Thread by @SquigglyVolcano

Okay, I've resisted long enough: it looks certain that that big explosion in the Caspian Sea wasn't a ruptured oil or gas pipeline or a rig fire, but the paroxysmal eruption of a mud volcano.

What is a mud volcano, I hear you ask? Let me help out.

THREAD TIME! *klaxon noises*

https://twitter.com/BNONews/status/1411762188721790979

First, let me say that this thread partly aims to amplify this excellent detective story by @CriticalStress_, while being informed by others, including @Chmee2. But I hope I can provide some more info too for those coming at this afresh.

https://twitter.com/CriticalStress_/status/1411839007823056897

And I'm hoping to write this up as an article, but July 5th isn't the best time to get in touch with my mostly American editors! So we'll see.

Okay. Let's dive in!

Q: What the hell is a mud volcano?

A volcano doesn't have to be made of rock and magma. A volcano, in my mind, is any opening in the ground that erupts the liquified version of the solid stuff it's surrounded by or build from.

Magma erupts partly molten rock = classic 'cano.

But you also have ice volcanism elsewhere in the solar system, where a slurry of various ices shoot out of a solid ice landscape. If that isn't volcanism, then what is?

Icy matter erupts out of Enceladus' south polar region all the time. Not only do these eruptions literally make one of Saturn's rings - the E ring - but they also power auroras so intense that they cook Saturn's atmosphere! Both are acts of magic. quantamagazine.org/cassini-data-s…

You can also get eruptions of thick, slurry material on some worlds. Although flowing "cryolava" has never been caught in the act, its remnant ghosts can be found on the dwarf planet Ceres, on Titan and on Pluto. nationalgeographic.com/science/articl…

It's also thought that some volcanoes erupt liquid iron. Psyche, the exposed iron core of a would-be world, may have erupted molten iron rivers long ago, when its innards were still hot. supercluster.com/editorial/scie…

Anyway—point is, if pressurised semi-liquid geologic matter erupts out of a vent, fissure or mountain, it's a volcano. So a mud volcano is exactly what it sounds like: muddy mounds that erupt mud, gases and fluids. They're gross and awesome.

Q: Okay, so how can a mud volcano explode like a flaming oil rig?

Good question.

Like all volcanoes, no two mud volcanoes are alike. Some just slowly ooze mud and belch various gases without incident. Others, like Lusi in Indonesia, engage in prolonged acts of epic mud cascades. (That one has made 40,000+ people homeless.) earthobservatory.nasa.gov/images/145198/…

As @CriticalStress_ notes, Azerbaijan has hundreds of mud volcanoes, both on land and offshore. Some hide just beneath the waves, sometimes popping above to say hey, while others remain as islands.

https://twitter.com/CriticalStress_/status/1411839033395736581

Some of these explode. This isn't the same way classic 'canoes normally explode: as in, a) gloopy magma keeps trapped gas highly pressurized until it reaches the surface and explosively decompresses, or b) very hot magma mixes with shallow water, creating a violent heat blast.

Mud volcanoes (more-or-less) explode in this fireball-like manner when oil and natural gas is tapped by them. Those in the Caspian Sea are more likely to do this because they sit on reserves of both fossil fuels, which is why so many rigs are also found offshore.

You can get a violent blast at a mud volcano if the mud-gas slurry is highly pressurised and it needs to force its way to the surface, sure. But fireballs aren't uncommon, and although the cause is unknown, the friction of rocks banging together mid-eruption may make sparks fly.

And @CriticalStress_ points out that perhaps the intense pressures below ground are enough to trigger a fireball. But no-one knows because it's pretty hard to observe this in real time or simulate it in a lab.

https://twitter.com/CriticalStress_/status/1411846425873244169

Q: So how do we know what caused the fireball in the Caspian Sea?

Sleuthing, and satellites. While @CriticalStress_ used video footage and photos to try and pinpoint the location of the blast, others like @simoncarn spotted heat spikes via satellite.

https://twitter.com/simoncarn/status/1411929446752325637

Both strongly suggested that the blast came from Ignatiy Stone Island, a mud volcano which last erupted in a major way back in 1945.

https://twitter.com/CriticalStress_/status/1411918523241095171

And today, a helicopter flyby of the island spotted signs of recent activity. Prime suspect: confirmed.

https://twitter.com/Liveuamap/status/1411928386897952774

As @Chmee2 explains, the fires in the central crater suggest a recent eruption, and he dark patches look freshly deposited mud volcano matter.

https://twitter.com/Chmee2/status/1411968698970218497

Mud volcanoes fireball like this several times per year, but this one went viral because a) it was a visually epic explosion caught on camera, and b) the anthropogenic fire in the Gulf of Mexico brought offshore conflagrations to everyone's attention.

https://twitter.com/Phil_Lewis_/status/1411084409021796354

Although both were caused by the same thing, only one was triggered by our precarious predilection for fossil fuels. The other was just nature blowing off some steam. :)

In short, volcanoes – which come in all shapes, sizes and types – are awesome.

End.