Episode 2 Expedition Volcano

Deep in the heart of Africa

are some of the most extraordinary volcanoes on Earth...

..prone to violent and deadly eruptions.

They threaten the lives of more than a million people

in a region already shattered by decades of violence.

Now, a team of international and local scientists are here

to investigate these rarely visited volcanoes

to try and predict when they will next erupt.

Here, we're seeing catastrophic eruptions,

just punching through this landscape.

They'll explore spectacular natural wonders and discover hidden dangers.

-It says, "Over the limit".

-That's a catastrophe for everyone's health.

They'll examine how volcanic forces influence every aspect of life here,

from conflict to the daily struggle for survival.

And they'll investigate

whether the volcanoes can be more than just a force of destruction.

So these gorillas are at the epicentre

of everything that makes these volcanoes both good and bad.

So far, the team have focused their efforts

on just one volcano, the mighty Nyiragongo,

to try and put in place a system to warn the nearby city of Goma

before the volcano erupts again.

DRONE BUZZES

Now, with only a week remaining,

the team are back in Goma for the next stage of the expedition.

They are about to fly to one of the most active

yet least explored volcanoes on the planet...

..Nyamulagira.

Nyamulagira lies on the eastern border

of the Democratic Republic of Congo, the DRC.

Professor Chris Jackson has studied volcanic landscapes

across the planet, but he's never been to Nyamulagira.

Few people have, for good reason.

It's actually in a fairly

dangerous part of the area,

so the only way to get there

is with a military helicopter. My heart's racing,

just at the thought of getting on that helicopter.

Only a few years ago,

an expedition like this would have been impossible.

For nearly two decades, the DRC was at the centre

of one of the bloodiest wars of modern history.

Millions of people died...

..and the country is still recovering.

Although the wars are officially over,

violent militia and rebel groups are still active.

Many operate in the forests that surround Nyamulagira.

So, the helicopter has to fly fast at tree-top level

to reduce the chances of being shot at.

We're hoping to land on top of the volcano,

right next to its active crater.

We need to collect some fairly critical data up there

to understand what might happen in the future.

Nyamulagira is capable of spectacular eruptions...

..on an almost yearly basis.

Most volcanoes this active and so close to so many people

are covered in monitoring equipment.

But there is nothing on Nyamulagira.

This is a rare opportunity to gather data

that could help predict future eruptions.

We're really banking sharply now to get a view down into the volcano.

It is an enormous hole. I cannot describe how big this hole is.

I'm not seeing any lava coming out

but there is huge amounts of gas coming from both within the crater,

but also all the way around the edges.

This is just, this is just phenomenal!

HE BLOWS WHISTLE

Back in Goma, doctor and humanitarian aid worker

Xand van Tulleken is leading the other part of the expedition.

I've been really focused on Goma and the immediate threat of eruption

and now I'm heading out of Goma to see what it's like

living in this volcanic landscape,

to see how much effect the volcanoes have, just on people's daily lives.

Xand wants to find out what role the volcanoes have played

in shaping life here -

everything from day-to-day existence

to the troubled history of the region.

His first stop is the town of Sake, west of Goma.

It's less than 30km from Nyamulagira

and is right in the line of fire when the volcano erupts.

To find out what impact eruptions have,

he's meeting two market traders, Therese Kalume and Mama Noya.

They've spent their entire lives here.

Nyamulagira's eruptions blanket large areas of farmland

in scalding hot, choking ash...

..destroying crops...

..killing livestock

and bringing famine.

I guess I thought it was just the eruptions, with the lava,

but you're saying the ash also destroys the crops.

How often does that happen?

It's three years since Nyamulagira last erupted

and the market is full of food.

Between eruptions, the ash that usually causes such destruction

breaks down, quickly releasing nutrients into the soil,

producing incredibly rich and productive farmland.

You have all this fantastic stuff

that the volcanic soil is doing for you

and yet, it's also causing all these problems.

What's it like living with the good and the bad every day?

They've got a very confusing sense

of what the volcano means to people's lives here.

It's not just about eruptions and lava

or even clouds of ash destroying crops.

It's that the volcano inserts itself into every single part of your life

and every single part of your body.

The volcano is the thing that feeds you and the thing that starves you.

Before he leaves Sake, Xand wants to investigate

a more direct effect that the volcanoes have on the people here...

..one that has serious implications for their health.

The rest of the team is about to land on Nyamulagira.

As it's been three years since the last major eruption,

another could be imminent.

Benoit Smets is part of a European group

working with local scientists to study the volcanoes.

I think we should first follow

-the cracks and then turn right, try to avoid them.

-OK, cool.

Benoit discusses plans with former Royal Marine Aldo Kane,

in charge of safety on the expedition.

Here you have the fracture network that's across the caldera.

This is where the gas escapes, so it's quite dangerous.

OK, all right, we'll get everyone out

-and then we'll have a bit of a brief then.

-OK.

It's not just the volcano that worries Aldo.

Be aware there are armed groups

operating in and around the slopes of the volcano.

If you do see someone that's not from our group,

then get on the radio, let me know.

There is a path and tracks going through here, so they are using it.

It is accessible to them, so keep your eyes peeled.

Hostile groups that saw them fly in

could be on their way up to the summit.

They can't stay long.

So, we've got two hours. We need to be back here,

everyone at the top and ready to go, in two hours.

-Cool?

-Sounds good.

-Thanks, Aldo.

-Thanks, Aldo.

The scientists face an almost impossible task -

two hours to find out what state the volcano is in.

To start, they need to find a place to see into the crater.

Kasereka Mahinda comes from the local Goma Volcano Observatory

and knows the summit better than anyone.

The teams split.

One group head to Kasereka's vantage point.

Meanwhile, American volcanologist Dr Kayla Iacovino is focusing

on one of the best clues as to when an eruption is imminent -

the plume of gases being given out by the volcano.

I want to find a place where I can actually get inside the plume

and put the gas box

and that can tell me more about the different chemicals

that are coming out of the plume.

Monitoring the changes in the gas chemistry

is what tells us whether this is changing

or whether it's moving towards an eruption,

whether there's new magma being input at the very base.

The gases really tell the whole story.

Just before an eruption,

fresh magma starts moving towards the surface.

As it rises, the magma releases more and more sulphur dioxide gas.

So, a sudden increase in the gas

often signifies an imminent eruption.

Kayla wants to find out

the concentration of sulphur dioxide in the gas plume.

But it won't be easy.

I feel like we're really pushed for time here.

There is a lot of gas coming out of here.

The problem for me is that, once it gets to the top,

it's become pretty diffuse,

which is why I'm having to chase the plume around.

As Kayla tries to sample the gas plume,

the others have reached the vantage point.

Oh, wow!

As you walk towards the edges of these craters, you get that feeling

in your stomach, like you're about to go off the edge of the world.

They need to check on the level of activity in the crater.

When Kasereka was last here,

there was a small cone erupting in its centre.

It's a worrying situation.

Volcanoes erupt when pressure builds below the surface.

Whilst the cone was erupting, pressure was being released.

With no active lava in the crater, the volcano may be blocked.

Benoit and his colleague set up a thermal camera

to check if there is still magma

moving between the thin crust of black rock,

but it means getting close to the cliff.

Just go careful on that edge. This entire edge,

even under where your camera is there, is overhanging.

That's millions of tonnes of rock there

and they're right on the edge of it.

They check the temperature.

Intense heat would mean the vent is still active.

So, what's the temperature down on the base?

So, everything has quite the same temperature,

-about 45 to 50 degrees Celsius.

-OK.

-It's totally dead.

No activity left at all.

And the question is now, is it just a break or is it just finished?

-Yeah.

-It means that the activity may change.

With the crater floor solidified,

pressure could be building deep underground.

The volcanic activity that we see

-is only a very small part of the real volcanic activity.

-Yeah.

There is much more happening below the surface.

The key question is whether new lava is moving up within the volcano.

That makes Kayla's gas measurements all the more important.

Only Aldo now realises that Kayla has moved out of sight.

She's left without her radio.

More disconcerting for me is obviously CO2 or carbon dioxide.

Carbon dioxide is a suffocating gas, given out by the volcano.

At high concentrations, it can kill in moments.

Aldo can't take any chances.

If she goes down and we're not there then,

there's pretty much not going to be much we can do for her.

Back in Sake, Xand is investigating the impact

of volcanic activity on people's lives.

He's spotted something that has major implications

for the health of the townspeople.

One of the things that really struck me was how brown and stained

their teeth were and that's very unusual in sub-Saharan Africa.

People in rural Africa don't have much refined sugar in their diet

so, normally, their teeth look pretty good.

And what I'm seeing was not neglect, it's too much fluoride.

It's a sign of dental fluorosis

and the most likely source of that fluoride

would be their drinking water.

Most homes here rely on central springs and taps.

Xand is meeting Mathieu Yalire from the Goma Volcano Observatory

and his long-term collaborator Dario Tedesco

to find out what causes the problem.

It's part of our job

to analyse water,

all the samples we can get around the region.

It's very strange to me

because we deliberately add fluoride to the water in a lot of the UK

because it strengthens people's teeth

but you just get slightly above that threshold,

and it destroys your teeth.

They use a small hand-held device to measure the fluoride.

Levels below one part per million can be beneficial

but anything over that would cause problems.

So, what's the number here?

The limit of this machine, this small equipment,

is ten parts per million

and it says, "Over the limit".

-That's a catastrophe for everyone's health.

-Yeah.

It's a really severe health consequence.

I mean, it's not just stained teeth, it's that your teeth stop working,

your bones stop working, your joints, your kidneys.

So, what's the solution?

Presently, we don't have any solution

because the best solution would be to bring water

-from very far from here in...

-Masisi.

Masisi, Masisi area. It's very...

-It's 20, 30km.

-30km.

-So, it's quite far.

This is not only this village.

It's more or less 100,000 people or more that live in the area.

Volcanoes tap the inner Earth, releasing usually rare elements

into the environment in much higher levels than normal.

It's what makes the volcanic soil so rich and fertile.

But it can also lead to unusually high concentrations

of more harmful elements, such as fluoride.

I'm amazed at how often on this trip that I've needed a geologist

to understand what's going on, even in health,

and I think I know a decent amount about human health.

For the next stage of the expedition,

Xand is going to investigate the role volcanoes play

in the violence and conflict that continue to affect this region.

On the summit of Nyamulagira,

the team is scrambling to gather data

to help predict the next eruption.

But Aldo has lost sight of Kayla.

And it's not just the volcanic dangers that have him worried.

All round this rim are the armed militia groups,

which are operating all over this place,

so there's more than one reason why Kayla shouldn't be off on her own.

But she's a scientist.

So, it is a relief when he does catch sight of her.

Ah, there she is.

We've got six or seven scientists here that are all running around,

doing their own thing.

We've got some hanging over the edge,

we've got some sitting in the middle of these fissures here

and Kayla disappeared.

They get so tunnel-visioned with what it is that they're trying to do

that they often forget about their own safety.

Not deliberately, but they may place themselves

in a little bit of danger, which is pretty much what I'm doing.

I'm herding cats, trying to keep my eye on everyone.

It's quite sulphurous now, isn't it?

Yeah, you can smell it really strongly.

We've got about 40 minutes left before we need to go,

and we need to keep an eye on the weather, so quick as we can.

Reunited with her radio, Kayla continues to try

and sample the gas, but she's struggling.

Unfortunately, the best place where the gas is coming up

is also on, I think, the most precarious part

of the entire crater rim.

It's why I'm not over there, where it's gassiest,

cos these thick layers of ash, that looks like the most unstable,

but I'm just trying to get as close as I can without being unsafe.

Benoit is determined to squeeze in one last experiment.

It's a technique that could reveal

whether there is pressure building within the volcano.

I would like you to follow the drone with the binoculars

to be sure that I don't crash it.

As it heads towards an eruption, the build-up of pressure

inside a volcano can change the shape of the crater,

making the ground swell and bulge in places.

I'm using a drone to take pictures of the pit crater

in different viewpoints and, with this set of images,

I will be able to create a 3-D model of the pit crater.

Benoit's 3-D model is a snapshot of what the crater looks like today.

Comparing it to models created on future visits will allow them

to instantly spot even small changes...

..a crucial clue to when an eruption is brewing.

Benoit has just enough time to finish his survey.

The two hours are up and, what's more, the weather is on the turn.

We need to head and there's a huge bank of cloud

that's coming our way,

so I think we take the weather window and we bug out.

If the storm hits, the helicopter will not be able to take off,

leaving them trapped.

They are too fragile to put in the bag.

If you need me to carry anything, let me know.

We are a long way from the helicopter

-and we still need to pick Kayla up on the way.

-Yeah, OK.

She's still over there, doing her gas box.

It's a frustrating end to the trip for Kayla.

She hasn't been able to get any meaningful gas measurements.

It's just so hard to work in places like this,

where access is nearly impossible. And then, when you get access,

you have two hours. It's just not enough.

Even so, this rare visit has been invaluable.

They've established that the volcano may be blocked

and pressure building towards the next eruption.

And they have a way to track changes in pressure in the volcano,

with Benoit's 3-D model of the crater.

On the way back, Chris shifts his attention

to the wider volcanic landscape and the next stage of the expedition.

It's amazing from up here the view you get.

From the ground it looks spectacular,

but from here, it is absolutely something else.

There's this flat land

with these volcanoes just punching through absolutely everywhere.

Every one of these hills and peaks is an extinct volcanic cone.

This extraordinary concentration of volcanic activity

is related to a much bigger geological feature...

..the East African Rift.

It's a vast chain of volcanoes and valleys,

stretching for round 6,000km up the eastern edge of Africa.

The Goma volcanoes are at the midpoint of the rift.

All along this line, the Earth's surface is being pulled apart.

If the rifting continues, Africa will eventually be torn in two,

creating a new ocean and a new continent.

With such immense geological forces at work,

there are potentially many more dangers

that threaten the lives of the people here.

It's these threats the expedition will investigate

in the few days remaining.

First, the expedition reunites, back in Goma.

Xand is investigating what role volcanic activity has played

in the violent conflicts that plague the region.

He's taking Chris and Aldo to a boxing gym

with a connection to a disturbing aspect of these conflicts...

..the use of child soldiers.

At its peak,

around 30,000 children were involved in the ferocious fighting.

Although the wars are officially over,

there are still armed militia and rebel groups operating around Goma.

And they still use child soldiers.

This gym is helping people trying to escape that life.

Many here are former child soldiers,

including the man who runs the gym, known as Kibomango.

-Bonjour.

-Bonjour, ca va?

-Oui, ca va, mon ami.

-Ca va?

-Oui, ca va.

Can we join in?

KIBOMANGO SPEAKS IN FRENCH

Kibomango just said, normally, due to a lack of discipline,

-you wouldn't be allowed to train for not bringing your PE kit.

-Oh, right!

-So, you're going to have to do it in your pants.

-Did he say that?

With his military past, Aldo is fascinated by Kibo's story.

So, Kibo, when did you join the army?

Which is two years younger than I was when I joined up.

How long did you serve in the army?

Aldo joined the Royal Marines at 16

but couldn't see frontline action until he was over 18,

unlike Kibo and the kids here.

I wouldn't mind betting that what Kibomango's doing here

to run this boxing club is partly for his own therapy.

As a child soldier, he's going to have seen some pretty nasty stuff.

After the workout, Aldo has a chance to take on the man himself.

Kibo is a former Congolese champion.

In a poor and job-starved area,

it is often only the militias offering money

and employment to the young.

And one of the main sources of the militia's funding

is directly connected to volcanic activity,

thanks to a mineral that most of us have never heard of

but which plays a crucial role in all our lives.

There's a lot of things at play, but one of the things is this stuff,

which you will know much more about than me,

but I've managed to get some coltan. What does this mean to you?

It's the kind of mineral I'd expect to find in an area like this,

an incredibly volcanic area.

My assumption has always been that just about any electronic device

I have has got, maybe, may well have Congolese coltan.

Every touch-screen phone, laptop, will have tantalum,

which is the "tan" of the coltan.

So places like Congo are, it sounds silly to say,

but they're an absolute gold mine for coltan.

-Right, right, for a coltan mine.

-Yeah.

Coltan is critical to touch-screen technology,

so it's in constant demand.

Even small mines can generate huge profits.

Just one kilogram of coltan can sell for over 100.

Coltan deposits are found throughout the region

but, in this lawless area, militia control many of the mines.

The income helps them recruit young people.

And this connection between minerals and the militia helps explain

why the violence continues.

We normally think about wars like a boxing match.

-You've got two sides, one side wants to win.

-Yeah.

But this is not a typical war around here.

You've got war that, in some cases,

-lots and lots of the actors don't want to win.

-Yeah.

They just want to have enough unrest, enough instability,

that they can run an illegal coltan mine, have child soldiers,

-involve the whole community in it and sell it internationally.

-Yeah.

And you have this kind of terrifying picture,

where there is no incentive to end the violence at all.

And it's very hard to hold this in your hands,

knowing how much we desire it

and knowing what it leaves behind and where it comes from.

It is a vicious cycle.

The chaos in the region helps the gangs control the mineral wealth

and the mineral wealth helps the gangs maintain the chaos.

After the boxing, the expedition once again splits.

Xand is going to travel deep into the countryside

to see if the volcanic resources can ever be a force for good

and help break this cycle of violence.

Chris and Kayla are also heading out of the city.

They want to investigate what other dangers

the epic geological forces at work have created.

I'm really interested to see some of the smaller cones

cos we've been looking at Nyiragongo, Nyamulagira,

you know the big boys.

But there's so much information that the smaller cones can have too.

That's what I'm interested in seeing.

They're heading to one such volcanic cone calls Lac Vert,

just outside Goma.

Wow, look at that!

In the centre of the cone is a crater

nearly a kilometre wide and over 100 metres deep,

containing Lac Vert, the green lake.

Local people scramble down to the lake shore

to wash clothes and bathe.

Lac Vert is now extinct.

But if a similar eruption were to happen nearby,

it could be devastating.

Chris and Kayla want to find out how likely that is

and what it would mean for the city of Goma.

They start by examining the rocks that make up the crater.

They're looking for clues that will tell them

what type of volcano this was.

For many years, the sides of Lac Vert have been quarried,

so, with a little effort...

-You got to go over the head.

-Over the head?

-Yeah.

..they get their hands on some samples.

Kayla is a specialist at interpreting volcanic rocks.

None of this is actually lava. This is all ash.

These are all ash deposits and that means this was magma

that came up through the ground, was exploded under the surface

and absolutely ripped apart into very, very fine pieces

-that you can see here.

-Yeah.

Imagine how much energy it would take to take solid rock

and just explode it into these tiny, tiny bits.

That screams to me that there was an interaction with the water

when this actually erupted.

When a volcano erupts through water,

it creates a powerful and sudden explosion...

EXPLOSION

..known as a phreatomagmatic eruption.

They generate huge amounts of fine-grained ash...

..just like the deposits found here.

So, Lac Vert was formed

by an explosive phreatomagmatic eruption.

The sides of the crater reveal something else.

The eruption wasn't just a single event.

What strikes me, as someone who's interested in sedimentology,

is how many layers of rock there are like this.

The layering in the rock behind us,

I wouldn't want to go over there and count them,

but there's clearly hundreds and hundreds of giant explosions

associated with this catastrophic eruption.

Goma sits in the middle of a string of extinct phreatomagmatic cones

The problem is new eruptions are possible

because they are driven by the rifting

that is pulling Africa apart.

As the rifting stretches the land,

it causes magma to well up from deep underground.

When it hits a layer of water-saturated ground,

just below the surface,

the magma vaporises the water into steam,

causing an instantaneous explosion of enormous destructive power.

We've still got lots of volcanism here.

We're still right next to the lake.

We can see, in Lac Vert, the water table is right here.

There's all the ingredients there for this to happen again.

A new phreatomagmatic eruption,

happening in the middle of the city, could be a catastrophe.

The good news is there would be warning signs.

As magma moves up, it forces the ground apart,

creating mini earthquakes that can be detected

by instruments called seismometers.

A network of seismometers has been installed

to help predict future volcanic activity.

Josh Shabira is a specialist in seismology,

working at the Goma Observatory.

The network should be able to detect magma on the move.

But the key is to work out where an eruption might happen.

The more seismometers in the network,

the more precisely they can do that.

A few days earlier, Josh was working with the expedition

to install the latest seismometer in the network.

As the seismic network grows,

the hope is the Observatory will be able to warn

of an impending phreatomagmatic eruption,

potentially saving thousands of lives.

But there is another danger that threatens Goma

and the area around it.

It comes from the one place the expedition has yet to explore...

..Lake Kivu.

Xand is on the road, far outside the city.

He is investigating whether the natural resources,

created by the volcanoes, can be exploited in a sustainable way.

I think there's one place that is really the best example

of all the good and bad things that these volcanoes throw up

and that's the National Park and, in particular,

the mountain gorillas that live there.

Meeting the gorillas means heading into forests

on the flanks of the dormant volcano Mikeno,

inside the Virunga National Park.

The park dominates the area,

covering nearly 8,000 square kilometres of volcanic landscape.

It includes both the volcanoes Nyiragongo and Nyamulagira

that the expedition has visited.

The volcanoes help make it

one of the most spectacular nature reserves on the planet.

But this is also a dangerous part of the country.

Xand couldn't travel without the protection of Martin

and his fellow park rangers.

There are over 20 different armed groups in the area,

drawn to the lucrative resources found in the park.

I always used to think of the crisis in the DRC as a political crisis

and what's very clear to me now

is that it is a crisis driven by this volcanic landscape

and you can kind of see the tension right here.

These volcanoes produce almost too much riches.

There are too many amazing things to exploit - incredible farmland here,

amazing National Park there, with incredible wildlife.

You've got minerals, you've got timber,

you've got all kinds of things here

that everyone wants to get a piece of.

That's the bit that I hadn't understood,

that the geography plays such a big role in it.

But the National Park is trying to break the cycle of violence

and use the resources

to transform the local economy and benefit everyone.

Oh, wow! I mean, Martin, this is amazing!

-Yeah, amazing.

-Yeah.

-Amazing.

And we've gone from this sort of field

into primary forest in about ten steps.

One of the key elements in the plan

is the income generated by tourists coming to see the gorillas.

Masks limit the chances

of the gorillas catching any human infections.

GENTLE GROWLING

This is completely terrifying.

All I can hear is growling and shaking bushes.

We can hear gorillas all around us, so it feels...

It's very magical and quite frightening

cos there is obviously some more gorillas behind us there

and, whenever they move, you can feel the whole forest shaking.

This is the Humba family.

I've always been fascinated by these animals

but I've never seen them before in the wild.

It's the most human non-human face I've ever seen.

There are fewer than 900 mountain gorillas left in the world

and over half of them live in the Virunga National Park.

XAND LAUGHS

Oh, wow.

That's very funny.

And she's gone from being incredibly dignified great ape

to being exhausted, harassed parent in about one second.

HE LAUGHS

Oh, yes.

Mountain gorillas only appeared around half a million years ago.

They evolved in the unique habitats created by the volcanoes.

The rich volcanic soils have produced a forest

diverse enough to support the giant apes.

They eat more than 100 different species of plant

and to get an animal that big eating plants,

you need a very, very fertile system

and that can really only happen on a volcano like this.

The draw of seeing the gorillas brings nearly 3,000 visitors a year,

generating around 600,000.

The park invest that money

in community and infrastructure projects,

supporting jobs throughout the area.

But the armed groups simply want to plunder the park

for its timber and minerals.

That makes the gorillas a target.

In 2007, the Rugendo gorilla family were brutally slaughtered.

It was a calculated attempt to destroy the National Park...

..by removing their treasured inhabitants.

It failed.

Thanks to the efforts of the rangers,

this part of the park is now the most secure it's been for years

and the gorillas are thriving.

The ambition is to build on this foundation,

increase income and create thousands of local jobs.

It's magical seeing the gorillas.

They are an incredibly valuable asset for this park

and you get a sense of the huge potential.

That's something you can't see anywhere else in the world.

And, if this place can tap into those kind of resources effectively

and make them work for everyone,

you can imagine a very different future for Congo.

But for the park to reach its full potential requires long-term peace.

Only a fraction of the park is currently safe to visit

and the rangers are under relentless attack.

More than 160 have been killed in the last two decades.

To try and get a sense

of whether this fight can deliver a better future,

Xand is going to visit the people

who have to live with the human cost of the struggle.

Chris and Kayla are meeting with Mathieu and Dario

on the waters of Lake Kivu.

They're here to investigate a danger

on a scale far larger than anything they've seen so far.

The hazard exists because the volcanic activity doesn't stop

at the shore of the lake.

It continues underneath the water.

That's created a hidden killer in the depths of the lake.

The only way to check on it is through samples

taken from deep beneath the surface.

-Let's do it.

-Let's try not to lose everything.

Dario and Mathieu send an open sample bottle

down to a depth of 55 metres.

50 metres.

And here we are, at 55.

-If you want to see it...

-I'll stand up.

There it goes. We'll leave it.

A heavy weight is then sent down on the rope

to trigger the mechanism that closes the bottle.

You can feel the weight of that.

I can feel, as I'm dragging it up,

pushing the water out of the way, as I bring this thing up.

I think... Yes, here it is. Look.

Wait, wait, wait, look at the gas coming out.

-Come here.

-Oh, my gosh.

-You see?

-Yeah, the bubbles.

-Wow.

-You see the bubbling?

Those bubbles are not trapped air.

They are gas coming from within the water sample.

Now, let's take it out.

-When you open...

-WATER FIZZES

-You can hear it.

-It's like opening a bottle of pop.

-Yeah, exactly.

-It looks like a soda. It's all completely carbonated.

-99% is carbonated.

-99%.

-Yeah.

The bottom of the lake is full of the potentially lethal

suffocating gas carbon dioxide.

The presence of the gas is a genuine concern

because of what happened at a similar lake in Cameroon.

Lake Nyos also has volcanic carbon dioxide trapped in its depths.

On the night of August 21st, 1986,

a landslide caused a giant pulse of the gas to escape

out of the lake and into the surrounding countryside...

..killing everything in its path.

Over 1,700 people suffocated as they slept.

Lake Kivu is far bigger than Nyos.

All the lake has a huge amount of CO2,

about 256 cubic kilometres.

That's enough gas to cover an area 25 times the size of London

in a suffocating layer, five metres deep.

It could kill tens of thousands of people around the lake.

But there are efforts underway to try and prevent such a disaster.

This is one of the most amazing things I have ever seen.

We're in this glass-flat bay and, all of a sudden,

you come to this platform and it's just... All hell is breaking loose.

It's a massive amount of pressure. It's almost like a geyser.

-It IS a geyser.

-It is a geyser.

It is a geyser and you don't see the geyser itself,

just because there is something on top,

a core that is just 50 metres, in order not to let the geyser blow.

The carbon dioxide is trapped at the bottom of Lake Kivu

by a layer of dense salty water that acts like a lid.

The aim is to slowly release the trapped gas

at concentrations that aren't a danger to human health.

A pipe runs down from the platform into the carbon dioxide-rich layers.

The gas-saturated water shoots up the pipe.

This controlled small-scale release allows the carbon dioxide

to quickly mix with the air, making it harmless.

This is a pilot to see

if there is a way to degas this part of the lake.

If it succeeds, we will make a very big one

to put a very big amount of CO2 in the air.

A controlled release of the carbon dioxide reservoir

at the bottom of the lake could prevent a future disaster.

And it shows how studying these hazards can help reduce

the threat from the volcanic landscape.

Xand has one place left to visit.

He's in the Virunga National Park.

The rangers are in a fierce struggle to preserve the park

and transform the local economy.

Many have died in the fighting

and the battle is far from won.

With the outcome in the balance,

Xand wants to find out if the people most directly affected think

the fight can deliver a better future.

I've forgotten it. I forgotten again. What is it?

Oh, couture. OK.

The women here are widows of rangers, killed in the line of duty.

To help support their families, the National Park has created

a sewing cooperative to bring in extra income for the widows.

Hippopotamus?

Oh, amazing!

This is fantastic!

Noella Wimena is one of the senior members

and takes on the task of giving Xand his first sewing lesson.

Are you ready? I'm going to start. Here we go.

Whoa! This is like a Formula 1 car

of sewing machines! This is...

I did not think sewing would be a high-adrenaline sport.

OK, here we go.

Argh!

Noella, how long have you been sewing for?

-Huit mois.

-Eight months?

-Oui.

-Had you ever used this machine before?

-Oui, oui.

-Yeah?

-No.

-No?

-No.

-You started eight months ago.

And were you as bad as me when you began?

Yes.

-LAUGHTER

-Yes! Great! OK, redemption.

Xand wants to hear

if these remarkable women think the fight is worth the terrible cost.

This is me.

Do you mind me asking what happened to your husband?

-Is that true for the other people who are working here as well?

-Yes.

Would you want your children to be rangers when they grow up?

OTHER WOMEN AGREE

-Everyone seemed to agree about that.

-Yes.

-Really?

Is the park very important for your future

and for the future of the community around here?

Yes.

For the widows, the park is the key to the future,

which makes the room next door all the more special.

Green stars have been painted on the walls,

one for each ranger who has died protecting the park.

It's an absolutely astonishing wall, isn't it?

You'd have thought, talking to a bunch of women

who've just lost their husbands,

that would be the bit that I'd feel choked up about.

The stars are deliberately bright.

This is a place for children to come

to see the memorial to the fathers they've lost.

You could imagine it on a child's bedroom wall, couldn't you? But...

Yeah, maybe it's that, um, there's no attempt to make it...

It's the most modest memorial I've ever seen.

There isn't very much in the history of this region recently

to make you feel optimistic

but there's something about being in this place with these people

that they're building something for the future, I guess.

Park's one of the few places where I can see the possibility

that all these amazing resources that exist here

could benefit everyone,

rather than simply causing division and chaos.

Is that right, little man?

After a gruelling three weeks, the expedition has come to an end.

The team can reflect on some significant achievements.

At Nyiragongo, they tested a new system

that could one day warn Goma before the volcano erupts.

Whilst on Nyamulagira,

they laid the groundwork for predicting future volcanic activity.

If you live in this amazing, amazing place,

you can live with the hazards,

but those hazards cannot be at the front of your mind all the time.

It would just stop you from doing anything, I guess.

The knowledge gained by the expedition,

combined with the work of local scientists,

means that the people here will be better prepared

for future eruptions.

That's never been more vital.

But these volcanoes can never be truly controlled.

This will always be one of the most extraordinary places

to live in the world...

..a landscape of both deadly hazards and incredible wonders.

We have this absolutely vast volcanic landscape here

and the people living right on top of it.

It's my hope that people can learn to understand that landscape better,

in order to not only protect themselves,

but also to reap the benefits from it.

Hey!