Over time they slowly drift down. It can take several years for it to disappear, and it ends with the sulphates being distributed around the world. But for a while, the sulphates form the pinnacle of the voyage of the magma, from 150 km down to 15 km up. It is a battle against gravity, using pressure to its advantage, in a journey from solid rock to air.

Winners

The ultimate winners against gravity are the continents. They lie some 6 kilometers above most of the ocean floor, because of their low density compared to the oceanic crust. That low density comes from an overabundance of magmatic silicates. We float on granite.

The original cause of this lies in magma. It starts in a cooling magma chamber at the bottom of the crust, at the moho. Over time it cools and the minerals with the higher melting temperatures become solid. Eventually, all but the silicates solidify. The remaining liquid is now less dense and more buoyant. But is it also sluggish, viscous. It pushes against the basement rock, forming large intrusions of granite called plutons. They stay deep in the crust. The process can repeat underneath mountain ranges where some of the continental can melt.

Continents once formed from series of such intrusions. Basalt does find its way up as well, either from greater heat or from greater water content: wet basalt also can have a rather low melting temperature. But it is the silicate intrusions that create the high continents. Without them, the entire world would be under water.

In many places these granite intrusions have come to the surface, after tens of kilometers of overlying crust has eroded away: Paarl mountain in Cape Town, the moors of Cornwall – do add your favourite places!

Stone Mountain, Atlanta, an example of a now-exposed granite intrusion. This how the continents grew up.

Erosion leaves the continents unharmed. Remove the top of a continent, and the rest just floats a bit further up to compensate. It is just like taking the top of an iceberg: you’ll find the iceberg is still there while the Titanic is gone. Continents are indestructable, unable to subduct or sink back into the mantle. Not for them the failure of King Canute to stop the tides. They are the winners in the struggle against gravity.

The air we breathe

But there is another winner, one we rarely recognise. It is in the very air we breathe. The volatiles that come out of the magma can reach the air long before the magma does. They can go on their own journey. The CO2 that comes out of the liquid rock joins the atmosphere. 40 per cent of the CO2 in the atmosphere comes from us, but the remainder comes from volcanoes. Water has a harder time traveling separately and comes up more with the eruption itself, but if you wondered why after 4 billion years of letting wet rock subduct we still have an ocean left, this the answer: it is brought back to earth by volcanoes. All of our atmosphere, with the exception of O2 comes from degassing. Degassing of rock requires heat, and this is provided by the rising magma. Your air has changed over time. The Earth had a very different atmosphere shortly after its formation, which we lost and which was replaced by something closer to what we have now. Only argon, which strangely accounts for 1 per cent of our air, survives from those hadean early days.

This is the journey of magma. It is a slow dance, a sarabande with gravity, driven by pressure and fighting inertia, ending by returning to the Earth. But it shapes our world, creates our air and builds our continents. Physics it may be, but the journey is a human one. Verne would be pleased.

Albert, Good Friday, April 2025

“Wherever he saw a hole he always wanted
to know the depth of it. To him this was important.”
― Jules Verne, Journey to the Center of the Earth

(Verne quotes from www.goodread.com)


Euer Grab und Leichenstein soll dem ängstlichen Gewissen ein bequemes Ruhekissen und der Seelen Ruhstatt sein.Höchst vergnügt, schlummern da die Augen ein. Wir setzen uns mit Tränen nieder und rufen dir im Grabe zu: Ruhe sanfte, sanfte ruh, ruhe sanfte, sanfte ruh!

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294 thoughts on “Magma rising”

  2. “Your grave and headstone shall be a comfortable pillow for the anxious conscience and a resting place for the soul. Our eyes will fall asleep there, most contented. We will sit down with tears and call to you from the grave: Rest in peace, rest in peace, rest in peace, rest in peace, rest in peace!”

    Fortunate, are the faithful. Not I. 😔

    Thank you Albert.

    • Frozen lava has earned its rest. It has been on a long journey

      • Ahh … I missed that allegory.

        The Netherlands Bach Society soloists are brilliant. What a surreal volcanic path this Friday evening.

        The “Chief Priests” are still amongst us.

        • They are very good. So is the violinist. It is a small orchestra and a light performance. I like it

  3. Another excellent article. Ayers rock or now known as Uluru is actually a sandstone monolith as are the near by Olgas – small detail

    • Thanks for pointing that out. I should have remembered. The rock has been dropped from the post

  4. ”But there is another winner, once we rarely recognise. It is in the very air we breathe. The volatiles that come out of the magma can reach the air long before the magma does. They can go on their own journey. The CO2 that comes out of the liquid rock joins the atmosphere. 40 per cent of the CO2 in the atmosphere comes from us, but the remainder comes from volcanoes. Water has a harder time time traveling separately and comes up more with the eruption itself, but if you wondered why after 4 billion years of letting wet rock subduct we still have an ocean left, this the answer: it is brought back to earth by volcanoes. All of our atmosphere, with the exception of O2 comes from degassing. Degassing of rock requires heat, and this is provide by the rising magma. Your air has changed over time. The Earth had a very different atmosphere shortly after its formation, which we lost and which was replaced by something closer to what we have now. Only argon, which strangely accounts for 1 per cent of our air, survives from those hadean early days.”

    Great point! maybe Super Earths that have a greater internal heat store than our Earth does coud be even much better at driving plate tectonics than the Earth is?. I imagines that some habitable Super Earths may have hyperactive plate tectonics and therefore enjoy much more stable climate histories and co2 levels than Earth have done through its geological history.

    • Then photosynthesis occurred and everything changed. Another piece of this astonishing jigsaw fell into place.

      I really hope that Super Earths do actually exist. The concept is strangely uplifting. Thank you Jesper.

      Oh and thanks for the link to the “Dream World” site. I suspect I’ll find it quite Jungian!

    • Super Earths 100% exist and have been confirmed by spaceprobes but our instruments lacks resolution to find out more about them

      • Right, I’m off to DuckDGo and Wiki etc. to learn more! Superearths are new to me.

        • You should not omit the dimension Time I think. The IPCC speaks of 33 percent since 175 years, so plus 33 percent since ~1850.

          • Today’s level is around 430 ppm. It still goes up year by year. For pre-industrial, values range from 260 to 280 depending when you take the starting point. IPCC takes 278 ppm. That gives 35% to 40% of CO2 being industrial. We already affected CO2 before industrialization, by agriculture and deforestation. That gives the higher estimate, based on CO2 levels 6000 years ago.

          • edited – admin

            As the last small ice age was over at the same time the story is a lot more complex, and after what I have read Water Vapor is a more potent greenhouse gas.

            I consider Carbon Capture important though and deforestation a major crime in that situation. I wonder whether China is working on Carbon Capture.

            The whole medial climate discussion is simple, under-complex, lacking sophistication, driven by some economic wishlists. It makes me sick. I prefer brillant sophisticated science with all opinions, say Owen versus Darwin, Gerta Keller versus Alvarez, Foulger versus all plume defenders, big controversies, leading to the truth by:

            “Science, my boy, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.”
            ― Jules Verne, Journey to the Center of the Earth

            Quote from your piece. Thank you. Verne was great.

      • Denaliwatch:
        Ever since I had a discussion with a US Dept of Energy insider on Co2 and climate change and carbon credits, I have been very turned off by the politicalization of this whole thing, in which China seems to be taking advantage of. While mankind IS contributing C02 to the atmosphere, nevertheless people are being exploited (or rather their true lack of scientific knowledge) and an attempt to subjugate the whole planet is taking place to a predetermined view. Worse is the self-righteous actions of people who have decided to take action. See https://www.zerohedge.com/weather/epa-chief-sounds-alarm-rogue-climate-group-launching-sulfur-dioxide-balloons-gzoengineer
        Everyone should be concerned when individuals or governments rush to action to fix a perceived problem and pressure is exerted “to go with the flow” and to not tolerate alternate viewpoints.

        There is an effort to get everyone to “group think” and no outside thoughts are allowed. I think this is dishonest and a discredit to rational thinking and discussion. I have seen CO2 and world temperature analysis from ice core data and we’ve had very high CO2 atmospheric content before without the planet going into an uncontrolled reaction. In fact the bathymetric data shows that ice ages are actually the norm for the planet as we can see the sea level much lower than at present.

        I am NOT a climate scientist, nor do I claim to be. But I am discouraged by the intense efforts for “group consensus” because NOT all the data IS in.

        • You may need to be a bit more specific which aspects you have problems with. The climate modelling is in good shape, and we are fairly certain we are on a track to +3.7C global warming. That can be reduced +2C with more action. Reports of +5C or more are were based on the previous upper limits of the modeled range but are unlikely. +3.7C would still be disastrous, +2C may be manageable with care. I assume that you are not arguing against this.

          Year-on-year fluctuations are less well understood, but they average out of over a decade or more.

          The impacts of the global warming will vary from place to place and require detailed modeling. The UK is relatively well off, in the sense that the climate will become more like southern France. The landscape will change a lot, as will farming, but not in an unlivable way. More floods and droughts, of course. Other places will have major issues and some places will become uninhabitable. Expect mass migration, nationalism, economic problems, etc. All things that require long term management.

          A major issue will be sea level rise. That is inevitable. It rises now around 4 mm/yr and this rate will increase further. Coasts are always dynamic environments and for instance sediment will counter some of the rise where it is allowed to do so. The Netherlands should consider drowning some of its polders for a century or two. The question is how far sea level rise will go. All current plans are based on the lowest predictions. Comparing CO2 levels with the past suggests we may get 9-13 meters of rise eventually.

          (You mention past eras with high CO2. Yes, they did exist and life continued. But they were very different from now. No ice or snow. No cold bottom water in the oceans. Sea level as much 100 meter above current levels. I would also point out that the Permian extinction when 98% of life forms went extinct was a CO2-driven temperature crisis. That is probably not a world we want to move towards.)

          We are currently living in an ice-age era. I believe that without out climate impact, we would have seen the Little Ice Age moving towards a real one. I don’t advocate going back to pre-industrial CO2. But we have already far overshot CO2 levels at previous interstadials.

          You may argue with what kind of action is required. Here I might agree with you, depending on what your opinion is.. Net zero is not needed. Before that we were talking about 80% reduction. I think 90% is needed, but not 100%. Fossil fuels can have a role but it will be a minor one. Electrification of transport is a good thing and should have been done a long time ago. But there is no need to ban the alternatives completely: promoting development of electric cars is much better than banning old types. Carrots in preference over sticks.

        • Forgot to add: unregulated climate engineering should be banned. It is unlikely the sulphur balloons will have any effect so it is harmless and useless, but this is a very slippery road. It is just as unwise as unmitigated CO2 additions to the atmosphere. But somehow many people only perceive problems with what the ‘other side’ is doing, not with their own actions.

        • With you. An open scientific debate is prevented.
          Everything that the mass media go with or push has to be regarded with suspicion, and when mass media and politics are nearly identical things become incalculable.

          Besides, concerning Alberts models I trust the physicists, but I do not trust global data. Data can be easily manipulated, and data from say Congo are certainly not reliable.
          In Germany Kiribati was always an example, but it is the worst example ever as the island will certainly become a guyot. The Pacific ocean floor around Kiribati is shattered with guyots. New islands will come up.

          The whole idea came up – I think – in California with Al Gore who btw. did not want a wind turbine on his own ground. California has complex problems. Steep canyons formed by sediments coming down and winds like Santa Ana winds, besides arson and people who are careless with bbq and so on.

          Another topic, off-topic: Read this yesterday:
          https://www.theguardian.com/world/2019/mar/28/canada-grizzly-bear-attack-mother-baby-investigation
          And this, worth studying including comments:
          https://www.facebook.com/JimShockeyFanPage/posts/this-will-be-a-long-one-a-really-long-one-right-now-i-am-deeply-saddened-and-ver/1919251314791511/

          Summary: Overprotection. leading to a population which is too big, top predator that breaks into tents and cabins and is mainly protected by urban people without knowledge.

          Two other gross cases:
          https://www.theguardian.com/world/2023/oct/05/bear-attack-bad-canadian-hikers-grizzly-banff
          http://www.latimes.com/archives/la-xpm-2007-apr-29-me-grizzly29-story.html

          Same problem in Yellowstone (park ranger killed), generelly in Wyoming, Idaho, Montana, BC, Alberta and so on. Similar problems with cougar and wolf. A cougar killed a person walking on a street! in Oregon.

          • In case somebody reads that all – not boring – I can analyze it a little bit.

            Third case: Johan and Jenna later did the hike again – trauma therapy. They certainly did not make the same mistake again. Talking all the time they had stopped talking before a sort of half-pipe with a bent in it as the view was breath-taking. Bear country: Talk loud and talk all the time. That mother with her cubs might have gone away.

            Second case: Bear spray is recomended. The couple in Banff was found with two empty cans of bear spray. So, this is of limited value. Their food was stored properly.

            You should never leave food on your rest places and best have it in bear cans. Obviously of limited value here as they were experienced and there was no food around.

            First case: Same goes for the food here. Gross mistake to take the baby up there, it was not her profession – she was a teacher. As she carried the baby she could not handle her gun.

            For tourists: Better go with an armed guide or in a big group where there is always some talk and laughter.These cases will accumulate with those politics and they are not pretty.
            Grizzly is the T-Rex of our time, top predator.

            Albert went up in Rwenzori. With a guide. This I recommend too for tourists hikers in The US west of the Continental Divide. A guide and a group.

            Grizzly is not a teddybear. No bear is. But black bears (Yosemite) tend to be less aggressive. Tend to.

        • I also agree with Alberts point about climate engineering. Not though about the things tat normal people need, while a growing number of elites and their staff plus journalists fly miles and more every single year to climate conferences, this year in Brazil, where they build a new hwy just for this conference. Some top people are certainly flown in by choppers.
          I have to add that this topic if taken seriously should lead to do e.th to finish a war which might lead to a world war. The contrary is happening in Europe with esp. Germany and Brussels pushing for continuation and re-armament while nobody would say that the production and use of weapons would not produce CO2. The same people who push the CC agenda most are also pushing for war and re-armament.

  5. Thanks Albert! This explains why a borehole below the crust or an asteroid impact outside the magma producting areas doesn’t produce an outpouring of magma.

    The Jules Verne story about a voyage into the Earth was probably inspired by karst caves. They can go deep below the surface of the earth and can give the impression that there are hidden worlds. But Limestone geology is only a small part of the Earth.

    • That reminded me that one of the hydrothermal boreholes in Iceland did accidently hit lava, a couple of years or so ago. Capped pretty quickly no doubt!

      And those “hidden worlds”, in collapsed sections of karst cave tunnels, were indeed discovered a few years ago. In Vietnam? I don’t remember where.

      • In/On Iceland the borehole was very close to Krafla and Iceland’s hotspot. If they’d done it far outside the sphere of the hotspot and MAR, it would be very different. A fictional wound in the Earth behaves different to wounds of the human body.

        • I think they were planning to make a new borehole into Krafla, trying to reach magma on purpose this time.

    • Impact melt can be seen as lava but its generated by the heat of the impact itself. Really large impacts ( bigger than KT ) will create whole kilometers thick melt provinces over many 100 s of km and thats also whats happened in the KT craters melt sheet. Asteroids hitting continental granitic crust results in a melt pool with composition that equals obsidian

      • An impact outside a hotspot or plate boundary would either hit the thick continental crust or the thin oceanic crust. The impact heat is much higher than typical geothermal heat. It can be even hot enough to vapor rock for a while. Therefore it produces very different types of rock than normal volcanism. After the main impact heat has cooled, the granite of continental crust is probably too viscous to run like lava. I’d imagine that it’s semi-liquid like honey, but that stays pretty much, where it is.

        The biggest impact was the one which created the “double planet system” of Earth and Moon. It was probably large enough to create a big hole in the earth … and a new formation of the planet with a new chemical composition. I think that the whole planet … and also volcanism on earth would look much different without this event. Also the double planet system has a geological effect on earth.

  6. Thank you for the choir from the Matthew-Passion on Good Friday and the piece about some basics.

    Verne made a big mistake as we saw with HTHH. They would have ended up in the Strato- or Mesosphere and died.

    I know it is only a novel. And a good one. I was fascinated when I was a youngster. But my favorites were 20.000 Leagues under the Sea and the two follow-ups. Imagine nearly 70.000 miles under the sea. The pressure! And the heat!

  7. Gravity sucks! (I’m allowed to say that, I’m a scientist.)

    It is fun that volcanic eruptions are due to buoyancy. Magma floats to the surface! Relative density…

    Once I worked on a pilot plant for a week. We were melting zinc slag and extracting the metals from it. I was on duty on the top of the bath reactor, about 4m above the molten slag at 1500 C. Several tonnes capacity. We did tests of various conditions, one of which was a good emulation of a volcano! I had burn marks all over my plastic safety helmet, and on a few bits of my anatomy as well. It was fun, although that test wasn’t exactly successful.

    My contribution is Rick Wakeman’s “Journey To The Center Of The Earth”, which I had on vinyl. Ridiculously good LP.

    Rick Wakeman – Journey To The Centre Of The Earth (1974)

  8. When we boil water it changes its physical state and climbs up to the ceiling. Similar with rocks becoming Magma. Now, not all the magma gets out, some often stays inside and serves further eruptions. The mass that stays inside when pressure goes down must be kept inside by gravity.
    When all the Magma gets out with extremely high pressure and temperature it can produce a flank collapse or a total collapse (caldera). But when some of the magma stays inside, a new cone or several will form (Crater Lake, Aniakchak). So too much pressure and material seems to have the consequence that gravity takes over.
    If we form a cone with dough it can look perfect and neat. If it is sitting on the baking tray without support it will come down with the heat and the changes in the dough. Gravity sets in. Grandma is very disappointed when her beautiful cone ends up as a little heap.
    Life I believe can only coexist with gravity, otherwise the eggs would fly away and be shattered, babies would fly away without the chance of being fed.

  9. Hi Albert,
    a great post.
    Unfortunately I struggle a bit reading nowadays so may well have missed some points but my comment.
    Firstly, pressure is isotopic so cannot really ‘squeeze’ liquids into droplets or anywhere because its isotopic. Buoyancy though is amazingly powerful when we are talking solid rock in kilometer-sized chunks. Back a bit I did (here) some simple calcs using known figures for rock density at various pressures and temperatures and the results astonished me. Differences of <1% produced enormous upwards forces. IMHO this is the major driver at depth (ie below gas fractionation depth). A large blob of less dense rock really applies a significant upwards force. Enough to raise continents (colorado area for example).
    The question, then, is how the volume of lighter material gets emplaced?
    Subduction clearly allows less dense crust to become dense enough to fall just because it's cold enough, driving plate tectonics. Inevitably this warms up at depths and melts and bingo less dense emplacement at depth.
    Similarly, mantle plumes can provide localised heating and produce a similar effect on the base of the crust.
    These things work as per your graphs above. Very clear.
    There are other things to consider. Phase changes can turn dense things into less dense things and vice-versa, killing or accentuating the density difference. The liquid-solid transition is the most obvious but I suspect solid phase changes can also be important. After all ~1% density changes can produce significant extra vertical force. Stable crystal states are temp and pressure dependent.
    We tend to think gas dissolved in liquids make no difference to the liquid volume, primarily because that's largely true for water, which has a lot of free space due to the open molecular structure and hydrogen bonding. I'm not so sure if that is true of rock, where silica and CO2 are very similar and I would (for example) expect CO2 to replace SiO2 resulting in a lower density. So a wet CO2 rich (eg carbonated) slab might well become more buoyant than you might think when it gets really hot.
    Gas evolution is clearly, as you say, a near surface effect, although admittedly very dramatic, devastating even. Its rather well understood.
    The only issue I have is with marine volcanoes and their water content for extreme events. I cannot see how you can inject gigatons of water inside a hot solid magma body when the pressures at any reasonable depth are about equal (at best, rock being denser than water) nor do I believe in mega explosions caused by seawater "entering the exposed caldera" at least as single explosive events. Steam is a good insulator and effective at cooling and to me this would be a longer and although dramatic, less explosive event.
    Nobody seems to mention any chloride or sodium signature in the cloud, which doesn't speak to me of a seawater naissance for the water. Water held in wet falling slabs, though, provides more than ample supplies of water to be emplaced at depth and superheated when it fractionates out.

    My tuooenceworth ….

    • Are you talking about HTHH? here: Quote: “Steam is a good insulator and effective at cooling and to me this would be a longer and although dramatic, less explosive event.
      Nobody seems to mention any chloride or sodium signature in the cloud, which doesn’t speak to me of a seawater naissance for the water.”

    • Isotropic pressure can still squeeze water out of a sponge. The reason is the difference in compressibility of rock and liquid. If the liquid has nowhere to go, you may still end up with larger water droplets throughout the compressed sponge. But it depends on the permeability of the rock. The pores need to be able to connect.

      You are right about the phase changes within a solid. They become important deeper in the mantle (the 410 and 600 km transitions) but there are a variety of such changes possible. I ignored these in his post.

      The problem with getting sea water into magma has worried me as well. You will need a hole to the magma, and reseal very quickly to put under high pressure. A thin layer of water will act as insulator and stops the rest of the water from excessive heat. That fails when the magma fragments and forms a magma mud – now the water is suddenly heated very effectively throughout. It seemed a complicated model. If you boil the water, the salt should stay behind as it has a higher boiling point. Or, if it does end up in the vapour plume, the salt will condense first and drop out.

      After the Hunga Tonga eruption, HCl in the stratosphere actually went down, not up. The is attributed to reactions with sulphates. The free chlorine caused significant ozone reductions. Whether any of that was due to seawater chlorine I don’t know.

      • Still very impressed by this art of separating water and magma efficiently:

        – And since there was less water around the interaction between the lava dome and the water was also effectively hindered. In the end the dome cracked open in an effusive manner instead of in the usual explosive way.
        https://volcanocafe.wordpress.com/2013/07/27/gunung-kelud-or-who-poked-a-whole-in-the-volcano/

        The eruption in 1919 had a death toll of 5000 people caused by lahars. With the tunnel that was finished.

        • This to all the above.
          1) I do not believe isotopic pressure will squeeze liquid into larger droplets. There is simply no differential.
          2) The usual way for droplets to grow in these situations is (surprisingly) effectively surface tension (here I simplify). Small drops have a higher surface energy than large drops, it’s how metallurgists control impunity sizes by heat treatment (Duralumin where controlling copper inclusion size by heat treatment is critical is an easily researched example (there are very many others). The second is solids crystallising, or more sensibly large crystals growing at the expense of small ones for much the same reason over time.
          3) A lava-water “mud” fine, but how to get gigatons of water mixed with gigatons of very hot lava particles in an instant is still almost impossible. There will be a very energetic boundarythat preserves their separation.
          4) Supply water from the wet falling plate is easy, it’s emplaced in situ in the cold slab and here the water has no way of escape. Further, the water is likely mostly from terrestrial sedimentation, so the water is freshwater and has no chlorine or sodium signature that should (and its absence is a dead giveaway) be copiously produced from a marine-sourced water supply.

          I rest my case. You guys can explain why Na and Cl have vanished.
          How much water in a subducting plate, I wonder …

          • I love how you always force us to think more. ‘Droplets’ was perhaps not the right word as we are talking about microscopic sizes. There is a pressure differential from the buoyancy and the liquid becomes mobile. The liquid has to travel through the pores.

            The amount of water involved in subduction is discussed in https://www.sciencedirect.com/science/article/pii/S0012821X04002663 (sorry, paywall, restricted information not allowed to be read by unauthorised public etc. I do not know why scientists insist on stopping people from reading their work. ) It amounts to around 100 meter of water depth, or about 1 meter per million years. Serpentine rock has a water content of some 10%. The sediment loses it water very quickly, half is gone by the time 30 km of depth is reached. The crust and serpentine mantle wedge lose their water at ~ 150-200 km.

          • “I love how you always force us to think more.” Agreed.

            Do not agree: “Further, the water is likely mostly from terrestrial sedimentation, so the water is freshwater and has no chlorine or sodium signature that should (and its absence is a dead giveaway) be copiously produced from a marine-sourced water supply.”
            As most subducting plates – think Ring of Fire, Indonesia i.e. are oceanic, ocean water should go down with the plate and some of it back up with parts of the subducted slab. So there would be HCl.
            And even the sediments near the coast contain lots of salt. I was once living near the coast. The pedals of my piano became rusty after a while. In the house.

          • Concerning salt: Hope you all had perfect easter eggs. With salt. In the Canary Islands they have s.th. delicious, very cheap:
            Papas arrugadas con mojo.

            They cook potatoes (papas) in ocean water until they have a crumpled skin, white from salt and look like a one hundred year old person after a bath in the Great Salt Lake.
            I prefer the green mojo. The red one is hotter.

          • The pic from Taal is from 1965. The eruption in 1911 was worse is assumed, but there was no American geologist on Taal Island who had to flee and was aloof enough to take some pictures.

      • Albert, I do NOT believe that steam pressurization from ocean water contacting hot magma is the proper explanation for the huge explosions at Hunga Tonga. The acoustic recordings don’t support this hypothesis.

        • This in reply to all the above.
          1) (implied free) Water has a half distance ~30km. Fine, as expected, and goes where? The rest continues and
          a) Some will become chemically bound I am sure, very hot water under very (!) high pressure is extremely reactive and is unlikely to become free. This is likely a reversible process.of course.
          b) What is left presumably migrates to the surface. So we have LARGE (% of cu km) quantities of superheated free water heading upwards, this water is likely to arrive in a zone where it is physically unstable. Might even explode under appropriate situations.
          2) Most of the marine (soft) sediments are likely scraped off the subducting plate and if you drill into them (on land is convenient some time before subduction) generally fresh or brackish water is found.
          3) Lets be honest. If you vaporise gigatons of seawater and fire it into the upper atmosphere then the one thing you expect in large amounts is sodium and chlorine, a signature of seawater. Its absence is a really claring smoking gun.
          4) I did research (allbeit shallowly) the strange behavious of supercritical water in the Hunga thread to uniform lack of interest. Supercritical water is explosive stuff with a negarive ‘heat of evaporation’ and strange phases. But this is NOT surface behaviour.

          • erratum
            2) Most of the marine (soft) sediments are likely scraped off the subducting plate and if you drill into a subducting plate (on land is convenient some time before subduction) generally fresh or brackish water is found. The plate is thick, the marine deposits relatively thin.

      • Mind boggling and poetic piece that only you are capable of! Thanks!! And also thanks to All those who object and discuss the various details. The discussion ads so much to the model!

  10. What an article, Albert! Excellent! Well, that’s all my basic understanding of what goes on under the ground crushed and rewritten! Thanks for a very educational and enlightening work.

      • Really surprising it hasnt erupted yet after actually starting the other day. The tilt is nearly break even at UWD and probably the highest its been since the eruption started at SDH…

        • At night right now theres no visible lava but a pulsing bright orange glow at the south vent and weaker but constant glow at the north vent. Its still spattering like in the pic.

          SDH is now multiple microradians over any point still visible on the tilt. Its over 3 microrad higher than E16 that was a nearly 300 meter fountain lasting for close to 24 hours… UWD is about break even to E16. I think E18 will end up being another 1000+ ft fountain event, maybe even 2000, which would be a record.

          • On 18th April around 15 o’clock was probably a failed attempt to do the big eruption. So Episode 18 did commence on low scale and has continued on low scale after the short overflow on 18th April. There is a deep, invisible lava pond inside the southern cone, maybe 1% of the area that the 2008-2018 Overlook crater had. Small, but active erupting.

            The continuing inflation and steam/gas emissions mean that there is a lot of magma to follow. The climactic phase of Episode 18 can be a lava flood without spectacular tall lava fountains, but a big volume in short time. A bit like the Big Crack 1823, but inside the summit caldera.

          • It cant be a lava flood like in 1823, that was lava in the caldera draining down a crack but this is a vertical vent. It can have low fountaining but even other volcanoes with lava lakes have fountaining to some degree. The volume of magma in the vent itself is much less than in the magma chamber added since the last episode.

            I guess something has changed a bit to stop the overflows quickly running away. It is probably the elevation, so maybe as it builds taller the episodes get further apart and more voluminous.

            At some point one of 3 options can happen. The pressure to start a fountain might be so high it breaks the conduit, and the results of that might range from another vent next to the existing ones, to magma abandoning the summit entirely. Option 2 is the vent ovetflows as a very active lava lake but isnt fountaining. Option 3 is that it just keeps going as it is now but overflows.

            There is a 4th option of it all just stopping but I dont think anyone believes this is plausible. If this vent stops its going to restart somewhere else…

          • Episode 18 has – until now – turned into a state of steady activity as a lava pond inside the southern cone. We can’t see it directly, because the webcams have bad view, but the last helicopter photo showed it clearly. Also the bright illumination of steam clouds above the southern cone is an evidence for an active lava pond.

        • It is probably already erupting on low scale inside the south vent … as a deep lava pond.
          The thick steam and gas plumes hide the eruption well.

      • It will be very fun to see the future development in this vent complex its going into unknown behaviour territory breaking from the past months lava fountain cycles. The magma supply with is gas is always there it have not gone away or gone elsewhere in the system so maybe we will get a gigantic paroxysmal event this week getting record high fountains due to the crazy deformation it is just rising. If two months of stuff goes by without any vents”rocket blaster” then thats perhaps a soure signal of a change in the eruptions behaviour but since lava did leak out Im pretty soure we will get another mega fountain soon unless the vent have become very open. Magma is always accumulating under Kilauea so something will break sooner than later at this vent

    • As you mentioned yourself any time. Most gaps were short. One gap is significantly longer, from 1734 to 1751. As the French were rulers then of that part of the world, including Mauritius which was furnished with an incredible number of African slave the gap should be real, 13 years. But this seems to be a huge exception.
      https://fr.wikipedia.org/wiki/Histoire_%C3%A9ruptive_du_piton_de_la_Fournaise

      No worries – it is mainly numbers. Inconnue means unknown.

      2018:

      • 17 years. I often mix up 13 and 17,numbers I do not favor.

          • No. You cannot do anything with them. You can divide 12 through 1,2,3,4,6 and 12 and get nice round numbers. 13? 17?
            13 is also damaged by superstition (Room 1408), here the cross sum.

          • Very interesting , A.Karkukainen (are you Finnish, at least originally?).

            If you happen to live in America, do you know whether it is true that the rattle of rattlesnakes is similar to the noise of cicadas?

          • Yes, I am, and currently living in Finland. The only snakes here (apart from Åland and terrariums) are common European viper or adder (Vipera berus), and the nonpoisonous grass snake (Natrix natrix), which is actually quite cute with its yellow “ears”. Haven’t met or heard any rattlesnakes in real life.

          • Vipera berus are nasty things when you go too close ( hisses like a xenomorph ) the blue variants seems extra aggressive. Its not a very toxic snake at all but they are very agressive for their small size even if humans are not om the menu

        • Here is a nice little teaser for you.
          No need to show working but:
          Can you prove that the square root of two is neither even nor odd (or both even and odd) and this show that it is not a rational (ie expressible as i(integer A)/(integer B))?
          This means it is a transendental number and not in the infinite number group aleph{0}..
          A fun and quite easy test for easter sunday when the infinite deity is to the fore.

  12. What state of phase minerals woud exist deep within the lower mantle a large Super Earth? the pressures and temperatures will be much higher than our planets mantle..

  13. ‘Diamond Pipes Do It In A Hurry’, no ??

    Excellent description discussion etc.

    Each such educates and entertains…

    Sorry, I’m too tone-deaf to enjoy the choir, but *RESPECT*.

  14. Talking about the interior of celestial bodies: I did not knew that the sun was this very hot over much of its own interior volume! looks like most almost all of our star cooks at millions of degrees c with only the photosphere being cooler than that. Perhaps the solar interior is very good at storing the energy thats welling up from the core over long timescales?

    • Lucky the outer photosphere is not that hot! then it woud be a SERIOUS problem if that was the case for soure

    • Oh the sun is very big and dense.
      From memory, it takes about 100,000 years for a photon generated in nuclear fusion in the core to be emitted into space.
      Interestingly enough this is approximately the interglacial interval.
      Fusion is exquisitely dependent on temperature and pressure in the conre.
      Consider this:
      what if nuclear fusion is in fact an explosion that heats the core, reduces the pressure (expanion) which then stops nuclear fusion. Over time (say 100,00 yeras for it to dissipate it) it re-explodes.
      Yes a very very long period variable star.
      Although the thermal wave would be very attenuated by diffusion to the surface, could it give a few thousand years when the sun is (say) 10% brighter?
      Interglacials thus rather better explained than ~1% due orbital effects (which I find totally unconvincing).

      • Sorry, doesn’t work.. The timescale of 10^5 years comes from the transport of radiation: photons diffuse very slowly in the inner part of the Sun. The outer part is convective and convection transports energy much faster. Put an explosion in the centre, and the whole star becomes convective. It now takes not 10^5 yr for the energy to come out but much less than a year. You’ll fry the Earth. Luckily nuclear fusion in the sun is non-explosive (it takes a hydrogen atom on average 10 billion years before it succeeds) and very stable.

        • Another one of these lucky circumstances we enjoy on Planet Earth.

        • Surely that depends on how big the explosion is. I am thinking of a small volume (lets call it the core) deep inside the sun. Basically instead of a continuous production of energy its pulsed. Not necessarily even on-off, think of a well damped oscillator.
          How good is our modelling of variable stars? I imagine depletion of H or He in the fusion core will also have an effect.

          • Doesn’t work. There is no explosion: there is fusion at a very low rate. The temperature isn’t anywhere near high enough for explosive events. And if a region were to increase its fusion rate, the temperature would go up, the gas would expand, therefore cool and it would immediately return to the previous state. Fusion in the Sun is very stable process which is self-regulated on very short time scales. So no, can’t do. There will be a time when this changes, when there is not enough hydrogen left in the core. But that is still 5 billion years away.

          • Contrary to the theory of the Big Freeze this is consoling. The “Big Freeze” corresponds to Nihil and is devastating, although we will not exist any more.
            For me the thought of beauty being destroyed is utterly devastating.
            It is not nice either to imagine that the Pillars of Creation might be gone already. Extraordinarily beautiful structures.
            In order to find mankind more beautiful than say Tallis I have to think of scientists in NASA and similar institutions and their achievements. It helps thinking of Hubble.
            And when scientists study nebulae like you do they probably hope to one day see the birth of a star like the sun or find a star like the sun already in place, surrounded by planetesimals.

          • On the other hand, just a few days ago, the thought of the giant reddish Sun eventually swallowing Earth gave some positive vibes to me, as I realized that then it will also melt all the ugly cities and architecture the mankind has ever created. But of course, by then they have already been subducted deep into the mantle, or otherwise eroded.

          • A. Kar.

            When I say beauty I mean nature, rocks, oceans and volcanoes plus the Cosmos, but also men who are interested in these entities, do science or brillant photographs.
            However, the Romans and also the churches built some impressive things

          • I have a picture of Bing without a title on my screen right now. I believe it is Mohave. It has a composition of the Milky Way above it. This I mean with extraordinarily beautiful. Even some short 50 Years ago nobody would have seen the beauty of a desert like Mohave. Next time we go to the US we are planning to stay over one nicht in Mohave or Death Valley. Just to see the stars and hear no sound whatsoever. Hopefully no rattling either.
            I guess you can have that in Finland as well. Minus rattlesnake.

        • Well, explosion is perhaps not the right word for solar physicists. A system that is somewhat underdamped such that the core cycles between high energy output and low energy output. I imagine that the output rate is controlled by density and temperature and high temperature leads to expansion as well as higher rates of generation.Expansion would, I think, result in lower density and thus lower reaction rates. With a massive outer layer not really doing much but acting as a blanket and containment system, I would expect very long oscillation times to be not unexpected. Offhand I can see no particular reason why an oscillation could not be a stable state as these are very common in self-sustaining situations.

    • Astronomers look way too much on sunlike stars but sunlike stars are not that common most stars are smaller than the sun, and Infact those are the most common, Super Earths in the outer habitable zone around a larger red dwarf on the border of orange dwarf, souch stars acually shine rather sunlike, just being dimmer overall and having a smaller habitable zone, but worlds with dense nitrogen pressure like some Super Earths may have can orbit further out and stay warm with that density and avoid tidal locking that so many other sunhugging Super Earths suffers from. Complex life seems to take a quite some time to evolve on Earth it took almost 4 billion years! So having a long lived star is crucial to allow life to evolve on Earth it have taken almost Half the suns lifetime thats 10 billion years to get large animals, so all larger stars than our sun are out of the question to search for exoplanets they live too shortly. A small K dwarf star ( Orange Dwarf Star ) is tought to be ideal life they can be quite sunlike ( but dimmer ) but lives 10 to 50 times longer than our sun will giving much more time for life to evolve… than here on Earth. Many exoplanets suns is a bit smaller than our sun is K to borderline M dwarf star and that one will live around 500 billion years so thats 50 times longer than our suns entire lifetime! giving plenty of time for complex life to develop on souch planets around souch stars, and beacuse of this fact, Red Dwarf Stars and Orange Dwarf Stars that live much longer than our sun will do are today prime candidates in search of habitable exoplanets among astronomers beacuse of their incredibley long lifetimes, today larger red dwarfs and orange dwarf stars are seen as ”superhabitable stars” the smallest Red Dwarfs maybe questionable but Orange Dwarf Stars looks like good life stars better than sunlike stars…they live for so much longer too than our sun will

      • The ideal star for life maybe an Orange Dwarf Star at 40% the suns mass, thats saied maybe a very small Red Dwarf coud work too ..the smaller they are the longer the stars burn

      • IIRC, one of the ‘WhereAreThey’ paradox solutions is that much ET life may arise from tidally stirred mega-moons of ‘sub-giants’ on the cool edge of their star’s hab-zone.

        Why ? Well, ET would soon notice our G2V star has no such sub-giant’s ‘Doppler Wobble’, so strike us from list of potential candidates.

        Of course, we have statistically rare configuration, a tidally stirred ‘terrestrial’ planet thanks to over-sized Moon…

        There is another aspect, that ET may have noted Sol’s in-bound trajectory towards local ‘Super Bubble’, left ahead of on-coming fire-wall…
        🙂

    • The surface of the sun is ~as hot as the Core of the Earth. Only the lightning is hotter, it is the hottest natural heatsource on earth.

  15. Happy Easter! the Xenomorphs are ready and are happy!!

    • Jesper, I can tolerate this photo.

      Easter, however, has to do with Jesus giving himself up for mankind and staying in some form. I think whatever progress we do make in science and AI, that this event is important and can keep mankind from becoming too off-hook and arrogant, forgetting ethic values.

      Basically that spider is a non-go for Easter for me. Sorry for that. Some nice pahoehoe would have done as rocks are resurrected and rearranged all the time.

      But thank you for your wishes.

    • The Xenomorph never gives a nice easter or christmas to be very clear about 😉 but I understands your point

  16. Happy Easter everybody!

    Painting by Tintoretto, San Giorgio Maggiore, Venice
    wikimedia com.


  17. (S2 Cam, live)
    Looks like episode 18 resumed (or, personally, beginning of episode 19) has began about 40 minutes ago with a lava flow.

  18. So, Newberry Caldera in the Oregon Cascades, with it’s high Obsidian count, could at least potentially be of extra terrestrial origin?

    • Why?
      Obsidian was first discovered by Roman explorer Obsidianus in Ethiopia, spreading ridge. Oregon has spreading ridges in the ocean, possibly also subducted ones and a triple junction.

      • Obsidian was used in Mesopotamia some 9000 years or so ago (from memory – the year needs a fact check). It was a valuable tool in the Stone Age. The Mesopotamians obtained from a volcano in Turkey, quite a distance away, indicating there was a trade in it. The Roman explorer may have gone it named after him, it was known long before. And yes, purely terrestrial.

        • Sharps were traded everywhere humans interacted as far back as there is evidence (usually it IS the evidence). Flint from England is found all over europe, obsidian from the andes all over s.america etc etc. It was valuable and small flakes were just as good as big lumps so were probably used much more extensively than people think. They are just harder to find. Really good knappers waste very little of the flint they work (unlike crass amateurs seen on the web). Each shard has a use.
          The stone age went on for a very long time indeed and in Americas and Australia into historic times. People forget these were entirely stone age civilisations. TBH ancient egypt was predominantly stone age, metals were expensive until the iron age.
          An english historian (about 18C IIRC) found stone sickles in use in scotland and the farmers using them pointed out that they were cheaper than steel, and didn’t need sharpening many times a day.

        • 1894 BC?
          https://en.wikipedia.org/wiki/Babylonia
          Here we report our findings for two obsidian amulets and two cylinder seals in the Yale Babylonian Collection and Metropolitan Museum of Art.
          https://www.sciencedirect.com/science/article/abs/pii/S2352409X18308137

          So, in any case, before Obsidian who possibly described it first.

          One more from archeology:
          According to Ellery Frahm of the University of Sheffield and Joshua Feinberg of the University of Minnesota, decades of studies had shown that nearly all of the obsidian used in Urkesh and sites throughout Mesopotamia came from volcanoes in what is now eastern Turkey.
          https://archaeology.org/issues/january-february-2013/digs-discoveries/urkesh-syria-akkadian-empire-trading/

          Could make a nice piece 😊

          Obsidian arrowhead:

        • Denali,
          I am almost always here, but most people have more detailed knowledge of volcanoes than I do, so others are better placed to comment.

          • Look at Jesper, he often comes around the corner with s.th. totally different. You could certainly do the same as long as it is somehow related to Science in general, Chemistry, Physics, Earth Sciences, Medicine, Archeology, History or Agriculture. Albert often touches all these fields in his pieces, and when there is litlle resonance and then right afterwards a big leap to Kilauea or Reykjanes I am sometimes bored.

          • Farmeroz often chimes in when it is in his areas of knowledge. Many people here do. But all comments are welcome – you don’t need to have expertise to comment or ask a question.

    • What makes you think that a volcano on earth can be extra terrestrial in origin? Sounds like lunacy to me.

      • I gathered that Richard referred to the Obsidian. As Obsidian is named after Roman explorer Obsidius (not Obsidianus) though who found it first in a rift zone it is probably terrestrial.

      • You have a point: The Chix’ impact should have created a volcanic province, surely, but it settled for mere slumping, rebound and geo-thermal effects due up-welling.

        Caveat: Chix’ shock waves *may* have fracked declining volcanism near India, AKA Deccan Traps’, but their ‘main event’ timing does not seem to match…

        The vastly more ancient impacts such as on the Canadian Craton prompted lots of up-welling and geo-thermal mineralogy, but no actual volcanoes.

  19. V1 live webcam shows the active South vent in the background. We can’t see the lava pond, but it illuminates the steam & gas clouds a lot:
    https://www.youtube.com/watch?v=oG5zz9Sjw3E

    Maybe the lava pond is slowly rising like a yeast dough, that once spills over the crater rim. Or the deflation moment comes and we get a lava flash flood in the summit caldera.

    • We have lost a great man. Not a perfect one but one with humanity.

      • It’s a shame that he died, but he was a hard-working man and definitely earned my respect

        • It is a blessing that he was called home (like the church sees it) as he was a very sick man.
          I read that he had a difficult operation on his lungs when he was young. Wild guess of mine would be tuberculosis at the time. That would explain why he did not recover from Pneumonia although they have brilliant doctors in the Vatican and in their hospital.
          Rest in Peace is all we can say.
          He was not perfect says Albert. Right. Karol Józef Wojtyła (Pope JohnPaul II) was closer to being perfect and very close to the youth of the world, and his friend and disciple Josef Ratzinger (Pope Benedict XVI) was deeply religious and the author of fine books.

          Btw, I am very worried that now, in the interim before the next Pope the German gov. deliver the Taurus, and that those unreliable people will send it on the Kreml and start a WW. Francesco was absolutely for ending this war by all means.
          After the funeral it will take another two to three weeks before the Conclave gets together.

          He will be laid to rest in Santa Maria Maggiore belonging to the Vatican but situated in Rome according to his wishes, first Pope in along time who will not be lais to rest in the Vatican.

  21. Looking at the V1 feed from Kilauea. There is an glow on the floor of the crater to the east of the south vent. I looked back in the feed and it has been there for around 9 hours. Is this a skylight on a lava tube?

    Mac

    • V1 doesn’t show the southern vent. It shows the northern vent and a rocky hill behind, that seperates the twin cones. During last night we could see a bright steam cloud above the hidden southern vent. This confirmed the continuing existence of a lava lake/pond inside the southern vent. So the eruption continues – now “un-episodical” – until something changes. We have to wait for next significant deflation, then this may change. All in all we currently have a convecting lava pond inside Kilauea Summit like 2008-2018, but smaller.

      How long is the steady eruption going to happen? Will it remain a part of an episodical eruption or will it turn into a more longterm eruption mode?

    • Deformation still continues cyclic with short steep and long flat parts:

    • I saw that too, I dont think its moving lava or a skylight or lava would be active out in the caldera but its worth keeping an eye on.

      I have been wondering now if the episodes are about to be much bigger and further apart, more like Pu’u O’o that was often over a month or even 2 months at one point. The golden and eastern pumice from some point between 1790 and 1823 was probably from eruptions just like the current one, but with fountains apparently up to 1 km tall, and that must require some pressure. Such numbers are easy at a stratovolcano or an alkaline mafic volcano but in tholeiite basalt it is hard. Those eruptions back then must have had huge volumes of lava erupted too, maybe even most of the pre-1823 caldera fill, so some really huge eruptions compared to observed summit eruptions. But thats still a wild guess.

      Still maybe we get no fou tains for weeks, and then a record breaker for days on end 🙂

      • The lava level still goes up and down, and more rapidly than before, it seems to me. And there are overflow eruptions but no fountains. That means no gas: the magma is degassed or the gas has an easier way out somewhere. This sequence of eruption episodes may be coming to an end. The inflation pattern seems stable with regular step-ups of the tilt every 2.5 days. The next one should be one day away. The magma keeps accumulating at a uniform rate but it is not inducing vigorous eruptions. We may be heading for a stable phase with regular overflows – until something else breaks.

  22. A splendid article, Albert – and Troubadour Magma is an absolutely wonderful hoppy Ambree.

  23. Europe placed in some other parts of the world at same latitudes. Its a shock that warm sunny Sicily is really as far north up as north central China that certainly haves severe continental winters at latitude 37

    • Nice idea, but Brittany isn’t as cold as Nth Dakota and Ireland certainly isn’t like Saskatchewan. For which of course you can thank the Gulf Stream! Would’ve worked better if they’d matched the British Isles with British Columbia, since the climate is much more similar. Spain and Portugal fit well with California too, all that nice wine!

      For that matter Mongolia is nothing like northern Italy. The Dzud can reach -60 C in winter.

  24. New youngest magmatic eruption at Yellowstone. 35,000 years old in the Henry Fork area west of the more well known caldera. I do remember seeing a pyroclastic cone there in google earth that was pretty uneroded.

    https://www.usgs.gov/observatories/yvo/news/thinking-outside-caldera-understanding-basaltic-eruptions-yellowstone?fbclid=IwY2xjawJzwQtleHRuA2FlbQIxMQABHhVk9lBwjTolNhVUstVzEJ_uOkYLUNWIsxBN__3YCzVvyqjjx8EAGqlDvqk6_aem_OgvoxM8A-woxLu0N1DMpHg

    Sounds like they are doing mapping of the area, so we will see how big the eruption was. My guess is probably quite large being from such a powerful system and going on the trend of SRP volcanism being generally huge scale.

    • Quick look on google earth and at Pinehaven there is a pretty clearly visible lava flow, although its not easy to see its source. It looks like inflated pahoehoe though so the eruption was likely large and long lived. The obvious pyroclastic cone is breached in that direction too so it could be the vent, in which case possibly around 1/3 of the caldera was covered, maps will be very interesting when they are released.

    • Interesting news. Wondering what VEI they will attribute to that eruption.

      • Probably a VEI 1 at most, its hard to even locate a source vent. The obvious cone apparently is called Hatchery Butte. The name come from a map, not much appears in a search.

        The best I could do for a map gave about 18 km2 but it must be much larger if it starts at Hatchery Butte. It might instead start at Osbourne Butte, much closer to the lava, but that doesnt look like a young vent or even really a vent at all to be honest.

        Hatchery Hutte has got a notch in the west side, and a flat crater floor. The flat floor might be erosion but the notch looks like a lava channel, so the outflow might have been quite high.

      • Yes I never even considered that area active at all, I figured the basalt filling the Henry Fork caldera was all about a million years old and predated the formation and collapse of the newest caldera but apparently it is much younger…

        Its veen 35000 years, and it was about the same before that to the next youngest eruption, so its not very likely to do anything soon. But I do wonder if all the expected warnings of a rhyolitic eruption would apply to a basaltic one. The caldera has been apparently mostly deflating for millennia but that presumably is related to shallow processes, maybe uts even entirely hydrothermal. A basaltic eruption might happen with no regard to this.

        • I think the entire Snake River Plain should be considered active. The basalt eruptions in the Yellowstone area are part of the same vast basaltic field that includes Holocene eruptions along the plain.

          • I believe the same, albeit I think the VEI might be smaller for the following reasons:
            1. When the big ones happened most of the magma might have come out, but not all of it.
            2. That might have been helped by either ice or melt water during the Gelasian glaciations.

            For these reasons I believe that scare mongering by the media is totally wrong and a special feature of media to create clicks.

            3. We love this:

            Pictures Grand Prismatic Spring, Yellowstone.

            We love it for beauty. Our ancestors settled in such places as they loved them for fertility.
            Conclusion: Beautiful places are often volcanic. And they bear a certain risk which should in no case be exaggerated. Ife we want to eliminate all risk we will live a boring life.

          • Agreed, the last Craters of the Moon eruption, which is even further west was only 2000 years ago.

  25. Not many people get to play football on the top of a volcano.

    Grindavík gets green light to play football on home turf (RÚV, 21 Apr)

    In November 2023, a series of powerful tremors nearly tore the town of Grindavík apart. A deep crack split the indoor football hall and ran through the gable of the newly built sports center. Since then, sports activities in the town have come to a halt.

    The outdoor football field itself was spared any major damage. Now, the men’s team is determined to return and play there this summer.

    The photo of the football hall is fun. Looks like they went fairly close to having a lava fountain right in the middle of it. I suppose that would be the ultimate red card.

  26. Woud Venus surface even be visible even without the sulfur clouds in the upper atmosphere? all clear gases scatters light and things fades in the distance like it does on Earth. The denser an atmosphere is the more light is scattered at Venus its nearly 100 atmospheres of pure CO2 pressure, nearly all the carbonate mantle materials in the atmosphere due to the carbon – sillicate cycle being broken down. An atmosphere as dense as this will have some very strong light scattering indeed I read that visibility in clear venusian air at the surface is only three kilometers before light scattering makes the horizon or surface features fade away so its possible even without the clouds that Venus woud just be a pale blue orb from orbit with no surface detail because its incredible strong reyleigh scattering sky color from the ground even without clouds maybe white too simply because scattering is so strong. The sun seen from the ground at a cloudless Venus maybe a dark red orb in a white sky due to the strong scattering

    • Standing at Halemaumau placed at Venus.. you woud never be able to see Mauna Kea the dense air scattering is simply so very dense and thick which is kind of disturbing, you woud see a sickly yellow looking murk after a few kilomoeters from you, still well lit by the hidden sun

      • The question why we are here in this ideal place to have a broad view into the Solar System and the Milky Way and also parts of the Universe and admire and describe it will never be solved:
        “The first gulp from the glass of natural sciences will turn you into an atheist, but at the bottom of the glass God is waiting for you.”
        Most likely Max Planck, second likely Werner Heisenberg. When the Germans were still deeply into Theology and Philosophy.
        On the bottom of the glass wait the questions: Why are we so interested at all? Why do we have an admiration for the wonders of Earth and the Universe (I know there is also financial interest and geopolitical purpose)? I am talking of the ones who do not earn a cent with it, but know of the value.
        Like us here, volcano nerds and nerds of tectonics like me who just love the place.

    • Mars is the reverse stuff an atmosphere so thin that its equal to almost 40 kilometers above Earths surface, the reason Mars have a sky color is the fine dust, clear CO2 at souch very low pressures have a very weak scattering effect. At noon with least scattering I guess that without any dust, Mars maybe woud have a space black sky only being somewhat blue at evening.. .

      • Atmosphere is too thin to stop even small bolides, local magnetism inadequate to stop even minor solar flares, never mind CMEs etc etc.

        Global cratering in ‘mid-range’ resembles monogenetic volcanic province. IIRC, orbiters have mapped several recent ‘arrivals’ complete with strew-marks…

        Even if there are multi-layered surface domes, they will so need deep-buried ‘storm shelters’. ..

  27. https://cnevpost.com/2025/04/21/catl-sodium-ion-12c-shenxing-freevoy-dual-power-batteries/

    This is actually a revolutionary change. All those claims over the years have just escaped the lab all at once… CATL make 1/3 of all the batteries on the planet, so this is a pretty massive deal, they dont need to pump stocks for funding.

    180 kWh in a normal sized car not a truck or bus. And this is with existing chemistry, no mention of solid state cells or high silicon anodes or carbon nanotubes that are significantly more energetic…
    I have driven several EVs and they can hold 110 km/hr with 18 kw easy, so this is a real world 1000 km highway range. 1500 km is entirely possible in standard mixed driving. And only about $35 AUD to recharge 🙂

    Also high volume production of sodium ion batteries this year.

    • Its a pity northern europe is so short of sun for several months in winter.
      ALSO its so densely populated that the vast acres of solar panels/turbines are not well accepted by the population.
      Statistica says global fossil fuel consumption worldwide is 140k TWh (seems low).
      Earth radius is 6400km, intercepting 130×10^6 x 10^6 sq m. = 130 Tm*2
      Intercepting sunlight worth 130kx24x365 TWh/annum = 9000x fossil fuel energy consumption BUT
      annually, photosynthesis is about 1% efficient so that’s equivalent to 90 earthsworth of vegetation BUT
      the earth needs food ….
      probably only 20% has significant productivity so say 20 earthsworth.

      • If everyone had a home battery and solar on the roof it would mostly solve the problem. Such batteries can be second hand EV batteries, theres lots of Teslas that are reaching ages that they are cheap, and maybe not desirable to be seen in now… but the battery is big enough to give you a week off grid 🙂 Data suggests that very little degradation happens below 85%, even many years later

        3% of the earth surface area is covered in urban development, so if everyone had a solar panel roof and 15 kWh battery it would probably already meet demand, let alone other sources. The march for more energy is going to lead to solar by default, the most iconic sci-fi structure is literally just a colossal solar farm (dyson sphere). Fossil fuels are just solar with extra steps… Maybe aliens dont talk to us because they dont view our society as actually advanced yet however far we thing we have come…

        I think one very important part of the battery development is that EVs are vastly more durable than any internal combustion engine vehicle. 5 million km of outputting and recieving up to 1 megawatt, now imagine how long it will be if the battery only has to output 1/1000 of that, its so overengineered its basically indestructible. For self sufficiency its truely revolutionary.

    • Wow its doing actual strombolian eruptions not just spattering. Might mean the magma rising now is extra gas rich, this never happened earlier in this eruption.


  29. (UWD, tilt, live)
    Maybe it’s reaching its breaking point. Episode 17 has gotten down so far that Episode 18(or 19) needs to take a longer time to start, collecting pressure until it gets there. Now, the UWD has reached at the level of Episode 15…

    • Theres a rapid overflow of the south vent, went off screen in seconds. No fountaining visible yet but this might be it, the flow rate is very high.

    • And that lava flowed quickly, too. Wonder of fountaining would follow…

      • I think its probably pushing out the degassed lava in the conduit itself and the fountain will follow soon after. Question is how long will this take. It looks like E18 has begun for real though, 5 days late 🙂

        I think it will be another long episode, at least a day at near peak output. Might end up covering nearly all of the floor of Halemaumau.

        • Now I see fountaining at south vent. It’s make or break here…

          • It has 1000% begun for real now. South vent is ountaining above its cone and the north vent is filling up.

          • Deflation has begun and confirms, that the main climactic part of the episode 18 has begun:

            ?fileTS=1745329583

          • From the tilting rate it looks like this episode has similar or slightly higher effusion rates as episode 15, which had been the most intense thus far, in terms of eruption rate.

      • The V2 cam shows that the lava fountain behaves a lot like a water fountain in a French formal garden:

        https://www.youtube.com/watch?v=oG5zz9Sjw3E

        I think that there is kind of a magma pressure pipe that does the fountain, not gas. That’s unlike Geysirs, but more like artificial water fountains.

        • The lava is flowing like water over a rock on the side of the north vent, spraying up over it. Even compared to other eruptions here this lava looks particularly fluid, I wonder if this might be hotter. Both vents are fountaining very strong, very gas rich lava despite the long gap. The south vent is just about going above the rim now already.

          • I have the idea that the liquid pressure was unusually strong enough that the lava fountain comes out with high “water” pressure and big rate.

            It is in fact a voluminous and fast fluid eruption like the 1823 eruption, but inside the summit caldera and less absolute volume.

          • This is how every fast eruption at Kilauea or Mauna Loa are… 🙂
            1823 was like the lava lake drainout eruptions at Nyiragongo, low fountaining under pressure but no gas, what you described in the other comment. But this is exactly the opposite, a gas rich (50,000 tons/day or more) high fountaining eruption at 1 km above sea level. An 1823 style drainout might happen at some point in the next 10 years but its not what is happening now. This is much more like an Etna paroxysm, which it actually is doing right now too, so dual volcano viewing 🙂

  31. The north vents are getting much more active and fountaining is visible above the south vent cone, its still a dome fountain but 50+ meters tall.

    I think this is about to go full geyser above the rim very soon.

    • Magnificent view! But I think the two vent configuration might be a problem for really tall fountains, to get tall fountains the melt needs to get very frothy so that the density of the magma column is rapidly lowered and can accelerate upwards to very high speeds. However, two conduits add a lot of complications if one is too wide, so that it allows convection. It can drag the other conduit down by mixing degassed lava into the system. So I’m not really sure we can see those 500-meter sustained fountains of Mauna Ulu or Kilauea Iki unless the south vent can act independently. There seems to be some complication particularly with the north vent that refuses to do high fountains even with very high effusion rates.

      • I think that no historical Kilauea eruption has done a huge lava fountains like this only with magma pressure. Kilauea Iki, Mauna Ulu, Pu’u O’o and Fissure 8 Leilani Estates 2018 were either smaller or more gas driven.

        I’d estimate the lava fountain now as 200m tall or more … and this with degassed magma! That’s very impressive and unusual. Mauna Ulu an Pu’u O’o could divert the liquid magma pressure horizontally towards the lava tubes or satellite vents towards the coast. The summit currently has to build up the liquid eruption vertically without significant help by gas.

        • Could it be that the North vent is dealing with primarily degassed lava and the South vent has access to the the system where the lava has not yet released most of its gas? It also looks like the south vent has a second fountain going.

          Mac

          • Yes, looks like we have a new fountain! Kilauea always reinvents itself.

        • “and this with degassed magma!”

          Well, it isn’t degassed. If it was, then the open conduits would not explode into geysers all of a sudden which can only be achieved by triggering the formation of gas bubbles…

          The north vent does have some particular circumstances going on, maybe there is degassed magma being mixed in, or the conduit has a very elongated section. And since the two conduits are likely connected to some degree I suspect the north vent might drag down the south vent’s ability to go full high fountain mode. In fact, the tallest fountains thus far have been when the south vent erupted solo.

          *2018 Leilani is probably the eruption that was the most pressure driven (by the weight of a much higher rock column under the summit), and yet had the smallest fountains, cause pressure is not what drives tall fountains, it’s conduit geometry and gas content.

          • I think that once the north vent pond collapses (like other times), then maybe the south vent would explode into very-high fountain mode. It seems the north vent acts as a valve…

            The opening of other vents might indicate this is under very high pressure, if I presume.

          • 2018 had one proper tall fountain, same day fresh lava began erupting fissure 17 shot up like a geyser. I remember watching it live and it was clear something changed. There might be a save of it still on youtube. Theres also a video of it from the north quite a ways off and its a sustained pillar of orange, although no ways to get an exact size it was almost certainly over 100 meters. But as we know F17 was evolved and borderline explosive, certainly not degassed… 🙂

            The north vent seems to be much more powerful this time, I am wondering if at some point the flow rate will erode the rim and remove the lava pond. Might let it shoot up past the rim sustained too.

          • It’s true, I overestimated the degassing effect! I also have noticed that the southern lava fountain grew towards the sky. There was probably a change of relatively degassed magma towards more gasrich magma.

            This means that the climactic eruption inside Episode 18 was driven by gas. Maybe there was more gas pressure needed as before, to ignite the eruption.

    • Looks like the canaries where the gas vents from one vent, and degassed liquid spews from another,,,


  34. From: https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://pubs.usgs.gov/pp/1056/report.pdf&ved=2ahUKEwjZ2fOclOyMAxUSCDQIHQMqBQQQFnoECDkQAQ&usg=AOvVaw1vH-mvyYyGSj2vmkmfCT0a
    This kinda reminds me of Mauna Ulu in 1969-71, where it had 2 vents before moving to a single vent and collapsed. Later on, I think, more vents broke out. Is this Halema’uma’u shield in a stage where it might begin to do this? As noted, there’s another beside the south vent and the north vent is a collection of vents now…

    • Personally, I think this might go on, but each episode pause would last a week (except for small magma leakages) and continue doing, producing more vents until it reaches a certain point. I will say maybe 5 to 10 more of these until it starts doing something different. In that time, the cinder cone would grow, limited by collapsing into the vents, but overall heightened the cinder plateau…

  35. Pele gives a show: souch spectacle and its nearly yellow in daylight in some shots its super super super hot I guess this maybe 1230 c or something perhaps even much more this looks really super super hot. I guess that its really deep magma from the main deep summit chamber thats erupting now and all the shallow materials is now flushed out since christmas times when this started. I remember shots taken by USGS looking into the active vents showing bright yellow lava even exposed in direct daylight so it coud be once again over 1200 c. The deep summit magma chamber maybe 1220 – 1300 c and the magma source 1600 c it cools in its way up but it looks like fresher and hotter stuff are surfacing as times goes by. Since the Pahala Sourge is likey really a thing ( now with increased supply ) then the whole system is likey pumped full by more primitive magma thats now likey much hotter than past historical halemaumau magmas. The older and colder magmas have now been removed from the upper cap of the shallow chamber as well. Some photos shows yellow lava exposed to direct daylight the first time I ever see this for any volcano in my whole lifetime… this coud be a temperature record for any erupting lava I have not heard yet anything from HVO about lava temperatures but its very hot stuff and looks it have gotten alot more fluid now than it was in christmas suggestive of more primitive deeper stuff emerging. I have only really seen one other lava that have looked like this and that was Fagradalsfjall in 2021


  36. (B2 Cam, live)
    Besides the vents, one of the channels diverted earlier and now heading to the B2 camera…

    • Is the B2 cam falling apart before our eyes? Could it be affected by the heat – given the wide angle it’s hard to tell how close it actually is to the lava.

      • To my untrained eye it definitely looks like the camera is melting, starting around 18:28 UTC. We’ll see how long it can keep grabbing images and transmitting, but it may be RIP B2cam soon.

    • B2 has been removed from the webcam list so it might have been taken. But HVO hasnt replaced the thermal cam so I dont expect a new B2 either. I guess theres very few flat places left above the lava now…

      • Looks at around 20:42 UTC some outer protective layer finished melting off, and the camera survived a few minutes more. Last image (upside down) was at 20:48 UTC.

        RIP B2 cam.

    • One of the last images from the camera now that above pic is blank. The last 24 hrs gif page is now giving me a 403 forbidden error.

      • Do we know the distance between the camera and the vent?


  38. (B1 cam, live)
    Looks like the south flow has reached the “crust overturn” plains…

    • On the north side too, long lava flows around both sides. Its only been 7 hours and its lost half the inflation, the flow rate is huge. E17 was different so this might not be reliable, but for E15 and E16 the majority of the eruption length was AFTER the north vent shut off, so if that holds then this might be the biggest yet and still in the early stages. Although naturally this would also come with a longer repose after.

      I think over time episodes will get bigger and further apart, and perhaps weak activity will be present all the time between until the activity either becomes continuous that way or an episode just doesnt stop at some point. I dont know if the vents are high enough to intrude a shallow dike to the SWRZ at lower elevation and erupt there, in the way both Pu’u O’o and Mauna Ulu stopped fountaining by intruding downrift slightly and leaking out.

  39. As an aside from Ms Pele’s fine show, here’s one for Santorini watchers.

    Could an almighty eruption destroy a dreamy Greek island? (BBC, 21 Apr)

    BBC News spent a day on board the British royal research ship the Discovery as they searched for clues.

    This work, coming so soon after the earthquakes, will help scientists understand what type of seismic unrest could indicate a volcanic eruption is imminent.

    Beneath our feet on the ship, 300m (984ft) down, are bubbling hot vents. These cracks in the Earth turn the seafloor into a bright orange world of protruding rocks and gas clouds.

    The robot descends to the seabed to collect fluids, gases and snap off chunks of rock.

    Those vents are hydrothermal, meaning hot water pours out from cracks, and they often form near volcanoes.

    They are why Isobel and 22 scientists from around the world are on this ship for a month.

    So far, no-one has been able to work out if a volcano becomes more or less explosive when sea water in these vents mixes with magma.

    “We are trying to map the hydrothermal system,” Isobel explains. It’s not like making a map on land. “We have to look inside the earth,” she says.

    I’ve quoted only a little of the long article. It’ll be interesting to see the results of their survey, especially of Kolumbo after that large recent swarm. And devoting a geoscience ship for a whole month suggests the Greek authorities are fairly concerned, which means I can forgive the BBC for their rather hyperbolic headline.

  40. The nice thing about making predictions is that you can be proven wrong. Impressive!

    There once was a mountain on fire
    that tried many times to retire
    every time it stopped
    a new eruption popped
    and the fountain of fire went higher

  41. Can someone link the Magellan Venus Data Overlay for Google Earth? so I can explore Venus surface radar in high resolution

    • I will see if I can find my copy. I meant to do a Volcano-Venus version of Volcano Earth but I don’t think I’d live long enough to put data pins on allllllllllllll those volcanoes.

      I also have one for my favourite li’l ball of volcanoes, Io.

    • A Super Earth woud suit you well too: the bigger a planet is the greater the internal heat budget and production: means more volcanism

      • I remember reading that the best resolution for heat signatures on Venus is about 1 km2, so its actually pretty plausible that there are active volcanoes with open vents or even lava lakes that just arent hot enough to stand out through the atmosphere. This ignoring the elephant in the room that something actually looks hot on a planet with 400 C average temperature… if it isnt lava then thats actually way more interesting.

  42. Looks like the eruption is over…
    Stay tuned for maybe next week (or more).

    • 14 microrad of deflation in 10 hours, about 700,000 m3/hour or 200 m3/s average eruption rate. Might be the highest yet.

      • Not quite the highest fountains, though, but something in the records. On this day, we might’ve lost a webcam inthe process…
        Rest in peace, B2. Go to webcam heaven…

        • Two other webcams were destroyed a while back, the thermal cam and a visible one in the same place. Buried in tephra.

        • Fountains were still going above the rim for most of the episode too, so at least 150 meters. Probably over 200 meters at times. HVO actually posted a volume too this time, about 5 million m3 and 140 m3/s, so a bit lower than my earlier estimate but they do say only approximately.

          https://www.facebook.com/share/v/1APTMfgKCu/

          Here is a link to a timelapse of the B2 cam. The lava flows go from barely in view to flooding the whole foreground in 3 frames so about 30 minutes I think. And even this far away and fed by a huge fountain, the lava is still a thin pahoehoe flow. The lava in general looked especially low viscosity this time, there were times it was spraying over obstructions in the lava cascades out of the north vent and it looked like water.

          It would be great to get more data on the composition and temperature. 50,000 tons/day of SO2 is about 0.6 tons/second. At 140 m3/s and 2500 kg/m3 the lava eruption rate is 350 tons/second, so the lava is about 0.2% SO2 by weight, which seems very high.

          • Hard to say anything about temperature, but it does look very similar. And being an open hole into the magma chamber that now permanently glows it would surprise me if the lava isnt over 1200 C, it was before 2018 and with a way higher surface area.

          • “The lava in general looked especially low viscosity this time, there were times it was spraying over obstructions in the lava cascades out of the north vent and it looked like water.”

            It may simply be that the north vent fountain was very dense. The south vent instead looked dull because it was spraying it high up into the air, causing it to rapidly cool, while the north vent was like a huge lava overflow being able to keep the lava hot and fluid.

          • Actually my comparison was to the north vent overflowing a few weeks back, it always flows fast but usually you can still tell it is a thick liquid. This time it was noticeably different. I agree the fountain fallout cools a lot more so the flows arent as liquid after, so the south vent looks more dull.

  43. Bad volcano movies (which seems to be most volcano movies) really cheat the viewer out of the most fascinating part of what makes a volcano work. How many times have we seen the magma chamber portrayed as a big half-empty cavern with a lake of glowing orange melty rock sloshing around? Also how many times have we seen the start of an eruption portrayed by a slow mass of lava just seeping up out of the ground like a tar pit?

    The theory that really gets my imagination fired up though (see what I did there?) is that part of why Novarupta was so swift and violent was that there was a shallow sill of magma close to the surface and the tremor created by more upcoming magma just set the whole thing off like striking a tuning fork and then plunging it into a glass of soda. (I miss playing with the tuning forks but don’t miss the trouble it got me into).

    I wonder though if at any point in any of our lifetimes somebody will be able to set a lander on Io and conduct experiments like the InSight program on Mars. If I had Phony Stark’s money, that’s what I’d do with it.

    • Was Novarupta fast? It happened over several days, which is pretty slow as far as ignimbrite eruptions go really. Not that it was slow, but nothing like Hunga Tonga or Krakatau, which blew up and finished mostly within an hour.

    • Usually volcano movies are about family drama and hero action first. Volcanoes are only the coulisse behind the actors. I liked Dante’s peak with Pierce Brosnan and Linda Hamilton. Better than many other volcano movies which often resemble Sharknado movie style.

      I miss a bit the education oriented documentaries of the 20th century. New documentary movies are often more fun and entertainment oriented. Film makers of 20th century showed strong interest. The slow analog handcraft in making films had a different impact on the style of documentaries than the fast digital methods and travel conditions today.

      • Miss the 20th century too. Not only the films. Everything had mor depth and quality.

  44. M5 earthquake in NSW, Australia, east of Newcastle. Not that common: perhaps once every 2 decades. Last time one of those hit Newcastle itself there was significant damage

    • I didn’t feel it, but it was around 3am our time, so I slept through it.

      I definitely felt the one in 1989, it was right under me. The ground movement was mostly up and down though, so there was no damage where I was living. The bad damage was down on the plain of the Hunter River with side to side shaking plus liquefaction.

  45. M6 earthquake reported in Istanbul. Not known yet on which fault.

    • USGS has published the location. The earthquakes were on the fault in the Marmara Sea, just at the western end of the locked part of the fault. This definitely increases the risk of a major earthquake in Istanbul. The locked part of the fault has not had a major earthquake for 250 years and runs close to Istanbul. It can in potentia cause an M7.

      • It’s possible the M5.9 quake in 2019, which was from reverse faulting about 10-15 km north of this M6.2 could have been a pseudo-trigger/foreshock. Coulomb Stress modelling at the time of the M5.9 suggested it would have added significant stress to the Marmara Fault’s western tip of the transitional segment almost exactly where the M6.2 nucleated. If so, then it is inevitable that stress was increased both ahead and trailing the primary RLSS slip zone. To the west is the creeping segment of the Marmara/North Anatolian, so it’s already mostly stress-relieved, but to the east of the M6.2 primary foci the fault gets progressively more locked where energy gets stored and accumulates.
        If stress has indeed increased to the east of the M6.2, is the locked segment now in jeopardy? IMHO, follow-up/aftershocks along/near the transitional segment should occur prior to the locked segment nearer Istanbul letting loose since there is less stiction in the transitional zone which should fail under lower stress conditions (assuming the overall slip rate along the fault is the same).
        Given the similarities to our San Andreas FZ, any aftershock within the transition zone greater than the preceding M6.2 would be very unlikely since segments of a transform fault with similar stiction can only move as far as the segment ahead of it…but this raises the question of how far has the transitional segment moved (over centuries) relative to the locked segment? Tough to tell given there is both slow and fast stress relief going on within the transition zone …so the M6.2 aftershock pattern over the next few weeks could prove to be quite revealing in how much stress is actually present along the locked segment (cumulative seismic moment).

  46. http://www.worlddreambank.org/S/SIP.HTM

    Repost: Earth with kilometers lower sealevels: results in a very alien world indeed, yet famililar in some senses. This woud make it impossible to summit Everest ( see Asia section ) due to it being much higher up in the Earths atmosphere in this scenario. I guess we are lucky that Earth haves its current water content that it is neither completely flooded or being too dry even if Siphonia woud be very habitable in the hot muggy green lowlands. Its tought that many exoplanets maybe completely oceanic having more oceanic content than Earth with granitic continents submerged too, Siphonia is a Earth scenario with less water than in the real world. Much lower sealevels may make the shallower oceans of Earth more fertile due to more land and minerals having contact with less seawater

    Click on the map below for pages that explore local areas on this alternate Earth its indeed quite rad worldbuilding. Modern day continents becomes cold dry highlands in this crazy sea drained scenario..

    • This lowering of sealevel woud make Reykjavík impossible to live in due to it becomming a tall highland plateau way up in the atmosphere likey becomming an Icecap or something like a polar desert. The new Iceland coasts woud be very livable they are kilometers down an under higher air pressure than in real world, so perhaps quite warm and temperate

      • The least of your problems. All of the current continents become uninhabitable, including the continental shelfs. That leaves the ocean floor but you haven’t take away enough water so almost all of that is still submerged. The exceptions are the youngest seafloor near the mid-oceanic rifts and a few hot spot regions. However, the young seafloor which lacks sediment is basalt with a far smattering of heavier metals such as cobalt. That is not going to grow anything as the rock will be both infertile and toxic. Where oceans floor has ended up on continents (as in Oman), very little grows.

        • Hi Albert, I could live with Olives, wine, bread and some Feta 😂:
          Not without water though. My ten coffees alone. And tea in the afternoon. Those grapes need water as well.
          The resulting vegetation of Mediterranean climates are the garrigue or maquis in the European Mediterranean Basin, the chaparral in California, the fynbos in South Africa, the mallee in Australia, and the matorral in Chile. Areas with this climate are also where the so-called “Mediterranean trinity” of major agricultural crops have traditionally been successfully grown (wheat, grapes and olives). As a result, these regions are notable for
          their high-quality wines, grapeseed/olive oils, and bread products.
          Passage from “Mediterranean Climate”, wikipedia

          • Around California: south Tethys Ocean, around the San Andreas Farallon Plate, Mediterranean Tethys Oc.. Chile: First Phoenix, now Nazca. Atacama comes to mind: nothing much at all.
            Australia and South Africa do not fit in though.
            So I suggest this is maybe more complex like nearly e.th.

      • The continetal rims maybe fertile as well as some oceanic rises but it woud be a very strange world indeed with little less water

        • The continental shelfs will a very high, dry and cold plain. May be better to emigrate to Mars. And very few plants, so few or no land animals and nothing for you to eat. Please put the oceans back ..

          • He would fall from those shelves, poor Jesper. While looking out for Iceland.

          • Its unclear to me how quickly the seas vanish in this scenario.
            What was the proposal for their removal?
            Clearly an earth with much smaller oceans for gigayears would have different erosion and sedimentation patterns. Evolution would have coped.
            If giant Jesper just teleported it away then it would be a different place with limited abilities and locations to survive.

          • Not said how it is done. Jesper’s comments on habitability seem based on sea level dropping by 0.5-1 km. If he drops it by several km, as he said, none of the areas he lists as habitable will support current complex life. He makes a good argument against geoengineering.

          • It is assumed (hypothesis I guess) that the sea-levels were 300 m lower when Pangaea had been assembled with all the shelves exposed. This is proposed to have contributed to the Permian Extinction besides the Siberian Traps. All the ammonites ended up having less habitat. Drastic changes always led to partial extinctions.

            The subduction of the ocenic plate of Tethys in the Mediterranean area north is supposed to be resonsable for the exposure of parts of the southern coast and therefore for the skeletons of enormous whales in Wadi al Hitan Egypt, so another mikro-ectinction caused by the isloation and then desiccation of that part of Tethys.

            Jesper seems to ignore this fact. He is just playing however.

          • Oh btw, if I follow Albert the soil of Wadi al Hitan might have been toxic, high concentration of minerals and salt.
            The giant whales were nicely fossilized in mud I guess.

          • The oceanic floor material that ends up on the continents (scraped off during subduction) is called ophiolite. It is found in various places, including Oman and Cyprus. It has little vegetation because of the toxic metals which few plants can cope with. It is not in the Wadi al Hitan as that side of the Mediterranean has not suffered subduction.

          • Sure that Wadi al Hitan has not had subduction, but it dried out. There was subduction in the north which shrank the ocean, in the south there must have been many desiccation prosesses, not only this wadi.

        • lowlands will be warm and habitable but yes lots of habitable surface area is lost

          • Warm yes, but the soil (ocean floor) will be toxic. Habitable – no.

          • Habitable like Wadi al Hitan, Jesper, I propose.
            You should listen to Albert as this is getting ridiculous.
            Keep in mind that you wrotr great stuff about Io and Nyaragongo.

            For me this is okay as long as it stops at some point. It goes on and on and on though and is not scientific. Besides that site is not safe.

    • Siphonia will have very fertile and biologicaly productive oceans due to the fact there less seawater and more minerals and nutrients flowing into these waters. The dusty continetal highlands will add alot of fertile dust to them as well feeding the plankton and the whole oceanic food web

      • Do remember that you still have the same amount of salt, as that comes from that run-off. So the small oceans will be much saltier than ours. You are not thinking this through enough.

  47. Another star at Snaefellsnes. They are coming thick and fast – that is two this year,

    • Again near “Grjótárvatn”. Craters and lavas fill the valleys in the region (f.e. “Hagahraun”), comparable to Fagradalsfjall’s lavas in the valley of Gelingadalir and Meradalir. This volcanism in water made valleys resembles Rejuvenated volcanism of Hawaii, where lava flows ran through valleys that were eroded by water.

      We can expect f.e. a volcanic cone like “Hjrobjörg” inside a valley that rises 100m above the valley floor and sends lava flows towards the ring road, but too short to reach it.

  48. http://www.worlddreambank.org/S/SHIVERIA.HTM

    Shiveria: an Earth with alternative tilt so two large landmasses ends up over the poles allowing for extensive glaciation indeed. This woud result in two antarctica sized icaps even with todays CO2 levels much of Earth is cold and dry and dusty in this scenario

    • Scandinavia in this scenario becomes a tropical savannah

    • Iceland woud be a very pleasant place indeed to live in this scenario! warm but not hot and not very humid with seasonal monsoons in summer

      • You ever read a book? Just in case – one can listen to many. Life in different worlds>

        Out of the Silent Planet (Mars aka Malacandra), Perelandra (Venus) by Clive Staples Lewis. Good stuff. Great man, Lewis.
        Died of a heart attack the same day JFK was shot down. Had to look when Lewis died. Tea-time in Oxford, England. Kennedy was still alive.

        • Also another British author, Aldous Huxley died on the same day, November 22nd, 1963.

          • Thank you. Interesting. About the opposite of Lewis. A. Huxley more modern, Jack Lewis was the classicist, a top literature professor in Oxbridge (both), a very big and very intelligent soul., an early fighter against National Socialism. At the time mankind still dreamt of life on Mars and Venus. Perelandra was published in 1943. In 1961 the flyby of Venera 1 plus the following flybies and landings revealed the truth.
            The Martian Chronicles by American writer Bradbury were published in 1950. We dealt with Martians.
            Science has taken some fun away, no dreams any more of other habitable planets in the Solar System.

            “Brave New World” is dystopian, Lewis is never dystopian. It is clear from the beginning that we are reading a novel and always a novel with a good ending. In his novels Evil is beaten by the Good. The Huxley Vision though might become true.

    • UK where Albert lives will be rather very livable here too an Tanzanian looking Savannah perhaps with a seasonal rainfall pattern and a good
      7 c cooler than the real worlds equator as it is today

    • Antartica will be prime habitable land in this scenario, Africa will be little changed compared to today just with alot more extensive savannah and deserts due to the Ice Age

    • http://www.worlddreambank.org/S/SEAPOLE.HTM

      Seapole an Earth tilted so both poles ends up over the oceans that woud mean no base for any continetal glaciation even with todays CO2 levels resulting in a much warmer world overall. .. even with pre industrial CO2 the only ice here is sea ice. Tilt scenarios maybe more realistic than Siphonia

      • I like ‘What if’ scenarios like that. My favorite is… What if Betelgeuse was as close as Proxima Centauri? (there’s actually a 1980s science fiction book with a similar premise, unfortunately I don’t recall the title or author)

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