Original subtitles

*

After decades of lying dormant,

a volcano explodes.

Superheated rock and ash thunder downhill with irresistible force.

This is what happens when powerful forces deep within the Earth erupt.

New land rises out of the Pacific Ocean.

The Earth's violent interior pushes into the sea.

This is where lava meets the ocean

in one of the most spectacular shows on Earth.

This is where scientists come to witness

the power of the planet firsthand.

Geologist Ken Hon monitors landscapes in the making.

This region is one of the few places in the world

where you can see the world change before your eyes.

Couple of months ago, the land behind me wasn't here.

None of it was here, it was just a sea cliff into the ocean.

It really is truly dynamic.

Hawaii's Kilauea is the most active volcano on Earth.

It's created by a hot spot of molten magma

that lies 65km below the surface.

Here, heat is constantly released

and rivers of molten rock turn seawater to steam.

It's not like steam you have in your kitchen.

It's coming in contact with lava that's close to 2,000F

so the steam gets superheated.

So it's very, very explosive.

Ken is compiling a video log of Hawaii's changing coastline.

To capture every detail of the action,

he uses slow motion photography.

What we film out here, most of the time,

just helps us see things that we can't see with our own eyes.

Hawaii grows out into the Pacific

at a rate of seven and a half hectares a year.

The volcanoes here are highly active but not often deadly.

This is unusual.

Most volcanoes in the world can be much more dangerous.

Volcanoes that erupt regularly

are less deadly than those that lie quiet for centuries,

building up pressure inside.

When dormant volcanoes explode, they can also unleash tsunamis,

mudflows, avalanches of burning rock

and superheated ash clouds.

Throughout history, these explosive eruptions

have claimed countless lives.

Kilauea has been spewing out superheated molten rock

for the past 26 years

but few people have been killed.

This kind of lava is largely made up of basalt

which hardens to a black crust.

Since 1983, new lava has covered over 100km square.

By 2008, Jack Thompson was the only one left

in the town of Royal Garden.

Oh, it was all just pristine forest.

It was green all the way to the ocean.

It was just a wonderland.

1983, the lava started

and I got up one morning and looked over the back of the mountain

and you could see a glow.

That's kind of a shock ruining all your scenery,

all the sudden changes for something totally different.

Luckily, the lava advanced slowly enough

for people to get out of the way.

Nearly 200 homes were destroyed.

Park ranger Jay Robinson witnessed the destruction

that's still going on today.

We've had over 200 homes and structures now destroyed

in this eruption we're having right now.

But no-one died because you just walk away.

The lava only flows as fast as a baby crawls in most cases.

Because Kilauea's flanks are gently sloping,

the lava spreads out sideways,

cools quickly and slows down.

So Kilauea's lava may look dangerous but it rarely kills anyone.

But when cities sit on steep volcanic slopes,

eruptions can pose a serious threat.

Those who live on this volcano need to know

whether the lava will cool quickly and stop

or remain hot and keep on flowing.

Southern Italy is a region threatened by many volcanoes.

On the island of Sicily,

Mount Etna is the biggest and most active volcano in Europe.

Etna has erupted four times since the year 2000.

When it blows, the lava flows destroy everything in their path.

The lava flows usually remain on the volcano's higher slopes.

But not always.

Sometimes, larger eruptions invade towns lower down the mountain.

Over the past 300 years,

16 villages have been destroyed.

In this highly populated region,

the pressure is on to work out what Mount Etna will do next.

*

*

Europe's biggest volcano, Mount Etna, looms over a million people.

Dr Clive Oppenheimer is a volcanologist

In this tunnel below Mount Etna,

he's learning how the volcano's lava has behaved in the past.

What we're looking at is the solidified wall of a lava tunnel.

This was formed 400 years ago and you can get an impression

of just how this lava was,

so fluid that it dribbled off the roof.

You can see here a little droplet of lava

and this tells us the lava was very, very hot,

very fluid and runny.

If lava is insulated by a tunnel,

it remains hot, fluid and extremely dangerous.

Instead of flowing maybe five miles down Etna,

it flows ten, 15 miles down

and reaches some of the towns on the flanks.

Clive wants to know if there are any lava flows

hidden below the flanks of the volcano right now.

He uses a thermal imaging camera to detect them.

He discovers the upper slopes are riddled with lava flows

and at over 2,000 degrees,

they're fluid enough to run down the mountain.

These constant eruptions release pressure

from the magma chamber below Etna.

But it's the volcanoes that don't blow regularly

that build up pressure which prove most dangerous.

Rising above the densely populated city of Naples,

this is one of the most dangerous volcanoes in the world.

When Vesuvius erupted 1,400 years ago,

it buried the town of Pompeii in ash and claimed 2,000 lives.

In 1944, during World War Two,

the US Army faced an unexpected adversary - Vesuvius.

An eruption killed 26 people.

Vesuvius is quiet now,

building up for the next big one.

But Dr Clive Oppenheimer is interested

in the island volcano of Stromboli nearly 300km away

which is constantly exploding.

It might look a relatively small volcano.

It goes about three quarters of a mile above sea level

but below the sea, there's another one and a half miles of this volcano

so it's really massive.

At the foot of the volcano is the village of Stromboli.

80km beneath it,

one of the Earth's tectonic plates is sliding under another,

generating a series of continuous explosions.

No other volcano on Earth is known to erupt so often and so consistently.

Clive Oppenheimer studies volcanic gases

to better predict eruptions.

Here on Stromboli, he has a constant source from the magma beneath.

So one of the things I'm really interested in

is how the gas escapes from magma

and I think we can even hear it

as this vent on the volcano is breathing.

It's the volcano's puffing.

(PUFFING WIND)

If magma is the fuel of volcanoes,

the trigger for these eruptions is the gas that's contained in it

and that gas, as it comes up to the surface,

it expands really violently

and then it blows the chunks of bubble skin,

magma bubbles flying into the air.

Like a champagne bottle, Stromboli is full of gases.

So when it's uncorked, the gases escape

and propel showers of lava into the air.

When we see this kind of activity going on,

it's impossible for me to imagine

how we could actually control volcanoes.

But we CAN try and understand how volcanoes work

and use that information to predict eruptions.

Clive uses a spectrometer to analyse the volcanic gases.

They tell him how deep within the Earth

the explosive bubbles are formed.

Look at that. That is fantastic.

I think the vent there has got really choked

so when the magma's trying to get through,

it's blasting out all the rocks that have choked the vent up

and pulverising the rocks into ash.

There's a beautiful ash cloud coming up here

and I think it's drifting right towards me.

It's raining ash.

A moment ago it was 2,000 degrees in the vent of that volcano

and now it's a cooled down little piece of ash

seconds later in my hand

and that rock was just made just now.

That's quite an amazing thing, really.

Ooh...

There again, another instantaneous explosion.

You can't help to feel something emotionally

when your whole body is vibrating with the shock wave.

But actually, this is small fry in the deadly arsenal

of active volcanoes on planet Earth.

Stromboli's bark is worse than its bite.

Many of the world's other volcanoes are much more dangerous.

*

*

When hundreds of years of built-up pressure blasts out of the Earth,

it completely changes the landscape.

Here, in the cascade range of the Pacific North-west,

many of the mountains are sleeping volcanoes.

When one finally blew,

it produced one of the biggest volcanic eruptions in living memory.

In 1980, Mount St Helens had been dormant for over 120 years.

So when swarms of earthquakes shook the mountain

and a small crater formed at its summit,

scientists from the US Geological Survey noticed straightaway.

Richard White was one of them.

There is a certain fatalism amongst geologists

that have worked around these volcanoes

'cause we all know that if you're gonna work around one

that's getting ready to erupt, there's some risk.

Richard's colleague, David Johnston, was also on the mountain.

David Johnston was up on this ridge,

just a quarter miles from where we are now

and he was monitoring Mount St Helens in an official capacity.

David had parked his trailer in front of the volcano's north flank

to keep an eye on an ominous bulge.

That same day, amateur photographer Keith Ronnholm

made his way to a scenic spot

also overlooking the volcano's north flank.

Bear Meadow, where I was 28 years ago in 1980,

I was ten miles from the mountain.

It seemed like a perfectly safe place to be.

But just after 8.30 that morning,

the last of a series of earthquakes hit,

triggering one of the largest landslides in recorded history.

I glanced over at the mountain and the entire north face

was in motion, was sliding down

and it's such an unbelievable view

that I shook my head and I said, 'Am I really seeing this?'

I dove for my camera and stood there and started taking pictures

and the very first picture

shows that the entire side of the mountain blowing out.

It was quiet, there was no sound

so there was no big explosion, noise

or anything that would make you want to run.

The landslide had released highly pressurised volcanic gases.

But instead of shooting upward, they blew out sideways.

The blast roared across the landscape at nearly 500km per hour

and hit geologist David Johnston's trailer.

12km away, Keith Ronnholm was still taking these pictures.

In one of the pictures, you can see projectiles

being ejected out with, like, trails behind them

and those are like house-sized objects.

You could see it coming towards me

and then it hit the most distant ridge out there.

It began to break over like a wave breaks over a breakwater

and curl over and churn.

You just want to watch it but on the other hand, it's getting closer

and so there's a conflict of, do I stay and watch or do I go?

Keith Ronnholm was lucky.

The blast tore past to the west of him.

But fisherman Danny Balch had set up camp beside a river

and was directly in its path.

It was a beautiful setting,

the birds and animals were totally quiet.

It was so dead quiet.

Danny Balch was 25km away and couldn't see the mountain.

He knew nothing of the explosion until it thundered towards him.

As it went over the top of our heads,

it was pitch-black and you could see nothing.

A couple of seconds later, then it started hitting us.

Started knocking all the trees down.

I was pressed to the ground like a pancake,

all the air pressed out of me and everything

but I was also at that point starting to feel burnt.

This was just like a snap of the fingers, it was that fast,

and I believe that if we would have been

in an eruption that would last longer,

we would have baked, we'd have been dead for sure.

Danny Balch was just far enough away from the explosion

to survive with third-degree burns.

57 others weren't so lucky.

When geologist Richard White flew over the landscape,

everything within sight had been obliterated.

And nearly 400km square of forest flattened by the blast.

Richard's colleague, David Johnston, had been killed.

We never found any trace of him, really.

The camp was over there

and there was a camp trailer, aluminium camp trailer.

Pieces of it were much later found scattered down slope.

We found cups and stuff out of it, just some debris out of the trailer.

Bits of aluminium from the trailer and so on.

So the trailer itself got shredded.

It happened to be David Johnston over here on May 18th

but it could have been any of us.

The eruption of Mount St Helens was 150 times more powerful

than the Hiroshima atomic bomb.

It turned great sways of Washington State Forest

into something more like the moon.

But in some parts of the world,

devastating explosions happen all the time.

Big volcanic blasts are exterminators

but volcanoes have more than one way to kill.

In 1995, a volcano erupted on the Carribbean island of Montserrat.

The blast created a pyroclastic flow,

a speeding avalanche of hot rock, dust and gas.

These deadly surges charged down the slopes of a volcano

and across the landscape.

At temperatures of more than 800 degrees,

they race over water on a layer of superheated steam.

Japan, 1991.

After lying dormant for almost 200 years,

the volcano Mount Unzun roared into life.

The eruption attracted the attention of scientists and press.

But one group made a fatal mistake

when they went into the exclusion zone

and got caught in the path of a pyroclastic flow.

43 people died as superheated gases burned their lungs.

Mount Unzun is one of more than a thousand active volcanoes

that circle the Pacific Ocean.

This chain is called The Ring Of Fire.

The volcanoes occur above subduction zones

where submerged oceanic plates dive under continental land masses.

The most dangerous section of this volatile chain is Indonesia.

There are 130 active volcanoes here,

more than any other country on Earth.

Some are less dangerous because they release pressure constantly.

But others have produced the biggest explosions ever known.

Out in the Sunda Strait, 72km west of Java, lies Anak Krakatau.

In 1883, this volcano's parent Krakatoa exploded with a force

equivalent to more than a thousand atomic bombs.

It made the loudest bang in recorded history.

It blasted almost the entire island out of existence.

Tsunamis over 30m tall flooded the coast of Java and Sumatra

up to 65km away.

Krakatoa claimed at least 36,000 lives.

In the 1920s, geologists watched

as a new volcano Anak Krakatao, the child of Krakatoa,

rose out of the sea.

By the 1980s, this island had grown to over 200m above sea level.

But the volcano did not stop there.

Geologist Mike Ramsey has come to Indonesia to study Anak Krakatau,

which today is one of the world's most violent volcanoes.

I would like to see how the volcano's changed in the eight years

since I've last been here.

I know that it's had a lot of activity, a lot of change.

The bay Ramsey is crossing is where the original Krakatoa once stood.

Back in 1883, everything you see behind me was part of one island...

...and when you can eject this much rock and magma and water and land,

the forces are enormous.

And smack in the middle of this crater is the current active volcano

Anak Krakatau and that's the current hot spot

and the current active craters are still very dangerous.

The new volcano, Anak Krakatau, has grown over 300m

in less than a hundred years.

From the summit, the extent of the original volcano becomes clear.

These outer islands are all that's left of the old Krakatoa

that once filled this 8km-wide bay.

Geologist Mike Ramsey retreats to a safe distance

to take further measurements of the activity in the new cone.

Right now, Krakatau's erupting a small Strombolian style eruption.

It's basically putting up ash column

somewhere between half a mile and a mile high.

The island will continue to grow, continue to get larger.

At some point, maybe in a hundred years or more,

there might be another larger eruption like there was in 1883.

Monster eruptions like Krakatoa are rare.

But they still occur.

In 1991, another giant eruption along The Ring Of Fire

threatened 60,000 people in the Philippines.

*

*

Mount Pinatubo in the Philippines had been dormant for 600 years.

Even when it started rumbling in 1991,

few had any idea how dangerous it was.

Geologist Andy Lockhart was part of the team sent in to observe.

Pinatubo just didn't look like a volcano

to anybody who wasn't a geologist.

Now, as a geologist, you'd look at it and say,

'That's a very bad volcano'

because this volcano, when it erupts,

this one just blows itself apart so this is not a good place to be.

Clark Airforce Base was situated at the foot of the volcano.

It was home to 20,000 US military personnel and their families.

Sergeant Maree Rogers was one of them.

The volcanologist was saying that this was death underground

that nobody would want to mess with.

When the airbase was evacuated on June 11,

Rogers and Lockhart was part of the skeleton crew left behind.

One day later, Pinatubo blew its top.

But this explosion was minor compared to what followed three days later.

I went outside the hangar and turned around and looked

and all of a sudden it looked like, I guess you would describe it as

the mountain range exploding from left and right.

This was the second biggest eruption of the 20th century.

When a column goes up like that and it hits the stratosphere,

and you get this nuclear cloud thing,

when you get the mushroom cloud, it spreads out on the stratosphere.

The ash cloud turned day into night.

All it was, just dark, dark, dead dark, dead,

hard storm in the middle of the night, 'no lights at all' dark.

It's a feeling you can't really describe

when the sun you can't see, you know you're supposed to have sunlight

and everything is dark.

And yet, you're getting all this mud and stuff on you.

I thought that, this is it.

This is it, this is the big one.

At midday, it was more like midnight for miles around.

Ash clouds from volcanic explosions

can completely block out all daylight.

But these terrifying phenomena

can have far-reaching and more damaging effects.

The ash from the cataclysmic eruption of Mount Pinatubo

shot more than 30km into the stratosphere.

In less than a month, it circled the globe.

Eventually, ash particles drifted across the entire planet

and reflected so much sunlight back into space

that it lowered global temperatures for at least two years.

In the Philippines, millions of tonnes of ash covered 700km square.

In some places, it was 180m deep.

Everything was grey, everything was monochromatic and grey.

There were clouds and they were grey,

they were the same colour as the ground.

It's something that you will never forget.

It makes you realise that we're truly living on a planet

that's raging.

It drew me closer to my maker.

Volcanoes don't have to explode to be lethal.

Some are less violent but no less deadly.

At the Eastern tip of Java, Indonesia,

is the active volcano of Kawah Ijen.

Dr Clive Oppenheimer travels the world

measuring volcanic gas emissions to help predict eruptions

and this volcano is unlike any other in the world.

Kawah Ijen belches out tonnes of sulphur dioxide gas.

Dr Clive Oppenheimer is interested in the chemistry of the lake

in the volcano's crater.

The chemistry is reflecting all of the gases coming out of the magma

and these are all very, very acidic gases.

Sulphur dioxide is just one of the volcanic gases

that make the lake acidic.

And even Clive is surprised by the pH reading of the water.

That's incredibly acidic.

It's below zero - even battery acid would give a reading of three.

Most things would rot in the crater lake

or in the gases around the edge of the crater.

Metal will corrode.

If you put some sensors in there,

they're probably not going to last very long 'cause it's so acid.

As well as being acidic, the lake is extremely hot.

To get that amount of water, 210F,

requires a phenomenal amount of energy

coming from the deep bowels of the volcano up to the surface.

Ijen is the hottest acid body of water on the planet,

I'm pretty sure of that.

On the banks of the acid lake,

sulphur dioxide gas condenses in pipes

drilled into the side of the volcano.

Local villagers mine the deposits of pure sulphur

to sell to the sugar and cosmetic industries.

They carry baskets weighing 70kg

up the steep sides of the volcano's crater.

I have to say, working in this sort of environment

is really, really harsh.

It was just horrendous down at the bottom there.

The visibility was almost zero and the fumes were coming across.

My eyes are really stinging now.

They feel like they've got gravel in them.

Human teardrops react with the sulphur dioxide fumes

to make sulphuric acid.

Life expentancy here is just 40 years.

Kawah Ijen is one of more than a thousand active volcanoes

that together spew ten million tonnes of sulphur dioxide

into our atmosphere every year.

Hawaii, March 2008.

An eruption of sulphur fumes punches through Kilauea's summit crater.

Like many Hawaii residents,

ranger Jay Robinson was taken by surprise.

One night there's a crack open up and all the fumes coming out.

For people who've lived up here for so long,

to look out your back door and a couple of miles away,

see this huge fume cloud blasting up, it's a little unnerving.

It's also toxic.

When sulphur dioxide hits the air,

it forms droplets of sulphuric acid.

And here, there's a lot of it being released.

In the last 24 hours, we've had around 8,000 to 9,000 cubic tonnes

of sulphur dioxide coming out of here.

That's enough to fill 100 Goodyear blimps every day

with sulphur dioxide gas.

In the crater next to the summit, conditions changed in an instant.

This morning, we were hiking into Kilauea crater

and it was great air quality - crystal clear.

You could see through ten miles.

But within 20 minutes, you couldn't see any more than a mile away.

The fumes were so bad and we started smelling it, tasting it, coughing.

We got out.

These fumes may be noxious

but volcanic gases also maintain air composition and climate

so are crucial to life on Earth.

Without volcanoes, the world would be a very different place.

They have created much of the land we live on.

This island in the North Atlantic was formed from a volcanic eruption

as recently as 1963.

And in March 2009, another eruption emerged unexpectedly

out of the South Pacific ocean off the coast of Tonga.

With the Earth in relentless motion,

volcanoes will always have the power to both create and destroy.

itfc subtitles

*