Supervolcanoes

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Isn't that right, Brian Cox?

First on BBC Sounds.

Robin Ince.

That's teamwork, isn't it?

It really is.

Professional.

Professional.

I'm Brian Cox.

I'm Robin Ince, and this is the Infinite Monkey Cage.

Now, Brian is, I suppose, more more often than not, known as the adventurer out of the two of us.

You've been to some very hot places, haven't you?

You've been to some very, very cold places, and you've seen some big, scary things, and some tiny little things as well.

And you've pointed at them all.

And

I'm not as well known for being an adventurer, but actually, I am.

Even though I don't travel like Brian, I spend a lot of my time in second-hand bookshops.

And I was in the peak district yesterday, and at one point, there was a book on a very, very high shelf right next to a leather-bound 1832 dictionary of entomology.

And when I pulled the other book out, the other huge book nearly fell, and I could have died.

That was an art of disappointment.

It wasn't.

If he died, that'd be Dara by now, isn't it?

It'd be much better.

Surely the best reaction you've ever had to be joke.

This wasn't a joke, and you just sighed in sympathy.

I would put it as whimsy rather than a joke.

Actually, my favourite story of your adventures is Venice, where was it you went and you were you went totally mad?

it's a long I'm not going to do that now we'll be here

tell us how the adventure ends I'll give you the last line the last line of this adventure is I said I want a one-way ticket to Caracas

it's a great story but we haven't got time for it now whereas yesterday I nearly died moving between Matlock and Cromford I went along the river Derwood on a path which only halfway along the path turned out to have a sign saying this is not a path it was far too late to tell me that this is not a path knew it wasn't the work of McGreet, by the way.

And then, so there I was, three huge bags of books and a rucksack on, and the end of my thing is, get me to Matlock Bath, and it cost me £1.20.

Considerably less than your flight, from what the BBC said.

Anyway,

today, we're talking about super volcanoes.

What are they?

What do they tell us about the planet we live on and how soon are we all going to die in a cloud of toxic volcanic ash?

We may well deal with that last bit first, just in case, because you might change your mind about whether you actually want to listen to this show with just how imminent your doom is.

Anyway, joining us, we have a volcanologist, a geoscientist, and an ostensible feminist, and they are.

My name is Professor Chris Jackson.

I'm based at Jacobs and at Imperial College.

And my favourite planetary spectacle are lava lakes.

My name is Tamza Maitha.

I'm a professor of volcanology at the University of Oxford.

My favourite planetary spectacle are fire fountains.

My name's Rachel Paris.

I do comedy and music, and my favourite planetary spectacle is the colour that my pet chameleon goes when he's happy.

And this is our panel.

By the way, just so you know, in the preparation for this show, where we were meant to be learning about super volcanoes, actually, the majority of the afternoon has been Brian spent pretending to be Dr.

Evil saying magma in the Austin Powers movie, isn't it?

That's intelligent.

That's an afternoon well spent.

Come on, do it.

Magma.

There we go.

And that's as far as he got in that four hours, right?

Was that live at the Apollo?

He is available, of course.

Well, I think we should begin with the definition.

What is the difference between a volcano and a super volcano?

Can I take that one?

Yeah.

I think I know.

Is it that there's volcanoes and then there's volcanoes that are just absolutely brilliant?

That's very similar to when we had Brian Blessed on the first time.

And he, I think he was talking about wave-particle duality, and he had to say, it's in a superposition.

But he said, it's in a superposition, which I would love if there was more of that in quantum mechanics.

I think it would cheer people up a great deal.

So a super volcano is just a better sort of.

So a super volcano is defined by how explosive it is.

So regular volcanoes are less explosive and chuck out less stuff than a super volcano.

And so, we have a scale for measuring the explosivity of volcanoes, goes from zero to eight, and a super volcano is a number eight.

So, a super volcanic eruption will put about a thousand cubic kilometers or more of magma

onto the surface of the planet.

A thousand cubic kilometers, just to put that into a very important scale of disaster, which is whales.

That would bury all of Wales to about 50 meters of depth.

Really?

Wow.

Not that we'd wish that on Wales, just to be clean.

And that's a super volcano.

It's a super volcano, yeah.

A regular volcano would cover Cardiff.

But it's, yeah,

it's okay.

There aren't any super volcanoes in Wales right now.

Barry Island is perfectly safe.

So that's the scale that we measure.

So we go from zero to eight, and those measurements are in cubic metres.

Cubic kilometres of magma.

Yeah, of volcanic rock.

So an eight, if you went down to a seven would be a hundred cubic kilometers.

So only five meters over Wales.

So yeah, because it doesn't sound much, does it?

When we're talking about these things, you say, well, it's an eight, it's a seven.

A seven doesn't sound too much different to an eight.

But in fact, you're talking about an order of magnitude, a factor of ten.

Yes.

And that's what makes it hard to communicate the severity of something is geologically speaking when you go up one point on a scale.

It sounds like one point, but actually it's ten times as big.

And we have the same issue when we're talking about earthquakes as well.

When we think about the earthquake magnitude scale, you go at one point, and suddenly it's not just a little bit bigger, it's substantially bigger.

So, what's the largest, in terms of when I say our lifetimes, I'll use me as an example, about 100 years, right?

So, in 100 years,

in the last hundred years, what's the worst volcanic kind of disaster as such that's happened for civilization?

In the last 100 years, it's probably the 1991 Pinotuba eruption, but that was several orders of magnitude smaller than our super volcano.

So, what would that have been?

That was a five or a six.

So, it was big, but and you kind of use the word disaster there.

There's a difference between the size of a volcanic eruption and the disaster that is caused as a function of that eruption, because a volcano can be very big and very explosive, but if it's not near a lot of people, then it doesn't put a lot of people in jeopardy.

So, I think we often want to talk about the biggest and

the most explosive, and therefore it's the most dangerous, but often that's not immediately the case.

You're saying there's parts of Wales you're willing to sacrifice.

I'm from near Matlock already, so I've already tried to kill Robin yesterday.

Why do people live near volcanoes, I suppose, is one of the one of the because there obviously must be advantages because no one's going to go, do you know what, this looks like a great place to live just because it's near the thing that might explode.

So there must be other things that are brought by being near a volcano.

So there are lots of reasons.

So there are opportunities that volcanoes bring.

They bring resources, lots of different types of resources, but they can change also local weather.

So for example, in on Sicily, the greatest rainfall is around Mount Etna.

So the best kind of farmland, best place to grow grapes and other produce is around Etna.

So that makes sense to live there.

They could be big tourist attractions, so they could have big industry about that.

And there's often a lot of pressure on land, so sometimes it's not the premium land that you might want to live on, but it's the free land, it's the cheapest land, and that's where people can be.

And sometimes it's also just because it's their home and they love it.

Yeah, and also when people turn up to live in a certain area, unless the volcano is actively erupting, you might not know.

So, you know, hundreds of years ago, thousands of years ago, when places were being first settled, there is no hazard there as far as the settling population is concerned.

So, we often think about it in light of what we know now, but really, it's useful to think about the answer to that question in the context of what would it have been like when you rocked up on a Tuesday 2,000 years ago or something.

On a Wednesday.

Is it possible for volcanoes to lie dormant for

not tens of years or hundreds of years, but indeed thousands of years?

So it would take you by surprise in some sense.

Yes, absolutely.

So on the Island of Montserrat, when it started erupting in 1995, people didn't realise they were living near an active volcano.

It was a big realisation, and they had to kind of adjust to it very, very quickly.

Whose fault was that?

Was that the estate agent?

Oh, don't worry about that hole over there.

Just an old smoking thing.

You know, estate agent.

We'll sort that out.

So that would have not erupted in recorded history, that volcano.

No one had any memory of that volcano erupting.

I think that's a very interesting thing because they all have different recurrence rates, and that's often the very tricky ones, is where they have very longer recurrence rates.

There isn't a collective memory of the volcano erupting.

So there isn't a sort of folklore around it, and then suddenly it kicks off.

When I was growing up, my mum and dad had been to Mount Etna, and they had, you know, when you're little, there's like various things in your house that you find really interesting and special.

And they had this old box of rocks that they'd been sold by someone, and it was meant to be rocks from Mount Etna, from like inside.

There are plenty of rocks on Mount Etna.

Yeah,

and they were the most beautiful.

There were like nine of them, and they were so all different colours, really beautiful.

And I was always like, oh, this is the most special, amazing thing.

And it was only in fairly recent years that I looked at them again.

And my mum had to be like, yeah, that was just a real tourist thing.

Like, that is just a piece of blue glass.

This is just an old doorknob.

Like, it was really clear.

But it didn't stop being special.

It was still really lovely.

And I like to think at least one of them probably was a rock from Mount Etna.

You believe that.

I'll hold on to that.

My first ever volcanic rock, my granny bought a rock back from Mount Atna.

Oh, so nice.

Maybe it was the same.

Quite spiky.

Right.

Sounds more like that.

I got a prize once.

it's a science prize where they give you, it's a piece of wood and it has an enormous piece of well, by my standards, volcanic rock on top of it.

It says well done for sporting science.

But it's very badly designed because you can't glue the piece of volcanic rock on properly to the piece of wood.

So it nearly broke my foot.

So it's the worst science prize.

It says, we are scientists, well done.

And then you don't trust them because they don't even know how glue works.

Just want to make sure you don't get to sport so you stick with the science.

Yeah.

Tamsa, could you take us through what happens in a volcanic eruption?

So you have magma building up, magma, building up inside the Earth's crust, and

gas is dissolved inside the magma, and that will come into bubbles within the magma storage area within the liquid rock.

And at some stage, the Earth's crust will fail, so it'll break, and a conduit will open to the surface.

And then, because that rock is all under pressure, it basically expels very fast onto the Earth's surface, perhaps explosively or perhaps as a lava flow, depending on how much gas you've got in that rock and how much rock you've got trying to get out there.

And why is it that particular regions of the world are more susceptible to that?

What is it about, you know, for example, Iceland or as you said, the Philippines, for example, Italy?

So, the grand unifying theory of volcanoes is plate tectonics.

Yeah, yeah.

So, we've got three main tectonic environments where we get volcanoes.

So Iceland that you just mentioned is where two tectonic plates are moving apart.

And so it drops the pressure on the Earth's mantle and melts it, and that's why you've got loads of magma coming up there.

You've also got a hot spot under Iceland in the Earth's mantle.

So that's helping that melting.

And you've got hot spots under places like Hawaii as well in the middle of the Pacific plate.

But then the really probably most dangerous volcanoes on the planet are in subduction zones.

So subduction zones are where you've got two tectonic plates moving together, and one tectonic plate sinks into the Earth's mantle underneath the other.

And water and other things that are on that tectonic plate sinking down actually get sort of boiled off, if you like, the lower plate, and they alter the composition, they alter the chemistry of the Earth's mantle.

So, it's like putting salt on your driveway in the winter, and that melts the mantle, and that gives you magma that causes volcanoes.

Why do you refer to those as the most dangerous?

Is that because they're unpredictable or

eruptions?

They tend to because they've got that water going into the zone where the magma is made, they tend to have more gas in it.

So it's like, you know, it's got more explosion potential, if you like, because it's got more of the water which becomes steam and drives the eruptions.

And that also tends to make the magmas change their chemistry.

So they become more viscous, stickier.

So the bubbles are trapped in them more and you get more explosive potential as well.

Yeah, it's like trying to see, I guess, bubbles coming out of golden syrup or honey versus bubbles just coming from a bottle of fizzy water, you know, they escape much more readily in the water than they do in the honey or golden syrup.

So it's a bit like you know, if you shake up a bottle of Coke and then you open it and it explodes everywhere as opposed to just opening it gently.

That doesn't happen as much anymore though, does it?

That prank doesn't work.

The brilliant prank when we were children when you could shake things up and then your friend would get covered in Coca-Cola and then be stung by a wasp, hilarity.

That led to anaphylactic shock.

And I changed the recipe.

Syrup stays as good though, so well done for making the show more detailed.

You've got another way of killing your mates.

Is that what you say?

Yeah, I just think.

Well, actually, next week we are doing bees versus wasps, so in some ways it's a little kind of trailer for that.

But

could we know before we were actually able to start understanding, you know, actually seeing what was under the earth, if you observed a volcano, what would you be able to understand about the structure of the earth and about the history of the earth from just watching that activity, Chris?

Well, I guess volcanoes are useful for us as geologists because they give us access to materials and information that otherwise would be inaccessible to us.

Because this magma is being generated several tens of kilometers beneath the Earth's surface, they're almost sampling the composition of the materials down there, and then very vigorously and quickly, in some cases, in the case of kimberlites, these really energetic diamond-bearing eruptions we have.

They bring that material to the surface.

So they let us know about the conditions, the otherwise unseeable conditions beneath our feet.

So volcanoes have a great utility in that respect.

And it's not only the the solid material, there's also gases as well.

That you can look at the gases, and some of the gases and material that come out can only exist in a certain set of pressure and temperature conditions beneath our feet.

So, they do tell us about that as well.

I suppose it's a bit like Dr.

Pimple Popper.

Oh, I cannot watch that.

Really?

Do you watch it?

It seems to divide people.

Yeah, I love it.

I can't get enough of it.

If anyone doesn't know, Dr.

Pimple Popper's like, it's on YouTube and she's got her own TV show.

She's a dermatologist who, in very close-up, takes great joy in popping people's pimples, ranging from white heads and blackheads all the way through to cysts.

You're calling me a pimple popper.

Not necessarily.

But, you know, you don't know what's there under the surface.

You need that opening, don't you?

Yes, we do.

Puss, puss, pussity, puss, isn't it?

Until the puss comes out, and then you know what's there.

And it's terrible in its time it's on because my dad would always watch a double bill of antiques road trip, which he thoroughly enjoyed, all manner of extraneous milk churns that made more money than you might imagine.

And then it would go straight into Pimple Popper, which was worse than once when he was watching Foyle's War, and that somehow led to him seeing Naked Attraction.

Real sense of shock came over him there.

I'm just saying both are culturally important.

But with that sense of balance, I accept that.

Thank you.

And we and we've now reduced volcanoes to the zits of the earth.

Yes.

There's pimples and super pimples.

Yes.

What we've learned.

It's interesting when you talk about the difficulty of understanding the structure of the planet, because it's almost, especially if you almost take it for granted.

We go that here's the core and here's the mantle.

Could you first of all just talk through?

It's worth, I think, just reflecting on what we know about the structure of the planet.

If you sliced it in half, what those different layers would be.

And also, I suppose, how we discovered that, because as you say, even if you're 20 kilometers down or something, it's extremely difficult to we can't go there.

Yeah, so I mean, the planet is,

the radius is about 6,400 kilometers, so it's about the distance from London, Chicago.

Right at the very centre, we have the solid core, and then we have the liquid outer core.

And then the sort of great bulk of the Earth is the mantle.

And that's mainly iron.

That's right, the core is mainly iron with other gubbins put in there.

You come here for the science, don't you?

That's exactly what apart from the iron.

Well, here on the periodic table, we have the gubbins area.

We call them the siderophile elements, but Gubbins does too.

They love Gubbins, aren't they?

What's the Earth made of?

Well, the steel, magma, and a lot of gubbings.

But it's radioactive gubbins, son of it, isn't it?

Oh, yeah, the serious gubbins.

Hot gubbins.

His gobbins sounds like the best circus act you would ever see.

That was Cold Cole the Clown.

Now, please welcome radioactive gubbins.

But doesn't quite a lot of the heat now comes from radioactivity, doesn't it?

Yes, a lot of the heat comes from radioactivity, and then also the primordial heat that the air still has locked into it from its formation.

And then, also, the inner core solidifying releases latent heat that is driving like the dynamo of the liquid outer core as well.

And then the mantle is solid, which is the bulk of the earth, but it's creeping very, very slowly, so it convects on very, very slow time scales.

So, about the same time scale as your fingernails grow.

And then we have the crust on top of that, which is this very thin layer that all the action goes on in terms of our lives.

Can I ask more questions?

What's the mantle made of, and how far down, like if I was in my garden,

I don't actually have a garden, I live in London.

How far down would you have to dig to get to the mantle?

Kilometers, kilometers.

Yeah, so don't worry.

You can

try there.

But what's amazing is, I mean, like, you know, from GCSE geography, maybe, you know, the slice of the earth, the image of the kind of different layers, it seems so obvious and immediate to us now.

But part of your question is, how did we find that out?

It's an incredible story of so many different techniques coming together.

So, geophysical imaging, the fact that acoustic waves, so sound waves, travel differently through different materials, and therefore, when you have an explosion on one side of the planet, different waves are recorded on the other side of the planet at different times.

You know, that tells you a little bit about those layers of the Earth.

We have volcanoes, we have earthquakes, we have all of these things, which now give us these beautiful diagrams that we toss around, you know, in our heads all the time.

But it's the amazing story of discovery, really, how that was done over hundreds of years.

Absolutely, and there was all sorts of different strands of evidence that brought together, even just thinking about the way the Earth spins and the way that solid, like if you have a boiled egg versus a raw egg, they spin in different ways.

And that was one of the ways that people worked out that the inside of the Earth wasn't mainly molten.

But then we discovered that we did have this molten bit because of different types of seismic waves.

So you have seismic waves that are compression waves, like sound waves, and then seismic waves that are sinusoidal waves, like a Mexican wave going around a stadium.

And the waves that are Mexican waves can't travel through liquid.

So they discovered they lost

the other side of the planet.

So it's really a detective story over many centuries to work out the internal structure of our planet.

And what's the mantle made of?

It's made of olivine,

yeah, lots of different minerals.

And also, I mean, the mantle contains some materials which are only kind of stable at those pressure and temperature ranges.

And so when we find them at the Earth's surface, it's quite a unique set of circumstances that get them to the Earth's surface that we can then sample them.

So, we don't readily find those materials just languishing around on the Earth's surface for a long time.

But the volcanic activity we're talking about, we're talking about the crust there.

We're just talking about processes that are happening in the first, what, 10 kilometres or so?

So, the magmas come from the mantle and then work their way up through the crust, but from the upper mantle, kind of it comes up in a hurry or it can be stored over different time periods in the crust.

So, every lava has its own story.

I guess it would be fair to stay.

So, they don't fall.

And some of the thermal energy for volcanoes like Hawaii comes from potentially very, very deep inside the earth, perhaps as deep as the core mantle boundary and these massive thermal plumes rising through the mantle.

Oh, really?

So we can be seeing material from thousands of yeah, but it gets contaminated as it rises through.

So there's fingerprints of its interaction with different materials as it rises through.

And the challenge is trying to distinguish that kind of primary composition from all of the muck that gets mucked like gobbins, all the gobbins that get mucked in his face.

And that's a double act.

I'm at Blackford's Pier in 73.

Well, I was thinking I'm going to get a challenge for the listeners, which is because you've mentioned quite a few foodstuffs.

If you could listen to everything that's mentioned by our volcanologists and then turn it into some kind of ready-steady cookie, you've got two eggs, one's soft-boiled, one's hard-boiled, you've got honey, you've got syrup, you've got gobbins, and you've got a crust.

Now, Radio 4, let's make this a cookery show.

We could see our listenership just zoom up.

But I've.

What could possibly go wrong?

It's like the easy harriet of volcanology.

Is that the challenge?

Yeah.

I think you can make it, you know.

Have you been to a volcano?

Have I been to a volcano?

I'm just going through, where have I been?

No, only

a social volcano.

Oh, I've been, yes, I've been to San Francisco, so not really, but I've been to a volcano.

Have you been to Edinburgh?

Yeah.

So Edinburgh is built on an ancient volcano, so it's a Carboniferous volcano, so 300 odd million years ago.

So you've not been to an active one, but you've been to a volcano of sorts.

I think you should give yourself

credit for that.

Yeah.

That was funny, that was just like watching Brian at a party, by the way, because that's normally what he says.

Hello, I'm Brian.

Have you been to a volcano?

No, I haven't.

I've been to quite a few, actually.

I was about to say, do you want to come to a volcano?

To be fair, it's what I do at parties as well.

But close by, though, is San Francisco.

So, on the west coast of America, that's one of the big super volcanoes, the Yellowstone volcano, isn't it?

So, could you turn into super volcanoes?

I think it's hard to visualize how violent these things are.

You've given that one number in terms of the what is it?

It would cover Wales up to what was it?

I don't know why I'm laughing.

It would cover Wales up to 50 meters.

50 meters.

But in terms of the explosive nature, these things are global events.

But you said that

volcanoes are dangerous if you live near one and it erupts.

But a super volcano, you don't have to live very near to be in trouble.

No, so I guess the one thing about volcanoes is that they can impact the climate as well.

So we often think of the most immediate hazards like these pyroclastic flows, these big, hot, gaseous flows that come off these volcanoes and can burn you.

We think of lava, which is really hot.

But then when we get gases and particles going up into the atmosphere, it can actually cool the Earth initially.

If we have, I guess, sulphur dioxide and the ash particles can stop incoming solar radiation, so the earth cools.

But then we also have cases where there's lots of carbon dioxide, so a greenhouse gas comes out of the volcanoes, and that can cause longer-term heating.

And volcanoes have had impacts on the political history, I guess, of different countries.

Yeah, so it's not a super volcano, but in 1815, the eruption of Tambora in Indonesia led to the year without a summer.

So we had all sorts of impacts around the planet.

We had snowfall in June in New England.

There was famine in Switzerland.

They had to eat cats and moss.

The French rioted.

Everyone dealt with things in different ways.

Cats and moss.

Yeah, add that to the list of the recipe ID.

I did that on purpose.

I mean, there is something, Rachel, about what I love about talking about things like super volcanoes is it is a constant reminder that we like to imagine that we are in control of our environment and somehow we'll always find a way of managing to rise above natural events.

But, you know, what you're talking about here is, no, you know, this is, it reminds us sometimes of our own smallness and our powerlessness.

It reminds us not to go to Edinburgh again.

What were we thinking?

I recently watched Jurassic Park The Fallen Kingdom.

I don't know if any of you have seen that.

It's very clever.

And there's a volcano explosion in that on the island where all the dinosaurs are.

And I completely assumed that every aspect portrayed in the film was scientifically correct.

And in that, the volcano was explosively erupting, and Chris Pratt was actually paralyzed by a dart, but he was able still to roll himself away from lava, which was centimeters away from him,

moving that slowly.

And then they ended up jumping into the sea off a cliff, and there were balls of lava from the volcano going into the sea, but none of them touched them, luckily.

My question is:

Why was Piers Brosnan not in that film?

Yeah,

that was Jeff Goldblum.

How fast does lava flow?

And if you were, I suppose, would you have any chance of survival?

Obviously, you don't know how big the volcano was because you probably haven't seen the film.

Sadly not.

Yeah, I mean, I thoroughly recommend it.

I think I'd be a really exciting person to watch that film with.

I genuinely would love to watch that film with you.

So much of the film is a volcano explosion.

I mean, I'm really fun when a volcano goes off.

I would not watch a film with a volcano in with you, I tell you.

Let's start with how fast does lava flow?

I assume it's different speeds.

So, yeah, so I'm using for the reference point, Chris Pratt has been disabled by a poisonous dart.

Is that now a standard unit?

Is he able to keep rolling down fast enough to the standard unit?

Is one Chris Pratt revolution?

Okay.

So, some of the really like low-viscosity larvas that we have, so some of the really, really runny lavas we have, and they're very low-viscosity because they have low amounts of silica in them.

They can go up to about 40-50 miles an hour have been recorded.

So, those are lavas which you could definitely not out-run.

Or out-roll.

Or out-roll.

Did they mention the silica content of the larva?

I don't think so, but I'm now going to...

I'm not going to know that.

I'm not loving that as Chris Pratt's rolling.

It's okay, I've worked out the silica content.

I didn't think of the viscosity.

Yeah, but then there's some other larvas that are super sticky, super viscous, and they can't flow at all, I guess, rhylites, right?

So they

just come out.

Chris Pratt could have really taken his time.

But Hollywood would not have enjoyed that so much.

Oh no, the volcano, it's erupting.

But if you have a rhythmite eruption,

if you have a rhyolite eruption, you're more likely to get pyroclastic flows

or other sorts of pyroclastic density currents.

I do wonder whether they might have mixed up some different volcanic phenomena like they have.

It sounds like they have.

Likelihood of you streaming this film further and further away.

But Dante's peak, of course, we've got from that.

And the

hackers I love this with scientists, which is, you know, in the area of expertise, I think anyone in the, if they ever watch a film which involves something that they've studied, they will just go, this is all went up.

So volcano movies, you know, Krakatoa, Easter Java, didn't even get the position of Krakatoa correct, because I think it's Wester Java.

I'm happy to suspend my scientific training for anything between an hour and a half and two and a half hours and just sit through the most outrageous

lava bombs going in the sea and splatting around.

I just love it.

Have you seen Pompeii?

I just love it.

I love it all.

I just love the drama.

I like the splatting around.

You do it with musicals.

Do you get really upset?

No, I just love musicals so much, like a good musical, that no, I don't sort of sit there and analyse it.

Yeah, that chord sequence was really vulgar.

Yeah.

See, I love really kind of mundane facts that people like, like the Krakatoa, Easter Java, Western Java.

I remember reading in Look and Learn comic once about the errors in Oklahoma.

For instance, that the corn grows as high as an elephant's eye.

But actually an elephant's eye is quite low and that would be a bad crop.

I really like that.

If we get back to the subject.

I think we're on the subject now.

So I know that the Yellowstone volcano, the big super volcano there, is one that is of concern.

It's something that's monitored very closely.

So

could you describe what would happen, what we expect to happen if we see see a problem with that volcano?

Could you characterize the eruption that we expect?

I guess there's a number of fingerprints for these large eruptions.

So, you might expect, or you could anticipate, that the ground will actually start to deform.

So, the Earth's crust itself will deform, and we might even be able to see that from space from satellites.

So, the Earth's crust could go up by as much as a few centimetres, and that's because magma is moving inside the Earth and building up beneath the volcano, and it pushes on the rocks above it and lifts it up.

So, we might see crustal deformation, and I think we could also see changes in the gases coming out of fumaroles as well.

They heat up, there'll be more gas coming out.

We've not actually, fortunately, ever seen the run-up to a super volcano.

So, the last super volcano was 26,500 years ago, and we didn't have many seismometers around at that time

or satellites.

So, we don't really know is the answer.

But, based on what we know of other systems where we have seen the build-up to eruptions, that's how we extrapolate to work out what we might look out for.

And what would be the response if you see a volcano like that beginning to be active and you think there may be an eruption?

What scale of eruption are we talking about?

And what do we do about it?

So, one of the things with these systems is they don't just do super volcanic eruptions.

So, a super volcano is a volcano that has the capacity or has had a super eruption in the past, but often between times they have much smaller eruptions as well.

So, that would be one of the, I guess, the first thing that you would think was maybe it's going to do one of these smaller eruptions.

Fingers crossed.

Yes.

See, isn't it bad news that there's not been one for 26,000 years?

Is that the only go, it's been a while?

Is there anything we can take from that?

Based on the statistics, so you know, people go around the world and map these out.

We reckon that we have between one and twenty super volcanic eruptions every million years.

So that's quite a wide range.

And we've had about five in the last million years.

So you've either had four too many or you've got fifteen to go, depending on what you're at.

You left just

off to one and twenty because I could hear people going, is this going to be days?

Yes.

I'm trying to get I'd I'd like to get a picture of the potential scale.

We don't have to pick on that particular volcano, a super volcanic eruption, a super volcano.

So what are we talking about globally?

It's hard, I mean it's kind of like Tamzin said, because we've never seen one, you can only go to the biggest one we have seen and try and put in people's minds what that that thing looked like and then make people realize it could be 30 times larger.

And I mean, how do you hold that in your head?

You know, there's this big eruption, you know, there's Pinotubo, we've got videos and we've got all these, we've got footage of it, but how do you imagine something being 40 or 50 times larger?

I mean, I think it's quite hard to even, even for us who are, you know, worked with I mean, so the last super volcanic eruption of Toba, which was 75,000 years ago, scattered ash.

There's great thick layers of ash over India, there's ash over Africa as well.

So that's a big footprint of ash.

And then there'd be a lot of sulphur dioxide and other noxious gases that would get into the atmosphere.

And we would feel a global cooling from that.

When one of these volcanoes goes off, probably what happens is we get a really explosive eruption column, something we call a Plinian eruption column, after Pliny the Younger's account of the AD 79 eruption of Vesuvius that destroyed Pompeii and Herculaneum.

So it'd be this enormous kind of tree-like structure punching up into the stratosphere and taking gases like sulphur dioxide up into the stratosphere and scattering ash and pumice everywhere.

And then, as the eruption progresses, we probably get that eruption column collapsing in the pyroclastic density currents, the pyroclastic flows, these super-hot avalanches that cloak the landscape around the volcano.

That's what wiped out the people in Pompeii and Herculaneum as those went down the sides of the volcano.

But with a super-eruption, it's so big that it actually empties out the Earth's crust.

So, it empties out the magma storage area in the Earth's crust.

And at some stage in the eruption, you get a caldera forming.

So, the roof of the magma chamber just collapses under its own weight.

It gets a massive crater forming where the volcano is.

And there is evidence that actually then you get magma being pushed out round that ring fracture, that fracture in the Earth's crust, and you get more pyroclastic density currents coming out of that fault in the Earth's crust itself and spreading more material out onto the planet's surface.

And in terms of impact on climate, you said the 1879 eruption was it

gave us a year without a summer.

You said these are 50 times

these eruptions.

So what would be the climate impact of such a thing?

Well, I guess immediately after the eruption or for a few years after that, we'd expect to have a cooling because we've got this dispersed ash and this sulphur dioxide going up into the Earth's atmosphere forming this kind of like volcanic haze.

You know, so we have reduced solar radiation reaching the Earth, so the planet cools over a few years, and then we'd have warming over a longer time period.

I think it was the Lackey eruption in Iceland 200 years ago, when it was argued to be one of the reasons for the French Revolution, was because it was the final, you know, the kind of famine and the peasants revolting was precipitated by the fact there was a crop failure because there was this back to riots in France.

There's not been any volcanic eruptions in France recently, but they're still rioting.

So, like,

I think that's my nature paper.

It's a good one.

It's to go my one.

Volcanoes, they're really hot.

Any cool thing.

There have been models run of super volcanic eruptions, and we reckon there'd be a cooling for about a decade after a super volcanic eruption.

But there's all sorts of interesting things that go on in terms of atmospheric chemistry in the stratosphere, so there could be positive and negative feedbacks.

Actually, the warming effects that Chris is referring to, probably it's like the large igneous provinces back in Earth history that are associated with things like mass extinction events where the carbon dioxide flux is really significant and can push the earth system out of kilter.

So you're talking about, I don't want to alarm any people who are listening here, but you did say mass extinction events.

Yeah.

Do we think that there's a tidy chance, but are the volcanoes with the potential to really affect the climate at that level?

We've seen with COVID and things like that how complicated supply chains are.

So it's going to be deeply inconvenient for us as a species.

Huge leap from extinction to deeply convenient.

But some but that's that's deeply inconvenient.

It's a very British way of supporting.

Ladies and gentlemen, it's deeply inconvenient.

We've almost come to down here when we couldn't get tomatoes in Vinion.

No cucumbers anywhere.

The mass extinction events aren't actually what we call so much super volcanoes, but these large igneous provinces.

So this is something a bit different.

This is a form of volcanism that kicks off and lasts about a million years and puts about a million cubic kilometers of magma onto the surface of the planet.

So, that's like doubling the rate of volcanism on the planet for about a million years.

So, those are the sorts of events that can potentially lead to mass extinction events rather than the super volcanoes, which are these short-lived explosive events.

And we might expect one of those as well

at some point, yeah.

Because it's interesting, isn't it?

Because you tend to think of these huge volcanic events as things that happen in films about dinosaurs, as you said, not something that will be a part of our future as well as our past.

It feels that the planet was really active in the past and it's now rather benign.

But I think that's the, again, that's the kind of magic and wonder and the stimulation for studying the Earth, is that for long periods of time it can seem incredibly benign and incredibly passive.

You know, it's just quite dull.

Dare I say it.

And then all of a sudden it's not.

You know, it shakes or it's...

The geologists go, it's really dull and boring when civilization flourishes and everybody's dead,

it's really dull, and then suddenly it's not, and everyone's dead,

and then we get funding,

Rachel.

Now, you know, having listened to the show so far, where has the super volcano gone in terms of your chart of anxieties?

Do you have a number one?

Family functions.

Large family functions is probably number one.

A super volcano.

To be honest, there's something about from what you've said: a super volcano, not a volcano, but specifically a super volcano exploding.

There's a sort of comfort to that, which it sounds like you can't really see it coming, you can't really predict what the effects are going to be apart from that they're going to be absolutely catastrophic.

And there's a sort of, well, you've just got to give up worrying about that.

Do you know what I mean?

Like, can't really control it, and it's going to be huge and devastating.

So, you know, that I can roll with that.

That's a very English answer, isn't it?

Oh, what a relief a super volcano.

I can finally give up.

It is interesting that because some of the big threats, you know, so asteroid impact, for example, we can conceivably do something about it.

But in this case, with the activity of the planet,

what can we do with the non-steroid impact further?

You send Bruce Willis on.

I thought, you might be zombies.

we know this, to drill a hole in it.

I don't want to miss the thing.

Is that

only what we've given away is we have discovered this week that Brian's scientific knowledge entirely comes from Hollywood film.

We normally think of volcanic eruptions with dinosaurs.

We can survive an asteroid strike due to the spaceship we'll send up with the people in it.

We tested it about just a few months ago.

So it's been done.

But essentially, with the activity of the planet, there really is genuinely nothing that we can do about that.

So So, the summary is: don't worry too much about the next super volcano eruption, but it's coming.

Now, we asked our audience a question as well, and we asked them: if, like the people of Pompeii, your last action was frozen in time, how would you like to be petrified?

Yeah, we got there, Brian.

I was very worried about this.

There's a question.

So, we have hoovering up the initial ash, as it's going to be even worse when it's finished.

Oh, yeah, I don't know what what that means either.

That's why I gave it to you.

I know, you've given it to me because you're not sure if it's rude, and neither am I, so I'll just take a risk.

The down dog?

Oh, okay, thanks very much.

So, for someone like me who doesn't really, that is rude as far as I knew for this form of exercise.

What's it look like?

Can you do it?

Can you do the downed dog?

Yes.

I can, but I'm not.

I tried to do a forward roll here about three months ago.

I've got cancelling my subscription to the Vesuvius Appreciation, Protection and Education Society,

also known as Vapes.

I've got dunking a hobnob in a nice cup of tea.

Note from wife, laws of probability say this is highly likely due to the sheer number of hobnobs consumed.

Thank you to our panel Tams and May, the Chris Jackson and Rachel Paris.

And next week we have our long-awaited sequel, almost reboot, to bats versus flies.

What are we doing, Brian?

We're doing bees versus wasps.

If wasps created honey, would that mean we forgave them for everything else?

This is a big kind of right, Chris.

You're shaking your head.

So, bees versus wasps.

Yeah, got to go for bees, right?

They give you the honey.

The wasps are just interlopers just trying to like muscle in.

What would you think?

You could put all the bees or all the wasps into a volcano and completely eliminate one species.

Which would it be?

Meet wasps every time.

But

they're pollinators.

Don't care about

what it's going to be about.

Thank you very much for listening.

We'll be back next week with wasps versus bees.

Bye-bye.

Jason Manford here.

And I'm Steve Edge.

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