Original subtitles

(volcano rumbling)

(volcano rumbling) (gentle suspenseful music)

(rock crashing)

(volcano roaring)

Volcanoes.

They erupt with a force that we can't control,

a fire we can't put out.

Their mysteries are still being explored.

(lava roaring)

Scientists are asking,

how did volcanoes shape the world we know today?

(lava roaring)

(majestic music)

(suspenseful music)

Our story starts in space.

This is what Earth may have looked like

4 1/2 billion years ago.

This small planet, called Theia, is heading straight for it.

(suspenseful music)

(planets crashing)

Early Earth had multiple impacts,

but this one was the most destructive.

The collision shatters Theia,

and vaporizes Earth's outer layers.

Over time, the surface reformed as a fiery, molten sea.

But this is not a fire as we usually think of it.

Rather, it's an unimaginable amount of heat,

that is continually flowing out of the planet.

It is released most dramatically through volcanoes.

(lava roaring)

(suspenseful music)

This is Marum Crater on Vanuatu, in the South Pacific.

Deep inside,

a lava lake, one of only a handful on Earth.

(lava roaring)

Could this be what our planet's surface looked like

4 1/2 billion years ago?

As the lake churns, lava is thrown out

and cools to form the newest rocks on the planet.

And every rock tells a story.

(lava roaring)

By analyzing the rocks,

geologists can learn secrets about Earth's beginnings.

But first, you have to get to them.

This crater is deep enough to swallow a skyscraper.

The only way in is a treacherous rope descent

down a sheer, unstable rock face.

And, if that isn't enough, the air is toxic.

It's a place no normal human would go.

Carsten Peter, however, is not normal.

(playful music)

Carsten is a "National Geographic" photographer driven

by a passion for exploring volcanoes,

no matter how remote

(rock crashes)

or dangerous.

(suspenseful music)

For decades, his camera has captured the Earth in action.

I want to be as close as possible

to kind of give a intimate view into a volcano.

(gentle majestic music)

Plain photography is maybe not really enough for me,

so I always, I like these additional challenges

in climbing down volcanoes.

(gentle majestic music)

Decades ago, he led one of the first scientific

and photographic expeditions down to Marum's lava lake

where he collected rocks for study.

Ever since, he's been looking for a chance to do it again.

But right now,

the miserable weather has been his biggest obstacle.

For two weeks, there have been torrential downpours,

and sulfur dioxide gas is now turning them into acid rain.

Acid attacks everything,

everything from your skin, the eyes, mucous membranes,

to technical equipment, to the ropes.

They get a break in the weather.

It's not perfect, but this may be their only chance.

(pensive music)

Carsten is working with a team that specializes

in high-risk climbs,

expedition leader Geoff Mackley

and climbing expert Chris Horsley.

(suspenseful music)

(suspenseful music continues)

(lava roaring)

You feel definitely very insignificant

down there.

The walls are kind of straight up,

and then you have this raging monster next to you.

Yeah, it's amazing feeling, of course.

(lava roaring)

(gentle majestic music)

Their luck is short lived.

Rain is moving back in that could trigger deadly mudslides.

They have to come back up and wait.

(volcano rumbles)

(wistful music)

As the days go by, it becomes apparent

that the seasonal monsoon rains have started early

and will continue for months.

Carsten will have to come back and try again.

It is always disappointing

when you cannot fulfill what you intend to do.

Vanuatu is not finished for me.

So, if the Earth's surface

once looked like Marum's lava lake,

how did it go from that to what we have today?

One theory suggests,

after Earth's collision with Theia,

gas and debris were blasted into space,

and likely formed our moon.

(suspenseful music)

At that point, the Moon was a lot closer,

and its gravity pulled at our planet,

helping keep the surface molten.

The Earth's rotation slowed as the Moon drifted away,

and the surfaces of both cooled and crusted over.

(suspenseful music)

It was a dynamic time.

New crust was created by cooling magma,

and where the heat broke through, volcanoes were formed.

(majestic music) (lava roaring)

(rock crashes)

(majestic music)

(ash crackles)

(majestic music)

Their eruptions sent out vast volumes of gases

that helped build our early atmosphere,

(majestic music)

(birds calling)

and provided water that contributed to our first oceans.

At the same time, volcanic activity carried minerals

to the surface, and the landscape began to change.

(geyser gurgling)

These hydrothermal pools give us a sense

of what early Earth might have looked like.

In here, are simple elements that are the building blocks

for life.

(gentle majestic music)

(suspenseful music)

The Earth's surface was probably too hostile

for life to take hold.

In the ocean, it was a different story.

A majority of the world's active volcanoes are underwater.

These boiling hot hydrothermal vents

are called black smokers.

(mystical music)

Scientists believe

that simple life forms may have originated here

and then spread through the oceans,

becoming more complex,

and eventually moving onto land.

This was just the first chapter

of how volcanoes may have helped create life on Earth.

(birds chirping)

(volcano rumbling)

(ash roaring)

(wistful music)

I was always fascinated by volcanoes,

so I asked my parents to go to Mount Etna in Sicily.

It was not active, but still, I was kind of blown away.

And I wanted to see my next volcano active.

His next experience was almost his last.

(birds chirping)

Well, we did everything wrong

what you can do wrong with volcanoes.

We went very close to the vent.

Suddenly, there was a big eruption.

(lava roaring)

Just running for our lives.

(lava roaring)

We realized immediately how dangerous volcanoes can be.

(light energetic music)

That close call marked the start of his career

as a photographer.

(light energetic music)

(birds chirping)

Today, he's on a remote island in Indonesia,

headed for a rather moody volcano called Dukono.

It's part of a region referred to as the Ring of Fire,

where plate tectonics cause a lot of volcanic activity.

Dukono erupts every 15 minutes, hurling rocks.

(birds chirping)

About a mile and a 1/2 from the volcano, they find a rock.

It tells the story of an earlier, massive eruption.

And it's a reminder that even at this distance,

they have to keep their wits about them.

(light energetic music)

(volcano rumbles)

To get the vantage point he wants,

Carsten needs to set up on the rim of the crater,

unnervingly close to the active vent.

This is where his considerable experience means everything.

(volcano rumbles)

(ash roaring)

(lava roaring)

(lava roaring continues)

You push yourself all the time.

You also get caught in the moment,

and while it's so mesmerizing, so beautiful,

and I mean, how does the next one look like?

Hmm, it might be louder, bigger, and better!

Before remote technology,

the images that Carsten and his colleagues took

were sometimes the only way for volcanologists

to see this activity up close.

(lava roaring)

If you look directly into the vent,

it's like if you look into a cannon.

The projectiles can come very, very fast,

faster than you might notice them.

They make a sound like a fuse, so you immediately know,

"Oh, that was close."

So why do some volcanoes ooze lava,

while others explode?

It's all about the gases.

Explosive volcanoes contain a very sticky magma

that does not flow well, and can plug the vent.

Rising gases can't escape easily, causing pressure to build.

And when that pressure inside reaches the breaking point,

(rock crashes)

(lava roaring)

now free, the gases rapidly expand, shattering the plug.

(rock crashes)

(lava roaring)

What we call ash is actually pulverized rock.

And it's the next chapter

in the way volcanoes shaped our world.

The ash holds a hidden secret.

It's full of nutrients.

And where it falls,

it lays the foundation for vibrant ecosystems.

(somber music)

This crater is all that remains

of an ancient volcano called Ngorongoro.

Ash from that eruption laid the foundation

for a rich and diverse ecosystem,

the Serengeti Plains.

(hooves beating)

(joyful music)

One of the major reasons is the volcanic soil

that produces nutrient-rich grasses.

(joyful music)

Ol Doinyo Lengai erupts every few decades.

(gentle bright music)

This is the summit crater full of hardened lava.

And after a series of major eruptions, it looked like this.

All that ash has become vital plant food for the Serengeti.

(camera shutter clicks)

500 miles to the west,

volcanoes helped create another spectacular ecosystem.

(volcano rumbling)

The Virunga Mountains shelter one of the last groups

of mountain gorillas.

The nutrient-dense foods have been linked

to brain development in ape species.

What has been great for these gorillas has also been great

for us.

Over centuries, humans settled next to volcanoes.

We farmed their fertile slopes,

built civilizations in their shadows,

(vocalist warbling)

and mined their minerals.

Today, those ancient settlements have become some

of the world's major cities.

But there's a paradox here.

Volcanoes build, but they also destroy.

(suspenseful music)

Volcanoes can be dormant for thousands of years,

and people settling near them had no idea

of the potential danger.

In 79 AD, a massive eruption

from Mount Vesuvius wiped out the Roman town of Pompeii.

The only warning signs were a series of small earthquakes.

But when the volcano finally erupted,

(rock crashes)

it was with a ferocity that staggers the imagination.

(volcano rumbles)

Hours later, a burning hot avalanche

of gas and rock obliterated the city.

(somber music)

Thousands died in Pompeii,

and in the towns and villages that surrounded Vesuvius.

(somber music)

The ash preserved everything so perfectly

that as archeologists started to uncover the ruins,

they discovered evidence of a sprawling, vibrant city.

(somber music)

The remnants give us a sense of what life was like

in those last moments.

(somber music)

Today, tourists come from all over the world

to see this city frozen in time.

(somber music)

Pompeii is a cautionary tale,

a reminder of how powerless we are

in the face of an erupting volcano.

(somber music)

Vesuvius is still a threat.

It has erupted frequently since Pompeii.

And now with millions of people living in its danger zone,

even a moderate eruption could be catastrophic.

(somber music)

Scientists still can't predict with accuracy exactly

when a volcano is going to erupt,

but they can tell when one is waking up.

(volcano rumbling)

Indonesia is the most volcanically active

and monitored country in the world.

Yet Sinabung wasn't even on the radar

when it suddenly rumbled to life in 2010.

Thousands of earthquakes prompted authorities

to evacuate the area just in time.

Those settlements are now ghost towns,

and will be until Sinabung goes back to sleep.

(somber music)

Around the world, nearly 1/2 a billion people live

in areas at risk from active volcanoes.

(somber music)

On the big island of Hawaii,

the Kilauea volcano has been closely monitored

for over a century.

Since the mid-1980s,

it has been erupting in a mostly slow and stable pattern.

That predictability gave people the confidence

to build houses in areas they thought were safe.

In the spring of 2018, something changed.

(somber music)

A full 25 miles from the active summit,

a surge of magma pushed its way

under a residential neighborhood.

The ground began to split and spatter lava,

burning a number of houses to the ground.

(somber music)

Even though this is one of the most watched volcanoes,

no one expected the magnitude of what came next.

(lava roaring)

In a matter of days, more than 20 fissures opened up,

and huge fountains of lava shot hundreds of feet

into the air.

(lava roaring)

(somber music)

There is no way of stopping this much lava.

All that residents could do was watch

as their neighborhoods were consumed by the flows.

(somber music)

(lava roaring)

In just a few months, Kilauea had dramatically changed part

of the island's landscape.

And while no lives were lost,

for the thousands of people in the area,

life will never be the same.

(lava roaring)

I've never seen Hawaii like this.

This is a huge eruption.

Everything is in a big, big change.

It's a really historic event.

(lava roaring)

(lava roaring continues)

In three months, Kilauea produced enough lava

to cover Manhattan Island almost 20 feet deep.

(lava roaring)

Some of the most striking features were the fountains

that shot lava over 100 feet in the air.

(lava roaring)

If you imagine how heavy magma is,

I mean that's pure rock,

and shooting up like that in front of you.

(lava roaring)

(lava roaring) (fire crackling)

This eruption is part of an ongoing process

that built this island up from the bottom of the sea.

In time, new life will return to these blackened landscapes

as the cycle of destruction and rebirth continues.

(rock crashes)

(suspenseful music)

Volcanoes are a powerful force.

At times, you can see that power in amazing ways.

At Yasur, explosions are so energetic

that they generate visible shock waves.

(earth rumbling)

(earth rumbling continues)

(earth rumbling continues)

(suspenseful music)

Six months ago, monsoon rains forced Carsten

to give up his descent down to the lava lake

at Marum Crater.

Now, he's back.

But Carsten can see a drastic change in the lava lake.

It's now a fraction of the size.

Could the lake be draining back into the Earth?

(suspenseful music)

This time the weather is perfect.

So, Carsten and climbing expert Chris Horsley go for it.

(suspenseful music)

(majestic music)

After a grueling two-hour descent,

they make it to the crater floor.

(majestic music)

(lava roaring)

I mean, this lake

is one of the wildest lakes you can imagine.

Huge waves.

The whole thing is rumbling, the whole Earth is shaking.

It's absolutely incredible, the energy you are facing there.

Once again, Carsten's adventures have taken him

to places few of us will ever go.

And he's bringing back some new rocks

for scientists to study.

If every rock tells a story, imagine what these might say.

Maybe it's just a word, or a sentence,

but even small contributions can add up

to a major discovery.

And that could lead us to a new understanding

about volcanoes

and the way these fires of creation have shaped our Earth.

(lava roaring) (majestic music)

(joyful music)

(joyful music continues)

(joyful music continues)

(joyful music fades)