And the sea was no more: the story of the Tethys marbles


The Elgin marbles

The Elgin Marbles. A head of a horse from the chariot of the goddess Selene, carved from Pentelic marble. The Greek god of horses was Poseidon, who also rules over the sea.

International controversies can seem intractable. This particular one is about history set in stone. The Elgin marbles were the decorating sculptures of the Parthenon of ancient Athens. The Earl of Elgin (Thomas Bruce), ambassador to the Ottoman empire, acquired them in the early 1800’s. The acquisition had doubtful legality, although opinions differ on this. The Earl’s aim was to use them in his garden in the UK, so that artists could come and draw them from the originals rather than from imagination. Originally he had planned to make casts of the sculptures and take those, but it turned out to be easier to just take the originals, not just from the debris (the Parthenon was in very poor condition at the time, after gun powder stored there had blown up) but also from the parts of the monument still standing. One of the ships which transported the treasures sank on the way – luckily the cargo could be recovered. Elgin later went bankrupt, which allowed the British Museum to acquire them from his estate. The Elgin marbes still remain one of the prize possessions of the British Museum. Obviously, Greece would like them back! Public opinion in the UK is largely in favour of some form of return or shared ownership, but the museum is reluctant and the government not supportive. Trying to solve this seems to be a form of Sisyphean diplomacy. In the mean time, three times as many people see them in the British Museum each year than visit the Parthenon itself!

The Parthenon temple was originally part of the cult of the goddess Athena, although its precise role in this cult is not known. Athena, also known as Pallas, was the protector of Athens and is part of the founding myth of the city.

Elgin properly recognized the sculptures as supreme works of art. Good art makes us see things in a different light: it changes the way we view the world around us. The sculptures did this by connecting the magnificence of the building on the Acropolis with the mythology and history of old Athens. They gave purpose to the building and connected it to Athena. The Elgin marbles do not have the same impact when shown separate from the place where they belong. One may wonder though how long they would have survived in situ. If Elgin had not taken them, would there have been anything left by now? Even Stonehenge only just escaped the damage of the past, making it to the era where we began to protect rather than destroy our heritage. (Perhaps back in 1800 the Greeks should have taken its stones, to protect Stonehenge from the English.) The Elgin Marbles are part of Greek living history. But it was not important to the Ottoman empire as it wasn’t their history. So they sold them.

Greek culture is integrated in the thought patterns of the western world. The Parthenon is a world heritage site for good reason. Cultures can transcend borders, and the culture of ancient Greece has become a foundation stone of the modern world. It is embedded in our language, where so many of our expressions come from ancient Greece, ranging from Cloud Cuckoo land (the mythical fantasy land between humanity and the gods) to Pandora’s Box (with the precious gifts for which we were not ready). We are told to beware of Greeks bearing gifts (especially large horses) – but those gifts included the immaterial treasures of democracy and science, which are now under attack in our modern world. Although much of our social fabric stems from the Near East, much of our thinking is from Greece.

Without the visible connection to the Parthenon itself, the English created another connection in the Elgin marbles. To them, the stoneworks reflected the magnificence of the natural world. This was the time of Romanticism, which was looking to nature as an anti-dote to the insecurity of a rapidly changing society. Keats commented on how the Elgin marbles resembled the mountains from which they came, by their sheer size (or weight) and their physical deterioration:

On Seeing the Elgin Marbles

My spirit is too weak – mortality
Weighs heavily on me like unwilling sleep,
And each imagined pinnacle and steep
Of godlike hardship tells me I must die
Like a sick eagle looking at the sky.
Yet ’tis a gentle luxury to weep
That I have not the cloudy winds to keep
Fresh for the opening of the morning’s eye.
Such dim-conceiv’d glories of the brain
Bring round the heart an undescribable feud;
So do these wonders a most dizzy pain,
That mingles Grecian grandeur with the rude
Wasting of old time – with a billowy main –
A sun – a shadow of a magnitude.

John Keats

The Elgin marbles connected us to an ancient world, a world of stone and water. They contain an echo of a sea, but it is not a sea we know today. This is a story of another world, from which our world descended. The Elgin marbles belong to the Earth.

The Parthenon


Our word ‘marble’, unsurprisingly, has Greek origins. It comes from the word ‘mármaros’, meaning shining or sparkling. The ancient Greeks were fond of marble and used it often. White marble was a particular favourite – and this was not just in Greece: the Taj Mahal in India and the Supreme Court in the USA are largely built from white marble, taken respectively from Makrana in the northwest of India and Vermont. Much later, the word marble became in use for a children’s game involving small white balls made of glass porcelain or indeed of marble, which could be won or lost – and losing them was a major embarrassment. These games were still popular when I went to school and I had my experiences of winning or losing my marbles. In the late 1800’s it became a synonym for losing once’s wits.

Marble is a much hardened version of limestone. It still remains relatively soft, and is easy to cut and polish. Marble comes in a variety of colours. Red to yellow colours may be caused by iron impurities. Serpentine impurities can make marble appear green. Even where these are absent, there may still be grey stripes in the white marble: these come from layers of clay in the original limestone.

Limestone is mainly made from calcite, CaCO3, deposited in shallow, warm marine waters. It is mostly of biological origin, the debris of marine organisms in need of the security of shells and skeletons. A coral reef is a limestone in the making. But it can also form non-biologically in hot springs, as for instance in Badab-e Surt in Iran.

The process of turning limestone into marble involves heat. The transformation to marble happens when the limestone becomes deeply buried and is subjected to the heat and pressure underground. A heat of several 100 C is required, but the heat should not be so much that the limestone melts. It is called the glass transition temperature, and indeed the limestone becomes glass-like. It crystallises, and these crystals create the marble.

The heat can also happen less deep, when magma comes into contact with the limestone. It happens mainly where tectonic plates collide. (‘Tectonic’ is another word that comes from Greek) The metamorphism (from ‘meta’ and ‘morph’, both Greek) can occur in various environments, but marble requires that either oceanic (a Greek word) or sedimentary (Latin rather than Greek) crust is involved. The limestone needed water.

Image taken from

Mount Pentelikon

A Pentelikon quarry

The main source of white marble in ancient Greece was Mount Pentelikon. The mountain lies between Athens and the Bay of Marathon. Even though it is some 15 km northeast of Athens, the suburbs of Athens now almost surround it. The mountain is about 1100 meters high, and the southern slopes are covered in quarries, both ancient and more recent. On Mount Pentelikon, the ancient Greeks clearly followed the famous advice from the oracle of Delphi, to leave no stone unturned. Nowadays the region is protected and Delphi’s advice itself has been overturned. The marmer can be used for repairs to the Acropolis but for nothing else.

The marble from here was used for the first Parthenon, build around 490BC, and then for the current Parthenon, an upgrade which was build some 50 years later. In Roman times, marble from Mount Pentelikon was used throughout the empire. There were 162 different quarries on Mount Pentelikon, following three main marble units. All three are located on the southern slope, in three long linear lines each running southwest to northeast up the mountain. The northern-most line contains more recent quarries: the ancient quarries are the lower two lines.

The rocks taken from different quarries have slightly different isotopic ratios of carbon and oxygen. The marble of the Parthenon itself has not been examined for these, but the Elgin marbles have. They show a slight enrichment in 13C and a larger depletion in 18O. Although that pattern is found throughout the Pentelikon marble, the specific ratios are all present only in unit 3, the southernmost of the three lines. At least some of the Elgin marbles were made from stones from the uppermost quarry of unit 3. That is surprising, since the stone work for the Parthenon itself is thought to have been quarried much lower on the mountain.

Marble in general can show a wide range of isotopic ratios. It depends on the source of the original limestone. Limestone from fresh water tends to be depleted in 13C, the heavy form of carbon, while deep sea limestones are enriched in 18O, a heavy form of oxygen. The ratios found for the Elgin Marbles are opposite to this, and are more typical for some corals and red algae. The limestone came from a shallow, warm sea. Long after, there was subduction and heat, and a transformation into marble. Later still, they ended up on the top of a mountain. It was a geological journey, a local expression of events that affected a much wider world. An ocean was born – and died.

The Cyclades

East of Mount Pentelikon and the Bay of Marathon lies the Aegean Sea. Underneath this sea lies a submarine plateau, which is dotted with smaller and some larger islands. These are called the Cyclades. There are over 2000 islands but only the largest ones are inhabited. Santorini may be the best known of the inhabited Cyclades. The sea here is only 100 to 200 meter deep and in fact during the ice age the eastern part was one large island. During the bronze age, the civilization here already produced marble statues which were traded far and wide. The marble came from several of the Cylades, especially: Tinos, Naxos, Paros and Delos. Mount Pentelikon is at the far end of this marble belt which stretches west to east across the islands. Clearly, the Cyclades are at the heart of our story.

The Cyclades are a region of thinned continental crust, only 22-24 km thick. This lack of depth of crust causes the region to lie a bit deeper, deep enough that the platform has become submerged by the shallow Aegean sea. What caused this region to sink? Why are the Cyclades islands and not mountains?

Subduction and the arc

Two of the islands of the Cyclades are volcanic: Milos and Santorini. The latter is only a shadow of itself, having blown up rather spectacularly 3500 years ago, in an event that caused widespread destruction around the Aegean. There have been many small eruptions in the crater since. A surprisingly large (and underrated) explosion occurred in 1650 at Kolumbo, several kilometers from Santorini. It left 200-meter deep deposits, and caused a 20-meter high tsunami: it was in a way an early Hunga Tonga. The Kolumbo eruption was triggered by a flank failure. In contrast to Santorini, the other volanic island, Milos, has not erupted in the Holocene (the last eruption is dated to 90,000 years ago). However, it has geothermal activity. The nearby small island of Antimilos is also volcanic with eruptions dated to 300,000 years ago but appears extinct. There are actually far more volcanic domes in the volcanic arc, but those are hidden below sea level. Three such domes are east of Antimilos; many more are located in the area of Santorini.

The volcanic arc is powered by a subducting plate which at the location of Santorini and Milos lies 130-150 km below the surface. The subduction involves the oceanic crust of the Ionian sea, south of Greece, which belongs to the African plate. The Hellenic trench where the subduction occurs (or has occured) is located south of Crete. Tartarus’ trench is subducting northward, and it has pushed up an arc of islands, of which Crete is the major one – as usual, this region immediately in front of the subduction trench has no volcanism. South of the Crete arc lies a subsidence basin, and south of that is the volcanic arc. The Cyclades beyond this arc are not volcanic.

There is some doubt about the current state of this subduction. The oceanic plate may be experiencing roll-back, with the actual sinking of the plate now occurring further south, at the lower red line in the figure. A new subduction zone is forming here, and the region of the Ionian sea in between the two subduction zones will eventually change allegiance and become part of Europe. In the battles of the plates, the borders are grey zones, not to be trusted.

Everything to the north of the current trench is being pulled southward in response to the rollback. This pull has turned the Aegean Sea into a zone of extension. The rapid movement has caused the crust here to stretch and thin. (With a slight cultural detour, think thin-crust pizza.) As already mentioned, this thinning is why the Aegean Sea has become a sea – there was insufficient depth of crust left to keep it afloat.

Speaking of changeable borders, the Aegean Sea used to be part of the Eurasian plate. But this has changed in recent (geologically speaking) years. The North Anatolian fault in Turkey started extending into the northern Aegean Sea a few million years ago. In consequence, the Aegean sea plate south of this fault has been disconnected form its parent and has become its own microplate. That has affected the movement. The stretching and thinning occured while the plate was still connected to the mainland. Now it can move as a block, so that the crust no longer needs to stretch any further. At the moment the Aegean Sea plate is moving southwest, pushed by Turkey moving west and pulled south by the roll-back of the African oceanic plate. This movement is not shared with the rest of Greece, which is now fairly stationary.

The Hellenic trench connects to one in the Adriatic Sea. Here, there is northeastward subduction of the Adriatic sea underneath the Balkan. An African connection is not obvious since the Adriatic sea has no connection with Africa. But things are more complicated and the borders wars are at times more like insurrections. There are bits of Africa in places where this would not be expected, deep inside Europe and far from the battle front. The ancient Greeks would have understood: their nation is Europe’s Achilles heel. Africa has been sending Europe gifts of land and sea, each a Trojan horse. And Europe has been taking them in.

The mountains of Greece

Greek mountains. source:

The current phase of the collision between Africa and Europe, south of Greece, began some 25 million years ago. It has come to a cross road: the Ionian Sea is almost gone and soon the collision will involve the continental crust of Africa. At that time, we can expect a new mountain range to form along the southern limits of Greece.

But there are mountains already in Greece. The high mountains including the home of the gods, Olympus, are in the west, near the Adriatic sea. How did they form? It turns out, there is a long history here of mountain building, and it has to do with the origins of Europe. But it is complex, multi-phased, and the geology has presented a Gordian knot, near impossible to entangle.

Let’s start at the end, the present. As mentioned, the Mediterranean south of Greece has been subducting underneath Europe. This is pushing up a ridge just in front of where the subduction occurs. Crete is on this ridge. But as the subduction is rolling backward, a new push-up ridge has been growing on the seafloor of the Mediterranean itself. It is called the East Mediterranean Chain in the map above but it is also known as the Mesogean ridge. (The term Mesogean comes from the name of the current Mediterranean oceanic plate.) The on-going collision has therefore already built two ridges, as well as the volcanic arc of Santorini, over the past 25 million years ago.

But this was just the last phase of events that go much further back. Before the Mesogean plate was the Apulian plate. This was a small continental plate, moving northward into Europe. It slammed into Greece and Italy, being pulled in by a subduction zone. In front of the Apulian plate was another oceanic plate, and this subducted underneath western Greece. It brought melt and heat but it was not active enough to form a volcanic arc. Apart from that, this was very similar to the Mesogean events, although more to the west. In both cases, the heat largely stayed in pockets underground, each pocket pushing up a small mountain above them. These elevations became the Cyclades, each island a separate heat pocket. The heat reached a few hundred degrees underneath. There was some granite formation but there was not enough for major melt. However, there was enough heat the metamorph the buried limestone and create marble. This happened 45 million years ago and again around 10 million years ago – in Greece, history repeats itself. (The idea of eternal return, that the same events will happen again and again, was part of the Greek philosophy of stoicism.) Thus, the Elgin marbles have a lost oceanic plate or two to thank for their source material.

The Apulian plate arrived, eradicating the ocean in front. It formed a mountain chain at the collision front, and docked. And it is still there. Nowadays the Apulian plate is better known as the Adriatic plate: it lies west of Greece, along the entire Italian east coast, and includes much of the Italian coastal regions themselves as well as part of Slovenia and all of Malta. The mountains on the eastern side of the Adriatic, including western Greece, formed in this collision.

The Apulian plate also had an African heritage: it had split off from Africa and journeyed across, with an older sea in front and a young one behind. This was how the current Mediterranean (the Mesogean) was created.

The subduction of the older ocean and the subsequent collision with the continental plate both formed mountains – the mountains of Greece and the Adriatic thus formed in two phases. It is complicated. And it is old: the Apulian collision was 45 million years ago, whilst the preceding subduction happened more than 60 million years ago.

But the Apulian was not the first lonesome traveller on their odyssey to Europe, blown across on the winds of Aeolus. Long before the Apulian plate was the Cimmerian plate. This too had been part of Africa, and like Apulian after it, it eradicated an ocean before it and formed a new one behind it. This plate took a more easterly route – it docked, and stayed, making its home in Eurasia. The name ‘Cimmerian’ is taken from a small mountain range in Ukraine, along the southern coast of Crimea.

The Cimmerian plate formed parts of northern Turkey as well as Greece. This plate brought us the Cyclades region itself. The Cyclades too were immigrants. And again there were mountains that formed, this time along a wide region to the east.

And so plate after plate had come and joined, and the mountains they formed were on the land donated by the previous arrivals. The Cimmerian plate has seen mountains growing on its own land from collisions with the oceans and plates that followed. Mount Olympus, home of the Gods, is a gift from Africa. The Herculean task of building it and the other Hellenic mountains was carried out mainly by workers from Africa.

A landscape with trees and mountains Description automatically generated

Crimea mountains, Ukraine (

The Elgin marbles and Mount Pentelikon have a long history. The original limestone was brought by Cimmeria. It was deposited in a warm shallow coral sea, on the continental shelf of Cimmeria, to become part of Europe between 200 and 150 million years ago. The Apulian plate and the subduction that preceded and followed its arrival changed the region. Pockets of heat transformed the limestone and created marble. The heat also caused mounts to rise. Over time, erosion took hold and eventually the buried metamorphosed limestone came to the surface – ready for marble mining.

East to west and south to north


Take a look at a map of the world. There are two long chains of mountains. One runs north-south along the western side of the Americas and into Antarctica. The other is not as easily recognized, is older and appears less joined-up. It runs from the Pyrenees in Spain through the Alps, the Caucasus, the Hindu Kush and the Himalayas to find its terminus in southern China. It consists of many different ranges and they don’t alwasy connect well. In some places they even run double. But the chain is unmistakable and everywhere. Why is it here?

Now take a look at Europe and Africa. All over southern Europe are short mountain ranges, including in places far from Africa. In northern Africa, there are no such mountains: the land is old and eroded. The only exception is in Morocco, which looks like, geologically speaking, it belongs to southern Europe. The titanic collisions between Africa and Europe have left scars are all over Europe – but not in Africa. Why is that?

The answer is, of course, that the collisions have not been between Africa and Europe. It was done by migrations. Pieces of Africa came off, drifted across, and collided. Europe, on the other hand, has not done the same in return. It received but did not reciprocate. The process is still continuing. In the past 30 million years, Africa has lost Arabia, part of its Craton heart. (Kratos, of course, was yet another Greek god, son of Athena.) That is now moving north and will soon collide headlong with Iran. In the process it is also pushing Turkey west, into Greece. It is a geological and political nightmare, inviting the Greek god of Chaos. But apparently, all this has happened many times before. The siren call of the north was irresistible.

Drifting fragments of continents need oceans to drift in. This is also a story of that ocean.

The Tethys ocean

The battle indeed had been Titanic. The ocean was called the Tethys, and Tethys was a daughter of the Titans. Her parents were the Titans Gaia and Uranus (not the most obvious combination) and she was married to the Titan and river god Oceanus – so ‘Tethys Ocean’ refers to the couple. (Oceanus was also her brother – Greek mythology was a soap opera of dubious morality.) They had thousands of children – one for each river in the world.

Oceanus was the god of a river that went around the entire world. The Tethys ocean was a sea stretching from China westward to America. There is indeed a similarity between them. Perhaps a more appropriate name for the Tethys would have been the Oceanus ocean! (This might however invite a conflict with Poseidon. It is complicated.)

A map of the earth Description automatically generated

Pangea, 420 million years ago. Source: Wikipedia

The story of the Tethys starts with Pangea, 400 million years ago. All the continents had come together into a single supercontinent. (Only one small village still held out against the Pangeans…) There was a small indentation in the Pangea coast line, near to where China is now. That indentation was a sign of trouble to come, but is hard to recognise as a danger on the map. The curse of Cassandra was that no one would believe her prophecies of disaster. The indentation became larger and developed into a bay and later a sea and eventually an ocean (no – not a river). The southern shores drifted away and became their own world. Gondwana was born.

The ocean eventually split the supercontinent east to west, extending as far as the ocean basin of the Gulf of Mexico. It was an equatorial ocean, tropically warm and full of life. It was the ultimate coral sea, at least on the northern shores. Gondwana drifted too far and became colder. Seeing the error of its ways, it stopped and started to reverse course, back towards the warmth of the equator. (‘To blow hot and cold’ is another expression from ancient Greek mythology.)

What actually happened is that the new ocean had become an old ocean and old ocean floors sink and subduct back into the underworld, Hades. The spreading ridge that formed the ocean would have been located close to Gondwana, so the ocean floor there was young and buoyant. The oldest oceanic crust was next to the northern shores. Subduction developed along this coast: it began to close the ocean and pull in Gondwana. At this time the Tethys ocean was still extending westward through several branches. One of those branches would find the rifts of the proto-Atlantic, and through these connect as far as the Gulf of Mexico. This completed the division of Pangea into Gondwana and Laurasia, while the Tethys ocean was already beginning to close in the east.

A different maps of the world Description automatically generated with medium confidence

Growth of the Tethys ocean

As Gondwana odysseyed back north, new rift zones developed further south. These east-west rifts occurred inside Gondwana and resulted in Gondwana fragmenting. A large fragment, or perhaps a series of pieces, left and crossed the ocean ahead of the rest. This became Cimmeria. It joined Laurasia, and added new land, stretching from Greece to Malaysia. Turkey, Iran, Tibet and many other places were born as Gondwanan refugees. It is an enormous region: this was not just a sliver of land, it was a continent by itself. But whether it came in one piece or in pieces is not known.

A map of the earth Description automatically generated

The splitting-off of Cimmeria

A map of the world Description automatically generated

Cimmeria after the merging. The regions between the lines contain remnants of Cimmeria.

Behind Cimmeria, a new ocean formed. Nowadays we call the first ocean the Paleotethys and the new one the Neotethys. The latter is also just called the Tethys ocean. The ocean received a new floor and a new name but otherwise remained the same.

Events took place and history was made. At times the world, like Icarus, flew too close to the Sun. The Siberian traps which nearly wiped out life on Earth happened just north of the Paleotethys ocean, at about the time Cimmeria separated from Gondwana. The million years of rain drenched the shores and started both the age of the dinosaurs and that of the mammals. Much later, the Deccan traps occured in the Neotethys ocean. The Chicxulub  impact happened on its shores. But even this ecological disaster led to a new and richer world. At times, the narrow western arm of the ocean ran out of oxygen, and the huge sediments of tropical organic matter were unable to decay. This organic matter became buried and metamorphed to black gold: it formed the oil of the Middle East. So much of our society depends on the produce of the Tethys. Later, India crossed the Tethys and joined Asia, pushing up the Himalayas. This started off the southern Asia monsoon, the rains that feed much of our world. Only Australia is still holding out as the Gondwana survivor, but it too is on the way to rejoin the north.

The Tethys ocean had the Midas touch. The biggest disasters turned to new riches: everything it touched turned to gold. Greece escaped the particular riches of the black gold, but this is just sour grapes (an expression from the tales of Aesop). Instead it ended up with the purest white marble. Tethys is the gift that keeps on giving.

Greek gifts that last

Is anything left of the Tethys ocean itself? Apparently, John of Patmos who lived on one of the Cyclades islands, did not think so: he wrote that ‘the sea was no more’. But this is disputed. Sometimes the Black Sea is considered a Tethys remnant, a part of perhaps the Paleotethys that did not quite close. But it was never an integral part of the Tethys. The Gulf of Mexico is also a survivor from the days of the Tethys ocean and it was connected to it. But it has its own history.

The Mediterranean sea is often considered the remnant of the Tethys. But it is not the same as the ocean that there was before: the original Tethys ocean was further north.

Can oceans migrate? When a new oceanic crust forms, is it still the same ocean? The Mediterranean has seen plates come and go. Does it need to be the same water? But the Mediterranean ocean once dried out completely, 5 million years ago, leaving a deep gash in the Earth and an ecological disaster that dwarves that of the Aral Sea. The Earth is like the Titan Cronus, devouring its own children for fear of being surpassed by them.

The Mediterranean is really its own sea: a descendent of Tethys but not the goddess herself. This is a good heritage to have. The children of Tethys included Eurynome, whose children we call the Charites, the goddesses of grace and beauty. Another of her children was Metis, the mother of Athena in whose honour the Parthenon with its marble sculptures were built.

The real remnants of the Tethys ocean are not found in the sea. They are in the mountains that were formed along its northern shores, which often including material from the Tethys and Paleotethys oceans themselves. The life of the Tethys has formed the highest mountain on Earth: the fossils of Mount Everest are such a memory of Tethys. But so is the marble of Mount Pentelikon which formed from the coral reefs of this tropical world ocean.

The Elgin marbles are so much more than just human history. They come from, and belong to, a lost ocean. The Tethys ocean has shaped our world in so many ways. The Elgin marbles are part of its history. They are a Christmas gift from our greatest ocean. Keats saw it well. It mingles Grecian grandeur with the rude wasting of an ancient ocean.

Albert, December 2023

From all of Us to all of You: VC wishes all you readers a Merry Christmas, and a touristic volcanic 2024!

And for the traditional Christmas games

How many numbers do you see?

Spot the circles!

The stable painter

Source: van Gogh

291 thoughts on “And the sea was no more: the story of the Tethys marbles

  1. A happy Christmas, too.

    — Just outside your Greece map, where the beaches of Agii Theodori are, the volcano Sousaki is located, where you go and if not beaten by a dog, you might suffocate from toxic gases, which is maybe a bit exaggerated, but my wife really disappeared into that strange valley with its strange odor (yes, boiled eggs), and she didn’t come back. I mean, she came back, but for a while I was uncertain. After all Greece is the land of myths and drama, you can lose your wife to a volcano? You can be killed by dogs? Remember Homo Faber and the snake incident, which happened only a few kilometers away? So if you go there, take your gas masks with you and some (throwable) sousages.

    • Reminds me of an unfortunate sailor in Haifa Isreal. We were returning to the ship in the duty van and came across a sailor desperately clingy to a lamp post, trying to avoid the angry dock front dog that “owned” everything in sight. We got him into the van, but the dog bit the fenders quite a bit.

  2. Thank you very much, Albert, that was a great gift. What a saga.

    Like Keats, I feel the existential dread, and the overwhelming wonderment. Geologic time and history is really too much for my feeble human senses to grasp . Perhaps that is why the gods appear …….

  3. All a very happy and hopefully peacefull Christmas! 🎄

    Albert, thank you very much for this highly interesting article. With many asides and funny references, it was a joy to read. Especcially as I like the Tethys and its complicated history! Really a christmas present 😊

  4. Thank you.
    FWIW, I flatly refused to go near one of the mainland’s famous sulphuretted thermal springs / spas: A chemist by training, that ‘rotten eggs’ set off my nose about 50 metres short, and I’d go no further. My parents thought it a great adventure, but were ill all afternoon. Uh, so was I, as the local retsina was astringently potent…

  5. Thank you for this wonderful Christmas gift Albert.

    As a Grecophile living there 4-5 monhts a year I found this to be a very nice Cristmas eve read. I did not know “our” Island Chios/Xios in the NE Aegean is geologically drifting towards the Greek mainland. With Turkey following. I will keep checking the distance to Cesme, Ikaria ans Samos on those cristal blue clear days in the future… Not so sure the local islanders should be told about this fact though. For geopolitical reasons. While when it comes to people being people, the turks are neighbours only 25-30 mins away by hydrofoil. And both people are good neigbours. 🙂

    On volcanic origon and historical volcanic activity of these North-Eastern Agean Greek Islands I have not read very much, but I do know there are three geothermal active areas on Chios where one of them has been utilized with a curative bath there since the 1930’s. Agiasmata. The other two are are Agia Markela (holy site) and Nenita (village).

    Remnants of ancient volcanic activity is clearly visible many places and the soil is very fertile and mineral rich.

    When mentioning black gold there are actually large deposits along the eastern Aegean and outside Eastern Crete. Eps. from natural gas. I saw a low estimate of apx $ 200 billion when nat gas prices were low three years ago. However a long ongoing dispute between Athens and Ankara has left all in place. At least for now.

    Thank you again Albert. Really enjoyed this.

  6. Merry Christmas 🎄

    Thank you for a year of wonderful articles and comments. 🥂

  7. When you say,
    “Limestone is mainly made from calcite, CaCO3, deposited in shallow, warm marine waters. It is mostly of biological origin, the debris of marine organisms in need of the security of shells and skeletons. A coral reef is a limestone in the making. But it can also form non-biologically in hot springs, as in the lost pink and white terraces of Tarawera.”
    It is true that limestone may be abiotic but the pink and white terraces of Tarawera is not a good example. As far as i am aware they are made of siliceous sinter oozing as hot springs from the volcano which can change its mode of eruption from felsic through to mafic. In your post on Tarawera you also acknowledge that the terraces were siliceous sinter.

    • Thank you for pointing that out. My memory failed me on this one! I have replaced it with a better example.

  8. Thank you, Albert! And Merry Christmas!

    I wasn’t aware that marble could form without the geothermal route, but that explains much, such as the size of many marble deposits, and their frequency. Thanks!

    Marble has long fascinated me, though perhaps it’s merely nostalgia due to the fact I lost my marbles long ago. 🙂

    I loved the games images too… especially the Starry Night combo. That one shocked me by how effective it was.

  9. Thanks Albert, one to read when I gave access to a computer, rather than my phone.
    Merry Christmas.

  10. Tethys I think alot of, woud be a beautyful sight to walk its shores, white beaches and clear sapphire blue waters, you walk under the hot cretaceous sun and the sand is hot under the feet, It woud be a pretty sourrene sight, while very inaccurate today in terms of biology the ”Cruel Sea” episode of WWD gives a hint of what it woud look like at least in terms of enviroment. Mediterranean today retains many the Tethys landscape forms souch as white beaches and calk landscapes, while the prehistoric enviroment may not have been craggy as it is today. Being a greenhouse world the seawater woud have been pretty warm I been reading some estimates by drill core chemistry that well over 40 c became the sea surface temperature in south part of that sea. I guess the warmth and humidity there woud be leathal for humans today thats evolved during cooler drier conditions in pleistocene

    In Jurassic times Europes coasts woud mostly be lined with conifer – fern forests, but in the late cretaceous it woud likey be modern tropical broadleaf rainforests. Sahara was a tropical swamp and coral sea in Cretaceous, not soure about Scandinavia but it woud be mostly coastal forests.


      I really loves Cruel Sea episode despite its inaccuracies and outdated biology. Benjamin Bartletts soundtrack and soundscapes for the episode suits perfectly the tropical tethys ocean, a very beautyful yet terrfying place all at once, and indeed all of his compositions are musical masterpieces for any nature documentary. It woud be good with a real remake of WWD with updated biological knowledge and graphics as its defentivly quite outdated now

  11. Thank-you for the pleasure of this Christmas-Dinner at Volcanocafé, Albert!

    The Mediterannean Sea has parts with folding and parts with subduction, sometimes both mixed somehow. The subduction zones are short, but can do apokalyptic earthquakes like Messina and Crete. Earthquakes from there destructed many of the ancient “Seven Wonders”, f.e. the Colossus or the Lighthouse.
    Do limestone and salt stone in the Mediterannean sea support alkali volcanism? Calcium belongs to the Alkaline earth metals. If they are incorporated by a magmatic melt, it may change the chemistry. The Mediterannean Sea also hosts sediments of Salt (NaCl) which may feed Natrium loaded volcanism.

    Santorin (Nea Kameni) last was active 1950. According to GVP is has a variety of magma from Basalt to Dacite. The frequency of eruptions there reminds me to Askja. It can erupt on occasion, but we shouldn’t expect it too much.

    To imagine the Tethys Ocean we need a lot of phantasy. It contradicts our current global geographical experience. It was a real ocean like the present Indian Ocean. The Mediterannean Sea developed after the Theys was closed. During the times of Thetys, the southern coast of Europe followed more or less the present Danube river. There they found fossile marks of sea breakers. There was kind of a margin sea of Thetys (like present Baltic Sea to Atlantic Ocean).

    • Not sure it would be so hard, Indonesia is probably very similar to what Europe looked like back then. Mix of volcanic island arcs, terranes, continents in various stages of submurgence, and composed of multiple ocean basins. Actually some of the ocean basins within southeast Asia are even deeper than abyssal plsins in the world ocean.

      And then there are the animals, with a mix of species from the northern hemisphere but also a number of typically gondwanan lineages, I guess like a Cretaceous version Wallace’s Line.

      I guess the modern Mediterranean, part of which does have Cretaceous seafloor, is just the last of those ocean basins of the Tethys, maybe it was the biggest one. I guess it is also a little arbitrary when the Tethys stopped existing further east too, as India was an island within it, and the convergent zone at the north of the Tethys still exists, the Sunda and Vanuatu trenches are continuous with it, as well as the Himalayas and all the stuff the article talked about regarding Europe. Was definitely not nearly so clear cut as the closing of the Paleotethys behind Cimmeria anyway.

      I wonder if the eventual proper closure of the Mediterranean, as well as Australia with Sundaland, will that create a so called supermountain stretching from Portugal to eastern Australia? Maybe India will have stopped moving north by then though but still.

      • I raised that point in the post, when to call an ocean ‘new’. There isn’t a clear-cut definition. Behind India I would call it a new ocean. In effect, this was an Africa rift forming a new ocean, like the Red Sea now. Africa has been trying to collide with Europe for a very long time. Every time it ends with a bit of Africa rifting off and a new sea dividing the two. May be continental collisions are like that: the last bit is the hardest and takes for ever.

        • In a way they are. Each has a separate cause but the interaction between the Gondwana remnants and Eurasia is part of the picture. Weak volcanism is not uncommon where two continents collide. The deepening crust can allow for some melt at the bottom. This is how granite forms although those intrusions do not reach the surface. There can be a bit of oceanic plate below the collision zone. Magma also needs pathways, and these can be provided by faults in the region: this is the case in the Caucasus. And collisions can cause rotation in the victim plate, causing a zone of extension somewhere: this happens in the Eifel.

          • The Eifel like the older volcanic provinces of Westerwald and Vogelsberg sits in an area, where the Upper Rhine Valley Rift splits into the today dormant Mjøsa Rift system (Oslofjord) and the active Lower Rhine Rift (Cologne). Is it a distant effect by the Adriatic plate that pushes violently against Austria & Switzerland, while France is more exempted?

          • France is not exempted. If you follow the volcanic line, it lines up with the Massif Central and the volcanic activity in northern Spain.

          • I have been to a few sulphurous hot springs in Spain, even one in Southern Spain which surprised me. Too hot to actually swim and notices requested not to as it made it uncomfortable for other bathers.

  12. Kilauea not making a lot of quakes right now but 7 microradian inflation in the past week, very fast. Maybe the rift is full and now pressure is building all over. Maybe we get an eruption for New Years here too 🙂

    • If I’m reading that right, the current inflation has exceeded the prior points of rift intrusions? If so, it could indeed be getting ready to do something. The question is, where? I’m hoping for the summit or SWRZ – or anywhere else that does not involve an inhabited area.

      • It exceeded that point a long time ago 🙂 this graph is just the last week.

        • I definitely misread that graph timewise, and that’s after you saying it was for a week, plus it has the dates on it. Oops. Thanks for the correction!!

          So, the volcano we just saw erupt in Iceland seems (based on a sample size of only two) to create dikes if it reaches a certain level, but Kilauea does not. I’m going to guess this is because Kilauea has magma chambers and other features of a larger, vastly more active, and far more complex system?


          • Kilauea is still recovering from the collapse in 2018. Its about 60% of the way if the cross-caldera GPS is taken (a bit of a guess, the 2018 collapse has been gone from the chart for a while now)

            Svartsengi has no caldera to recover, its all under pressure, like at Bardarbunga before Holuhraun only the magma storage is a sill complex rather than a singular chamber. Svartsengi is also very flat while Kilauea is elevated. Central volcanoes are usually elevated, Krafla is the only example of a central caldera in Iceland I am aware of doing cyclic repetitive rifting eruptions, possibly because it has basically 0 relief from tbe surroundings.

          • I had no idea that Kilauea had recovered only 60% or so from the 2018 collapse. Thanks!.

            That being the case, why are we expecting more in the near future than caldera infilling eruptions and minor deep intrusions, as we’ve seen since it became active again? Or does that fit with its history?

          • By some measures it has indeed recovered more than half. This includes relaxation/rebound, so the stress may not have recovered as much, but then it doesn’t need to as the summit is quite damaged from 2018. Less stress is needed to break through.

          • I think its nit a matter of ‘only’ when talking about a volcano recovering more than half the volume of what would have been a solid VEI 5 if it was explosive. Bardarbunga is barely in the double digits percentage recovered after Holuhraun, which was about the same time and twice as long ago. Its debatable but Grimsvotn might have only just started to recover from Laki in 2011, and Katla probably still hasnt recovered from Eldgja.

            The other reason is because Kilauea seems to be capable of flank eruptions after its summit crater floor elevation reaches about 900 meters abice sea level, it is presently 930. 2018 lava lake was usually around 950, it got over 1000 just before the 2018 eruption.

          • The other reason I expect flank eruptions soon is because if the rifts go inactive the caldera will overflow in every direction within 20 years at the current rate of magma supply… 🙂

            I used to think that would actually happen but the SWRZ quaking since 2021 has made me reconsider.

    • Probaly will be something rather large and fast perhaps a 1974 or bigger when magma is accumulating as fast as this. My favorite volcano ”never gets old” meaning yea intrest never cease for me either. Hopes to see some spectacular caldera lava falls next time it erupts, if it flows into there, lava falls and Ohia blooms are a spectacular combination indeed

    • Maybe it needs time to prepare the next eruption, because the build-up towards it is different than all the eruptions we’ve had on Kilauea since 1983.

  13. Just now I was viewing the livestream of Austurvollur Square. People chatting, lovers holding hands, children hugging…

    (zooms in)

    children rubbing snow and ice in each other’s faces.

    Don’t change anything, Iceland. Not a thing.

  14. A small swarm of earthquakes has appeared at Kilauea under Halema’uma’u, I think over the past 1-2 days, in the past week monitoring maps of HVO. I think this is the first substantial seismic activity at the summit since the September eruption. This may show overpressure in the summit area, which last time featured very little seismic activity before erupting. I wouldn’t be surprised if a summit eruption is one or two weeks away, or even less. It’s probably due to a weak surge in magma supply that has affected the summit of Kilauea since December 18, after a few days of no inflation anywhere, and led to a 4-micro radian UWE tilt increase. The SWRZ has been inflating since December 24 when Kilauea emerged from a DI event complex that had kept Kilauea in low pressure for about 10 days, and the recovered pressure after the DI complex must have started pumping magma into the sills southwest of the caldera, the inflation rate is low though, and there is not much connector seismicity, so maybe the deep rift is not opening and overall activity seems to be sluggish right now which may favor the summit.

    • Its the summit shallow magma body thats getting close to rupture point, thats what happened in previous summit eruptions, magma pressure trying to break the lid. Very diffrent summit situation now compared to before 2018 .. defentivly

    • Do you think anything like 1971 and 1974 is on the horizon? last eruption was not too diffrent, something will break soon if this keeps going as it always will with kilaueas magma accumulation. If we are lucky the lava will cascade down caldera and pit walls like immense glowing hot waterfalls as they did in the 1900 s summit events

      • 1971 and 1974 were the years where the pressure of Kilauea was nearing its highest mark for the past 70 years of measurements. Some of the places that erupted in 1971-1974 have high elevation due to being raised by overflows during summit overflowing periods. Erupting was probably made possible by the very high pressure in those years manifested by the peak radial tilt that was reached just before the 1974 December eruption. Right now, with the low pressure that likely prevails across Kilauea’s system eruptions are only possible in the deep summit caldera or the low elevation distal rift if rift magma transport is efficient. At least that’s what I think.

        • How did they observe the high pressure 1971-1974? Today there are locations with high inflation which looks to me like “high pressure”, but what are the real indicators?

          • The Uwekahuna tiltmeter has been recording data since the 1950s it measures how much the ground slopes away from a volcano. When pressure is higher the ground is thought to slope away from it as it deforms upward above the inflating chamber. The following image shows tilt for the whole recorded period, it was steepest just before the December 1974 eruption and major dike intrusion.

          • Eruptions in 1971-1974 occurred in areas that have at other times failed to erupt. For example the area around Keanakakoi Crater erupted twice, first in 1971 then in 1974. There have been many later intrusions in that area that have failed to erupt. Also the area SW of the caldera that unzipped in 1971, and the Pauahi and Hiiaka Craters that erupted in 1973. But most importantly the Puu Koae area that erupted in December 1974, where dike intrusions in 1963 and 1981 did not erupt. All these locations are made mainly of 15th century summit overflows and have produced many non-eruptive intrusions over the years.

          • Thank-you Héctor! It looks as if the period of Mauna Ulu 1969-1974 was the period of highest pressure and overall activity of Kilauea. There were many kinds of exciting varying eruptions of all rift systems and with different durations.

            Does the present low pressure mean that Kilauea is entering a weaker active period than we’ve observed 1950-2018? Is Mauna Loa going to receive more pressure and activity in future?

          • Well, much is still a mistery to me, but I’ve been playing with the idea recently that the was a deep magma recharge in the 50s and 60s. First manifested as strong swarms north of Kilauea in the 50s and then with a large peak of Mantle Fault Zone activity in 1961 that exponentially decreased over the next few decades. I have this suspicion that I’m not very certain of that in 1960 massive amounts of magma started to accumulate 10-30 km under Kilauea triggering earthquakes in the Mantle Fault Zone. In the 1960s large amounts of dense primitive magnesian magmas may have made their way into the 2-10 km deep rifts of Kilauea displacing away the flank and triggering the spectacular series of dike intrusions of the 1960s, where locations along The UERZ were affected 4 times by major dikes, and to a lesser degree the Koae Fault System, the SWRZ, and the MERZ. Eventually all the dike opening may have led to the M 7.5 earthquake of 1975. Some evidence for this could be that some eruptions of this time were highly magnesian. For example, some episodes of 1959 Kilauea Iki were erupting lavas with 20 wt% MgO, which may well be the most primitive magma erupted on Earth in modern observation times, which I suspect may have risen from the magma associated to the Mantle Fault Zone. And Mauna Ulu erupted entirely magmas with 10-14 wt% MgO, compared to Pu’u’o’o that has erupted mostly magma with 7 wt% MgO, and I don’t think ever went up to 10 wt%. It’s hard to tell because Kilauea contains magma in different stages of evolution. For example Halema’uma’u always does 7wt% MgO. Whilst the distal rifts erupt magma with 6wt% MgO. But I do get the impression that some of the eruptions in the 1959-1974 period were unusually magnesian/primitive. The Pu’u’o’o era has been more uneventful, with a lot of lava coming out of the vent but little rifting. Mauna Ulu was much more dynamic and rifting events were frequent during the eruption. The Pu’u’o’o eruption has also erupted increasingly evolved magma and the pressure of Kilauea has gradually gone down since the 1974s, whilst Kilauea continued to pressurize during Mauna Ulu. I think the Pu’u’o’o era represents a leaking volcano that keeps erupting but is not getting much magma recharge at depth. Paradoxically the eruption rate has stayed quite high. I believe the 1960s Mantle Fault Zone crisis may be more inportant than it seems. But I could be wrong. In this context, Pahala is interesting because the swarm there that peaked in 2021-2022 was 3-4 times more intense than the MFZ zone crisis of the 1960s, regarding rates of earthquakes above M 2.8. Although I don’t know if earthquake rates are fully representative of volumes involved. The Pahala area is like a twin of the MFZ, but whilst the MFZ is adjacent and nearly coincident with the SWRZ of Kilauea, the Pahala is adjacent to the SWRZ of Mauna Loa and is more complex. So one of the options I considered is that Pahala magma would enhance activity of Mauna Loa. But this doesn’t seem to be happening, for now, the inflation rate of Mauna Loa has gone down over the year and is now insignificant compared to Kilauea. Instead, 2023, has seen some extraordinary activity of Kilauea,and, if only intermittently, inflation rates of the summit and SWZR has been spectacularly high. I still have to compare the Uwekahuna tilting rates of this year to the decades long tilt record, but I do suspect tilting was at times unprecedented. Magma has been going into the SWRZ in very large amounts despite the pressure at the summit still being low, this could be explained, just one option, by dense primitive magma that is flowing horizontally from the summit and opening up the rift. So there is more indication for continuing or enhanced Kilauea activity than a Mauna Loa resumption, but a lot is still unclear.

          • Maybe to play with that idea further, the rush of magma into Kilaueas deep system in the 60s and early 70s was followed by magma rushing into the ERZ after 1975 to fill in the space created by the quake. Pu’u O’o formed above all that which I think is no coincidence.

            In 2018 all of that magma drained out, so huge supply of deep magma could occur again as it did after 1960, which was also a low altitude LERZ eruption of high intensity. So that part appears to be common. The lava erupted in Halemaumau now may not necessarily be newly arrived fresh magma but because only the stuff on the first day has ever been referenced publically its a but of a mystery. The September lava looked extraordinarily fluid and gas rich in some of the videos though, I would not be surprised to see it being very primitive and magnesian.

          • What I’ve been thinking is that the 1960s, and to a lesser degree the 1970s, were really “rifty”. I don’t have my Kilauea intrusion list here right now but the number and size of dike intrusions is remarkable. Every dike swarm originating from the ERZ connector rifted multiple times. For example, the area of Napau to Pu’u’o’o was affected by 4 dike intrusions: 1961 (maybe the largest Kilauea dike of the past decades), 1963, 1965, and 1968. The year 1963 featured as many as 4 dike intrusions, all of them kilometric in scale: a non-eruptive dike that rifted the Puu Koae area, another non-eruptive dike that initiated from Hiiaka Crater and extended several kilometres into the Koae Fault System, then the eruptive dike of Alae Crater, and the enormous Napau dike of that year. And not to forget the massive double Aloi-Alae event of 1965 that rifted the whole Kulanaokuaiki Pali and ERZ down to beyond Kane Nui o Hamo, plus the double Aloi-Alae dikes of 1962, the Aloi dike of 1969, and the Alae dike of 1969. The major double Hiiaka and Pauahi Crater dikes of 1968 I’m also yet to mention, as well as the 1973 dikes of Pauahi and Hiiaka. And of course the 1960 dike of Kapoho. Not sure if I’m leaving any out, point is that an enormous section of the rifts got meters of spreading at shallow depths.

            I don’t think the ERZ unblocked in 1960, it had already done two minor dike intrusions that cracked open the Chain of Craters Road in 1938, from Hiiaka Crater and from Pauahi or Aloi. Meaning Kilauea was capable of starting intrusions along the ERZ connector beforehand. But in 1960, all of a sudden, it threw this rampage of dike intrusions to the point the entire area between the summit and the present location of Pu’u’o’o must have opened some 4-8 meters. If the deep rift, 2-8 km deep opened in unison with the shallow that must be an enormous volume. Maybe it even was the driving mechanism of the intrusions due to dense magnesian melts forcing open the rift which then graded to intense overpressure in the 1970s that shifted the whole flank in a M 7.5 earthquake. In comparison during the 35 years of Pu’u’o’o eruption the Napau area rifted twice, or thrice if you count the intrusion that created Pu’u’o’o, but these dikes did not extend as far down as in the 1960s. Whilst the Aloi-Alae section I think had two dikes which did not extend into the Koae Fault system. Pauahi and Hiiaka had no meaningful dikes in Pu’u’o’o times, just some small localized intrusions that did not reach the kilometric scale of those in the 1960s. And of course the SWRZ was not intruded. Regardless of the mechanism it is clear that rates of rift zone opening were very high in the 1960s, maybe peaking around 1963, and then declined over the decades. Maybe compositional changes have partly regulated the change from intrusion dominated Kilauea in the 1960s, and the eruption dominated Kilauea during the Pu’u’o’o eruption. The 1970s being transitional between the two ends.

          • Interesting to read in depth about the varying Magnesium content in Kilauea’s magma. Do we see it the signs of Magnesium as white colors anyhow?

            Did the pressure on the summit move to Pu’u O’o during the longterm eruption? Once we talked about that Pu’u O’o 1983-2018 behaved a lot like a temporary Summit volcanic system. So maybe all the pressure and positive deformation went there.

            Do we currently see a similar development on SWRZ? I’ve noticed that some GPS stations (f.e. HLNA and MANE since October) relatively close to SWRZ show a strong positive trend. Is this a sign for rising pressure there?

          • Is Kilauea’s SWRZ going to do a comparable case to Pu’o O’o? Maybe with smaller output rate and volume, SWRZ can still build a cone that erupts for years relatively steadily and tourist friendly. Something like 1919-1920, but for longer time.

          • Magnesium rich igneous rocks are darker, light colour is usually indicating a felsic (rhyolitic) composition. Light colour of rocks on Kilauea can also be a surface layer of (Mg,Ca,Fe)SO4, which is from SO2 reacting with water, air and the bedrock. Basalt is also often chemically reduced with iron as Fe2+ and this will react with air to go to Fe3+ and form rust on the surface. But it all starts as black rock.

            Obsidian is rhyolite but it is also glass, I dont know if this is proven but my theory is it is transparent and the tiny percent of black minerals in it stand out. But it could be other reasons too.

            The 20% MgO lava in 1959 though that is crazy. Kilauea lava is about 50% SiO2 but with such a high MgO content it might fall under ultramafic classification. Some basalts erupted low on the rift zones at Kilauea and Mauna Loa have over 20% when including olivine crystals in the bulk composition but the Iki lava was a summit eruption and mostly crystal free and at one point described as a blinding white incandescence in comparison to the usual orange yellow glow. Something was going on there.

          • I also see no reason to expect a SWRZ eruption to have a lower effusion rate than a similar ERZ eruption, 1919 was when Kilauea was not as productive as today and the amount of lava within the caldera is also much larger today too. Mauna Iki isnt a good analogy to an eruption from the SWRZ connector as it mostly happened from a crack that drained out lava within the open lake at Halemaumau, and so is entirely dependant on conditions at the summit. An eruption on the rift connector would be like an ERZ eruption, and probably of much higher intensity initially than Mauna Iki was.

            Pu’u O’o was a bit complex so I doubt a SWRZ eruption would evolve into that, but something more like Mauna Ulu might be possible. Both if those cases are more likely at an ERZ eruption in the future though. All they really are is an open conduit with a clear connection to the magma chamber. 1959 also formed an open conduit, if the ERZ was dead at that time perhaps Kilauea Iki would have filled and overflowed but it was not to be. I expect at some point Kilauea will form an open conduit again, probably within the 2020s. If it is in the caldera then things could stay centered around that for a long time even if rift eruptions do happen. If the SWRZ becomes very open then the OC could form there instead. It could form on the ERZ again. Perhaps even Pu’u O’o could erupt again as it could well present a weak spot still. Pu’u O’o began forming less than a decade after Mauna Ulu stopped so if the conditions are right it seems rather easy to do this sort of eruption. One thing is certain is that Kilauea will look as different in 30 years as it looked 30 years ago 🙂

    • 2023 I’ve had the impression that the summit eruptions shift their behaviour gradually from the “gradual filling” towards more episodic fissure eruptions. Maybe we get a single day eruption like Svartsengi, but with lower fountains and shorter fissure. 1982 Kilauea did eruptions like this:
      April 30th and September 25th. The first one was close to the location of the eruption in September 2023. The eruption on September 25th was on the southern crater rim.

      • Think that shift happened about a year ago, the 2021-2022 eruption ended abruptly with an intrusion under the summit, it was at the same time Mauna Loa was doing stuff but probably mostly unrelated.

        The lava lake has barely risen much since then, and now magma being forced into the rifts seems it is basically at the height limit. If the next eruption is a summit eruption it will probably be over in a few days. The September eruption of Kilauea was actually bigger than the Svartsengi eruption, 18.5 million m3, while the latter is probably at best half that volume though I have not found a number for that published anywhere yet. The intensity of Svartsengi at the very start was probably higher but dropped off quicker.

        • The eruption of Kilauea in September lasted for 7 days. The output rate was likely smaller than Svartsengi’s optimum hour, but the length added more volume. If Kilauea had only erupted for 1-2 days, the eruption would be of comparable volume.

          • Was 5 days, and followed a similar decline curve. The first few hours probably Svartsengi was more intense but the two were very similar.

  15. Back to VC later.. I face a dangerous health situation and Im very busy

    • I’m very sorry to hear about the dangerous health issue, and I wish you a speedy recovery. Get well soon!

    • Jesper,

      Take care of yourself, get better and get back.


    • Bone infection… its degenerating my entire body and mind, as a result of broken foot last year. I feel I dont have the energy to write VC articles for now. Numerous ways of curing are typicaly effective as well as invasive operations but its a stubborn case.. but they are working on it.

      And its sometimes difficult to trust anything what the doctors say, as healthcare and health practises have been and are very market driven, or based on flawed grounds thats was developed for economic intrests ( as its the case of the disasterous ideas that created the food pyramid that have killed many 100 s of millions of persons since 1960 s )

      I have kind of difficult to trust doctors.. when economic intrests and pesudoscience have been running the show for a long time at least in terms of some kind of ”traditional knowledge” in terms of healthcare.

      But they also defentivly knows their stuff even if they are sometimes little blind. Thanks to diffirent types of medical procedures its at least not getting worse. We are working with diffrent types of treatments, and I guess it coud take a long time ( but its not getting worse at least ) I will be back on VC much later

      • Really sorry to hear you are having so many health problems Jesper. I shall miss seeing your interesting comments. Take as much care as possible Jesper. I read up about bone infections and the amount of pain they can cause so rest as much as possible please. A tired body takes longer to heal. Sending lots of best wishes to you.

      • They are working on it.. and Im lucky living one of the worlds most developed amd richest nations that provides its citizens with cost free education and hosptial healthcare.

        Most other countries does not, even most other rich countries does not

        I enjoy whats probaly pure luxury for most of VC readers here = acess to souch services without paying a single thing ..

        I will be back later when I gets better and less busy ( screens are also bad for eyesight )

        • Just a reminder that social care is NOT cost-free.
          We all pay for it. In the UK 2022 the NHS cost £180 B or with a working population of circa 40M, £4500 per working population. To pay IN TOTAL income tax (no allowances) of £4500 you need to earn £30,000 and with the average uk income of ~£32,000 taking into account allowances the average worker spends ALL the tax take on the NHS. Its increasing too, leaving less for education, social services, police, military, roads and all the other things government wants to do.

          Strangely the more we spend the worse it seems to get. No politician, though, dares to suggest curtailing the many treatments that nobody except the multi-millionaires in other societies can afford. At some point the people who wring their hands when someone does prematurely (and to include mass starvation in parts of the world) will have to face the fact that in actuality nothing can, or really should be done.

          Pop Ethiopia 1960 22M. , 2023 123M.
          Many parts of the world similarly, so when a major harvest failure happens will even the UK be able to feed all its peopel, importing from where?

          • There are unexpected shortages of antibiotics at the moment. Those are imported but it is unclear where the supply problem comes from. I am wondering whether they are being used for cattle rather then humans. Pressure on the system is not just in food supply but also in medicines. Interestingly, both could be solved by cutting red meat from our diets!

          • Albert.
            1) Routine use of antibiotics at low level in animal feed has been banned in the EU&UK (and I think the US) for decades.
            2) Any human use antibiotic will overprice (by lots) any animal use, so a shortage will affect animals before humans if they are the same product.
            3) Antibiotic use in pets is major, possibly more than agricultural, and possibly higher priced.
            4) In the EU (and UK) animal antibiotic usage is solely for animal welfare use (this also includes organic farmers who DO use antibiotics). This means few sheep (foot rot only, used to be a sulponamide), even fewer beef animals (almost all never see an antibiotic), dairy (dry cow therapy, if its still in use) are treated.
            Pigs are now mostly in disease-free farms (ie kept disease-free by isolation and management), as are crate or barn chickens. I imagine disease control in free-range hens is harder due wild birds.
            5) Basically a sick animal makes you no profit (most likely a loss) so best keep your animals as disease-free as possible. Fortunately, and despite popular opinion, livestock farmers are rather fond of their animals, as my cowmans wife said ‘he likes them more than his family’ (and I rather agreed). Why else go out 24/7/52 in all weathers and times of day to look after them? Why does nobody want to do it any more? Quel surprise!

          • Always enjoy getting the facts from the experts! I can confirm that it is impossible to go the the Vet with a pet and not come back with antibiotics. I don’t know whether animal use is impacting availability. The antibiotics come from far away and a lot can happen.

            According to what I found, for cattle growth it has been banned in the EU (incl the UK) since 2006. The EU banned all use in 2022. The US banned the use for growth in 2017 but other use is still allowed. I don’t know the UK situuation.

            According to a recent paper (data up to 2022) animal antibiotic use use in the US dropped by 30% in 2017 but has increased a bit again in recent years. In spite of the ban, is still given with feed but it is now for disease prevention. Use in chicken farming is way down. The dominant use in the US is now for turkey farming. Of those antibiotics, 40% has no medical use for humans but 60% does.

            I think in the rest of the world it is still used and there was a report that 75% of antibiotics worldwide are used for animals.

        • Lower meat intake to use less natural resources and spare wild spaces. Resource intensive and not substainable with 7 billion persons wants that.

          But health wise meat is excellent food. The truth is that meat is one of the most healthy things you can eat, and specialy so grass feed, contains all primary the nutrients you needs and our hunter ancestors ate nothing else. IF we where less humans on the planet we coud eat much more meat.

          Heart disease is caused by sugar inflammation .. it haves nothing to do with meat or fat. but the real truth cause of western diseases have through decades been blocked by economic intrests. We can eat nuts and greens instead of the dangerous processed crabohydrates and sugar.

          I will be back when I gets better

      • Hope you get better soon, Jesper! Don’t be too negative about doctors. If they recommend an operation, go for it. They are much more experienced even than doctor google.

      • Will be small scale operations soon and should be effective. Well they know their stuff defentivly and I have their trust, and they have my trust too

        But there are some things in terms of health and healthcare advice that needs to be re – learned from scratch like the carb laden food guidelines thats are as flawed as a flamingo with no head… but better to discuss that in another forum

        I will be back when I gets better

      • Im getting nearsigthed too from screen use with my genetics so can be good to limit social media too ( sadely computers are addictive)

      • Bone infection sound very bad. That’s difficult to cure. I hope that you get good care and that they find a way to create an upward trend!

  16. Been a little upwards blip on the GPS, like those that preceded the last eruption. If it is a trend (can’t really tell from a single instance), action sooner rather than later?

    • Another jump and December 29th is looking feasible after all …. but any action would most likely be later

      • So it lost about 70mm of inflation during the first eruption and has already almost recovered it. It’s about 4 days away from doing so?

    • The likelihood of an eruption increases every day:
      They’ve observed 730 earthquakes since 22. December. Inflation continues with the same speed as previous to the eruption. Magma accumulation continues steadily and this will likely lead to a new eruption (or intrusion). 11 million cubic meters left the magma chamber during the eruption, and it will take around two weeks until the same volume is refilled inside the magma chamber. There is high uncertainty to determine the point, when the pressure in the magma chamber is high enough for the next eruption.
      (All cited & translated from the linked website)

      If this tendency continues, Svartsengi will do many Fires after short intervalls. It won’t wait as long as Krafla (often one year) or Fagradalsfjall (11 months), but do it again and again every few weeks. The lava layers may accumulate on each other like a pyramid cake, if the fissures happen on the same place.

      • If the eruptions are somewhat predictable for location as well as time, I still think this can become a very nice tourist experience. Make travel to several safe viewing areas easy and enforce their boundaries – and charge a little money for foreign visitors. Might pay for repairing Grindavik plus present and future lava barriers.

        • It’s very predictable in what area eruptions are likely. If tourists avoid Zone 2 and 3, they’re relatively save. Also hills should be got points to watch and to be spared by lava barbecue:

    • I posted the 4 hr image chart for the SENG GPS unit and one person said that snow loading on the antenna was the reason why we see the upward blips. I don’t quite buy this explanation, as I don’t think it was snowing on Nov 10th in the region? Or am I wrong?

      • You’re right. Snow would have to explain 3 blips at this point, and all toward the end of their inflation cycles. Might not be accurate with regard to elevation (though they could be) but I doubt it’s atmospheric.

    • The AUSV GPS station also shows a blip on the elevation reading, see

      • One common reason for blips, according to Sigrun, is birds on the antenna.

        • If all instruments show a simultaneous jump up, it means the calibration is off. That may indeed happen if one antenna is significantly off but is still used in the calibration. The GPS also needs the precise orbits of the satellite, and those orbits are sometimes a bit off. They get updated I think once a day.

          • That’s correct, and I meant residual apparent ‘jumps’ after correction!

    • By the way, yesterday evening I saw black smoke around the eruption area. It was very dense for a while but I didn’t see any fire so not sure what it was. I tried to come on here earlier to see if anyone else saw it but I got an access denied message. So not sure what was causing that. at least now I can get on to report that and see if it was noticed by anyone else.

      • I witnessed this phenomenon a few minutes ago. This is a guess: All the surrounding snow covered areas are reflecting light back up to the bottoms of the low clouds, while the surface of the lava patch is about as non-reflective as the surface of the earth gets. Virtually no light is being reflected up to the clouds over the lava field. I doubt we could see the difference as clearly as we can without the camera adjusting its aperture to maximize contrast. On a first look, it sure does look like black smoke rising from the lava and accumulating over it. I thought, “Here it comes!”

    • Impressive and beautiful, is it still Strombolian or already Vulcanian?

  17. M1.59 at 210m depth at Hekla, after a deeper quake a few hours earlier…

    • Hekla 2000 started SW of the mountains. The quake swarm shot over under Hekla and popped the top in about 40 minutes.

    • Also Krysuvik (f.e. Kleifarvatn …) has had some earthquakes. Are they caused by Svartsengi’s tectonical action (graben extension…) or should we expect that Krysuvik slowly begins to join the Fires Party of Fagradalsfjall and Svartsengi?

  18. Early this morning 9:34 am, a (I assume) search and rescue helicopter went over the the west side of the Sundhnakur fissure complex. Has anyone in Iceland heard about this operation? The helicopter was scanning the fissure fields and localized on 2 areas, for over 18 mins. It had two very powerful search lights. See

  19. Question:
    In consideration that the latest fissure eruption was in the Sundhnukar region, not too far from the row of craters along an obvious fissure line, just south of Stora-Skogfell, and not on or near the computed dike intrusion which extended into Grindavik, is it plausible that magmatic gas pressures pushed eastward from the dike until coming to the weak area in the crust of this fissure linement and then found the way upwards? I keep wondering how magma is transporting so far east from the Svartsengi area??

    • The eruption was pretty much exactly on the November dike, which also went about as far north of the eruption site as it did south under Grindavik. Its normal for rifts like this to erupt along the middle section while dikes go further but stay underground, there are numerous grabens on the north edge of the peninsula but almost no vents. Holuhraun was different because it erupted downhill of an elevated central volcano so erupted near the end of its rift.

      • Chad:
        You are exactly right on. I checked back and found this map from the IMO and the main vent was just a bit north of where the yellow segment and the orange segment meet, which I assume is the middle of the dike lineament. I am sure how I got my interpretation that the dike centerline was further west than it is. So my idea of an eastward push is entirely incorrect.

    • The magma is transporting so far east in the Svartsengi area because it is all one sill. It then turns into a dike at the edge, which ran along that old fissure line to Grindavik and the sea. This eruption was roughly in the middle of that zone.

  20. My initial guess (for the next Icelandic show) was late on January 5th, 2024. Looking at the gps data today though, I get the feeling we won’t be rid of 2023 when the next lava fountains forth.

    • Yes I am starting to think I was too pessimistic around the timeline now, its really gone up fast. Looking like it might go on New Years even.

    • Yeah, I’m also starting to think that my guess for Jan 1st is a bit too late.

    • HA02 inflation is still suggesting around the 3rd. However, inflation didn’t go as high as the first inflation event before the intrusion. Other stations appear to be higher than the last event already, but the inflation in those areas wasn’t as obvious, so they are less sensitive. Another option is that the area of inflation us larger than before.

    • I was looking at today and some of the stations are dropping in elevation like KRIV and HVAS and VOGS and REYK, so apparently the north end of the Reykjanes Penisula is slowly dropping? It is a very recent change of the last 5 days or so.

    • I said Dec 31st at 23:39 just in time for new year’s and that’s what it’s gonna be! 🙂


    Nice drone video of Fissure 17 looking rather like Etna or Hekla fissures ( minus the speed and size ) evolved basalt from shallow rift as the incomming fresh magma was pushing out the stale stuff. In the beginning there where even explosions of andesite throwing large grey lumps 100 meters, later Basaltic Andesite as seen in video was extruded making a fissure row and a fountain lava cinder cone. The evolved SWRZ eruptions produced similar eruption products.

    Social Media and VC is getting me more and more nearsigthed so eyes needs to get away from the screens and my foot needs to get better, so I will be back later

    • I remember watching it live, watching the fountains get larger and more powerful then building up the tall cone that eventually formed there. On the night of the 17th May 2018 the fountain really shot up probably well in excess of 100 meters and stayed like that, I remember thinking at the time it is probably starting that next stage as fresh magma starts to erupt.

      The next day and all the nearby fissures started gushing lava, and then a full curtain of fire sending lava to the ocean by nightfal.

      • I think the thing that is most impressive to me, is that the 2018 eruption was already Kilaueas 3rd biggest historical eruption *before* fissure 8 reactivated…

        • I wonder how big 2018 would’ve been if the M6.9 hadn’t happened.

          • I think it would have probably been a lot smaller, possibly with the dike stopping at Pohoiki road like it did initially, and vents probably opening up further west as the trend was originally. I doubt any vents would have been big enough to flow to the ocean but perhaps a few cinder cones would have been built. So smaller version of 1955 basically. Once that quake happened though it was all over, the point of no return was crossed. It was lucky the new magma had to push out some older stuff stored in the rift, otherwise the eruption probably would have started off at full power, not all that unlike Svartsengi except it stays like that for a few months not a few yours…

            I think that if the 2018 quake didnt happen though then the quake would have happened anyway within a few years. Pu’u O’o was getting very tall and so was the summit lake. It was obvious in hindsight something was going to break and I remember expecting a fissure eruption near Pu’u O’o, as did HVO. We all got a lot more than bargained for…

          • That is a very good question. So is whether the M6.9 would have been as big if the eruption hadn’t started.

          • Another question is why Pu’u’ō’ō was able to inflate and pressurise so much before rupturing, compared to previous times (2014, 2016).

          • I think Pu’u O’o had been declining for years before 2018. Up until 2011 the lava lake in Halemaumau was very low, it got to -70 meters below the rim when the March 2011 eruption happened, and again in August at the same time as another lake existed in Pu’u O’o and drained. In September 2011 it had refilled again and overflowed before the conduit ruptured deeper and fissures opened on the east flank, which sent lava flowing south and into the ocean within 2 months, before it all died back to basically nothing but some strombolian activity at one vent from Pu’u O’o over the new year. Things did recover slowly but the last few years of Pu’u O’o were pretty weak compared to before, while the lava lake at Halemaumau was constantly at a high elevation after 2013 and overflowed twice. I think there was also evidence of inflation on the ERZ downrift of Pu’u O’o too, and that is where the 2018 dike started from too.

            The ERZ was also due for a slide event, happening roughly every few years. I guess all these things happening at the same time was enough. The 2018 eruption being so big though was probably entirely because Halemaumau had formed into a homogenous chamber which may not have existed in 1960 or 1955. Without it the 2018 eruption probably would have been similar to those in volume, though more like the latter in behavior. Pu’u O’o probably also would have survived too so perhaps the big one would have occurred anyway just a few years later or perhaps Pu’u O’o would even be ongoing now and we would still be talking about how Kilauea like it is a harmless tourist volcano that could never compete with Holuhraun 🙂

  22. OT: NASA is getting ready for a close up look at Io on December 30th. It will be the closest approach of the Juno space probe or any other craft to Io in over 20 years. All cameras will focus on the various volcanic features and we can expect a real smorgasbord of data from this visit.

    Another, equally close visit will take place on February 3rd. In a few months we will get plenty of new pictures and data sets to ponder.

  23. Suppose I have 800 m wide and 20 km long dike, the total volume of the dike is around 3.2 km3 if I am not mistaken. Just confirming before I add that fact to my new article.

    • Dike volume is set by length, width and height (depth). Depth can be 1 to several km, width is 1 meter to a few meters. The width is in part determined by the pressure, as it has to push the sides of the dike apart against the pressure of the rock.

      • Never calculated dyke volumes before,
        Length: 19428 m
        Width: 801 m
        Depth: 3449 m below sea level(Chamber Depth is 9 km below seal level)
        Dip:36.63 degrees
        Can someone tell me what the volume of the dike is?

        • 19400 x 3500 x 800?

          54,320,000,000 m3
          54.3 km3.

          I have done this a few times though and estimating the volume that way is not super reliable. Im assuming this is for Chiles Cerro Negro? 🙂

          Also not sure something 800 meters thick can be called a dike either, maybe more of a magma chamber with the rough shape of a dike, like is imagined under Mauna Loa or Hekla. I guess its a bit arbitrary though.

          • You’d be correct. The volcano is a mystery no more. The deeper magma chamber has formed a dike over the last few years and the dike is plugged. The current swarms are almost definitely the result of the dike expanding. If the plug breaks, the volcano will erupt. Assuming your estimate is correct if 10% of the Magma from that dyke erupts, we’ve got a solid VEI 6.

          • I guess its all dependant on how the volcano behaves. What you describe sounds like what Santa Maria did, a new vent forming in a plinian eruption that got bigger than normal, and then continuous effusive activity most of the time since. Which is also what the two cones of Chilles and Cerro Negro actually look like too, something between a dome and a stratovolcano, like Santiaguito.

            It could be the reverse though like Quizapu, where it starts off effusive and does a plinian eruption at the end. But Quizapu seems unusually low viscosity for a silicic magma, looking almost like evolved basalt despite being in the rhyodacite spectrum, while CCN is basically crystal mush of rhyolite with mafic crystals, so perhaps not a good analogy.

            I recall that Santa Maria might have taken quite some time to reach the point of erupting, so does seem a good comparison. So a VEI 5-6 seems quite plausible.

            Who knows though, maybe after 10+ millennia things have changed up. The first eruptions might be basaltic as happened at Krakatau, and Santa Maria seems to have been somewhat bimodal in 1902. That large recharge of hot magma may be needed to get an explosive eruption otherwise its just going to form a dome slowly.

          • Chad , read up on the Great Dyke in Zimbabwe, up to a mile in thickness and traverses almost the whole country.

        • 54 km3 (assuming that the width is given horizontally rather than perpendicular to the dike). Which of course is completely unrealistic. A dike can be 8 meter (a very large one). Not 800 meters. That would require the rock on either side of the dike to be pushed by several hunderd meters.

          If you meant a width of 8.01 meters, divide the volume by 100.

          • Erm, Albert, the Great Zimbabwe Dyke is up to 8 miles wide.

          • What we call a dike is a crack in which magma extends vertically, and can move over significant distances. They widen by pushing the sides of the rock apart. The Great Dyke looks like a different kind of structure, an intrusion that created a very large sill or magma chamber. In deep, more ductile crusts they can grow large. So it depends on what Tallis has in mind! I was assuming it was traditional dike extending towards the surface

  24. How did you get the width though? Height and length can be relatively easy to constrain given that the base or top of dikes tend to be seismically active and if they reach the surface you know the top, or the width of the graben can give an idea. But the width of the dike is probably smaller than the error in location of earthquakes, unless they are accurately relocated. Deep perpetual dike bodies might widen over time, whilst shallow short lived dikes are 1-2 meters wide for basalt, and up to tens of meters wide in some silicic magmas. So knowing the width of a deep dike body can be complicated.

    • This was a question for Tallis, ended up elsewhere.

        • It’s layered intrusions no? Still impressive in size and stature.

          • They talk as if it’s a recent formation and they say it’s still active so I doubt it.

        • “Pyroclastic deposits of past eruptions were H2O-rich, of high silica content (~70 wt% SiO2), were explosive, and occurred 15-20 kyBP”

          Wow. Tallis I’m pretty pumped to revisit CCN, incredible find and can’t wait to read.

        • Presentation begins at 43 mins in

          FRINGE 2023 – Day 3 – Volcanoes II

          Variable Ground Deformation Rates Since May 2022 at Chiles-Potrerillos Volcanoes, Ecuadorian-Colombia Border • (ID: 488)
          Presenting: Patricia Ann Mothes

  25. On the Langihryggur cam there is new smoke rising. Not sure if it is just off gassing showing in the cold air or what else. Quite a bit of smoke though.

    • Hard to say if it is steam or smoke but still continuing in a good volume. It appears to be behind the previous fissure.

      • Also behind a slight rise so cannot see properly what is causing it. Not aware there is anything else out there that cause cause the steam. Not Svartsengi for sure.

        • Did the move this cam? I am starting to thin this must be svartsengi so sorry folks. I would get 100% lost if it was hiking in Iceland. In the snow everywhere looks the same, black and white. Hangs head in shame.


    Very interesting paper about the 2021 eruptions of Etna. 58 paroxysms in one year which is nearly twice as many as occurred in the first 70 years of the 20th century… 🙂

    Long story short the 2021 paroxysms erupted about 70 million m3 of material, which is a VEI 3 technically, and is a bit less than I had expected (more than 100 million). It also wasnt more than Fagradalsfjall 1 and about 1/3 as big as La Palma, so while Etna deserved more attention certainly it wasnt quite robbed of the biggest eruption title.
    But considering some of these were literally the tallest lava fountains ever observed and it repeated more times than there are weeks in the year, it was an extraordinary eruption sequence. And Etna hasnt gone to sleep afterwards, there have been many paroxysms since and it is an open vent at present. Etna has changed greatly in the past 50 years, it seems to currently be in an episode of cone building, where before that it was more often leaking lava from its flanks during major eruptikbs than blasting it from summit vents.

    • Etna does a beautiful mixture of effusive and explosive eruptions with tall lava fountains, quick lava flows, Strombolian ash plumes and bombs. It is a complete volcano. In some cases even Pyroclastic flows are possible. 2021 was like a “Fires year” o Etna, when it did a swarm eruption. Maybe this reminds to active periods of Mauna Kea, that then also does swarm eruptions in a short time period.

      But anytime Etna can switch to a Hawaiian flank eruption with little warning.

  27. Interresting article from NOAA on the effect on the stratosphere from Hunga Tonga. They estimate 150 million tons of water were injected into the stratosphere causing a 15% reduction ozone levels almost immediately. Found on my Google news feed.

  28. A major threat of the Aegan subduction zone are megathrust quakes. 365 and 1303 were megathrust quakes near Crete. They can cause high tsunamis that devastate the coasts and islands from Sicily to Egypt.

  29. A helicopter just flew over the lava field and landed at edge of the lava field. Scientific expeditions at dusk seems strange?

    • Ulwur:
      I wish that some Iceland news agency could inform us of what is going on. When you see a helicopter shining 2 incredibly bright lights hovering in the air motionless for several minutes, next to the Svartsengi lineaments, it really makes you wonder what is going on? The continued inflation seems to be an increasing cause of concern to all.

      • One of the Iceland locals told me that it was a Iceland Coast Guard helicopter winching off scientific equipment, and also to look for the IMO possibly announcing that they have new equipment to try out in the field.

  30. Some definite smoke/steam on the Vogastapi cam facing southwestward.

    • I agree. I have bee watching that for over 30 mins. Biggest amount of out gassing if that is what it is. It suggests to me that magma may be flowing under that area and heating the previous lava flow. That is of course a guess. However I continue to watch because it is so strange.

    • Arrgh!!! The search engines are no help here. Can you please post the link to the camera? Thank you!

  31. While Im away Im going to create Selenoacetone and Thioacetone in my home lab setup. Its very possible and fairly simple to do with a basic chemistry gear setup, even if there is many steps of doing so. I guess even with kitchen fume exahaust the outdoor will smell so awful that the police will come… but its the stinky stuff thats the fun of it! Thioacetone I will start with..with using acetone

    The big stink its comming but because the smell is so ”fearful” I wonder if I should really do it, I do have the equipment. We should be very happy that volcanoes dont belch these gases.. it woud reek

    • Jesper dont try to make it, a fume hood wont do sht against the smell of something like that, we made normal boring H2S in a proper fume hood at school and it predictably filled the room eventually.
      H2Se is also basically a chemical weapon of the highest calibre, its LD50 is 0.5 ppm. H2S is about 1000x less toxic than H2Se. HCN is 100x less toxic than H2Se. Even white phosphorus in open air on your skin is less dangerous than this stuff Jesper…

    • I had a friend in high school who knew that I knew chemistry, so like an idiot I gave him the formula for ammonium chloride from HCL acid and Ammonia and he proceeded to smoke up all the high school chem windows. Then he asked me for thermite, which I gave the formula, not realizing that he was going to set it off. When the brilliant white hot light dazzled and blinded nearly everyone, he plops to the floor and cries like a slobbering blubbering baby, begging that someone help him escape for this terrible mess. The high school teacher came in, finally found out what happened, did NOT ground me, but he made changes in the class and locked down all the chemicals… and the rest of the class blamed us for it. After that I decided that I could not share the chem formuli with just anyone.

    • Based on the photos, they were taken at the base of the Thorbjørn hill at the Grindavíkurvegur road. The cracks are perpendicular to the road… different angle of stress put on road or the magma is going under.

    • I have mixed feelings about all this. When I lived in CA, we all knew that earthquakes were part of life and not to get upset when an earthquake occurred and upset our pattern of life. People living on an island with active volcanoes need to expect movement, change and activity, as I am sure that most Icelanders are doing. I respect them for dealing with their environment. I guess I am saying that we need to learn to adapt and not oppose this necessity thrust upon us.

  32. „ increased probability of a volcanic eruption north of Grindavík“

    latest met update
    they didn‘t say why only that the risk of eruption or gases increased between grindavik and hagafell after sticking their heads together

    • I’d put my house on the next eruption occurring near Hagafell. Grindavik would be most fortunate if it occurs northward.

      • I would recommend not to put your house on the eruption. It probably invalidates the insurance

        • If Chuck Norris built that house it would invalidate the eruption! 😀

        • Except in CA where you can put your house on unknown faults, then later blame it on the insurance company for not telling you, after the ground moves and your house splits in half.

          • Unknown faults are precisely what insurance is for. I was more surprised by the beautiful houses in Palmdale built within meters of the very well known San Andreas fault. Plus the aquaduct. What could possibly go wrong

    • Someone(s) need to come forward and explain what all those helicopter flights are about.

      • Coast Guard flight transporting and winching equipment.. a person who partially knows let me know

    • Where has they moved the population to? Maybe they should resettle them to “New Grindavik” for some decades until the threat is over.

  33. Looking at the chart and drawing the general trend line and making a BIG assumption that the trigger point for a fissure eruption is the same elevation height (around 175 or 180 mm) as the previous 2, then we might see more fissure activity on Dec 31st. (this depends upon the BIG assumption)

    • seems to indicate 1st week of January when the next fissure eruption occurs.

      • I’ve been watching that one and HS02. They seem to be the closest and both indicate around the 3rd, making the same assumptions you did.

        • It looks like a new intrusion into the upper east rift zone. Mainly rock cracking at the moment

    • I like the map at minute 1:03 to 1:11 that shows the length of the December 18th eruption. It is as long as the distance from Litle Hrutur to Natthagi valley. So nearly whole Fagradalsfjall length of three eruptions with their lava fields (but Fagradalsfjall had to deal with very fragmented morphology).

  34. Big Kilauea SWRZ swarm. More than 200 earthquakes automatically located by HVO, mostly in less than half a day. One of the highest earthquake rates we’ve seen this year. Up to 4 earthquakes per minute at times, in the seismograms, and usually at least one per minute. The earthquakes are affecting the SWRZ connector, from OUTL to Puu Koae, with no spatial migration as far as I can see, I think magma is just rushing into the deep rift. The summit was inflating extremely fast for 12 hours before the swarm, above the previous highstand before the DI event. Then it started to deflate during the earthquake swarm. I suspect a very intense magma surge that briefly showed up at the summit and is now heading into the Southwest Rift Zone.

    • Where / in which part of SWRZ would you expect the first eruption?

        • But the swarm still is far away from Kamakaia Hills, if my geographical orientation is correct. Can the intrusion go there without much noise?

          • Does the magma there rise from the summit reservoir towards Kamakaia Hills or is there an isolated SWRZ “magma finger” directly going up from the Pahala quake area?

    • HVO statement:

      “eismicity followed a sharp increase in the rate of inflation on the Sand Hill tiltmeter that began at 12:30 p.m. HST and is continuing. The increased seismicity began just to the south of Halemaʻumaʻu and has progressively included a larger region to the south of the caldera about 2–4 km (1–2.5 mi) south of Halema‘uma‘u crater. The seismicity is occurring at depths of 1–3 km (0.5–2 mi) with magnitudes ranging from a maximum of 2.5 to less than 1. There have been over 80 locatable earthquakes in this region in the past 6 hours and many smaller earthquakes.

      The summit of Kīlauea remains at a high level of inflation and eruptive activity at the summit is possible with little or no warning.

      Earthquake swarms like this can precede eruptions, but there is no lateral or upward migration of earthquakes that would suggest magma is moving toward the surface at this time. There are currently no signs of an imminent eruption at Kīlauea, but the volcano’s summit region remains unsettled, with a high level of inflation and continued seismic activity. ”

    • Now there’s some spectacularly fast tilting in the SDH tiltmeter. The swarm continues unabated, if this keeps going through the rest of the day HST it might have the largest number of earthquakes in a single day since the 2018 eruption.

      • It looks as if Kilauea beats Svartsengi in the race for the next eruption

        • Earthquakes are shallowing now at the start of the upper rift zone

      • DI event happened, probably a bit if the magma chamber wall that started peeling off. Pressure went down with the event. Coincident with this the SWRZ swarm nearly died out. I guess flow will resume when the DI event ends.

  35. The latest data point on the 4 hour Svartsengi GPS uplift graph is now at exactly the same level as when the last eruption started:

    • Yup. Been watching that chart, quakes and a couple of cams all night, just sure I was going to witness this one. Nope. I’m going to bed, so the eruption will start sometime in the next four to six hours. They need to have one of the borbjorn cameras pointing just north of Grindavik where that fairly shallow 2.1 was. Right now both borbjorn cams are pointed where the last eruption started. If it starts further South, there’s no cam to catch it (that I know of).

    • Thanks. I think the crust south of the previous eruption is slightly less ductile, so it may take that bit more energy to break.

    • The four GPS stations I believe are the closest, HS02, Skiptastigshraun (SKSH), Thorbjorn (THOB) and Grindavik (GRIV) all still have a little way to go before they reach the same level. I have based this on the fact that they show the greatest uplift and from their relative lateral movements to each other. HS02 appears to be the closest to the centre. They are still a few days away from reaching the same level as the day before the eruption. It should also be noted however, that the height just prior to the eruption was lower than just before the intrusion started.

    • GutnTog made a video from Fagradalsfjell with views both of Svartsengi’s new lava field and the Fagradalsfjall eruption craters:

      How close are the magmatic roots of Svartsengi and Fagradalsfjall to each other? The surface distance between the fissures and lava fields could be different to the base at Moho. The whole magmatic systems might be either more close or more distant to each other than we see on the surface.

    • Looking at the charts linked from the page, the Svartsengi GPS is about 10mm below the level the day before the eruption. The HS02 level is just over 40mm below. At the current inflation rate, the HS02 inflation should reach the previous level in about 4 days, Svartsengi in about 2 days. The Grindavik GPS also suggests about 2 days, with Skipstigshraun showing about 4 days, the same as HS02. So, if you take the middle, about 3 days :P. It seems pretty consistent over the past week or so, so I will say 1st-3rd January.

      • Hi Richard

        According to the 4-hour SENG chart ( ) it seems like uplift is already at the same level as directly before the previous eruption, at least to my novice eyes. Same story for the 8 hour chart if I’m not mistaken.

        Assuming that’s correct (again, any expert feel free to correct me here!) we could be looking at another eruption or intrusion pretty much imminently, within the next day most likely.

    • Best case or worst case if Kilauea and Svartsengi erupt coordinated on same day?

      • For my attention span to getting things done around the house….worse!

    • The 4.1 earthquake that happened at 30km depth (big blue circle) on 12/23 was not far away from the location of the present shallow earthquake swarm:

      Does magma rise directly vertically up there towards the SWRZ?

      • No but I think it could be a sign of magma movement from the massive sills under the Pahala swarm going towards Kilauea. For being probably the hottest mantle on our planet right now the lower crust of Hawaii is pretty seismic particularly under Kilauea. I think this probably reflects in part the young age of Kilauea and its variable and presently very rapid rate of growth and deformation. But it also probably shows the huge magma flux, Kilauea is by far the most powerful thermal radiation source of any volcano, it sitting doing basically nothing in the mid 2010s it was throwing out as much heat as many other basaltic volcanoes do in full eruption. Even Holuhraun failed to knock Pele from her 1st place throne in either 2014 or 2015. I believe the typical thermal radiance from Kilauea was in excess of 1 GW continuously for years on end… 🙂

        All that heat has to come from somewhere, even if the magma goes into the deep rift the heat escapes to some degree. I would be a little surprised if another open vent doesnt form in the next decade somewhere, after magma supply increased in 1950 it took only 9 years to make the first, and that only failed from the magma draining out the rift, even then only for another decade before Mauna Ulu. The September lava looked like foamed olive oil.

  36. Little question for everybody for the new year!

    What was Kilauea summit height reported as in the past? Today in the latest advisory it was reported at 1247m. I have included links to some earlier measurements below, but take a guess on your own, then see how you did with the links below from around 20 and 40 years ago. Most of this change was not from eruptive events….”Radiating away from the summit caldera are two linear zones of intrusion and eruption, the east and the southwest rift zones. Repeated subaerial eruptions from the summit and rift zones have built a gently sloping, elongate shield volcano covering approximately 1,500 km2″


    2003 paper, height is reported in the text.



    • 1247 m is the elevation at U’ekahuna, where the HVO building was. The elevation of the lava lake in 2018 was about 1040 m. In 1974 Mauna Ulu was about 1100 m, and in the 1880s-1924 the top of Halemaumau was as high as 1200 m though I forget exactly when.

      The summit of Kilauea was probably as high as 1300 m when the flows making U’ekahuna were erupted. But it wont get anywhere near that while eruptions on either rift zone are possible.

  37. Howdy Y’all! Hope all Y’all had a merry Christmas. Long time lurker down in brown section, but I have always enjoyed Y’alls articles. According to the 10 year plot of Kilauea’s UWEV GPS station over yonder, she is roughly at the same displacement as in 2014, 4 years before her big 2018 blowout eruption. She grew slightly less than 0.2 meters between 2014-2018 but has made up half that just since the September of this year. I know it takes more and more volume to increase the displacement of the “cone” shaped Halemaʻumaʻu, but it makes the current inflation cycle all the more impressive. I figure Kilauea will lose displacement in the UWEV plot during a probable SWRZ eruption, but if it instead goes into Halemaʻumaʻu, we could reach the 2018 level by this time next year. Although I have training in research, I am a rookie geologist. Feel free to correct my assumptions. Thank ya mighty kindly!

  38. Yeah well. Well done. A lot of work before Christmas. And then on the map in the lower quadrant on the right for the Cretacious everybody can see quite clearly that a meteorite – if there was one indeed – must have fallen into deep water as Tethys was old, very old, and ready to subduct, and subducting ocean plates are old, and the depth is considerable.
    Besides water levels were high at the end of the Cretacious.

    Thank you very much for the brillant piece and all the best for the New Year!

  39. 2022 Hunga Tonga sent water vapor into the stratosphere:
    In Réunion they observed an unprecedented amount of water vapor in the stratosphere. This changed the chemical condidtions in the stratosphere and reduced the concentration of Ozone by 30% during the highest concentration of water vapor.
    Does volcanic water vapor in the stratosphere increase the Greenhouse effect by CO2? This could be a short term positive climate effect, contrary to negative effects by sulfuric clouds.

    • Well. The effect would have been fairly instant if there was any. Like we see historically from SO2.

      The question that nobody seems to ask is why has not apx. 4.000 ppm more water vapor in the stratosphere. done anything (that can not be attributed to El nino) noticable to the weather/climate? It is well established that water vapor is a potent greenhouse gas. Raman Lidar spectroscopy as apposed to IR spectroscopy gives the answer.

      • Correction; apx. 400 ppm water vapor added. From 4.000 ppm normally. (0,4% water vapor throughout the atmosphere before Hunga Tonga). Not in ppmv.

        • The change in stratospheric would be more interesting since below 3000m there is ooodles of H2O, some even falls as rain occasionally….

          • Given how much rain we have had, there can’t be much water left in the atmosphere! The stratosphere is normally bone dry. It is a cold trap and water condenses and freezes out at the bottom of the stratosphere. Hunga Tonga injected water above this trap where it is warmer again (temperature rises because of ozone). There is no effect on global warming at the surface because the added amount compared to the total in the atmosphere is negligible. But the effect on the stratosphere can be significant.

    • WV is much more potent as a GHG than CO2.
      As such, heat from below (the troposphere) cannot escape, thus heat accumulates and stratifies the atmosphere. This in part may explain the extraordinarily high planetary heat index that we’re currently seeing.

  40. While everyone seems to have noticed Svartsengi area rising, there appears to be some GPS stations gradually sinking, some on the northern half of the Reykjanes Peninsula as a very recent change and trend.

    From the GPS website:


    The following stations show sinkage the past week or so (some longer)


    KEIC (gradual)






    Any idea on what might be happening? This is a noticeable change from the previous year or two trendlines.

Comments are closed.