University of Bristol professor and Volcanologist Jenni Barclay joins WIRED to answer the internet's lava-hot questions about volcanoes. How do volcanoes cause lightning? What would happen if you fell into a volcano? What do volcanologists study day-to-day? Are there any super volcanoes in the world overdue for an eruption? Why does Iceland have so many active volcanoes? These questions and many more are answered on Volcano Support.Learn more about Professor Jenni Barclay https://www.bristol.ac.uk/people/person/Jenni-Barclay-251603f7-bef1-4ebe-9adf-6b4906f3fc55/Director: Anna O'DonohueDirector of Photography: James FoxEditor: Philip AndersonExpert: Jenni BarclayProducer: Efrat KashaiLine Producer: Joseph BuscemiAssociate Producer: Paul GulyasProduction Manager: Peter BrunetteProduction Coordinator: Rhyan LarkCasting Producer: Nicholas SawyerCamera Operator: Neill FrancisSound Mixer: Mark CheffinsProduction Assistant: Jack HaynesPost Production Supervisor: Christian OlguinPost Production Coordinator: Ian BryantSupervising Editor: Doug LarsenAdditional Editor: Ron Douglas; Jason MaliziaAssistant Editor: Andy Morell
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00:00I'm volcanologist Jenny Barkley. This is Volcano Support.
00:09At Serene B. Russell, not gonna lie, the most jarring part about being in Italy
00:14was casually being told what looked like a normal mountain super close to where we had been staying
00:20was Mount Vesuvius and that it was still active. Excuse me? She's absolutely right.
00:27It is still an active volcano and in fact the last time Mount Vesuvius erupted was in 1944.
00:33And like many volcanoes, we tend to hear about them in the news. When there's lots of activity
00:39going on they have a huge impact. But at any one time around the world we manage to live quite
00:44happily with about 40 to 50 volcanoes erupting anywhere on the earth. It is true that for Naples
00:51Mount Vesuvius having another eruption would be a big deal. Sometimes it has a really large
00:56eruption like it did famously burying Pompeii in Herculaneum. Sometimes it has an eruption like it
01:01did in 1944 where it generated a relatively more quiet lava flow and a few smaller explosions.
01:09And Mount Vesuvius is capable of generating both of those types of eruptions. Okay this question
01:15is from jzaciana. God just be making pointless a**. Why the f*** do volcanoes exist? Volcanoes
01:24do seem a bit destructive but actually over geological time volcanoes first formed and what
01:30they did is they transported a lot of really useful things like water and oxygen from the
01:35interior of the earth to the outside of the earth. So to be honest without volcanoes on the earth
01:41we wouldn't be here either. At El Caprich says there's a volcano in Indonesia that spews blue
01:48lava. I mean what sorcery is this? Blue's not really a color that you'd associate with volcanoes.
01:55It's red but the blue is a really special condition for that particular volcano. It's
02:01really full of sulfur and when that sulfur erupts as the lava's coming out it's not the lava itself
02:09that's blue but it's the gas that's associated with it and it creates this ethereal blue flame
02:15that really does look pretty spooky over the top of it. So the next question is from at one air
02:21brough 18. Why are Iceland volcanoes so active? So Iceland is an island sticking out in the Atlantic
02:30Ocean and Iceland is there just like Hawaii because of the huge amounts of volcanic activity over time
02:37and that volcanic activity has meant that that has built up from really deep in the seafloor
02:42and now sticks above the ground and unlike Hawaii Iceland is also located on a rift so where the
02:49plates are moving apart like that. So what that means is there's two different mechanisms that
02:55help to generate that magma and every now and then that magma has to make its way to the surface
03:01and that's why their volcanoes are so active. So this question is from at more of a gene law
03:07What do volcanologists even really do except sit around talking about how badass volcanoes are?
03:13What else is there to be studied? Their volcanoes. Slightly rude. What I spend a lot of my time doing
03:20is I like to look at rocks. They're the secret recorders of some of the things that have happened
03:25to the magma before it erupted and it unlocks lots of clues about how volcanoes are going to erupt.
03:31This is basically frozen magma and by examining this we can understand what sorts of things were
03:38in the magma that caused it to erupt. Volcanic rocks are also erupted with crystals in them.
03:43You can maybe just about see the crystals now in this magma here and believe it or not crystals
03:50grow with very specific composition that we can use to unravel the pressures, temperatures and
03:56the changes that happened that caused that magma to go from being nice gentle magma sitting around
04:02quietly underneath the earth's surface to something that erupts and causes destructive mayhem that we
04:09associate with volcanoes. One of the really big challenges we've got as volcanologists is the
04:14warnings for us are understanding when that magma underneath the surface is on the move.
04:19These are my modern measuring devices if you imagine. What we can do now is imagine in the
04:25subsurface we've got these areas where magma might come through. Now as the magma pushes up here
04:33you can see it's starting to push and go where it otherwise wouldn't have been.
04:38So it creates all sorts of tension in the rocks around there which create little waves that we
04:45can pick up with our splendid detecting devices and we can tell how those waves have been generated
04:51and what's going on with that. And the other thing that happens is as the magma starts to push up
04:56it actually makes our little volcano start to deform and it will change its position which
05:03would mean that also what we can measure from, well here's my funky satellite here, what we can
05:08measure by satellite is changes in the surface of the earth. The next question is from brabot747.
05:16My question is what's your favourite volcano? Mine would be Mount St Helens. My favourite volcanoes
05:22are all called Soufrière. I've done huge amounts of field research in the eastern Caribbean. The little
05:28islands there are a line of volcanoes. Many of them have the name Soufrière in their title. So I love
05:34Soufrière St Vincent on St Vincent and Soufrière Hills volcano which is on Montserrat. When these
05:40volcanoes erupt what they do is they produce spectacular explosions and sometimes they erupt
05:46slowly and gently. Not the red hot lava flows that you might expect but build up of dome material at
05:53the top of the volcano. However when those collapse back down they generate deadly pyroclastic density
06:00currents, mixtures of red hot ash and gas and they come flying down the hillsides at speeds that are
06:06much greater than certainly than you can run from and almost definitely that you could drive from
06:11and these are something that are lethal for anyone who's in their way. At Han I17 how are people
06:17standing so relaxed near four live volcanoes in Iceland? Volcano tourism? So unreal. Volcano tourism
06:26isn't a new thing but if you remember the idea of the Grand Tour of Europe and one of the things that
06:31many tourists would do 200 years ago is they would go and visit the amazing volcanoes of Italy
06:38including Stromboli and Etna which are frequently erupting and of course the amazing spectacle of
06:44Vesuvius and Pompeii near Naples and one of the things that they can do that's really frightening
06:50is they can erupt explosively and suddenly and this can and does catch people unaware. Make sure
06:57you follow really closely official advice about that volcano. At Katie Nicholson 1 is wondering
07:05where is the biggest volcano? Define big. So if by big you mean the tallest, one of the tallest
07:14volcanoes are actually Mauna Loa and Mauna Kea in Hawaii. The remarkable thing about them is they've
07:20got about four or five thousand meters worth of height below sea level. They've had to build all
07:26that way up from the sea floor and then they've got another four thousand meters on the top so
07:31once you count that level of building they're taller even than Mount Everest. Technically the
07:36tallest volcano in terms of height above sea level they tend to be in the high Andes which is of
07:42course a very high mountain range and they're over six and a half thousand meters and the big
07:47tallest volcano in the world in that sense is Nevado dos Ojos del Salado. Another way of measuring
07:54how big a volcano is is how big the eruptions that it produces. So of course there are the super
08:00volcanoes none of which have erupted in living memory but historically the largest volcanic
08:06eruption was Mount Tambora in Indonesia which erupted in 1815 and that created noises that
08:13were heard in Australia. At Taylor McPee says forgive me, he's forgiven, but what makes a volcano
08:21a super volcano? Is it when multiple volcano eruptions combine like a perforated ulcer? So
08:29strictly what makes a volcano a super volcano is when it has a super eruption and your imagery of
08:36a perforated ulcer is kind of a little bit right in terms of all sorts of magma coalescing and
08:42coming together to create a huge volume of material that would be erupted out all at once
08:49and a super eruption is when you have a thousand cubic kilometers of material erupted all at once
08:56from the interior of the earth outside and luckily that's something that really doesn't
09:01happen very often. At Aaron's Wonderland is wondering why do volcanoes have different shapes
09:08and what plate boundaries do you find at each? Someone help, Google ain't helping. Strata volcanoes
09:14tend to have much steeper slopes that kind of classic volcano shape that we think of
09:20whereas shield volcanoes tend to have much lower angle slopes. In different types of plate
09:25boundaries there is a tendency for particular types of magma to be generated so in the seduction
09:31zones where we've got one plate going underneath the other big explosive eruptions create lots of
09:36material and so they pile up quite quickly creating what we think of as the classic volcano shape and
09:43in areas where you've got more gentle flows you'll have more shield volcanoes. At Abby Smith wants to
09:50know what has been the longest continuous eruption? Stromboli for example an island off the
09:57coast of Italy has been erupting for thousands of years it has little explosions even the Romans
10:04used to refer to Stromboli as the lighthouse of the Mediterranean and it's had a few pauses that
10:10mean it's not the one that's thought of as continuous but this volcano that we know that's
10:15been going the most continuously is Santiago volcano in Guatemala which has been erupting
10:21continually since 1902. At A Wasted Hour is wondering what country has the most volcanoes
10:29active and extinct? The United States of America which has got many volcanoes in many different
10:36states along the west coast but in fact I would say the country with the most active volcanoes
10:42so where for example there are seven volcanoes erupting right now is Indonesia and that's
10:48definitely the country that's had the most volcanoes that have erupted since for example
10:531950. So at Blah wonders super volcano overdue for an eruption could wipe out the whole US?
11:00Bitch what? I think what you're worrying about is perhaps the super volcano that you find in the US
11:06Yellowstone. Its super volcanic eruptions are about 300,000 years apart and to be honest
11:14super volcanoes don't always have super volcanic eruptions and what Yellowstone most often does is
11:20it has much smaller eruptions. Super volcanic eruptions so ones with those huge volumes of
11:25material happen really really infrequently. We're talking many many thousands of human lifetimes
11:32apart. So at Jedi Master Roman trying to wrap my head around how volcanoes can cause tsunamis.
11:40It is wild. You're right. In the case of volcanoes when they erupt a huge amount of material that all
11:46comes back down into the sea at once that creates the displacement that can generate a tsunami but
11:51the other thing is that volcanoes build themselves up chaotically and from time to time they can
11:58completely collapse. So if a volcano collapses down into the sea then it can generate a tsunami
12:04as well. So most recently there was an eruption of Anak Krakatoa and it had a big eruption that
12:11generated a tsunami and that inundated many of the villages nearby. At Red Aaron is wondering what's
12:18the dark glassy volcanic rock called? It's called obsidian. It's absolutely fantastic. If anyone
12:25plays Minecraft you might have seen this. This is real obsidian and this is actually from the
12:29island of Lipari off the coast of Italy. What this is is this is volcanic rock that was magma where
12:36the melt has quenched so quickly it hasn't made any crystals but actually turned itself into glass
12:42and if you took a tiny little shard off this you would almost be able to see through it. It's also
12:48very very sharp. It was used by many cultures as a cutting implement. So for example Native
12:55Americans in South America, the Maori in New Zealand, pretty much anywhere where they could
13:01access this really special type of volcanic rock. So at Pro Bucks asks, weather dummy here, how do
13:08volcanoes cause lightning? So volcanoes cause lightning separate to the kind of lightning
13:13phenomena that we see in the atmosphere because when we have an explosive eruption huge amounts
13:19of ash is thrown out into the atmosphere and that's actually electrostatically charged and
13:24so the differences in charge cross the plume that's generated by that explosion create lightning.
13:31At Quiet Bat People is wondering why do volcanoes become inactive? And that's an easy answer.
13:37Volcanoes become inactive when it runs out of magma that can get up to the surface. We either
13:43think of volcanoes as potentially active. Active which means in the process of erupting or extinct.
13:50So dormant I think really means when you think it could erupt again but it might not and we tend to
13:56refer to those as potentially active volcanoes and round the world on land there are about 1400
14:03of these volcanoes. At Cassie has got a really interesting question. Questions from five-year-olds.
14:09What would happen if I fell into a volcano? So if you fell into the crater of an active volcano
14:16and say for example it had a hot lava flow in the crater that lava flows at about 1200 degrees
14:23centigrade so super super hot so certainly a temperature at which it would be very difficult
14:28to survive for very long at all. This is an interesting question from at Mackenzie Turman.
14:34If volcanoes create new land how did the first volcano come about? Almost philosophical. Actually
14:42magma was first. Believe it or not when the earth was first formed it was a giant ball of magma and
14:49actually it was as that started to cool down slightly that land was able to be formed. So the
14:55volcanoes were absolutely definitely first but the planet was one giant ball of magma and it wasn't
15:02until it created the land that the volcanoes had to start pushing out through that land and forming.
15:08At Silver Dreams I just thought of something. If sea levels can rise and undersea volcanoes erupt
15:15to create new land masses does that mean earth is gradually becoming a bigger sphere over time?
15:22Can you answer this? Well Silver Dreams that's a really good thought. So if we're thinking about
15:27things erupting and moving apart like this then you would think that over time the earth would be
15:33getting bigger but actually because of plate tectonics these plates are growing and moving
15:38like this creating new land mass but at the same time at the other end there's plates that are going
15:44down underneath one another and destroying them and both these areas are where volcanoes can be
15:50created but they're what it means that over time the earth has remained the same size. The next
15:55question is from at Ira Cook. How does volcanic ash from South America stop flights to Melbourne?
16:02Pretty amazing stuff. I'm hoping my flight makes it. So perhaps you will all remember when flights
16:08were stopped in 2010 from Eyjafjallajökull and that was a really unfortunate circumstance of
16:13atmospheric circulation that was pushing ash towards Europe so they had to close European
16:18airspace and that's of course because there's all sorts of different types of atmosphere circulating
16:24and once volcanic eruptions are sufficiently big that they inject material up into the upper
16:29atmosphere or the stratosphere that ash and those particles get traveled all around and guess what?
16:36Aeroplane engines do not like those particles. They operate at temperatures that will turn that
16:42volcanic ash back into if you like magma and stick to the propellers which is really not a situation
16:49that you want if you want them to keep going round. So for that reason when there's volcanic
16:54ash in the atmosphere airplanes will avoid it. So at chaos and JD do volcanoes communicate with one
17:01another? So it's not like in the Disney film Lava where the volcanoes sing nice little songs to one
17:08another as they grow and fall back into the sea but it is possible that when magmatic systems are
17:14close together so the volcanoes at the surface are close together their feeder systems as there's
17:19things moving around in one system the resonance and the pushes and the shoves in the ground get
17:25transmitted to another. So it's not that they'll erupt all one after another but it's possible that
17:31some of those stresses and strains that we see in the subsurface do travel from one system to another.
17:37So at jessphoenix2018 is wondering have you heard any of the volcanic infrasound recordings?
17:44My colleague Geoff Johnson at Boys State records the sound volcanoes make below the range of human
17:49hearing. It's captivating. Yes I have heard those infrasound recordings and they are captivating.
17:55So when volcanoes erupt they cause all sorts of displacements and movements in the atmosphere
18:01and in the rocks that surround them as the magma is moving up and these generate waves and the
18:06infrasound waves when you change their frequency can be turned into sound waves that give an amazing
18:12record of some of these processes that are taking place. It's well worth checking out.
18:17At MatthewCR has the question when it comes to geological terms what is the ring of fire where
18:24is it in terms of plate boundaries? So here we go this is a map of the earth and these white dots
18:31show the plate boundaries of the earth and you can see marked really clearly around the Pacific
18:37Ocean here we have this big run of plate boundaries and they all happen to be the plate
18:43boundaries where one plate is going down underneath another that generates quite a lot of explosive
18:49volcanism hence the name ring of fire because there's lots of volcanoes all around this plate
18:54boundary and it surrounds the Pacific. Okay so at jhumphrey ever wonder why some volcanoes like
19:02Mount St Helens erupt explosively while others like Kilauea lose lava? One of the things that's
19:10really amazing about volcanoes around the world is there's all sorts of different types of magma
19:16and these different types of magma lose and grow gas within them in different ways so for example
19:24this is a magma that's a little bit more like what you might see in Kilauea and you can see
19:29it's got these great big bubble holes and that's because the gas can move around quite freely in
19:35the magma but other types of magma are kind of quite resistant to that and they create lots and
19:42lots of tiny little bubbles which creates huge pressures that mean when the volcano finally
19:48explodes there's a huge release of that pressure generating very large explosive eruptions and
19:54those large explosive eruptions generate something like this which is pumice which is super light
20:01and the reason it's super light is because it's absolutely full of holes which are a record of
20:07that gas trying really hard to get out being resisted by that type of magma but I'm going to
20:12put this into the beaker and it's going to float and it's floating because it's super light because
20:20it's largely composed of bubbles with just tiny little filaments of volcanic glass okay so
20:26at E. Batterson is wondering where do volcanoes get the magma slash lava and lots of people think
20:34there's a huge sea of magma just below the crust that's not true there's not magma everywhere it's
20:40particular conditions that are created to generate that magma and I'm going to show you this for a
20:46subduction zone so here's one plate it's diving down here's another plate here crashing into it
20:54okay now what happens is as that plate goes down it gets heated up and squeezed and it gives off
21:02fluids and those fluids create the special conditions where melt can be generated now that
21:09melt has got liquid in it so liquid rock if you like but it's also got gas and it's hot and what
21:17that means is that melt has a tendency to rise and as it rises up towards the surface it'll come out
21:25and then eventually what we have is our volcano I've been loving your questions
21:32from the internet this has been Volcano Support signing off