Episode 4 Volcano Live

We're standing on the crater rim of the world's most active volcano.

For 30 years lava has been spewing out a line of craters, engulfing

homes and property, and in 2008, that crater exploded into action,

forcing the closure of this park. Did does science know enough about

volcanoes to keep us safe? This is Welcome back to a glorious morning

here in Hawaii Volcanoes National Park. We are coming to you live

from the middle of the Pacific. Let's just remind you where exactly

we are. Now, we're on Big Island at the bottom of the Hawaiian

archipelago right there on the rim of Kilauea. As I said at the

beginning, the world's most active volcano. Yesterday we were at the

coastal community of Kalapana, but what we did was we packed all our

gear up. We moved the trucks. There you can see us moving across them

taking little Minnie Winnie all the way up here to the summit to this,

what's behind us here, which is the house of the eternal fire -

Halema'uma'u Crater. The thing is, that giant plume of gas coming out

there means we can't get any closer. Those plumes are toxic. Also, it's

hard to see into the crater. Also, the cameras are going to show us

the latest pictures. You can see from the camera at the top showing

just what it looks like normally, then the thermal below shows the

lava churning away. The heat is extraordinary - several hundred

degrees Celsius. That's what is behind us. You can have your

personal view of the Kilauea lava lake whrefr you like by going to

our website, bbc.co.uk/volvanolive. We've got various links to various

webcams on active volcanoes throughout the world, and also if

you go on to our website, you can join a web chat with the Professor

Jon Blundy from the University of Bristol. He'll be answering your

questions throughout the show. We have been looking at how volcanoes

work this week, haven't we? That's right, over the last three nights

really and today as well, we have been looking at how volcanoes work

and the processes that cause them to erupt, but tonight we're going

to explain just how good are we at looking at how volcanoes and others

like this have got in store for us. Tonight, a volcanic tragedy. My God.

Look at that. I come face to face with the 2,000-year-old victims of

Mount Vesuvius in Italy. I meet an Icelandic giant which could dwarf

the eruption of Eyjafjallajokull. Ed Byrne gets creative with some

balls in a rubbish bin to build a super-volcano. And the

volcanologists who go to the ends of the earth in pursuit of the

Now, our understanding of volcanoes has vastly improved in modern years.

We know where all the active volcanoes are, and we know why they

erupt, but the thing that really still scuppers us is when they're

going to erupt and for how long. That's right. That's one of the big

challenges is working out precisely when they're going to erupt, how

big that eruption is going to be, and how long that's going to take -

that's some of the key questions. What we're going to look at tonight

is, if you like, some of the tools of the trade. How do we know if we

take a volcano like this or others around the world, when trouble is

brewing? Later on we're going to meet Professor Steve Anderson and

his team who have been using cutting-edge technology to produce

3D images of the crater behind us that have never been seen before,

so that's something very much to look forward to. Well, scientists

from the Hawaiian Volcano Observatory - we can see it just

over there perched on the edge of the crater - those scientists are

looking for tell-tale signs of activity, and one of the things

they're looking at is the gas. In the weeks before the eruption of

that Halema'uma'u Crater, the gas levels just went through the roof,

and what that - what it means is that constantly-building gas plume

isn't just a health hazard for, it's one of the real indicators

trouble is brewing. Let's have a look at this film.

I'm Tamara Elias, and I work at Hawaiian Volcano Observatory

monitoring and studying volcanic gases. The gases can give us

information on what's happening beneath the volcano. It can give

clues as to what the behaviour of the volcano might be. The volcano

ash coming out of this vent has a variety of particles and gases. The

visible part is mainly water vapour and tiny particle, but there's also

a hat full of gases including sulphur dioxide gas, hydrogen

fluoride, hydrogen fluoride, a little bit of carbon moniex I'd.

It's a cocktail of gases. Volcanic gas are dissolved in magma, and

different species of gases bubble out of the magma at different

depths or pressures. One of the gases that's particularly useful is

sulphur dioxide or SO2. Those emissions rise and fall with the

activity of the volcano because it's emitted very close to the

surface. We actually use a small spectrometre, an ultraviolet

spectrometre system to measure how much sulphur dioxide gas is coming

out. It is basically measuring light, and conveniently, sulphur

dioxide gas absorbs you would a violet light effectively, so we can

use that property to measure or calculate how much SO2 gas is

We drive beneath the plume, and we measure the concentration of

sulphur dioxide above us. It can be reasonably extreme. You would smell

the SO2. You would taste the SO2, and you would feel it irritating

your throat, but we use a gas mask in the car. In 2008, we started to

see an increase in the sulphur dioxide gas that was being emitted

here at the summit, and we started measuring amounts that were

unprecedented in our era of making these measurements, and it let us

know that an eruption could occur, and in March of 2008, this vent

during this era. I think as humans, we believe that scenery is rather

static. I think that working here, you can see that whole landscapes

can change very quickly. She mentioned the gas level changes

that accompanied that 2008 eruption, and just to put that into context,

a normal baseline emission of sulphur dioxide from that volcano

is about 200 tonnes a day, but just prior to the eruption of that lava

lake, those levels went up ten times - 2,000 tonnes a day. And

that hole in the ground is the biggest sulphur dioxide polluter in

the US. Now, as we know, every so often Kilauea has these tantrums,

and someone who knows that first hand is Mark Patrick, geologist at

the HVO. I am going to show you some footage of an eruption of the

fire fountain that went on in March 2011. You were there. What was it

like? Of the two people there, you're the one on the left. What

was that like? Yeah, it was speck hacktacular. It was really the

highlight of my time here at the Hawaiian Volcano Observatory.

don't seem too close. We're not, actually. And that is because it

was so hot, it was just keeping you at this distance. It was like

standing in front of an oven. look at if you're kind of - I don't

know if this is the word - enjoying it. What you're trying to do is

second-guess when the volcano is going to be active. We have seen

you monitoring the lake levels and taum aura sniffing out the gas, but

you all work together, right? and that's one of the good things

about working at the observatory, we have all of these specialists

based right there. I can go down the hall and talk to a seismologist

or gas specialist. You need to pull it all together to get the big

picture. You put most of your data on the web, and you have webcams

where you encourage the public to have a look at the volcano. Are you

not a little bit concerned all of that data will turn people into

armchair volcanologists, maybe misinterpreting the data? Years ago

when there was lots of data on the web, there was a concern about that

but it's not a problem. The benefit there has been benefits of getting

the public involved in all of that activity. All the ground tilts

start to tell you trouble is afoot. How does that work? At some point

you presumably have to tell the park officials, "Look, we think an

eruption is likely." That must be a really tricky judgment call. It is.

It can be. The trickiest part is we have these instruments, and we can

track very well when things are ramping up, but the big question is

what's going to be the breaking point? But we have - we look at did

geological record for past insights on that and we look at all the data

we can. I guess that's a problem the world over with those people

observing volcanos? Absolutely. It's a universal challenge with

volcanoes that you can track when things are increasing and building

up, but it's knowing that critical point that is the challenge. Thank

you very much, Matt. One of the things that's interesting is that

monitoring gives you this really short-term baseline of a few

decades. Sometimes that's not really enough to capture the

behaviour of a volcano. That's where history comes in because

history gives you the longer-term perspective on the capacity of a

volcano. That's what I learned when I went off to the Roman town of

Vesuvius. Mount Vesuvius in southern Italy -

it's responsible for one of the most famous natural disasters in

history. In 79 AD Vesuvius erupted in

spectacular style blasting out a lethal cloud of ash and molten rock.

The cloud grew to 30 kilometres in height, and the wind blew it

straight to the Roman city of Pompeii. Three metres of ash and

rock rained down on Pompeii. Buildings collapsed under the

weight, and hundreds of people were engulfed and suffocated. Today,

their entombed bodies still lie exactly where they died. The ash

cloud swallowed Pompeii so quickly, the citizens wouldn't have known

what hit them. But here in the ancient city of

Herculaneum, 15 kilometres to the west, people would have seen the

horror unfolding. The wind had blown the ash cloud to

the south towards Pompeii, so from Herculaneum, they would have had a

clear view of Vesuvius. It's hard to imagine what must have gone

through their minds. Their mountain, which hadn't even been recognised

as a volcano, was exploding into life. A huge black cloud filled the

sky, and the ground was wracked by It must have seemed like the end of

the world was coming. But unlike their neighbours in Pompeii, the

people here had time to run for shelter. These homes and buildings

were found abandoned. The people had fled, but that didn't mean

they'd escaped. When archaeologists excavated these ancient chambers,

they made a shocking discovery. So in each of these chambers were

found 30 to 40 victims of the eruption. Are these real skeletons?

These are casts, but they're just to the real exact copy of the

victims as they were found. What's the story of these skeletons, then?

At the beginning of the eruption, the town was shocked by several

earthquakes. They thought these arcades could be a safe place, but

actually, this was not a good place to be for the eruption. Sheltering

here was no use because the earthquakes and the huge ash cloud

filling the sky was just the first phase of the eruption. Then came

the pyroclastic surge, a lethal mixture of heat and gas. It tore

through these streets at 150 kilometres an hour, obliterating

everything and everyone in its path. Many skulls were exploded due to

the direct effect of the heat on their bones and also due to the

over-pressure induced by the boiling brains. Boiling brains?!

This skull looks as if it has been crushed, but you're saying it's

actually exploded out because their brains have boiled? Yes. What a way

to go. So when the surge comes through the city, there's nothing

which could protect them. After such a devastating natural

disaster, you'd think no-one would ever want to live here again, but

where once stood a Roman settlement of 5,000 people, there now stands a

modern town of 50,000, and the people that live around here today

face the same threat as the citizens of Herculaneum because

In 1906 an eruption claimed over 200 lives. And 28 people were

killed when Vesuvius blasted ash and rock over cities. These

eruptions were relatively minor. A bigger one would be devastating ai,

lethal surge from a major eruption could easily travel 20 kilometres

or more. And that means they could reach the city of Naples. Threat

ngs the lives of over a million people. That's why today, very

suesious -- Vesuvius is one of the most heavily Monday order volcano

on the planet. Scientists use the most sophisticated technology to

keep watch over the volcano 24 hours a day. State-of-the-art

instruments positioned around the crater feed information back to the

control centre. So the scientists can monitor the volcano's every

move. There are different devices like this thermal camera like

detects any change inside the crater, in terms of temperature.

That's like hot gases and hot fluids rise together surface?

There are gas monitoring system and the seismic stations. So underneath

this station here there will be a seismometer will there, recording

that activity. Yes. The temperature of the crater and composition of

gases, the scientist will know when magma deep inside the kol vaino

moves towards the surface, a keel indicator that an eruption is

imminent. Only by merging data by all these instruments can we know

about an evupgs. Could a big eruption like 79 AD happen again

snfpblts yes, of course. Our Research instruments demonstrate

there is a wide magma chamber, as wide as 400 square kilometres. So

there is magma available for hundreds of large-scale eruptions

like the Pompeii one. These high- tech instruments can help

scientists predict when the next eruption might occur. But they

can't stop it from happening. So the danger facing the people who

live here today is as high now as it was in 79AD. The difference is

today we think we understand this volcano, by combining modern

scientific techniques with evidence of past eruptions like the one in

79AD. Scientists know what this volcano is capable of and believe

they can read its warning signs. That is only half the story.

Because the question is - when those warnings come will the

authorities down there be ready? Can we really evacuate all these

people safely? That, perhaps more than the science, will be the

really tricky part. Is there a plan, if it does happen? Do you think the

authorities can react and evacuate people? Yeah, there's a plan. The

assumption is that the eruption won't happen suddenly. There will

be maybe two weeks notice, either from gas or earthquakes or tilts or

something like. That the plan is that they're going to evacuate the

red area. The red area is the area with the pyroclastic flows which we

saw were so deadly. The trouble is that 600,000 people live in that

red area. Wow! That's extraordinary. Just the physical, how do you get

all those people out? If they have two weeks, the plan is to mobilise

16,000 police and soldiers to get 80,000 people a day out on 80 ships,

40 trains, 4,000 cars. Here's the thing, they might not have two

weeks. They might have as little as 72 hours. I was going to say,

that's a big assumption, we'll have two weeks and have it

organisationed. The other thing is, they may have to evacuate far more.

They might have to evacuate areas where the ash cloud is going. They

don't want another Pompeii. The other thing is, the assumption of

the size is that it's best an eruption smaller than AD79. But if

it's going to be huge, all those numbers have to increase. They're

not planning for the worst. They're planning for the best case scenario.

At least Naples has a plan. That's true. There's other volcanoes

around the planet with equally important threat, yet don't have

such a plan in place. It's scary. It is, it is scary. It's not just

in places like Naples. It's scary for the people who work here at the

Hawaii Volcanoes National Park. 5,000 visitors a day come here.

When you see that, don't you want to book your ticket? Jim Gale you

have the unenviable task of making sure that people have access to

this wonderful park, to these wonderful sites, but also being

safe. Now you've got the HVO, the scientist perched over there,

presumably you work together? Absolutely. They are part of the

team. They provide the most up to date science in the current

eruption. How do you measure what they're telling you in terms of how

you then need to react as far as the public are concerned? The most

important part is keeping the visitors safe. Yeah. Out of the

dangerous gases or away from thing that's could cause harm or have an

unpleasant vacation. If there's a shift in wind or something like

that, that's why we needed to close the road over there, because the

wind blows that direction and the gass are too much. There used to be

a road that went all the way round the crater? That's right. You've

closed that because it's the prevailing wind. Correct. So you're

kind of constantly monitoring the various conditions around the park

and reacting accordingly. Exactly. Has there ever been a time where

you have had to say, close the park, nobody in here? For one day we had

a forecast from the scientists that the plume was going to shift back.

Right. We needed to close the park because we were so afraid. We

didn't know what was going to happen. We neelded to protect the

visitors. For that one day, we closed the park tone sure that

visitors would not be in harm's way. What the scientists were telling

you was that plume would come in this direction, basically flooding

the whole area of the park? Right. Right now we're in good wind. We're

up wind of the vent. But the weather was shifting and it was our

first time that had ever happened, so we didn't know exactly what was

going to happen. And I mean, what was the sort of outcome of that?

Were people furious, did they understand what you were doing?

Well, we learned a lot. What we learned was that there's always an

open area of the park, noi, we can take people to a place that's open.

But one of the key things you learned was that people changed

their travel plans. They cancelled their airline reservations,

cancelled their hotel. implications were not just for the

park. You had a ripple effect on the whole island. Absolutely.

Because the island presumably depends on the economics that you

provide here. Right. Not an easy decision to make, then, but

presumably you have to put safety first? Absolutely. That's the whole

purpose is providing an approachable, visitor experience

with viewing the lava, but not at the cost of someone's health or

safety. I don't envy you your job, Jim. I certainly envy where you

work. Thank you very much. It's been a pleasure working with you

this week. Thank you. Now to Iceland. It's one of the most

volcanically active countries on earth. We all remember that

eruption of 2010, Eyjafallajokull, that caused chaos in all our lives.

Actually as I learned when I was in Iceland, that's nowhere near the

biggest volcano there. It's the next door neighbour that is really

mountainous terrain has been shifting and changing for thousands

of years. The scale of this landscape, it's just astonishing.

There are huge ca vass that have opened up as the glacier sweeps

down the side of this mountain. Of course, this isn't a mountain. This

is a volcano. Lying beneath the ice the volcano is one of the largest

and most active volcanoes in Iceland. When Eyjafallajokull

erupted just a few miles from here in 2010, there were also

suggestions that a big eruption here is now overdue. To find out

whether that's true, we're leaving the helicopter behind and hitching

a ride in specially adapted Jeeps to get us across the huge and

treacherous ice cap. Why is it necessary to have such

big tyres? Is it just to make you feel a bit more macho? A little bit

like that! No! It's a vast ocean of ice and we drive for several miles

without seeing a thing. Along the way, we're joined by a snow mobile.

It's a dramatic entrance, but thankfully this is no Bond villain.

It's one of Iceland's leading volcano onctions. -- volcanologists.

He leads us to a rocky outcrop, the highest poipt for miles around. --

point. We are actually at the edge of the rim. This is a depression

that is formed when magma chamber is emptied. What we're looking at

here is snow and ice covering that kind of classic volcano crater. And

this stretches in which direction? If you look around here we see the

edge of the rim. So all the high points? The high points here are at

the edge of the rim, all the way around. I mean it's absolutely

enormous. It's enormous, about ten kilometres diameter. How thick is

the ice? About 750 metres. Wow! They're the huge craters found at

the top of the very biggest volcanoes in the world. They're

formed by what are known as super eruptions, and Katla's caldera was

maid in that way. The explosions that created it, several thousand

years ago, were 50 times bigger than Eyjafallajokull in 2010,

depositing ash layers in Russia, some 2,000 miles away. Forchly, not

every eruption is that bit. But they've seen plenty of activity in

the last few hundred years. How active is this volcano? Well it has

been erupting roughly once or twice every century. OK, so the last time

it had a great eruption? It was in 1918. It was about, well, three

times bigger than the Eyjafallajokull eruption. In 1918,

heat from the eruption melted part of the glacial ice in the caldera.

An enormous flood was unleashed ripping ice from the glacier and

carrying them down towards the coast. That is almost a century ago.

Yes. Does that mean it's kind of overdue? I mean, no, I wouldn't say

that. Volcanoes aren't overdue. They change patterns on a regular

basis or irregular basis actually. They are irregular and complex

things. It might erupt in ten years or 50 years. It might erupt in a

few weeks. OK, shall we get this job done then?! The length of time

between eruptions here varies a lot. So the only way to forecast exactly

when the next eruption might be is by carefully monitoring its

behaviour. Bennie uses extremely sensitive GPS instruments and if

the ground here moves by just a single centimetre in any direction,

that movement will be recorded. It looks, to the uninitiated eye, that

it's moving quite a lot. Yes, it is. It is moving quite a lot. What we

are looking at now is volcanic unrest. That's a long-term

indicator that something is, could potentially happen. It could

potentially happen at short notice. But Bennie is used to seeing

chaotic ground movements in this area. What he's really looking for

is evidence that shows whether the pressure is building in the magma

chamber, deep beneath our feet. How does magma accumulating, kilometres

below us presumably, how does that affect a GPS instrument right up

volcano, and it's - there is magma coming into the magma chamber. It

increases the pressure in the magma chamber, so you basically -

increasing it in size. Right. So you... It's like blowing up a

balloon, so you see it on the surface. You see an uplift and

away... Oh. So Benny won't issue any warnings until he sees clear

movement up and away from the magma chamber over a period of days or

weeks. Only that would suggest that Katla is building up to a really

big eruption. In the meantime, Katla continues to rumble away, and

just last year, a small episode of geothermal activity was registered

beneath the icecap. Now that geothermal activity of 2011 heated

up the ice and caused a flood of water too come pouring off the

volcano and down this river valley, taking out the bridge and causing

mass devastation as it made its way to the sea. The flood was a smaller

version of the deluge in 1918. It's a reminder that even between big

eruptions, Katla can still pose serious problems for those living

nearby. That makes it vital that we continue to monitor this slumbering

It is an incredible country, Iceland, and it is incredible,

really, how the people there kind of cope with this volatile home

that they have chosen to live in. I have presented a one-hour special

on Iceland and its volcanoes which will be going out on BBC Two a

little bit later in the year - we think in the autumn, so keep your

eye out for that but it does seem to me, Ian, that this predicting

what a volcano is going to do and then telling people what your

prediction is is sort of fraught with problems and controversy

really. Yeah, that's the real tricky business. If you see the

signals and raise the alarm and nothing happens, then, there is all

sorts of disruption and panic. On the other hand, if you don't see

the signals and don't raise the alarm, then you get it in the neck

because there is a disaster then too. That's one of the reasons why

volcanologists have moved away from being predictive and gone for

forecasting, in other words, saying something about the likelihood of

an eruption, snai, days or weeks in large part so that people can be

prepared... Make their own decisions, feel informed about

making their own decisions. All of this week, we have had some very

up-to-the-minute information from the Smithsonian to tell us which

volcanos have had alerts, basically. They're all active and all

volcanoes people should be keeping an eye on. Here they are this is

the latest - all the volcanoes that have alerts on in the last 24 hours.

Many of you have e-mailed to say, why are you missing out New

Zealand? They have volcanoes. They have but none with the alerts on.

On the edge of the map. It's not being ignored. We promise. One in

Ecuador - that is - if we can have a look at the webcam, we have some

mild plume activity from - there it It's hard to see what is behind

that cloud, but we know there has been some plume activity coming up.

The problem with that is it's so close to Quito, the capital of

Ecuador. Even a moderate eruption from this volcano could have a

devastating effect, so a huge one to watch over the coming days.

other one, again, we looked at over the coming week is one in Japan you

know quite well. Yes, this is just on this isle in southern Japan. If

we can have a look at the webcam, I wonder what the latest is on that.

That is going to tell us a lot, isn't it?! That is the problem. You

can keep an eye on these by going to our website. I have to say also,

it's night-time in Japan. If you go there, it will be black. In 2005,

to give you an idea, this is Kagashima, one million population

city. This is one striking distance of big pyroclastic flows. I went to

the community and went into the school to see the kind of protocols

and practisings they have. The schoolkids - these are primary

schoolkids - every Friday have a drill. They rush out of the

classroom. They get their protective hard hats for the ash.

They get the gas masks for the ash. They run down the stairs and

assemble in the playground outside where they're checked out. This is

my favourite - look at these. Every Friday they have - you can't see

this, but just above the school is the volcano. The point is in many

of these communities around the world, although these people are

drilled for volcanoes in their midst - this is what people in the

UK forget about. That's it. We're not living in a volcanic landscape,

so we tend to perhaps build them up more than other people do, which

brings us neatly on to other questions you have sent in. We have

a fantastic amount. The first one from Alex in Rhyl. He's going to

Vesuvius this October with his school. He wonders are there any

laws on taking samples of volcanoic rock from Vesuvius back home to the

UK? That's a great question. I think there are. Many of these

volcanoes are protected sites. He'll need to check, but I don't

think you can. When I was there, I didn't take any because I was

certainly worried. Here you're definitely not allowed to. You're

not because there is a goddess called Madam Pele, who lives inside

the volcano. It is deemed hugely bad luck and bad form to take a

rock from here. In fact, the Post Office in Hilo here receives

hundreds of packages of lava being returned because they have had bad

luck and thought, I have to quickly send it back to the goddess. In

Kent, one viewer asks what the people of Pompeii thought it was if

they didn't think it was a volcano. The Greeks knew it, but it hadn't

erupted for centuries, so for the Romans, it was just a mountain.

Caroline Lomas wants to know - this is a very good question - can one

volcanoic eruption trigger a chain reaction? I know this is something

in Iceland people were worried - Eyjafjallajokull could trigger

Katla to go all. It turns off they have separate Magma chambers, but

could they? There could be stress between them, and also earthquakes

between them. One that is nice is between Kilauea and Mauna Loa here.

When Mauna Loa kicks off, Kilauea goes quiet. When Mauna Loa kicks

off, Kilauea goes quiet. John Howard wants to know are there any

active under-sea volcanos? Lot and lots, probably the most common, but

we don't issue alerts. One from Cardiff: "If Magma is being

released and forming new land, does that mean..." Shrinking? No,

because that builds new land. It I gets taken back into the mud. It's

a beautiful recycling system. you, as I say, for all of you who

sent in your questions. I want to make a quick mention, Jack, Dara

and others have said they want to be volcanologists and want to know

how. That is good point. This week we have talked a lot about this

high-tech stuff, but what has been a joy to me is where you see the

films of the people who study them and also the lengths they go to get

their data, and one that exemplifys that passion and commitment for me

more than any other is Clive Oppenheimer, and this week, Clive

I'm interested in volcanoes, why they work, why they erupt in a

particular way. If we want to be able to predict eruptions, that's

obviously one of the key goals of volcanology. We need towns how they

work, so we need to find laboratory volcanoes where we can make very

detailed measurements. Mount Aravus in Antarctica is the world's most

southern active volcano. It is over one million years old. Every

December I make the epic journey to this mountain with a team of a

dozen students and scientists to live and work for a month. The main

reason I go there is to measure the gas emissions from the lava lake.

They're really like messages from the earth's interior. It is a big

project to go there. You need a lot of time, but the scientific rewards

are just phenomenal. I have been coming here to the very edge of the

world for the past nine years. We fly to New Zealand, then on to Ross

Island where we pick up provisions, then finally take a helicopter the

last hop over Arabus. We go to an aclimatisation camp, called the

Fang Glacier. We call it Fang Camp. Going to high Ault altitude, you

suddenly realise you're in Antarctica, and the views are

spectacular. The camp here is pretty basic with just a few tents

and a bucket. We try to aclimatise for at least a couple of nights in

Fang. We travel by Skidoo to our main field camp. This is my home

for a month every year. It's a truly extraordinary place, and it's

a bit like landing on Mars. We set up camp next to two permanent huts

just an hour's walk from the summit of the volcano - the typical

temperature in the camp would be about minus 30 Celsius. If the wind

is up, even if it's just a few knots, then you really start to

feel it. And working up at the crater - particularly if you've got

to take your gloves off to fiddle with a screwdriver or something -

you lose fingers in seconds. The cold and altitude have also led to

two helicopter crashes over Erebus, but luckily, everyone survived.

It's just a reminder of the dangers of being up in that part of the

world. We do still sleep in tents. It's our one sort of nod to the

heroic era that you have Scott tents, and they're not black-out

tents, so it's a little bit difficult actually coping with the

daylight that you have 24 hours a day. Life is harsh here, but

studying the volcano makes it all worthwhile. Depending on the

weather, we try to get up to the crater rim every day where we

monitor its activity. The crater is half a kilometre across, and the

lava lake here at Erebus is one of only four major lava lakes in the

world. I am here to measure the gases in the volcanoic plume.

Measures the composition and flux of gases allows me to understand

why the volcano works and why it has a lava lake.

My favourite device on Erebus is my FTR, my infrared spectrometre. It

measures anything that's coming out of the volcano. There are seven

different gas species we can measure. The nice thing is we can

measure those every second with very, very high accuracy. That's

great for following subtle changes in the behaviour of the volcano and

very rapid changes. And the gas emissions themselves are one of the

best messengers to tell us where is magma in the crust? How deep is it?

Is it full of gas or not? Is it on the rise? Is the volcano gearing

towards a different kind of eruption?

The ice caves are one of the most stunning features on Erebus. And

they're a bit of a puzzle actually as to why they're there in the

first place. They're connected with the heat that's being lost from the

volcano and also from gases. We know that some of the caves are

very rich in carbon dioxide in their atmospheres, so we think

possibly they're connected also with the magma plumbing system of

the volcano. So we have an active research programme trying to

understand their formation and origins. A very exciting aspect of

Erebus's behaviour is that it explodes from time to time, unlike

other lava lakes, in fact. We use the camera to observe the volcano

when we're not up on the rim, of course, but also to capture the

explosions. Some of them are very dramatic. All the lava in the lake

is expelled. Sometimes they almost Each year, we look for new lava

bombs to sample so that we can analyse them back in the lab. There

is still a huge amount we have to learn about Erebus, but what we're

finding out here will help us to understand other volcanoes across

the world. One of the things that makes Erebus a fantastic place to

work is it's very cold, and it's very dry. Erebus is a great natural

laboratory to study how a volcano works, and that has all sorts of

generic lessons for understanding volcanoes worldwide. I think the

measures we have made of gas emissions at Erebus rivals anything

I have seen for volcanoes around the world. We've got really

detailed data and have been going there year after year. We measure

gas emissions every second, and that's really enabled us to piece

together lot of the detail about how the volcano is plumbed into its

network of magma bodies and feeder pipes below the surface. It's an

exceptional place to live and - I mean, just amazing privilege to get

to work there and to get to go back There you are, how would you like

to go down toant arbgta to study volcanoes. They have one of only

four permanent lava lakes in the world. One of the others is here.

Dave is with me now. Thank you for joining us today. You have been

spending the last months and weeks actually mapping this lava lake,

using this extraordinary piece of kit. Can you just talk me through

this? I've never seen anything like it. This is actually called a

ground based lidar system. It's a laser beam mapping system that

allows us to do high precision mapping at centimetre scale at long

distances. It allows us to actually map in three dimensions different

parts of the volcano. Why is that important? Why is it important to

have that sense of distance? Surely you need to get up close to really

understand what a volcano is doing. What's really important is we need

to get close, but nine times out of ten we can't get there. It's too

dangerous, the gases and heat and some of the other people have said

it's important to have a stand-off system that allows to us get

precision information at long ranges. These systems allow us to

do that. They allow us to map in 360 degrees, at very high precision,

without putting people in harm's way, but coming up with the science

information that we really need. Well, I'm going to have a look at

the results of your work with this extraordinary machine with Dave's

colleague, Professor Steve Anderson from the university of northern

Colorado. Good morning. Good morning. An impressive piece of kit.

Presumably giving you impressive results. Before we have a look at

what you've been able to produce over the last few weekends, let's

have a look at the view of the crater that we are more used to

seeing. It's a pretty good view. is. But I suppose from a scientific

point of view, a little vague. It tells you some things but not quite

enough to be analytical. Right. Beautiful views, as I say, so how

does the view that you have managed to produce differ from that? Since

the crater opened about four years ago, one of the biggest hazards

they've had to contend with here are rock falls from that crater

wall landing in the lava lake and producing impressive explosions.

producing impressive explosions. have footage of those rock falls.

It is dramatic. Let's have a look. That is one of the biggest risks of

this particular crater, It's true. So from your map that you've

produced, which I think we can have a look at, what has that told you?

If you can talk us through it. It's a bit confusing. This is the crater

here. We took this image back in February. Again, a couple of days

ago. This image from February shows the crater walls here. As it pans

around, you'll be able to see into the crater. This is the lava lake

here. It's down here. What we've noticed from February to today is

that the level of the lava lake has gone up about 20 metres. Wow.

that parts of crater wall, especially down here, have widened

substantially as rocks have fallen in. We're trying to get an idea of

how this crater works so that the park service and HVO can use the

information to make informed hazard predictions. Is there anything

you've noticed, I mean, you say that the lake has risen 20 metres,

are there any other features that have alerted you? When we first saw

this image, the thing that really jumps out is something you'll see

in a second, this rock ledge right here. As it turns, you'll see it

overhangs by about 30 metres. Now when you look at that, it's like,

well, that's potentially a problem. On the other hand, it could remain

stable for a long period of time. It could break off in a piecemeal

fashion. We don't know yet. The research is based on trying to come

to a better understanding of what's going on in there. Presumably this

very accurate mapping, it is extraordinarily detailed. It is.

Literally being able to pick out areas of rock, it is giving you and

the people here a much better understanding of that crater.

when you put these detailed views in the context of the history that

the field jeeologist -- geologist accomplishes, it allows for more

informed predictions that the USGS and park service will put out. We

try to provide some information and science and ask and answer

questions that could help. Thank you very much for joining us today,

Stevement Thanks. The more we study volcanoes, the more we know about

them. The one thing we definitely know is that if they choose to

erupt, there is nothing we can do to stop them. How big can those

eruptions be? Ed Byrne went to investigate.

The bright sun was extinguished and the stars did wonder darkly in the

eternal space. The icy earth swung blind and blackening in the

moonless air. Morn came and went and came and brought no day. And

men forgot their passions and the dread of this their desolation and

all hearts were chilled into a selfish prayer for light.

Cheerery stuff. Lord Byron wrote those words in July 1816, inspired

by the year without a summer. What he didn't realise was the reason

that the weather was so bad that year was because the year previous

to that mount Tambora erupted off the coast of Indonesia, the largest

volcanic eruption since records began. Which begs the question -

how does a volcano erupting thousands of miles away have such a

marked effect on the weather in Europe? It's all about the way

volcanic ash plumes spread through the atmosphere. Dr Jeremy Philips

specialises in ash plumes and is on hand to explain. To represent the

earth's atmosphere, he's filled a tank with salt water. Dense water

is at the bottom and less dense at the top. What you can see is a

plume source. That's going to represent a volcano erupting. The

plume rises up. The mixture then finds a level in the tank where

it's the same density as the fluid in the tank. Then it can't rise any

higher and it spreads across the tank. This is essentially what

happens with volcanic plumes in the earth's atmosphere. Typically this

level is somewhere between 15 and 25 kilometres high? The atmosphere.

The density of the lower Air Forces the plume up and then it spreads

out. Exactly. You can see these large clouds can spread until they

circle the whole globe. When Iceland's Eyjafallajokull volcano

erupted in 2010 the resulting ash plume covered most of northern

Europe. By xar son the eruption of mount Tamboro was a thousand times

bigger. Its ash engulfed the entire world. It became known as the year

without a summer. The ash blocked the sun's rays causing climatic

extremes that brought famine and death to tens of thousands across

the globe. Here's what's left of Tambora today, a gigantic crater

three miles across. There are other volcanoes which make even this look

like small fry. This is yellow stone National Park

in America and it's the site of a so-called super volcano. Incredibly

the entire park sits inside a giant super volcanic crater or caldera.

It's more than 30 miles wide and it last erupted over 600,000 years ago.

Scientists think there are at least 50 super volcanoes on the planet.

None have gone off for at least 26,000 years. It's difficult to

imagine just how immense these eruptions must be. Dr Jennie

Barclay, from the University of East Anglia, has explosive

experiments to give me an idea. The first involves a film canister,

milk, food dye and alka seltzer. That's pretty good. I hope that

wasn't supposed to be a super volcano. No. This is one we would

call VEI one. VEI is volcanic explosive index. This is a little

explosion, quite small compared to a super volcano. It goes up to

eight, eight being a supervolcano then. That's right. Here we have a

bin. What we've done is we've filled the bin full of water.

That's some of our magma. We will put coloured balls in to be broken

up magma coming from our explosion. We're using this contraption?

are indeed using this splendidly made contraption, which basically

allows to us put a bit of lick wit -- liquid nitrogen in. Yes! We need

to put our safety gear on. Righto. I like that I had to take off my

glasses and put only slightly nerdier glasses on. You're part of

the gang now. So this will turn into a gas and pressurise this,

causing an explosion to drive up and give us a sense of the

difference in size between these two types of eruption. It gives me

a chance to play with like wid nitrogen -- liquid nitrogen.

That was beautiful. That was a beautiful and colourful portrayal

of a global catastrophe. When mount Tambora erufpt today threw out 50

cubic kilometres of material. A super eruption could move a

thousand cubic kilometres. That could bring a volcanic winter which

could last years, if not decades and if we're really unlucky, plunge

earth into a new Ice Age. What are the odds of this eruption? The odds

typically go over hundreds of thousands or millions of years. So

there will be another super eruption, but the likelihood, the

chance of it happening over our lifetime and our children's

lifetime is vanishingly small. It's a lfl film, but for me, I know

this will get the tweets and e- mails going, I don't think we

should get toad fixated on super volcanos. They happen so rarely.

The thing we've seen this week is that active volcanoes are scattered

across the planet in. Many of them are right besides huge population

centres. We should take the science we've demonstrated this week and

apply it around the world to save lives. Well you can still get your

questions in. Jon Blundy is standing by. Bbc.co.uk/ volcanolive.

For us we've come to the end of our time here in Hawaii. Time enough to

thank the scientists here. And of course the staff at the Hawaii

Volcanoes National Park who made this possible. And Madam Pele for

giving us such a beautiful final day and we need to thank you. Thank

you for all your questions, tweets and your contributions. It has been

a really wonderful week. And we would just like to leave you with

shots of Hawaii in all her glorious volcanic splendor, because when she