The Infinite Monkey Cage - Supervolcanoes

Episode Date: July 1, 2023

Brian Cox and Robin Ince find out if supervolcanoes are worth worrying about. They are joined by volcanologist Tamsin Mather, geologist Chris Jackson and comedian Rachel Parris. They learn about the worst eruptions of all time, including the eruption that may have sparked the French Revolution. They find out what volcanologists like Tamsin are doing to monitor supervolcanoes and if volcanologists do predict an impending eruption, is there anything we can do about it? New episodes are released on Saturdays. If you're in the UK, listen to the full series first on BBC Sounds: bbc.in/3K3JzyFProducer: Caroline Steel Executive Producer: Alexandra Feachem

In our new podcast, Nature Answers, rural stories from a changing planet, we are traveling with you to Uganda and Ghana to meet the people on the front lines of climate change. We will share stories of how they are thriving using lessons learned from nature. And good news, it is working. Learn more by listening to Nature Answers wherever you get your podcasts. This is the first radio ad you can smell. The new Cinnabon pull apart only at Wendy's. It's ooey gooey and just five bucks with a small coffee all day long. Taxes extra at participating Wendy's until May 5th. Terms and conditions apply. BBC Sounds.

Music, radio, podcasts. Hello, we're back for a brand new series. New episodes will be released weekly, but if you're in the UK and can't wait... You can hear it all right now before anywhere else. Isn't that right, Brian Cox? First, on BBC Sounds, Robin Ince. That's teamwork, isn't it? It really is, yeah. Professional. I'm Brian Cox. I's Robin Ince. That's teamwork, isn't it? It really is, yeah. Professional.

I'm Brian Cox. I'm Robin Ince, and this is the Infinite Monkey Cage. Now, Brian is, I suppose, more often than not, known as the adventurer out of the Turbos. 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 and you've pointed at them all and uh i'm 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. If you hadn't died, that'd be Dara by now, wouldn't it? It'd be much better. Surely the best reaction you've ever had to a joke. It's supposed to be a joke and you just sighed in sympathy. It's really a joke. 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 went totally mad? It's a long story. I'm not going to do that now. It'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.

That's the end of the story. 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 Derwent 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. I knew it wasn't the work of Magritte, by the way. And then, so there I was, three huge bags of clothes, had a rucksack it wasn't the work of Magritte, by the way. So there I was, three huge bags of books, had 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 Tamsin Maver. 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 supervolcanoes, 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 an afternoon well spent. Go on, do it. Magma. There we go. And that's as far as he got in that four hours, right? What's that, live at the Apollo? He is available, of course. Well, I think we should begin with a definition.

What is the difference between a volcano and a supervolcano? 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 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 supervolcano is just a better sort of... So a supervolcano is defined by how explosive it is. So regular volcanoes are less explosive and chuck out less stuff than a supervolcano. And so we have a scale for measuring the explosivity of volcanoes, goes from zero to eight, and a supervolcano is a number eight.

So a supervolcanic eruption will put about 1,000 cubic kilometres or more of magma... LAUGHTER ..onto the surface of the planet. So 1,000 cubic kilometres, just to put that into a very important scale of disaster, which is Wales. LAUGHTER That would bury all of Wales to about 50 meters of depth really wow not that we'd wish that on wales and that's a super volcano it's a super volcano

a regular volcano would cover cardiff but it's yeah it's okay there aren't there aren't any super volcanoes in wales right now barry island is safe. So that's the scale that we measure. So we go from zero to eight, and those measurements are in cubic metres, or cubic kilometres of magma. Yeah, of volcanic rock. So an eight, if you went down to a seven... Would be 100 cubic kilometres.

So only five metres 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. 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 at 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 you know 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 100 years what's the worst volcanic kind of disaster as such that's happened for civilization in the last 100 years, what's the worst volcanic kind of disaster as such that's happened for civilisation? In the last 100 years, it's probably the 1991 Pinatuba eruption, but that was several orders of magnitude smaller than a supervolcano. So what would that have been?

That was a five or a six. So it was big, and you kind of used the word disaster there. There's a difference between the size of a volcanic eruption and the disaster that causes the 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 you know 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, 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, 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 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's concerned so we often think about it in light of what we know now but really we it's useful to think about the answer to that question in the context of what would it have been like when you erupted upon a Tuesday 2,000 years ago or something. Or Wednesday. Is it possible for volcanoes to lie dormant for tens of years, 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...

A spoky thing. You know estate agents would do that. So that would have not erupted in recorded history that volcano no one had any memory of that 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 long 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 all that was like nine of them and they were so all different colors 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 trap thing. Like, that is just a piece of blue glass. This is just an old doorknob. 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 Etna as well. Oh, so nice. Maybe it was black. Right. Quite spiky. first ever volcanic rock my granny bought a rock back from out at the resort oh so nice maybe it was black right and quite spiky right sounds more like a prize once it's a science prize where they

give you it's it's a piece of wood and it has an enormous piece of well to my 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 they don't even know how glue works just want to make sure you don't get into sports so you stick with the science yeah so could you take us through what happens in a volcanic eruption so you have magma building up magma uh building up in inside the the earth's crust and gas is dissolved inside the magma and that will come into bubbles within the magma storage area within the 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 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 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 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 mantles. 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

larger eruptions? They tend to, because they've got that water going into the zone where the magma's 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. 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 and 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 hilariously before you know it, that led to anaphylactic shock. They've changed the recipe. Syrup stays as good, though, so well done for making the show more delicious.

I've got another way of killing your mates, is that what you're saying 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 uh but i i'm what can 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 has been 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 solid material, there's also gases as well, that 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 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 whiteheads and blackheads all the way through to cysts.

Are you calling me a pimple popper? Not necessarily. But, you know, you don't know what's there under the surface that opening don't you yes we do know an access and then you know what's there so 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 foils 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 put it with that sense of balance i accept that thank you we've now reduced volcanoes to the zits of the earth. Yes. Well, there's pimples and super pimples. Yeah. That's what we've learned. It's interesting when you talk about the difficulty of understanding the structure of the planet,

because it's almost... I should be honest, take it for granted. We go, 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 kilometres down or something, it's extremely difficult. We can't go there. Yeah, so I mean, the planet is, the radius is about 6,400 kilometres. So it's a the radius is about 6 400 kilometers so it's about the distance from london chicago right at the very center 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 and 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 what's the earth made of well this is steel magma and a lot of gubbins but it's radioactive gubbins some of it isn't it oh yeah the serious gubbins hot gubbins sounds like the best circus act you would ever see 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 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 timescales. It's about the same timescale 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? Kilometres. Kilometres. Yeah, so don't worry, you can... I'm not even going to try.

But what's amazing is, I think, like, you know, from GCSE geography, maybe, you know, this 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 are brought together even just thinking about the way the earth spins and the way that a 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 these.

They're invisible, yeah, to the other side of the planet. 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. Olivine, yeah. 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 at different over different time periods in the crust so every lava has its own story i guess it would be fair to say so they don't and some of the thermal energy for volcanoes like hawaii come from potentially very very deep inside the, perhaps as deep as the core-mantle boundary and these massive thermal plumes rising through the mantle.

Really? So we can be seeing material from thousands? 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... It's muck like gubbins, all the gubbins. It's a double H. Fucking gubbins, shall we? I'm a Blackpool peer 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 cook. You've got two eggs, one soft-boiled, one hard-boiled. You've got honey, you've got syrup, you've got gubbins and you've got a crust. Now, Radio 4, let's make this a cookery show.

We could see our listenership just zoom up. What could possibly go wrong of volcanology is that the challenge yeah i think we can make it you know have you been to a volcano have i been to a volcano um i'm just going through where have i been um no only only a social volcano. Oh, I've been to San Francisco, so not really, but I've been to... Have you been to Edinburgh? Yeah. So Edinburgh is built on an ancient volcano. Is it?

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 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 the 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 supervolcanoes, the Yellowstone volcano, isn't it?

So could you turn into supervolcanoes? I think it's hard to visualise how violent these things are. You've given that one number in terms of the... It would cover Wales up to... I don one number in terms of the what it would cover whales up to what was it i don't know i'm laughing it would cover 50 meters 50 meters but in terms of the explosive nature these things are global events but you said that the 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 sulfur 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 call longer-term heating and volcanoes have had impacts on you know history, I guess, of different countries.

Yes, so it's not a supervolcano, but 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. Add that to the list of the recipe I did. I did that on purpose. I mean, there is something, Rachel, about what I love about talking about things like supervolcanoes 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 watchedassic 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 um and in that the

volcano was explosively erupting and chris pratt was actually paralyzed by a dart but he was able still to roll him 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 pierce 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? And I assume it's different speeds. So using 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 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. So some of the really low viscosity lavas 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 couldn't definitely not outrun or outroll or outroll did they mention the silica content of the love i don't think so but i'm now gonna have that i would love to know as chris pratt's only it's okay i've worked out the silica content. I didn't think of the viscosity. Yeah, but then to some other larvas, they're super sticky, super viscous, and they can't flow at all, I guess, rhyolites, right? No. So they just come out.

So 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 rhyolite... Very slowly. If you have a rhyolite eruption, you're more likely to get pyroclastic flows. Right. Or other sorts of pyroclastic density currents.

I do wonder whether they might have mixed up some different volcanic phenomena. It sounds like they have. It sounds like they have. Likely could have used streaming this film further and further away. But Dante's Peak, of course. We've fucked on that. I love this with scientists, which is, in your area of expertise,

I think anyone, 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, East of Java, didn't even get the position of Krakatoa correct, because I think it's West of 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...

Yeah. You know, the kind of lava bombs going in the sea and splattering 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 splattering around. Do 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 the Krakatoa, East of Java, West 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. LAUGHTER 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 supervolcano 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 a problem with that volcano? Could you characterise 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. Yeah, they heat up, there'll be more gas coming out. We've not actually, fortunately, ever seen the run-up to a supervolcano. No. So the last supervolcano 26 and a half thousand years ago and we didn't have many seismometers around

or satellites um so 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 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 supereruption 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, is it bad news that there's not been one for 26,000 years? Is that the way when you 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 20 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 15 to go, depending on what you're you left just last half full after one and 20 because i can't be going is this going to be days i'm trying to get 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

tamsin 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 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 bigger you know there's pinatubo 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 large i mean it i think it's quite hard to even even for us who are you know work 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 sulfur 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 sulfur 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 and 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 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's a massive crater forming where the volcano is and there is evidence that actually then you get magma being pushed out around 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? 1815. 1815 gave us a year without a summer. You said these are 50 times larger, these eruptions. So what would be the climate impacts 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 sulfur dioxide going up into the Earth's atmosphere, forming this kind of volcanic haze. 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. 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 to riots in france exactly there's not been any volcanic eruptions in France recently, but they're still rioting, so... I think that's my nature paper. The, um... It's a good one. It's to go with my one.

Volcanoes, they're really hot. N equals two. There have been models run of supervolcanic eruptions, and we reckon there'd be a cooling for about a decade after a supervolcanic 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 listen you did say mass extinction events yeah do we 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. That's a huge leap from extinction to deeply convenient. It's a very British way of putting it. Ladies and gentlemen, it's deeply and completely... We almost went down here when we couldn't get tomatoes, didn't we? No cucumbers anywhere. The mass extinction events aren't actually what we call so much supervolcanoes,

but these large igneous provinces. 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 kilometres 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 supervolcanoes, which are these short-lived explosive events. And we might expect one of those as well. At some yeah because it's interesting 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 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 it's really dull and boring when civilisation flourishes and everybody

it's really dull and then suddenly it's flourishes and everybody's dead. It's really dull. And then suddenly it's not and everyone's dead. Yeah, yeah. And then we get funding. Rachel, now, having listened to the show so far, where has the supervolcano gone in terms of your chart of anxieties do you have a number one family functions uh large family functions is probably number one um super volcano to be honest there's something about from what you've said a super volcano not volcano but

specifically 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, we can't really control it, and it's going to be huge and devastating. So, you know, 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, because some of the big threats, you know, to 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 asteroid impact?

We send Bruce Willis up. Yeah. I thought you liked these films. It's obvious. We know this. To drill a hole in it. I don't want to miss a thing. 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 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? I was very worried about this, was the 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 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? That's yoga. So, for someone like me, who doesn't really... That is rude, as far as I'm concerned, this form of exercise. What's it look like? Can you do it? Can you do the damn dog?

I can, but I'm not. Oh! 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. Nice! I've got dunking a hobnob in a nice cup of tea. 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. Thanks to our panel, Tamsin Mather, Chris Jackson and Rachel Parris. And next week, we have our long-awaited sequel, almost reboot, to Bats vs. Flies. What are we doing, Brian? We're doing Bees vs. 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 vs. 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? Meat wasps, every time. They're pollinators. Don't give away what the show's going to be about. Thank you very much for listening. We'll be back next week with Wasps vs Bees.

Bye-bye. APPLAUSE next week with Wasps vs Bees. Bye bye. Turned out nice again. Jason Manford here. And I'm Steve Edge. We just wanted to tell you about our new podcast from Radio 4 on BBC Sound's

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