Original subtitles

In the northern end of Africa's great Rift Valley

lies an area unlike anywhere on earth.

This is the Danakil desert in Ethiopia,

perhaps the most inhospitable place known to man.

Volcanoes and earthquakes continually rip the ground apart,

spewing lava and noxious gases...

and this is officially the hottest place on the surface of the planet.

The idea that anyone would actually live here seems absurd...

..and yet there are people living here,

as they have for thousands of years.

A legendary nomadic warrior tribe, called the Afar.

I'm setting off with a team of scientists on an incredible journey.

We hope to discover how people survive in this most extreme environment.

How their lives, and even their bodies,

have been shaped by the land around them.

You make it look effortless.

CAMEL RUMBLES

You need to be on good form in this environment just to carry on.

If you're off you will die, nice and simple.

We want to get to understand a community

where survival depends on working together.

I love this place. You just feel part of the family already.

They called me sister today.

We also want to delve beneath the surface of this extraordinary land,

to unlock its secrets.

It's a journey that will take us into the fabric of the earth,

broken apart by earthquakes.

Wow! Whoa! You are kidding me!

To think this happened overnight.

This is the stuff of Hollywood.

And we'll go further still into the raging furnace of volcanoes

that are still shaping this land.

Oh, my goodness.

No wonder the Afar call this place the Gateway to Hell.

We start our adventure in the Ethiopian highland town of Mekele.

So what do you need to mount an expedition

to what is reputedly the most inhospitable place on earth?

Well, our team consists

of 25 scientists, adventurers and specialist camera teams.

We're supported by over 50 Ethiopian drivers, fixers and guides.

And we've got, as you can see, about 2,000 kilograms of kit.

From here we drive about 120 kilometres to the edge of an area

called the Danakil depression, from there we have to go on foot

with camels to a small place called Dallol,

but it's famous for being the hottest place on earth.

Right, I think I'm ready.

To get to the Danakil depression,

we must first journey through the Ethiopian highlands -

our last contact with civilization,

cooler temperatures and greenery for the next three weeks.

Ahead of us lies an adventure that will take us

to the world's oldest salt mines.

Then onto a village in the very heart of the hottest place on earth.

We're also aiming to be the first to conquer the world's newest earthquake fissure.

As well its oldest active lava lake, but we're not just sightseeing.

This is an in-depth exploration

of this extraordinary land and its amazing people.

What I want to do is find out what it is that make the Afar

such great survivors in an area where most people would just perish.

The Afar can only live in this hostile environment

because of their livestock.

So what animals do they keep,

how do they keep them, and while I'm here, is there anything I can do to help?

Meanwhile earth scientist, Dougal, will be looking for evidence

to support his theory

that land the Afar live on is in the process of disintegrating.

And the only way to do that

is to get down and dirty in the rumbling bowels of the earth.

This part of Africa is literally tearing itself apart,

we've got steaming fissures,

active volcanoes and bubbling lava lakes.

I wanna go face to face with those volcanoes,

using the latest 3D technology.

After eight hours of bumpy roads,

we've finally reached the bottom of the highlands

and our first overnight camp.

What a journey. What a journey.

I think we can probably say we're officially in the middle of nowhere.

It was a long old haul, so yeah,

we've earned our water and hopefully some dinner.

It's too hot for tents, so we will sleep under the stars.

It does mean we'll have to look out for unwelcome visitors,

but luckily we have Steve on guard duty.

We're just having a quick scan around for scorpions.

The peculiar thing about them is that they fluoresce under UV light,

so we've got a UV light source.

Oh, here we go. Here we go.

See how it shines absolutely apple green, there's no mistaking that.

The thing with scorpions is that you'll be stung before you know it's there.

There are around 17 species of scorpion in this part of the world.

The dry rocky conditions make an ideal habitat.

Sorry, guys, we have found some scorpions just outside camp,

so just letting everybody be aware that they are knocking about.

They're not going to kill you, it's just going to hurt like fury,

so no sandals if you would.

We settle in for the night

and it's really starting to feel like the expedition is underway.

We're here now, and actually, sleeping under the stars,

that's a bargain. You've got to love that.

Big, full old moon. Yeah, very happy now.

Tomorrow's the start really of our first big physical test

here in this very remote and extremely hot part of Ethiopia.

I think it gets hotter as the journey goes on.

We're being let down gently into the heat,

but it's going to be a tough day, I suspect, but a good one.

We wake to a scene that has remained almost unchanged for 2,000 years.

This is the starting point for great caravans of camels

on their way to the Dallol salt mines

in the heart of the Danakil desert -

where our scientist's mission will begin in earnest.

Though first we have to get there.

It is accessible the long way round in a 4x4, but we want to experience

that journey as the locals do it, with a camel train.

Well, from now, these vehicles aren't going to be any good to us,

cos the route we're taking can only be done on foot...

and by camel, so these camels are all loaded up with everything

that we need for the next three days.

For Steve, this is an opportunity to study the camel in action.

He's picked one out and for some reason known only to him,

he's called it Jeff.

All right, Jeff, it's going to be fine.

What Jeff doesn't know is that he and his mates

are the key to the Afar's survival.

You might be thinking that Jeff's coping well with the heat,

but then so am I. The key difference between me and him...

CAMEL RUMBLES ..Yep, you, lad,

is that I have to drink about a litre of water every hour,

whereas Jeff, despite his complaining,

doesn't have to drink anything for the next seven days,

despite this heat.

They don't store water, he hasn't got water in that hump,

that's purely a fat reserve. He's got a little bit in his guts,

but the key thing that he does is that he doesn't lose what he's got.

He uses his long limbs and his long neck as radiators

to get rid of heat without losing water.

He hardly sweats at all,

he sucks every drop of moisture out of his food,

and he allows his core body temperature

to rise up to six degrees higher than normal,

which would kill a human.

It's all very well for camels to set off without water,

but we're going too.

And that means we have to take a vast quantity of water with us.

It really will make the difference between us surviving this trip...

or not.

So our expedition doctor, Mukul,

is determined to make sure we all get the message.

Sifa's our guide. He's going to tell us what we've got on today.

For the next days, we'll be walking on the salt caravan route.

This route is always really difficult.

There are many people who die from the weather, I mean, from the heat.

This is serious stuff. Just from the car yesterday,

a lot of us weren't as good with the water as we could have been.

I had a dehydration headache and I know several others did.

We've got to better here otherwise this will kill us.

We're in the middle of absolutely nowhere and it's going to get worse.

And the good news?

This is one of the great trade routes of the ancient world.

Over the centuries thousands will have set off from here

and I feel a real sense of privilege to be one the few westerners

to get the chance join them.

But this part of Ethiopia

can also be a dangerous place for outsiders.

Just last year, a group of British tourists were kidnapped

only a few kilometres from where we're walking.

These high-sided canyons make perfect ambush territory

for local bandits.

So it's comforting to have Afar local militia to look after us,

with the standard must-have accessory - the AK-47.

But while we move quickly and rather nervously through the canyons,

geologist, Dougal, can't resist taking his time

to get a proper look at the rocks.

We've now entered this world, which I'm really, really excited about,

because we're going down canyons where either side of the canyons,

I've got just geology, just geology exposed 100 per cent.

Whatever the dangers and the hardships,

for Dougal this is what the trip is all about.

Either side of the valley are fantastic sedimentary rocks.

These rocks are sediments that were deposited in marine settings,

so they would have been horizontal as they were deposited.

You get a series of rocks over thousands, even millions of years deposited through time.

What we are seeing here is these rocks are now tilted.

They've been tilted along massive cracks in the earth's crust,

which is essentially acting as big fault zones

and these things are tilting in. That's very important in this region.

And Dougal finds evidence that as the land here sinks,

it's bringing us closer to the volcanic layer beneath the earth's crust.

Here we have a crack in the earth's crust

and here you can see a brown rock is coming up through that crack.

This brown rock was molten rock before, magma,

which is lava when it erupts at the surface and feeds volcanoes.

What we're seeing here is like a freeze-framed plumbing system of a volcano.

As our second day draws to a close,

in the heat it feels like we've covered a huge distance,

whereas we've only done 18 kilometres -

well short of our target.

Day three and our first serious test begins -

a 30 kilometre hike to the next camp site.

And to add to the unrelenting sun and lack of water,

we have a new element to overcome - the Gara -

the wind of fire, which powers down from the baking sands of Arabia,

turning this part of the desert into a vast super-heated wind tunnel.

Today we've got a really hard day because, not only have we got to face the fire wind,

which apparently is similar to standing in front of a fan-assisted oven

with it on full blast all day,

but we've also go to make up all the time we didn't do yesterday.

So, we've probably got ten or 12 hours walking today.

If we can keep up an average speed of three kilometres per hour,

we should reach camp before nightfall.

Any one of us could manage that speed in normal conditions,

but these conditions are far from normal.

By early afternoon, the temperature has hit 46 degrees.

Despite our best efforts, all the elements nature has thrown against us

have slowed us more than we thought.

As the sun goes down, we still have several kilometres to go.

So we have no choice, but to keep walking into the night

to reach our overnight stop.

We're walking through what can only be described as a human-sized hair drier.

This is the fire wind we've all been talking about,

but obviously it's at night-time, so it's a bit cooler.

The reason we haven't stopped to camp is because this area is a bit unsafe

there's no shelter, there's no water provisions,

and also there's some rebels in the area.

All we can do is hope our guides know where they're going

as we play follow-my-leader in the wind-blown dark...

until we finally we make it to camp.

Eurgh, all the grit. Right, we're here.

A full 15 hours after setting off.

I'm just really, really glad I phoned ahead for the Penthouse Suite.

I'm looking forward to that tonight, I can tell you.

You know, all I can feel is this wind.

I have a sense of the fact that this place is a wide-open space.

Tomorrow, when the sun comes up,

I think we'll get a better idea of what we've got left.

We wake up in a place called Hamed Ela.

Officially it's a village -

in fact it's little more than a bleak military outpost,

just 15 kilometres from the border with neighbouring Eritrea.

After a decade of open warfare,

they're now enjoying a period of peace.

But no-one's quite sure how long the fragile truce will last.

That's the border with Eritrea...

so this is a very hot, political area.

There are police and army, basically stationed here at all times.

We were told very categorically,

"When you want to go for a wee in the night,

"don't go that way because you will be shot."

We are now just two hours walk from our first destination,

the salt mines of Dallol.

This is the point where we descend into the Danakil depression itself...

..to the hottest place on earth.

In the '60s an American mining company

set up a huge industrial operation here to mine potash for fertiliser.

The venture lasted two years before the unrelenting desert heat

forced them to close.

But during that time they recorded an annual temperature record

that still stands - an average of 34.4 degrees centigrade,

day and night.

Unbelievably, where the machines failed, humans succeed.

Part of Mukul's mission is to look at how the locals cope with working in such extreme temperatures.

So he's devised a little experiment.

He's volunteered two guinea-pigs, Steve and me, to try our hands

at mining while he monitors our body heat...from the inside.

You'll swallow some little radio transmitters that are temperature sensors,

see what the temperature is inside us.

The capsule is this thing, which is a little radio mic.

Little? That's a jelly bean.

So it's a radio transmitter? It's a radio transmitter

and it will tell me what the temperature inside you is.

Do you want this back?

You need to bring your own back.

When we get to the mine, Mukul hopes to persuade some local miners

to swallow identical transmitters. So he can find out if their bodies

have some in-built adaptation to the heat,

or if they've just learnt to put up with it.

Steady on there, Mukul.

We've walked just short of eight kilometres this morning,

the temperature now is 41 degrees and it's 11.10 in the morning.

But, the good news is, on the horizon

there are all sorts of extraordinary shapes, which can only be camels.

So I think we're in striking distance of the mines.

We are speechless as we arrive.

It's as though we have walked through a window in time.

This incredible scene has barely changed

since the time of Julius Caesar.

Every day hundreds of men and boys hack blocks of salt

from the ground by hand,

after they've walked the same exhausting route we've just taken,

in the baking heat.

You can see the scale of it because this is where they're working,

but look how far -

that's probably hundreds, if not thousands of years they've been doing it.

Oh, my God, that is incredible.

I'm kind of overwhelmed to be honest,

it's like going back about 2,000 years.

It also makes you think you will never, ever, ever take for granted

that little pot of salt on your table, ever again.

My Goodness.

There are two jobs here,

splitting and lifting the great salt slabs,

then shaping them into precise one kilogram blocks.

This turns one of Ethiopia's few natural resources into hard currency.

One block of this salt is how much for the caravan people?

THEY SPEAK ETHIOPIAN

One birr.

Right.

Each block is worth five pence down here,

but they're worth ten times as much in the markets in the highlands.

And the miner gets just £2 for a 12-hour shift

of back-breaking work in the hottest place on earth.

I thought mining down the bottom of a hole would be hard,

but this looks incredibly hard.

OK. Come on.

Which takes us to Mukul's experiment.

Are you ready? Yeah, I'm ready.

With our temperature transmitters working inside us,

Steve and I try our hand at mining - the Afar-way.

OK, so one, two, three, bounce. Two, three, bounce.

One, two, three, bounce.

Hang on, hang on, Steve. Wait, wait, wait.

I need to get more purchase here.

One, two, three.

One, two, three. One, two, three.

One, two, three.

THEY CHEER

I can feel my heart rate's gone up something rotten.

Meanwhile, Mukul is persuading the locals

to swallow one of his capsules.

One of the miners has kindly agreed to swallow one of the core capsules for us

and it'd be very interesting to see whether the miner reaches the same temperatures

that Kate and Steve will reach while they're working in these mines.

I'm not sure what our core temperatures are,

but after a few minutes, Steve and I are really struggling in the heat.

HE LAUGHS

I'm sweating!

While Garay, who swallowed the other capsule, seems totally unaffected.

You have to do more... Do it faster. ..be good, like Steve.

So what's Mukul's meter reading?

You look hot. Actually you have gone red.

I did, certainly I felt like I had.

What the readings show is that Garay, whose been working here all day,

hasn't really got very much above 37 degrees.

You guys who've only really done 15 minutes worth,

have risen a whole degree to 38 degrees.

One degree doesn't sound much,

but just two degrees higher would put both of us at serious risk of heat stroke.

It doesn't stop, that's the most amazing thing.

I can do it for short bursts, but nothing like this, it just goes on and on.

What is clear is that in this heat,

Garay's body actually functions differently from ours.

So Garay basically is...has adapted

or is genetically able to deal with this, what do you think?

That's the question we haven't yet answered in this trip.

What we've undoubtedly answered from the Afar and from Garay whose a highland Ethiopian

is that they manage it completely differently,

they're much more efficient.

At the moment, we can't say why the Afar

are better suited to the heat than us.

But Mukul hopes to repeat the experiment in a few weeks time

to see, if after a living here a while, our bodies show any signs that they've adapted.

But however well adapted we humans get, we'll never match these guys.

The Afar's camels are already the perfect desert machine.

Evolution is a very, very powerful thing.

There isn't a scrap of design in this camel

that isn't enabling it to cope with this environment.

They don't waste anything.

They can hang onto their water, they can push out very concentrated urine.

Mine gets fairly dark, but I have to produce a certain level of urine.

They produce a really, really concentrated urine.

Therefore saving that water to keep them going, to keep their blood pumping around their veins.

Oh! Got some fresh camel urine here for you.

As you can see, it's very, very dark, it's very, very yellow.

Which tends to mean it's concentrated.

The other way of telling that is, if you dip your finger in it

and then lick it, it's very, very salty.

Kate, do you want to come and try this?

What lick your camel urine?

I'd love to. I can't think of anything I'd like to do more.

Just dip a finger in and put it on the tip of your tongue.

You're serious? Serious, yeah. Just dip.

Whose is it? It's this guy's over here.

I just wanna know I'm not just tasting any old urine.

Does it taste salty? Tastes of urine.

Yeah, well what you didn't realise... Nice.

..I dipped this finger

and then licked this one. Ha-ha! Very funny. Thanks, mate.

You can't tell anything from tasting it.

While I wash my mouth out, Dougal and the rest of the team

are setting off to find one of the clues to why this is the hottest place on earth.

Apparently, it's all to do with why these salt-pans came to be here in the first place.

We are driving across one of the lowest places on planet earth,

120 metres below sea level.

So low in fact that when sea levels were higher tens of thousands of years ago, this was all ocean,

and some of the salt we see today results from evaporation

when those oceans dried up.

But the main reason is what lies beneath us -

a huge volcanic engine drawing salty ground water from the nearby Red Sea

and pushing it through the surface layer.

And the most incredible thing is that Dougal finds the volcanic engine is still running.

Believe it or not, this shallow mound behind me

is the world's lowest sub-aerial volcano

and there's very few geologists that get to see this in the flesh.

So I'm really excited.

The first evidence we're going to see of the dramatic situation happening beneath our feet.

As Dougal's team reach the edge of the crater,

its clear this is no ordinary volcano.

Like the surface of an alien planet,

Dallol is crowded with ridges and towers of crystals...

and pockmarked with hissing gas vents

and pools of concentrated acid.

Our scientists will need to treat this place with respect.

Quick safety briefing, very important, about where we're going.

You've got to follow the Afar guides. Sifa comes here quite regularly.

He was up a couple, say a year or so ago,

he stepped on what he thought was a fairly solid surface,

went straight through and this was the effect.

So when Dougal sets off to explore the volcano system,

he takes trip doctor, Mukul, with him.

What kind of acid would you have here?

Primarily you're looking at sulphuric acid.

You can see by the yellows, these lovely bright yellow and orange colours,

there's lots of sulphur crystals.

One of the major gases you get off the volcanic rocks

is SO2, sulphur dioxide.

These sulphur springs are evidence that the hydrothermal system

is still active, so at depth there must be hot boiling magma,

which is driving this salt engine factory.

Dougal's mission here is to find evidence

of how active the fault system is beneath the Dallol salt flats.

So, he's testing the acidity of the pools with a PH meter.

Let's see if we can get a reading form it.

The more acidic they are, the higher the influence of the magma below.

It's off the scale, absolutely off the scale.

It won't read the PH, because the PH is so extreme.

A few years ago, these acid pools were tested and had a PH of two.

Now they've hit zero, about as acidic as it's possible to get.

It means that the magma is highly active, and could erupt again soon.

For Dougal it's more evidence that this whole part of Africa

is getting more volcanic as the earth's crust splits apart.

The earth's crust here is really, really thin.

And it's really thin because beneath my feet

we're at the boundary of three major structures in the earth's crust.

These structures are literally tearing themselves apart.

When it tears itself apart, it gives it cracks and structures which

molten magma can work through to the earth's surface as volcanoes.

So as it sinks further into the volcanic underworld,

the hottest place on earth is only going to get hotter.

This is it, we're leaving Dallol.

All the vehicles are being packed up

and suddenly we're not gonna be on foot any more.

We're gonna be in these trucks heading south

to what is going to be our base camp now for the next few weeks.

Our destination is the village of Kusru Wad.

The journey should take four hours, if nothing goes wrong.

And that's a big if, because we're heading out across

some of the most rugged, hostile terrain in this part of the world.

And that's saying something.

THE ENGINE STALLS

We have a stuck vehicle. All vehicles stop now, thank you.

It's too hot for this.

I'm seeing the wisdom of using camels in this terrain.

Camels don't have alternators, wheels that get stuck,

they don't need power steering or pulling out by a rope.

This is becoming a bit of a chore now.

We've been going for nearly two and a half hours,

we've made probably about five, maybe six kilometres.

It's not going particularly well.

But it will be worth it, because we'll finally get to meet

the people who live out here permanently,

the Afar communities of the Danakil depression.

I'm incredibly excited because this why I'm here -

to work with and learn from these unique people,

to discover how they survive from day to day.

By the time we get to the village, its dark

and we have no idea what kind of place we'll be calling home

for the next few weeks, or what kind of reception we're going to get.

Hello! Hi!

Will you say from all of us this is very special for us

and to say a huge thank you for allowing us to come and stay

on their land and with them?

HE SPEAKS IN HIS NATIVE TONGUE

Congratulations to you and we love you. We are glad to meet you.

We love you.

Thank you very much. Thank you.

So, we needn't have worried. Not only do they love us,

they've even laid on some traditional dancing.

And though it's meant to be just for the men, I'm so glad to be here,

there's nothing gonna keep me off that dance floor.

Oh my goodness, I've scored and I've only been here ten minutes!

This is when you really feel like I'm in Ethiopia

and I'm going to find out about these people.

You fell like you really are being welcomed

into this big extended family.

It suddenly feels, after the walk and everything,

that we have really arrived.

It's five am and the start of our first day

living with the Afar people in Kusru Wad.

This is going to be the first time we can understand how the Afar live

day to day in this incredibly harsh environment.

I'll be living with the women, while Steve and team biologist Richard

will spend the day with the village chief.

Richard. I'm Steve.

My name is Gilissa. Gilissa.

The Afar are reputed to be one of the most ferocious tribes

in the world and the chiefs are commonly given a name

that reflects their power.

In English, Gilissa translates as frightening.

You have a very interesting name. It means frightening.

But he looks very friendly and hospitable and warm.

Though we've come all this way to find out about the Afar,

we find they're just as interested in learning about us.

I have to ask you a question.

Where we come from, the sun is not very strong.

The longer we stay in Ethiopia, the darker our skin will become.

To be honest, I don't know.

Gilissa's first job of the day is to tend to his camels.

Providing milk, meat, transport and status,

camels are the Afar's greatest single possession.

HE SINGS

So it's not surprising Gilissa sings to his

every morning before milking begins.

Guests are traditionally welcomed with fresh camel's milk.

So for Steve and Richard, this is a huge honour.

That's very nice, that's very nice.

And it's considered very rude not to finish it.

There you go! Get it down you! Thank you very much. It's great.

Camels' milk is a vital source of protein and fat

in the Afar's otherwise fairly meagre diet.

It's obviously important to him

that his male children grow up big and strong.

It just goes to show that these guys could not live here

without these animals. These animals are their lifeblood.

Look at that lovely big white moustache. Ha-ha!

This part of the Danakil Depression

is just as hot as anywhere we've travelled through,

with daytime temperatures regularly approaching 50 degrees Centigrade.

But it's also remarkably green here, and that's because there's water.

If you know where to dig.

It's a deep well, 15 feet deep.

Team medic Sue and I

are spending the day with Galissa's wife and daughters

and our first job is to collect water.

The Afar have always been a nomadic people,

travelling in search of grazing for their animals.

But for the last 30 years,

the people of Kusru Wad have settled here

because oases like this are few and far between

and the Afar know a good thing when they see it.

This is quite a luxury, really,

because having a well so close to the village is obviously a bonus.

However, you've still got to schlep down here,

pull the water up, fill your containers and schlep back again.

What feels like a luxury to the locals,

feels like damn hard work to me.

It seems to be the traditional way to carry water,

which makes a lot of sense, because as you know,

it's much heavier carrying something in your arm.

Sorry, I've got to concentrate here.

OK, which way? Under my arm?

It's not the most comfortable of positions to be in.

Like that?

Good? Everyone happy? OK, back up the hill.

Look at you, you make it look completely effortless.

The Afar women's day is a non-stop cycle of cooking

and collecting water and firewood.

But while I join the women in their daily labour,

Steve and Richard are sitting down with Gilissa

for a cup of tea in the shade.

There is a distinct imbalance in the workload here

that I'm finding hard to ignore.

It is a hard, hard life for these women, undeniably a hard life.

To me, a stranger, they seem very cheerful,

but maybe over the next few days,

we'll discover that life for the Afar women

isn't as cheerful as it appears on the surface.

If I can find a moment when the men aren't around, I may learn what

the women think about their lives here.

Day two and Dougal is heading off with his team

to continue his geological exploration of the Afar region.

On our journey here,

he's picked up evidence of increasing volcanic activity,

which could mean the horn of Africa

will eventually break away from the continent

and lead to the birth of a new ocean.

Just a few days' drive away,

there's evidence that this is happening faster than we realised.

Two years ago, there was an earthquake, which the locals say

produced a vast crack in the surface of the earth.

We're hoping to see something very visual from the ground up.

We know that this particular fissure

was involved in a small volcanic eruption.

There should be good evidence

of essentially the ground breaking apart under us.

The fissure is so remote,

it's only been mapped by satellite and no-one has ventured inside.

So this journey promises to be a scientific goldmine,

if they're able to get the team and their equipment

where no man has gone before.

While we wait for news of Dougal's venture,

Steve finds that the Afar rely for their survival

on another staple animal, just as important as the camel.

That universal ruminant, the goat.

Goats are one of the most amazing species. They can live everywhere.

The top of mountains or out in the desert.

We're going to follow these guys and we're going to see

just how they use their behaviour to exist out here.

It's a completely different role than the camel's.

Like camels, goats can provide milk and meat,

and though they're no use for transport,

they're a lot more placid and much easier to keep.

Responsibility for looking after them is given to the children.

The little boy who seems to be in charge,

that's Abdullah, he's probably about six or seven.

Given how important these livestock are,

and what a massive part of the wealth of this family

is tied up in these animals, that's a huge responsibility.

The vegetation here, despite the water,

is very sparse and toughened by the harsh desert conditions.

To find out just how the goats find enough to flourish,

Steve has decided to conduct a simple experiment.

I'm going to have to be a bit on the sly side.

Oh, steady! There we go. You're gonna be our test goat, OK?

I'm going to pop a little GPS tracker on him or her.

I'm gonna pop it round its neck. Good man, you hang onto goat.

What's the goat's name?

Afassi. Afassi. Red Mouth.

Red Mouth? Let's follow Red Mouth then, Afassi, and see where he goes.

Steve is hoping to collect samples of everything Afassi eats in a day.

Afassi, where have you gone?

A mouthful here and a mouthful there, that's what it's all about.

There's fruit, dry leaves, this other woody, herby plant.

It all aids the digestive process.

When Steve downloads the GPS data,

he'll be able to see just how far the goats have to go

to get a square meal.

You're doing a good job. You doing a good job?

Yeah, good. Good lad. Come on, then.

Come then! Come on!

Come on! That's it - you tell them what to do!

HE LAUGHS

Who teaches you to dance? It's very cool.

That same evening he gets the results of the goat test.

I'm downloading the data now. It's quite interesting, actually.

The X axis is time, moving along here.

And then the Y axis here is speed.

Zero is here. When she's at this point, she's stood still.

And you can see she's moving, stopping, moving, stopping.

In just an hour, Afassi stopped 30 times.

Over the course of the day, the little goat walked

a staggering 12km as she sought out enough food to survive.

What this really highlights is this ability of the goat

to seek out the good food.

It's not just wandering up to one bush

and munching away on that until everything's gone.

Quite often we would see the goats today,

they'd sniff at something and they wouldn't eat it at all.

You'd think that can't be a good survival trait

if it's turning its nose up at what looks to us to be good food.

Obviously it can detect that it's not quite as good as the next bush,

which means that they get the best out of what's available.

This is why the Afar rely so much on their goat herds.

The goat's ability to turn sparse bush into walking protein

is largely what keeps the people here alive.

The next day, on the dusty road to the earthquake fissure,

Dougal's venture hits a snag.

Not content with just going to the site of the earthquake,

Dougal's brought along over 100 kilos

of state of the art equipment to map the earthquake fissure in 3D.

But this is as far as the cars can go

and there aren't enough camels to take the kit.

As you can see, it's still a pretty horrendous, dusty place.

We've only got half the camels we asked for,

the other half are somewhere in the dust over there.

I guess we're going to load most of the heavy gear here.

Hopefully the other camels will pick up the rest.

We've only got basically a day and a half up there

to make sure the whole system works.

We'll push on ahead, hopefully we can catch up a little bit of time

and hopefully the sun will be a bit kinder to us today.

Fat chance! Ha-ha!

They have no choice but to load as much onto the camels as they can,

and set off walking across the lava fields.

What should be a half day's trek as a camel train

turns into a day-long hike

with no guarantee they'll have enough gear to do the 3D scan.

Six AM the next day,

and they're still a kilometre from the earthquake fissure.

Some camels have arrived, but the rest could be anywhere.

We've got basically one day of sunlight left.

We've got the fissure to do and that's it, we can't fail, this is it.

Today is one day and one day only.

But now there's another obstacle.

The last kilometre between them and their goal

is studded with volcanic vents spewing deadly sulphur dioxide gas.

It's like a chemical minefield which they have no way of avoiding.

So, carrying gas safety monitors,

Dougal and the team set off on the final leg of their journey.

Walking in with your detector,

I feel almost like a canary heading into a coal mine.

Hopefully I won't be a dead canary!

What he doesn't know is that the rest of his vital mapping kit

has finally left base camp and is on its way.

But there's still no guarantee it will arrive in time to use it

before it gets dark.

However, after a highly stressful and demanding three day journey,

Dougal is about to get his first sight

of the Dabahu earthquake fissure.

Well, we've still got some fairly low readings, which is good,

but we've got to be close... Keep monitoring it...

Ohhh! Oh, whoa...!

You are kidding me! Absolutely awesome.

I was expecting a small crack in the ground! Oh, my Lord, this is fantastic.

It's up there in the hall of geological fame, I think. My Lord.

Before the eruption, locals recall how the ground swelled

until it finally burst open in a massive explosion,

throwing thousands of tons of ash and rock across a vast area,

and swallowing their camels and goats.

This vast crack in the earth is all that was left behind.

To think this has happened... Excuse me, I'm out of breath with excitement at this stage.

To think this happened overnight... This is the stuff of Hollywood.

When you're a kid and you see those movies of streets breaking apart,

this would have just opened up and ejected a whole heap of magma.

This is just phenomenal.

I really hope we can get some really good stuff out of this, because having got here now,

I wish we could stay three, four days, maybe even a week, this is just geologic heaven.

This is fantastic.

There are only a few hours of daylight left for Dougal to make his scan,

but at least all the kit has now finally arrived.

This unit here fires, um...

millions and millions of laser points in a 360 direction to build up a complete 3D picture

of the landscape around it. The final thing we need to do is to fit a camera to the top

and what we'll do is we'll take high-resolution digital photographs

and the computer software will then be able to merge the picture with the scan

and that's when things get really exciting.

The reason the 3D scan is so important is that it creates

a snapshot of the exact state of the fissure at the moment,

because if, as Dougal suspects, the earth's crust is breaking apart here,

measuring it now will help geologists understand how fast that process is moving.

So to work out if the fissure getting deeper, wider or longer,

a 3D model is needed, and that's what Dougal hopes to make.

The only problem is, he'll have to get himself and his laser scanner

60 metres down there, before it gets dark...

and there are no stairs.

We're going to put a line, and it's like a cable car, if you like,

going across a cable,

and that cable we'll control from here, so we'll release the tension and that cable will slacken,

so the person that's gone to the middle will get lowered down in the middle of the V, if you like.

Whilst getting inside is a big safety concern,

the deadly gases that lurk below are an even bigger worry.

As well as sulphur dioxide, there's the threat of carbon monoxide

and hydrogen sulphide, all of which will kill.

Dougal has completed the scan of the rim of the fissure,

and is ready to get down inside for the final part of the picture.

But before Dougal is allowed in, expert rigger Mark Diggins

must first test the rig and the gas levels.

VOICES TALK OVER RADIO

Mark is going where no man has gone before.

OVER RADIO: 'OK, bit more, bit more...'

As well as the risk of gas, there is the constant threat of another earth tremor.

And that's before he gets to the bottom, wherever that turns out to be.

With just two hours of sunlight left to get Dougal and his scanning equipment down,

they can't afford the slightest hitch.

BEEPING

Stop there, guys, stop, stop, stop.

BEEPING CONTINUES

That doesn't sound good, I mean, one of his meters is going off...

The alarm means there's deadly gas, but no-one knows which one.

There's a lot that could be going wrong down there.

Wait, I gotta focus one sec...

So that was the H2S alarm going off. So this is hydrogen sulphide...

which is probably the one which is the most dangerous, and the one we didn't really want to be seeing...

Hydrogen sulphide can kill with just one breath.

If Mark's breathing apparatus had failed or his face-mask slipped,

the fissure would have claimed its first human victim.

Pretty much they say the last thing you'll ever smell

is the smell of rotten eggs, which is H2S, and is enough to kill you.

This is a once-in-a-lifetime chance to create a unique scientific record...

but at what risk?

You'll only get one crack at it, and if that BA equipment packs up whilst you're on a rope,

you're not going to be getting out of it.

We've taken the right precautions and made the right measurements

to ascertain that it's not a particularly nice place down there.

And so...I don't think we should pursue going in there any further.

This is a massive disappointment for Dougal.

His only hope now is that he can salvage something from the scans around the edge of the fissure.

Hey, come and have a look at this.

We've just got the first scans up.

It's raw data at the moment... Oh, my God!

If this scan's worked, hopefully the other two have, and we'll be able to stitch all three together.

I was worried there that we wouldn't be able to get anything today. It was such a rush.

I'm happy for you guys, this is good.

Despite having to abandon the final descent,

the scans from the edge have produced an almost complete 3D snapshot of the earthquake fissure -

the first ever.

Armed with this first baseline model, the rate the Horn of Africa

is separating from the continent can now be plotted.

But Dougal is not content with just one geological first.

He has an even bigger target in his sights -

a vast lava lake called Erte Ale,

which Dougal believes will prove how incredibly thin the earth's crust here has already become.

I feel a celebration coming on. Let's go and have a drink,

and drink to Erte Ale, and the future of the expedition.

But if mapping a hole in the ground was tough,

doing the same inside a live volcano is likely to push the team to breaking point.

Next time on Hottest Place On Earth -

While Steve tries to learn the local version of rugby...

I didn't realise they'd got knives on their belts.

My concern over the way the women are being treated comes to a head.

There's men everywhere, just listening in -

"Don't you dare, don't you dare give away our secrets!"

Mukul has to deal with a major medical emergency...

He's got a very loud heart murmur. Oh, my God...

I've held dying children and it's a terrible, terrible thing.

And we have to make some tough decisions

about how far go in helping the Afar people.

They basically take the child and the mother by force,

but this really is a matter of life and death.

And Dougal takes his team on a voyage into the unknown.

Whoa...! This is huge!

A daring assault on the oldest active volcano in the world.

Smoke me a kipper, I'll be back for breakfast.

All of us understood why the Afar think that this is the gateway to hell.

Subtitles by Red Bee Media Ltd

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