Volcanologist Tamsin Mather on her 'adventures in volcanoland'
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Tamsin Mather joins us today. She's a volcanologist and an atmospheric chemist and professor of earth sciences at the University of Oxford. And she's author of Adventures in Volcano Land, What Volcanoes Tell Us About the World and Ourselves. Professor Mather, welcome to On Point. Hello, Magda. Great to be here. So I imagine you have witnessed in person many an erupting volcano. Could you pinpoint that?

Your favourite eruption that you've personally witnessed so far? Oh, that's a tricky question to start with. It's a bit like choosing your favourite child or something like that. But I think one that really sticks in my mind was back in 2006. And I guess it was sort of a funny time. I'd just moved to Oxford, which is where I've lived ever since. And I started the day pretty early in the morning. It was a July morning in green, leafy Oxford, walking to the bus station.

And by that very same evening, I was up on the flanks of Mount Etna in Sicily, in Italy, witnessing some pretty serious fire fountaining going on above my head and a lava flow flowing past me.

I think it was an amazing experience to witness a volcanic eruption, but it was also that sort of strange journey I'd been on that day as well. Wow. Wait, so now we need to know more details. What happened in the intervening hours from waiting, walking to the bus stop to standing on the slopes of Mount Etna? A bunch of flights and then a jeep ride up the side of the volcano pretty much straight from Catania Airport.

So it was a day of travel hassle, but it ended with something completely spectacular. Had Aetna just started erupting that day?

So Etna's really active. So I think it had been erupting for a few days that time. But, you know, it's a pretty busy volcano. We were just there actually on a family holiday in Sicily, busman's holiday, back in April. And there were fire fountains and flares going off just then. We could see from the town square down in Taormina. So it's a pretty busy old volcano. Yeah.

So this wasn't anything particularly unusual for Aetna. It was, and I've seen other eruptions up there too. I think it just sticks in my mind because it was the end of, the beginning of the day started so very differently to the end.

And it's such an intense experience. Oh, yes. Okay. That's what I was going to ask you about. Because in pictures that we've seen of volcanologists on the flanks, as you say, of an erupting lava-spewing volcano, you see the scientist in that sort of tinfoil-y looking heat suit, I guess, to keep you safe. I mean, what is it like? What does your body feel like when you're...

on the volcano as it's erupting? Well, it kind of hits you through every sense you've got, I'd say. You're feeling the throbbing of the eruptions, the explosions through the ground. So you're feeling it up through your body, but you're also hearing it with your ears as they detonate. You'll be smelling it. So there'll be the smell of volcanic gases. So there's hydrogen sulfide you might smell in volcanic areas sometimes. That's your classic rotten egg smell.

But sulfur dioxide also has a very distinctive smell. It's a bit more like burnt matches or something like that. And then if you get close to the lava flow, the heat is really, really intense. So this particular occasion, I wasn't trying to sample the lava flow. So I was not I wasn't wearing the silver suit in order to try and sample. So I could really get a sense of that heat there.

And it's incredible. It's a bit like, you know, if you lean into a domestic fire, a barbecue or a bonfire, you know, you can feel that where it gets really uncomfortable, uncomfortably hot. And doing that with a lava flow feels really dangerous because you're pushing into something that's even hotter than a domestic fire. You know, these lava flows come out at about a thousand degrees Celsius, right?

So and then the sound in your ears, it's really incredible. And then the pulsating red, orange and black flying around as the different volcanic bombs are thrown out. It's an incredibly intense feeling.

It sounds very dangerous. Well, we were keeping a pretty safe distance. This is actually quite a small volcanic eruption and one that they understand pretty well. So it was of course not without danger, but we'd taken very careful stock of that. And as I say, we weren't there actually trying to sample the lava flow on that occasion, which is when people get very close and do need to wear the silver suits. Okay.

Sorry, I'm just thinking how this may, I don't know, this is fascinating to me. How do you stay safe in those situations, though? Because even though lava from Etna, I think, generally sort of flows, it can still, like you said, send out lava bombs, which may fly in completely unpredictable directions.

Yeah, so we were just keeping a good distance from where the actual explosions were happening. So the lava flow itself is much more predictable. It built itself up a nice channel and it was a bit like a river flowing beside us. So you knew pretty much where it was going to stay. Of course, you can have breakouts on Etna a few years back, particularly when there's a snow cap. This was summertime, but in the wintertime there was a...

a breakout of lava over the fresh snowpack or over the ice, and it flash vaporized the water, the ice. And that caused a little explosion on the edge of the lava flow where some journalists were, so they got some kind of footage of them running away with a bit of spatter coming after them, so that was a little bit dangerous there. Wow. Okay, I mean, the flash...

phase change of the ice. As you said, it's 1,000 degrees Celsius as it comes out of the volcano, which is like almost 1,900 degrees Fahrenheit. So that makes a lot of sense. These are lava volcanoes, though, which are not the only type of eruptions that I'm sure you've witnessed.

No, no. So the the as I say, these are kind of the low explosivity end, believe it or not, given my description, I just just went through, which I guess did have a bit of explosiveness about it. But actually, these are quite runny magmas or lavas. So we call these a sort of basaltic magma. So they're the kind of runniness of a kind of wallpaper paste, I guess, is is an analogy there.

They're quite runny, actually. They will flow and they will let the gases that are trapped inside them out relatively easy with a bit of spattering and fire fountaining.

But if you get to the stickier types of magma, so these are much, much like hundreds of thousands of times stickier than the wallpaper paste, the gas can't get out. And so it comes up to the surface of the planet and you've basically got overpressure bubbles that are just dying to escape and to expand to the volume they want to be. And they'll shatter the magma in order to do that.

So I've never got too close to something that is that explosive. I'm very pleased to say because I may well not be here to tell the tale. But a good example was working in Guatemala.

about a decade ago. And we were working on a volcano called Santiago Volcano. So Santiago Volcano is the new activity of a really explosive volcano called Santa Maria. So in 1902, a massive explosion of Santa Maria. I think ash got as far as San Francisco from Guatemala. So that gives you a bit of a sense of scale there.

But Santiago is not as explosive as this, but it does have some quite sizable explosions about once an hour or so. So they're fairly regular, but a much different type of explosion to the Etna explosions. And they tend to send like pyroclastic flows, so flows of hot gas and ash down the sides of the volcanic cone as well.

So we were going to sample some rocks there and we sort of clambered down to the jungle. And we'd taken lots of precautions. We were with local guides. We'd talked to local scientists. So we knew where it was safe to go and where it wasn't. But even so, having these booming explosions above our heads and then actually when we were on the lava flow, seeing the pyroclastic flows come down the sides and go down into this kind of deep gully.

which they never came out of. It was really eerie and very frightening. At the first moment of the eruption of a volcano that is producing that pyroclastic flow, as you talked about, how fast can those flows get? They're very fast. They're faster than you can drive in a vehicle. You can't really outrun them. If you...

Well, I strongly advise you not to be in the zone where you're likely to encounter a pyroclastic flow. But if anybody was unfortunate enough to have that terrible thing happen, really your only hope is to get up onto high ground and to get above them. They will stay in the lower... They'll stay in valleys. They'll get channeled a bit like a hot river. Yeah.

I'm only asking because I was five years old when Mount St. Helens erupted in 1980. And I lived, I mean, far enough away, right? We weren't within the blast zone by any means. But from our little apartment building, you could see Mount St. Helens as a significant lump on the horizon. And

And when it exploded, of course, we could see the ash column. And even though we were very far away for days, there was ashes falling on our rooftops. And I just have such a clear memory of that. I used to collect the ash in little baby food jars.

Because I thought it was the coolest thing ever. But I also remember from that explosion that the speed of how the flows basically just leveled the entire forest around Mount St. Helens was one of the things that volcanologists at that time hadn't really, in the United States, hadn't had a chance to witness before. So there was a lot of science that came out of that.

explosion, which is why it just reminded me of like, how fast do they flow? Fast is your answer. Exactly. I mean, what's a thing to experience as a young kid? I'm kind of almost jealous in some ways. For me, it was so when in 2010, when the Icelandic volcano, I thought Jokup went off and we closed all the airspace over northern Europe.

That was really cool for me, apart from all the inconvenience for everybody. But I was actually able to get volcanic ash off my window in my bedroom back in Oxford. So that was a real first for me. I never thought that would happen. The really interesting thing about Mount St. Helens, actually, you said it kind of took volcanologists by surprise. So it wasn't so much the pyroclastic flows, which volcanologists had seen before. Actually, you know, some really important work from as far back as 1902 and even further back on

on pyroclastic flows. But it was actually what we call a lateral blast. Yes. So the whole side of the mountain sort of swelled up like a blister. And then rather the initial blast wasn't even straight up. There was a sort of small earthquake in the side of the mountain fell

fell off or slumped down. The blast went off sideways and as you say, just flattened the forest covering the flank on that side. The pictures just look like matchsticks that have been blown over. It's really crazy. Yeah, to be fair to the scientists at that time, of course, as you know, the explosion did not catch them off guard because there was so much seismic activity around Mount St. Helens. But

But that's actually going to lead us to the next segment where I want to talk more with you about what happens during an explosion and how you got into this work. So we'll do that in just a minute. This is On Point. Support for On Point comes from Indeed. You just realized that your business needed to hire someone yesterday. How can you find amazing candidates fast? Easy. Just use Indeed. There's no need to wait. You can speed up your hiring with Indeed.

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You're back with On Point. I'm Meghna Chakrabarty, and today we are having a wonderful conversation with Tamsin Maither. She's a professor of earth sciences at the University of Oxford, an expert in volcanoes, and she's author of Adventures in Volcano Land, What Volcanoes Tell Us About the World and Ourselves. And Professor Maither, I promise we will get to discussing the importance of volcanoes, not just only in the geology and chemistry of the earth, but also in

You know, the perpetuation of life itself on this planet. We'll get deep into the science. But these stories are so wonderful. I'm hoping I can share one with you because I know you'll connect with it. It's about Vesuvius. And in 1998, I was studying in Italy and we were down in southern Italy and I had just visited Pompeii and Herculaneum.

the most remarkable archaeological sites I believe I've ever seen in my entire life. And then we got on a bus. And this rickety old bus drove us up the flanks of Vesuvius to the top of it, which I'm still amazed that that was possible. Dropped us off.

The bus driver was like, ciao, and he drives away. And there was hardly anybody up there. And we got the chance to walk around the rim of Vesuvius. And at that time, in 1998, there was just one little chain that was, you know, between poles that was separating us from the gullet of the volcano that had wiped out this part of the Roman Empire.

It was one of the most remarkable experiences of my entire life. And you also had an early experience with Vesuvius. Yeah, absolutely. Vesuvius was my first volcano I ever visited. So this was just on a family holiday when I was...

You know, 10 years old and really similar actually to you. We went to Herculaneum and Pompeii. And as you say, the archaeology there just is completely incredible. The preservation, you can really, you can see, you can see these, this town, the city,

And of course the bodies as well. So the skeletons that are left in the sea caves around Herculaneum and then in Pompeii where they've used plaster of Paris to recreate the voids left by the human corpses that were caught in the eruption and then subsequently rotted away and left these gaps in the ash.

And those plaster of Paris casts around the site of Pompeii and in the museum, you know, they really profoundly affected me. I mean, the way that the

The individuals, they're holding their hands, their faces, they're in fetal positions, they're trying everything they can to protect themselves. And of course, they can't really do anything against the power of this volcano. And then we went up, I think we drove up most of the way, hiked the last little bit. And as you say, it was really completely deserted then.

And I did the same thing. This was, well, we were supposed to go in 2020 and then it got postponed a couple of times because of the pandemic. But we eventually went there with my two children back in, yeah, back about two years ago.

And it was incredible, a completely different experience. You had to book in your parking slot, you had to book in your entry slot to get into the... We trooped up in a big column of people. It was still amazing. And I have a photo of my two kids in almost exactly the same place that me and my sister stood.

all those years previously. I suppose it's better this way, actually, to have it be a little more organized. Because at that time, when I went up there, I was like, how is this actually possible? How am I literally walking on the rim and I can peer over the side and look down the throat of this volcano? It was...

It was actually a little disconcerting, but in a way that made me feel sort of appropriately small when it comes to the scale of planet Earth. Yeah, for sure. I mean, Vesuvius has been very quiet since the 1940s now, but right up to the 1940s, there was a whole period of...

where it was really, really active. So it's been a really important volcano in the history of volcanology as well. So actually, the first volcano observatory in the world was on Vesuvius. That was founded in 1841.

So Vesuvius is really an important volcano, not just because of the famous AD 79 eruption, which is made famous by Pompeii and Herculaneum as archaeological sites, but also the amazing writing of Pliny the Younger describing the eruption and the death of his uncle, Pliny the Elder.

But, you know, it's also been a really, really important volcano scientifically because of the period of European history that it was very active for. Yeah. So actually Vesuvius also brings us to the long relationship between humanity and volcanoes because, of course, Naples is still right there, right? I mean, you can see Vesuvius from this huge modern Italian city and...

Should Vesuvius ever become like very active again, there's a large populace right next to it, which is not unique. There are many volcanoes upon which, you know, humanity is farming all the way up its slopes because volcanoes make for, you know, great farmland. Right. Can you talk about this long term sort of relationship between people and the actual sites of volcanoes?

Oh, it's a very rich topic. There's so much to say really on that. But yeah, I mean, the Bay of Naples is a fantastic example. And actually maybe something that you might not be aware of is actually Vesuvius is not the only volcanic system in the Bay of Naples. There's actually a much larger volcanic system called the Campi Flegrei or the Flegrei and Fields in English.

which is just over to the west of Vesuvius and actually has the potential to create much, much larger eruptions. So there's a whole suburb of Naples called Pozzuoli, which is in this sort of depression, which is actually a caldera or a volcanic, you know, a big volcanic crater there.

And Campy Phlegrae is very active. You can see it's got like fumaroles. One of my colleagues, a friend of his, he says he's got a fumarole in his basement. So you just go down to the basement and there's the volcanic gas leaking out of the ground. There's a crater there called Solfatara.

The last eruption there was in medieval times, but there's lots of seismicity going on there and the land sort of swells up and then subsides again and then swells up and subsides again. So the sea level, there's evidence of changing sea level in that area. And the next eruption that happens there could spring up in someone's backyard or someone's basement maybe even, and we just don't know. It escalates and then de-escalates.

so it's it's definitely something that the Italian volcanologists are keeping a really really close eye on and much more active than Vesuvius right now um

But, you know, volcanoes, people often ask me, why do people live on volcanoes or active volcanoes? And of course, there's lots of answers to that question and depends on the place a bit. And sometimes it is just that we've got a big human population on the planet and we haven't got infinite places for people to live.

So people have to live somewhere and maybe the land on the side of the active volcano is a bit cheaper or less in demand. So people end up there. But there can be really positive reasons.

for people living there too. So, you know, volcanoes are big mountains sometimes and so that can affect the rainfall so you can get better rainfall for farming and subsistence around the volcanoes as well. Volcanic ash tends to bring new nutrients to soil. So, you know, a sprinkler of volcanic ash every so often could do your farmland no harm at all. In fact, can help it out.

And also they can be big tourist attractions. So, you know, they've got all that industry as well. And often volcanoes are not active all the time. They're very active and then they're quiet for maybe a generation or two. So people kind of forget what their true nature is and just enjoy all the benefits. Yeah.

Well, we've been focusing on Vesuvius because it's so iconic. But, of course, volcanoes are all over the world. And I think some of the more interesting ones, in my view, are actually in the Americas. I'm thinking, of course, of Central South America. We mentioned Mount St. Helens. I mean, the entire Cascades Mountain Range.

And then, of course, there's Hawaii. We'll not forget our Hawaiian listeners. But I want to share with you this very interesting call that we got from one of our listeners in St. Paul, Minnesota. Her name is Dana Nelson. And back in 1995, she lived in Nicaragua.

And in December of that year, the Cerro Negro volcano erupted. And Dana wrote an email to her family as the eruption was happening. And she read a part of that email for us. Yesterday, the fine sand that's been falling on Leon turned...

into fine mud. It's misting mud. Real pretty to bike in. Last night and today it's been almost constant, very light sprinkling of ash. It's in my ears. What? It's in my eyes. It's crunching between my teeth. It's in my hair. It's in my nostrils, in my clothes. It's stuck to my skin. It's piling up a good inch on the ground.

Where I just came from, lunch, we all sat around the table with bandanas wrapped around our heads or baseball caps or plastic bags. It's many people's belief that if the ash piles on your scalp for too long, your hair will fall out. Yikes.

People hold up hankies against their mouths to breathe through. Every time I spit, my saliva and my snot is speckled with black ash. My friend Jorge told me that it's not good if it gets in your lungs because it can be like little pieces of glass.

Before it got so bad like this, I wrote, we were hiking as close as we could get to the volcano because it was so beautiful. It's glowing red and orange erupting lava was so beautiful. And now the city is not so hot out because there's no sun. The sky is thick, dark gray.

And looking at the sky in the direction of the volcano, it's even darker. This morning I rolled out of bed and cleaned the ash out from around my eyeballs. The crops in the surrounding area are ruined. Everywhere you look, women are constantly sweeping or beating the sides of their homes with the towel as the ash continues to fall. Nicaragua, the land of lakes and volcanoes.

That's Dana Nelson, an On Point listener in Minnesota, reading to us an email she wrote in 1995 when she was living in Nicaragua.

Professor Mather, I mean, there's so much to talk about in Dana's email there. Beautiful description. But I wanted to just simply focus on the atmospheric effects, right? Because that is actually your area of specialization is the gases that are emitted into the atmosphere from volcanoes. Can you just describe to us sort of what's in those gases and the role that they play in that?

in the Earth. Well, we could talk about primitive climate, but let's first of all talk about modern-day climate regulation and volcanoes.

Sure. So it's a it's a heady cocktail that comes out of volcanoes, I'll tell you, of gases. But I guess it's not it's not a huge surprise that water or steam is a really dominant gas. You know, we're such a water dominated planet, our blue marble. So water is one of the major gases coming out.

Now, in terms of atmospheric impacts, that doesn't have much impact at all. It really is important when we're thinking about different eruption styles because it's so dominant. But we've got loads of water in our atmosphere anyway and quite variable amounts. I don't know what the weather's been like for your listeners today, but here in Oxford, it's been pretty damp, I can tell you. So we've been pretty aware that we've got plenty of water in our atmosphere. The second most dominant gas tends to be carbon dioxide.

So you probably, we've learned quite a lot about the negatives of too much carbon dioxide in our atmosphere over the last few decades, for sure. Of course, we do need enough carbon dioxide in our atmosphere too. So if our atmosphere didn't have any carbon dioxide at all, we'd be too cold for complex life for us, like us to evolve. So it's kind of, we need exactly the right amount of carbon dioxide and levels of,

edging up beyond what humankind is really used to right at the moment.

And actually, all the world's volcanoes are putting out carbon dioxide. Just as a spoiler alert, because I do get asked this quite a lot, it's about 70 times less than anthropogenic emissions. So it doesn't get us off the hook in terms of saying, oh, the volcanoes are kind of outdoing us. I'm afraid we're very much outdoing the volcanoes. I'm sorry to interrupt there, but...

Please do correct me if I'm wrong, but I thought that volcanoes played a role in the Earth's infancy many billions of years ago in helping create the atmosphere of the Earth. Is that wrong?

Yeah, no, absolutely. So, you know, there's the first atmospheres of an early proto-planet or proto-Earth, little young Earth. It's quite complicated because we probably had an atmosphere that then got blasted off by bombardment and things like that. And then you get a sort of secondary atmosphere that comes. But the outgassing of the planets, that's what, you know, volcanic gases are the insides of the planet venting. That's a really crucial part in that.

And in fact, back in deep history of our Earth, our Earth is four and a half billion years old. So back in its really deep history, it might have been large swathes of it might have been like a massive magma lake or perhaps the whole planet was, the surface of the planet was molten sometimes in our planet's past. And all of that would be bubbling magma, bubbling lava with gases coming out and then forming our planet's atmosphere.

So, yeah, absolutely in the past. And actually, since then, the outgassing of volcanoes, which has changed quite a lot over the 4.5 billion years, as you might expect, but that outgassing has played a really critical role in terms of the balance of the planet.

So for carbon dioxide, carbon dioxide comes out of volcanoes and then it's taken out of the atmosphere by natural processes as well. So a small amount dissolves in the rainfall and then that rainfall reacts with some of the rocks on our planet's surface and binds the carbon dioxide out of the atmosphere.

We've got this balancing act between this drawdown, which happens faster if the planet warms up and slower if it cools down, and the outgassing of volcanoes, which actually sort of has kept our carbon dioxide regulated a bit and kept our planet's climate within certain bounds. So, you know, within bounds of just not too hot, not too cold, which has allowed complex life such as ourselves to evolve.

So, you know, volcanoes really have been crucial in our very existence, I would argue. Yeah. And so that's a really important point because we tend to think of volcanoes as these destructive forces, right? Because we're viewing everything from a purely human perspective. But when we think about their planet, the role they play in sort of the planetary balance that Earth has gone through over the four and a half billion years, they're also a creative force then, you'd say. Right.

Absolutely. And I think you sort of see that in terms of when people, if you talk to people who live in places like Hawaii, or I was just in the last year, I've been over to Montserrat in the Caribbean. And, you know, Hawaii is a good example because the volcano obviously can be very destructive. It destroys people's homes and lives and livelihoods.

That's very, very tragic. But it's also built great new swathes of the island. So, you know, Big Island has enlarged its area where the lava flows pour into the sea. So Pele, the goddess of the volcano in Hawaii, is a creator as well as a destroyer. So I think that's one of some of the really fascinating, one of the things that I think draws me back and back to volcanoes is all these different aspects of their personalities.

They are incredibly destructive, but they also create, and I would also argue that the human beings would not have managed to evolve to be the species we are without volcanoes having played an active role in our planet's history. Well, Professor Mather, hang on for just a second because I want to talk with you more about sort of humanity and volcanoes today in just a minute. This is On Point. On Point.

You're back with On Point. I'm Meghna Chakrabarty, and Professor Tamsin Maither joins us today. She's a volcanologist.

and a professor of earth sciences at the University of Oxford and author of Adventures in Volcano Land, What Volcanoes Tell Us About the World and Ourselves. And Professor Mather, if you allow me, Dana from Minnesota who had witnessed the 1995 eruption of Cerro Negro in Nicaragua, she read to us the first part of the email that she had sent to her family in 1995 saying,

She also has a follow-up email that she sent a few weeks after the volcano had begun erupting, and she read that to us as well.

I was having difficulty photocopying my teaching materials because most photocopy machines in Leon are out of order. They were full of black ash and sand that fell out of the sky onto Leon for days and days. It's been 23 days since then and I still feel ash on these computer keys as I type. I can't get over how it got

into everything, whether stuff was in boxes or in buildings even, it didn't matter. It was, it still got in there. It was a mess. A lot of people who live in their colonial part of town are busy this week replacing their beautiful Spanish red tiles or tejas for zinc roofs

because this is the second time in three years that the Cerro Negro volcano erupted and they've had to clean off the roof and clean each tile one by one, clean off the deposits of that naughty volcano. In case it wasn't in the news in your community, the Cerro Negro volcano, one of a dozen active volcanoes in Nicaragua erupted for about 10 days. It was a very big deal. A couple thousand people were evacuated from their homes and villages right at the base of the volcano.

where lava was spewing out and the air was smoke-filled. And I'm writing this in the height of it all. That's On Point listener Dana Nelson, currently in Minnesota, reading to us an email that she wrote in 1995 as she witnessed the Cerro Negro volcano erupt in Nicaragua. Professor Mather, you write something very compelling in the book about what volcanoes can tell us about the planet's future.

because they are, in fact, time machines themselves, right? The gases that come out of a volcano are coming from deep within the Earth, and by studying them, they can kind of take us back in time. So what have you in your research and your colleagues discovered about changes in climate from studying volcanoes that could tell us potentially what our future holds? Well, yeah.

Lots of interesting things to talk about there. I'm just thinking of where to start. I guess this is, it's been quite interesting for me because I started off my career sitting in the plumes from active volcanoes making measurements.

So actually the first volcano I worked on for my doctorate, my PhD, was in Nicaragua. It was not Sierra Negro, it was Masaya volcano, which is just along the chain of volcanoes, it's the other side of Managua from Sierra Negro. So the volcanoes in Nicaragua are very close to my heart and it was wonderful to hear those accounts there. It was actually really fascinating.

So I started off measuring the gases coming out and I was talking a bit earlier about the water, the carbon dioxide being important and then the sulfur gases as well. So sulfur dioxide and hydrogen sulfide. But actually more recently in my work, I've been thinking about volcanoes in much deeper time.

And it turns out that lessons that we learn from sitting in volcanoes and making measurements in the present day can be really relevant as well, which was a bit of a surprise. So one of the things I was doing when I was in the Caragua was measuring the very, very unusual metal element called mercury.

So some of your listeners of my sort of vintage might remember that we used to have mercury in thermometers at school. And if you broke them in labs, you know, these little silver balls would sort of, you know, skid along the bench top or along the floor. And great excitement. The teacher would get, you know, clear up, get out and play.

Yeah, it was always a highlight of the lesson for me, if I'm honest. Interacting with a poison, yes. Yeah, exactly. I'm afraid that there we go. We won't unpack my psychology today. But yeah, certainly in the UK, this has been phased out. I think globally now there's various treaties because mercury is a very poisonous element.

So we now, you know, kids don't get to use thermometers like that anymore, which is a good thing because it can cause horrible, horrible damage. But we were measuring volcanoes actually emit a lot of mercury gas and we were making measurements of how much was coming out in places like Messiah Volcano in Nicaragua. Volcanoes, we have not witnessed the full playbook of what volcanoes are capable of during our brief existence as a species on the planet, right?

So, you know, human beings have only been on the surface of the earth for a real fraction. So sometimes I kind of say, if you stretch your arm out and...

And 4.5 billion years ago is your shoulder joint. And the tip of your fingers is right now. That's your geological timescale. And just try to imagine what fraction of that human beings have been on the planet. And sometimes people guess maybe the tip of your fingers are your first knuckles and things like that. And actually, it's just take a nail file and pull it across your nails. And that's how much time, that's the fraction of time we've been on the planet.

And actually, back in our planet's past, there have been some even larger types of volcanic eruptions than those we've seen.

So some really important ones are things called large igneous provinces. And these are dotted all around the globe. They are enormous outpourings of lava flows, stack upon stack of lava flow. And a great example, which is in fact the youngest example, is the Columbia River flood basalts, which is around the Columbia River, not far from where you were describing earlier, in fact, gazing on Mount St. Helens. So up in the...

up in the northwest United States. Now these are very different types of eruptions, something like Mount St. Helens. These are really prolonged events. They last for roughly a million years of our planet's history and they kind of double the rate of volcanism on our planet during those million years. So as well as pumping out all that lava, they're also pumping out loads of gas onto the surface of the planet and changing the chemistry of the atmosphere a bit.

One of the fascinating things about these large igneous provinces is when you look at the geological record, they tend to coincide in time with really, really big global change. So a great example of this are mass extinction events. So people have probably heard about the Ancretaceous, the dinosaur killing event,

The impact, the big chunk of rock that fell into the Gulf of Mexico as well and wiped out dinosaurs.

Well, actually, there was an enormous volcanic event going on at the same time, the Deccan Traps, which you can now see the evidence of over the subcontinent of India. And then if you go back to the end Triassic or even the biggest mass extinction event of all, which is the end Permian mass extinction event 250 million years ago, these again coincide with these really, really enormous volcanic events. So the end Permian coincides with the Siberian Traps.

And using the lessons from present-day volcanoes, we've been both scaling up to think about what sort of impacts on the environment these large igneous provinces will have, and also using elements like that crazy mercury, which the volcanoes put out to look for the fingerprint of these past volcanic eruptions in the sediment record. The powerful thing about doing that is that can help us to understand

understand cause and effect. So we can see if there was a big pulse of gas coming out of the large igneous province, the volcanoes, and then the biology, the biological response, the mass extinction event follows that. And so we can try and tease out cause and effect. Well, can you help clarify something for me? Because you talk about in the book that we should hear alarm bells, as you write, ringing down to us through geological time. But alarm for what?

So what I was going to come on to say is these large igneous provinces are putting out loads and loads of carbon dioxide.

We've done estimates of how much carbon dioxide they're putting out. And even at their peak, they are not putting carbon dioxide out at as fast a rate as humankind is putting carbon dioxide out into our planet's atmosphere right now. And we see the consequences of these large scale events. And we should just really pause and dwell on the fact that nature has done this experiment in the past and it did not end well.

I think for me, one of the things I wrote in the book about the wildfires in Australia and when the wildfires were ravaging Australia, I was actually working on a paper looking at fragments of charcoal in the geological record associated with the period of volcanism in the Siberian traps, which was because the temperatures were warming certain areas of the planet were drying out.

And so, you know, when I got parts of Los Angeles on fire right now, again, it was in the news this morning. So, you know, with this increase in wildfire activity going on across the planet, for me, that's very, very sobering because these are the things we see in the geological record associated with these really catastrophic periods in our planet's history. Okay, so indeed a warning bell from deep in time coming from these volcanoes.

You know, stepping back, though, I feel very much as you talk about how you feel about volcanoes in the book that they are this beautiful part of the complex system that is planet Earth, right? Forces of destruction, forces of creation, glimpses into the past and future. I mean, like it just...

It fills me with this sense of awe about this little tiny blue dot that we live on. But I do want to take us back to how we interact. I don't want to over-romanticize them also because, you know, we talked about Vesuvius and

Just last summer, I was in Seattle. Well, I actually went up to Mount Rainier, which is very, very close to Seattle. And there were a lot of displays there about, you know, here we have this major U.S. metropolitan area that's in the shadow of a volcano and...

What would happen? Like, what would need to happen to protect people if Rainier decided to wake up and be extremely active? And it's not just unique to Seattle. This happens in a lot of different places. I mean, do you think that volcanology, as actually advanced as it is now, and that we can...

given the seismic indicators that volcanoes may give us, that people who are living in the shadow of these very powerful mountains are relatively safe in the event of an eruption? Well, yeah, the people of Seattle, you're extremely fortunate. You have the USGS, which is a very well-organized and well-resourced agency that is monitoring your country's volcanoes. So, yeah,

So, you know, I think I think I would have a lot of faith in the USGS to to give people as much warning as possible. And every volcano is a little bit different is the challenge. But they know their volcanoes very well. And you look back at, you know, Mount St Helens and there was some loss of life. But it was that there was also a good understanding. People knew it was going to happen.

We have got better and better at understanding volcanoes. We have some really powerful tools, new tools, actually relatively new tools in our toolkit as well. And I would say that, you know, satellite remote sensing is an incredible advance for volcanology.

One of the reasons this is a real advance is that we can actually take a global perspective on volcanoes. So as I was saying, when I go and work on a volcano, the first people I want to hear from are the local scientists because they know their volcanoes better than anybody. And that is absolutely great and so important. But also we'd like to take a bit more of a kind of almost like an epidemiological view to volcanoes in terms of looking to help us make better probabilistic forecasting.

And with satellites, we're able to look at, for example, their deformation signals worldwide. And we can look at which volcanoes are deforming around the planet and then the outcomes for those different volcanoes, even if they're very remote and not particularly affecting local populations. And the idea then is that we can get a much better of like, you know, what's the most powerful piece of evidence that gives you the best prediction of an outcome?

The only caveat I put, as I say, we get better and better. And I think there's some really interesting things happening with the activity in Iceland right now, because they've got this pulse of activity coming through quite close to Reykjavik in the capital. But the only caveat I sort of put on it is something I always say is that we have to remember the volcanoes kind of operate on a different time scale. Yes, indeed. So when we know a volcano is waking up, we could say it's very likely it's going to erupt in the next six months.

Or we could say, you know, it's woken up and it's very likely now it's going to erupt in the next five years. It's not very useful for the local population.

They want to know it's going to erupt next Tuesday and they've got, you know, they've got five days to gather their belongings and get out of there. And the problem is, is that you can get when you get that very, very final run up to the eruption, that can be really quite a short timescale. Yeah. So you can know that something's going to happen. You can know that something's likely to happen in the next month or so.

But the final kind of push might only be, I mean, in some volcanoes, it's the shortest of half an hour. You get the final seismicity that gives you that final indication it's happening right now. I mean, the audacity of Mother Earth. And that's a real challenge for those people managing populations because people want to stay at home for good reasons. You know, they have lives.

So that is always a caveat, is that the timescales, our human timescale and the geological timescale are always in sync. Understood. But like I was saying, the audacity of Mother Earth for not telling us exactly when she's going to...

Have a volcano erupt. I mean, how dare the planet? You know, you're talking about satellite imagery. I'm looking right now at the satellite imagery from the January 2022 eruption of that undersea volcano off Tonga. Yes. Oh, my gosh. It's so amazing. Yeah.

I mean, it sent a shockwave around the Earth twice, a tsunami around the entire world, and also put like a vast amount of water vapor into the atmosphere. It's amazing. We only have one minute left. Professor Meather, I'm so sorry. But I do want to know just briefly, I mean, you write about like, what do volcanoes tell us about ourselves? And what's your quick answer to that?

Oh, good. I mean, I think it's a bit what I was saying earlier, that they tell us about our... I think...

They take you into yourself. They're an incredibly awe-inspiring phenomenon of nature and they make you feel incredibly small. But I think looking into a volcano as well, we should also remind ourselves of our power as a species and our power now actually as a geological force in terms of how much we're changing our world. So I think we should sort of feel small in awe, but also a sort of reflection of ourselves and the power of volcanoes.

Well, the new book is Volcano Land. What volcanoes tell us about the world and ourselves. It's by Professor Tamsin Maither. Professor Maither, it's been such a great pleasure to speak with you. Thank you so much. Thank you. I'm Meghna Chakrabarty. This is On Point.