Original subtitles

Narrator: The island of santorini in the mediterranean sea.

Today, a peaceful paradise.

But buried deep within these colored cliffs

are the ruins of akrotiri,

an ancient city with a dark past.

A mysterious civilization wiped out by a volcanic eruption

100 times more powerful than pompei.

Goodman: That natural disaster changed the course of history.

It was truly a massive, catastrophic event.

Narrator: Today, investigators use innovative underwater robots

and pioneering techniques to discover the true extent

of this earth-shattering eruption.

Papanikolaou: I don't think that there's any other explosion

in recent history that comes close to the santorini eruption.

Narrator: For over 3,000 years,

this eruption has inspired myths of the ancient mediterranean.

Most of the people believe the lost a atlantis city

was here -- was in santorini.

Narrator: But what is the truth behind the most destructive eruption

in recorded history?

To find out, we'll unearth the lost city of akrotiri...

...Reconstruct magnificent homes...

...And dive deep beneath this mysterious island.

We'll unearth the fate of this lost civilization,

and reveal the secrets of santorini's deadly mega volcano.

-- Captions by vitac -- www.Vitac.Com

captions paid for by discovery communications

santorini is a greek island

located 140 miles southeast of athens

in the mediterranean sea.

A mysterious ancient civilization

living here thousands of years ago vanishes without a trace.

Papanikolaou: Thousands of years ago in santorini,

a highly developed civilization

and culture disappeared suddenly in the area.

Narrator: Today, this idyllic paradise

is famous for its towering cliffs,

colored beaches, and deep blue waters,

but hidden away at santorini's southern tip

are clues to its mysterious past.

Buried 200 feet beneath the ground,

archeologists uncover akrotiri,

an ancient city over 3,000 years old.

In its prime, its narrow streets

are intricately paved with stone.

Its town square is lined with picturesque houses

that tower three and four stories high.

An array of colorful stones decorate the facades.

What is this thriving civilization?

And what happens to its people?

♪

geologist dimitrios papanikolaou

investigates akrotiri's ancient past.

The ruins suggests a highly sophisticated civilization

flourishes here for thousands of years before its abrupt end.

Papanikolaou: It predates parthenon and the acropolis,

considered all over the world as a symbol

of a high level of culture.

Here, this is 1,000 years before that.

Narrator: Dimitrios examines the city's ancient stone buildings.

He discovers many of the rocks used to construct

the upper floors are volcanic in origin.

The upper part contains a lot of volcanic rocks,

either tufts or some louvers.

Narrator: Dimitrios explores further

and discovers more volcanic rock,

but this volcanic rock is completely different.

It's not used as a building material,

but is dumped unceremoniously.

Here we have some huge boulders of pure lava

and they are found here -- this one,

the other one also very big, another one a little smaller.

Narrator: The unusual rock provides clues to a major catastrophe

that annihilates this city.

The evidence suggests

a massive volcanic eruption buries akrotiri.

But there's no obvious volcanic mountain on santorini

or in the surrounding sea.

So where is the volcano?

To find clues, dimitrios explores the islands

at the heart of santorini's archipelago.

Santorini is a group of five islands --

santorini, therasia, and aspronisi,

form its outer ring.

The islands of nea kameni, and palaia kameni

lie at its center.

Here, the water is tinted in shades of rusty red.

And patches of colored rocks pepper the dark landscape.

Papanikolaou: Looking at the landscape,

we see that there are some contrasting points -- areas --

small areas where the color is whitest.

Well, these are locations

where gases are coming out from the interior.

Narrator: The colored rocks suggest the ground here releases

clouds of toxic gas.

Exploring further, dimitrios confirms his suspicion.

At the island's summit, he finds gas

escaping through cracks in the earth's surface.

It's clear evidence of volcanic activity.

I would say that I'm standing

really in the heart of the volcano here.

Narrator: The escaping gases hint

at what lurks beneath the island's surface --

a thick layer of fragmented rock stretches 2 miles underground.

Beneath it lies a spongy layer of crystals

and glowing hot semi-molten rock...

...All concealing a huge cavern below...

...Bursting with up to 1.5 trillion gallons

of molten magma hotter than 1,800 degrees fahrenheit.

Is this huge bubbling chamber of magma

key to understanding the island's past?

The whole island is the result of volcanic activity.

The type of rocks, the thermal springs,

the vegetation, the atmosphere,

the fumaroles, everything around here

is the result of active volcanism.

Narrator: Santorini is a volcanic caldera,

a huge depression that forms after a volcano erupts.

Stretching seven miles across and covering an area

over 30 square miles,

it's the largest active caldera in the world.

Its immense size hints

at the enormity of the ancient eruption.

This shows really the energy release

and the magnitude of the explosion.

Narrator: The eruption creates a huge 20-mile high cloud.

That blasts ash as far as egypt

over 200 miles away.

Ancient writers describe how the ash cloud

plunges the world into darkness --

veiling the sun and causing a global winter

for over two years.

A blanket of ash up to 200-feet thick covers the entire island.

♪

as the empty volcano collapses into the water,

it changes the shape of the island forever.

Like the roman ruins at pompei, the ancient remains of akrotiri

are preserved by hot volcanic ash.

A frozen snapshot of akrotiri's last moments.

But there's an unsettling mystery...

All over the excavated area,

there are no bodies found, in contrast to pompei, for example.

There you have plenty of bodies buried below the ashes.

Here there's nothing left.

Narrator: What happens to the people?

How does an entire civilization mysteriously vanish?

At akrotiri, evidence of man-made destruction

provides tantalizing clues.

♪

narrator: Santorini's mega eruption is the most catastrophic volcanic

explosion in recorded history.

I don't think that is any other explosion in recent history

that comes close to the santorini eruption.

Narrator: It varies the ancient city of akrotiri

in lava and ash up to 200-feet thick,

100 times deeper than pompeii.

But unlike that infamous eruption, at akrotiri,

not a single body has ever been recovered.

Papanikolaou: This is one of the big differences.

There have been no bodies found anywhere.

Narrator: Dimitrios believes a clue

to the fate of the people lies inside the city.

Hidden amongst the debris of the ruins,

investigators unearth a strange heavy stone

weighing over 30 pounds.

Archeologists believe the grooves once hold ropes so

it can be used like a wrecking ball.

And in a nearby house, two pots of plaster

and a pot of dried paint lie strewn on the floor --

a decoration job hastily abandoned.

Are these home repair and demolition tools,

clues to what happens to the lost people of akrotiri?

Today, akrotiri's empty streets remain eerily

filled with rubble and rows of destroyed buildings.

Papanikolaou: The present day ruins show

it was destroyed several times and was rebuilt.

Narrator: For dimitrios, the multiple repairs hold clues

to the fate of the people of akrotiri.

Papanikolaou: We can see in lower parts,

the construction is made of large blocks.

Then you have new construction on top of the early ones

where you have very small blocks.

Narrator: Different styles of construction suggests

that people desperately tried

to repair their homes after a major disaster.

Papanikolaou: They were trying to repair rapidly the city.

This is illustrated all over the settlement here.

Narrator: But what is the cause of all these emergency repairs?

Dimitrios examines the northern part of the city

and finds a major clue.

He discovers a solid stone staircase

split straight down the middle.

It's a pattern of destruction he knows well.

This destruction you can observe in many places in greece

due to earthquakes.

Narrator: The broken staircase is proof that a major earthquake

also devastates akrotiri before the eruption.

The earthquake may have warned the people

of impending disaster.

♪

but dimitrios believes that further warning signals

hit the city before the eruption begins.

He hunts for evidence along the coastline.

An open quarry provides him with a timeline of the events

leading up to the eruption

and a clue to the fate of the people.

Papanikolaou: This is different layers.

Each one meaning a different period

with different characteristics.

Narrator: The separate layers show the material deposited

during different phases of the volcanic eruption.

The lower the layer, the older the event.

♪

dimitrios examines the first layer for clues

to akrotiri's destruction.

Papanikolaou: The deposition of this layer

means the city does not exist as a city.

It is buried below this layer of several meters thick.

Narrator: On close inspection at the very base,

dimitrios discovers a thin layer of ash.

Papanikolaou: See this yellowish material.

This is a distinctive,

very tiny, thin layer, a few centimeters thick,

which is the result of the first explosion.

Narrator: The thin layer of ash suggests the volcano's first eruption

is a minor explosion.

Papanikolaou: This tiny first layer shows the first explosion,

which is not a devastating one,

and this made the warning to people to flee out.

Narrator: The first small eruption spews thin, light ash

across the whole of akrotiri.

The ash and tremors from the volcano's forewarnings

damaged local houses, which are painstakingly repaired.

But the tremors continue over the months

and cause more and more damage to the city's buildings.

As the warning signs increase in their frequency and intensity,

the people pack up their valuables

and evacuate the island to escape the erupting volcano.

Papanikolaou: They took whatever they could just carry

and they went away hoping that they might come back.

Narrator: Dimitrios believes the people escape across the mediterranean

following the volcano's warning signs.

The mega eruption instantly wipes out

all life left on the island.

But its effects are even further reaching.

A discovery 850 miles away in egypt

provides evidence of its shocking power.

How does this event become the most powerful

and violent eruption ever witnessed by humankind?

Narrator: Santorini's mega volcano is the most powerful eruption

in written history.

All life on the island is destroyed in an instant.

Papanikolaou: The island changed its morphology

and everything was changed here.

Everything was destroyed by a major explosion.

Narrator: A discovery 850 miles across the mediterranean sea

in egypt provides evidence of its immense power.

In karnak, archeologists discover fragments

of a stone slab that dates back to the 16th century b.C.

Known as the tempest stele of ahmose,

it's the world's oldest weather report.

It describes a huge storm that ravages egypt

where the sky is hit by a tempest of rain

causing intense darkness.

Experts believe this could be proof

of the far-reaching effects of the santorini eruption.

What makes this eruption more powerful

than any other in human history?

♪

ingo sonder is a volcanologist

at the university at buffalo, new york.

He investigates the volcanic process.

I am fascinated by this process.

I'm fascinated by molten rock, and what we can do with it.

Narrator: During santorini's eruption, seawater infiltrates

the volcano's magmatic chamber deep underground.

When the magma rises in the underground chamber,

it cracks the surrounding rock,

causing long fractures that reach the sea.

The cracks act like vacuums and suck the seawater

down into the chamber

so the cold water hits the scorching 1,800-degree magma.

Ingo believes this process of water

mixing with magma is key to santorini's explosive power.

But how can water fuel a volcanic explosion?

To test how water impacts a volcanic eruption,

ingo and his team create their own mini volcano.

They heat 130-pounds of rock

in a high powered induction furnace.

Sonder: The rock will melt above 1,200 degrees celsius.

We will heat it up a little bit higher,

so we have it really liquid once we pour it.

Narrator: Ingo sets up the equipment.

Four injection tubes will spray water into the magma.

When the magma reaches 2,300 degrees fahrenheit,

ingo pours it into the container.

First, ingo and his team will test what happens

when water slowly mixes with magma.

He triggers a countdown and clears the surrounding area.

♪

the explosion sends the magma flying 3 feet into the air.

But how does it compare to when the water is mixed

with magma at high speed?

Ingo adjusts the valves.

They run the experiment again.

♪

♪

sonder: Look at that.

Narrator: The molten rock is ejected over 9 feet into the air,

and melt is spread across the surrounding area.

Ingo's tests show the higher the speed of the water,

the more powerful the explosion.

The speed at which the water enters the melt domains

and creates its own mingling.

This is probably the most important component.

Narrator: The faster the speed, the more the water

and magma mix together.

And so the more heat shock the magma receives.

This rapid change in temperature

is converted into mechanical energy

and is what makes the eruption so explosive.

The amount of materials santorini's volcano expels

is a testament to the power of the magma/water interaction.

Papanikolaou: The magma from the interior of the earth,

it takes up together blocks and fragments

of the pre-existing rocks,

and everything is spread tens of kilometers away.

Narrator: As well as lava and ash, an erupting volcano

can spew out solid rock --

chunks bigger than 2 1/2-inches are known as lava bombs.

They can be thrown incredible distances.

In santorini, archeologists find lava bombs

as far as 5 miles from the volcano.

The explosion of santorini's mega volcano

showers the island with volcanic bombs

and covers its inhabitants in a blanket of volcanic ash.

Papanikolaou: Everything is escalated.

You have bigger and bigger explosions.

Narrator: But the danger isn't over yet.

As archeologists dive beneath the water,

they discover evidence that suggests

the eruption triggers another destructive force of nature

that devastates the surrounding islands --

a tsunami.

Can a discovery on the coast

75 miles away provide clues about santorini's monster wave?

Narrator: The eruption of santorini is a natural disaster

unparalleled in all of history.

It destroys the ancient city of akrotiri

and changes the shape of the island forever.

The power of the eruption was huge,

the equivalent of 600 atomic bombs, can you imagine this?

It was a catastrophe for sure.

Narrator: But the danger is far from over.

In crete, 75 miles from santorini,

archeologists find unusual, chaotic layers of soil.

They contain a strange mixture of debris --

pieces of ancient pottery, plates and cups,

chunks of wall plaster from once beautiful homes,

and fragments of cattle bones mixed in with volcanic ash.

Nestled amongst this debris

are 3,000-year-old sea shells and algae

as far as 1,000-feet inland.

Is this mixture of land and sea

proof of a mega tsunami from santorini.

As a santorini native, marine geologist, evi nomikou,

feels a close connection to the volcano.

Nomikou: I was born in santorini. My father was a sailor,

so I'm always close to the sea.

And of course, as a kid, we loved to walk on the volcano

and try to understand what is happening.

Narrator: Today, evi uncovers santorini's underwater secrets.

She investigates how the volcanic eruption here

could trigger a mega tsunami.

Nomikou: Some years ago, the scientists believe

the generation of tsunami happened

because of the caldera collapse.

Narrator: Some experts believe the collapse of the caldera

into the sea displaces so much water

that it triggers the tsunami.

The deadly wave is so huge, towering over 90-feet high,

it overwhelms boats and destroys everything in its path.

But is there any truth to the theory?

♪

evi works with remote-operated vehicle pilot

othonas vlasopoulos

to explore santorini's submerged caldera for evidence.

The secrets of santorini are on the seawater, not on land, okay.

We know lots of what is happening on shore,

but we need to get out what is happening offshore.

Narrator: Othonas prepares an underwater robot.

The cutting edge r.O.V. Is fitted with two cameras

to map and model the caldera floor.

They deploy the robot off the southern edge

of santorini's therasia island.

-We got him 40-meters depth now. -Wow. 40 meters.

Narrator: 130 feet below the water's surface,

evi makes a surprising discovery.

On the caldera floor is a massive landslide.

For sure this is the continuation

of a huge landslide, okay.

So the other water landslide tell us

this part of the island was land

and at the end of the eruption, this part was collapsed.

Narrator: The landslide is evidence that at the time of the eruption,

santorini's islands were connected.

Where the caldera lies today

was once dry land and closed off to the sea.

You have the caldera collapse,

but at that time, santorini was not filled up with water.

The caldera was dry, was completely dry.

Narrator: The caldera is dry and isolated from the sea,

so its collapse cannot be responsible

for generating the mega tsunami that devastates crete.

So what is the true trigger?

Evi analyzes her surveys

of santorini's sea floor to find clues.

The results reveal a huge volume of volcanic material

buried beneath the seabed.

This yellow layer indicates the pyroclastic flows,

so the thickness of the pyroclastic flows

is almost 300 feet.

Narrator: Pyroclastic flows are ground-hugging clouds

of hot volcanic material.

They reach temperatures of 1,800 degrees fahrenheit

and can travel up to 600 miles per hour --

three times faster than a bullet train,

destroying everything in its path.

Evi believes these huge 300-feet thick deposits

of volcanic material

are the true trigger of the mega tsunami that devastates crete.

The volcano's violent pyroclastic flow

tumbles into the sea, displacing so much water,

it triggers a series of powerful tsunamis.

The tsunamis devastate the coastline of crete

over 75 miles away

and even reach as far as the mediterranean's

eastern shores.

The height of the waves was almost 90 feet.

So you had a big tsunami that was devastating

all the northern parts of crete.

Narrator: At santorini's southern tip,

evi explores the pyroclastic deposits on land.

It's an alien landscape

dominated by 130-foot high cliffs.

They are proof of the huge volume of material

ejected by the volcano.

You need to imagine all this volume

of pyroclastic flows that were entering into the sea

with high speeds and generated the tsunami.

This was the total catastrophe of the island.

Narrator: The tsunami and ash wipe out civilizations on islands

for miles around.

But with so much destroyed, scientists and scholars

wage war over the precise date of these cataclysmic events.

Clues buried under water

over 600 miles away could provide the answer.

[ explosion ]

narrator: The santorini eruption explodes

with the power of two million hiroshima atomic bombs.

But when did this cataclysmic event happen?

Evidence for the date may lie across the mediterranean.

I believe that the eruption that led to its tsunami

that made its way to the shores of israel.

Narrator: Beverly goodman is a marine geo-archeologist.

She studies ancient tsunami evidence

along the shores of israel

and makes some surprising discoveries.

Not only do we have evidence for one tsunami,

we have evidence for many tsunamis

that have hit the coast of israel.

Narrator: Any evidence here of

the santorini tsunami could help date it.

Goodman: So the way that I go about trying to find information

about the coastal history

is that we look along the coastline,

but then we also especially go underwater.

Narrator: Beverly and her team head out to sea to collect sediments

near caesarea maritima,

a roman city on israel's mediterranean coast.

A team of divers works up

to 120-feet beneath the water's surface.

To retrieve a core sample, the team uses a hammer

to insert a hollow steel tube into the seabed.

The tube fills up with a section of sand.

The divers secure the core to an airbag

and launch it to the surface.

Back on land, beverly opens and analyzes the cores.

The cores can reveal major events

in the coastline's history.

Goodman: So what we can see here is that when we take a core,

the top of the core is our present situation.

This is today. And as we go down the core,

it's sort of like looking at tree rings

where we're looking back in time.

Narrator: Variations in the sediment can reveal major events

that hit caesarea's coastline.

We want to pay attention and see where we get any chaotic layers

or any big changes, but as we get down to this part,

whoa! Boom! We've got this massive, chaotic layer.

It's full of pieces of broken shell and tiny little pebbles.

Narrator: These chaotic layers

are evidence of ancient tsunami damage.

Beverly homes in on the larger stones and seashells.

This is actually our smoking gun.

This is our fingerprint of our tsunamis.

The core was collected in about 60-feet water depth,

and these are clams that like to live in much deeper water,

so we know that they had to be transported and moved.

Narrator: The cores display three strips of chaotic layers.

It's evidence for three tsunami events.

But is one from the santorini eruption,

and can it help date it?

The first two chaotic layers

contain fragments of roman pottery.

But at the time of the eruption, the roman empire doesn't exist.

It suggests those events

are too recent to be the santorini tsunami.

The third layer, however, contains no pottery whatsoever.

Because we don't see a lot of pottery in here, any pottery,

there's a very good chance that this is an earlier event

and maybe even the event related to santorini's eruption.

Narrator: Beverly sends shells

from this mysterious layer for radiocarbon analysis.

The results are conclusive.

The radiocarbon dates on these deposits

have given us the date of 1650 b.C.

Narrator: Her results give a decisive date

for the obliteration of santorini.

Goodman: These cores are the first evidence of a tsunami deposit

from santorini arriving to the shores of israel.

Narrator: The dating of 1650 b.C. Places the eruption close

to the mysterious collapse

of a mighty sea-faring civilization --

the minoans.

Although only 70 miles away from santorini,

the minoans have a distinct and separate culture

from the people of akrotiri.

The minoan civilization is situated in crete

and its surrounding islands.

While most people in europe live in simple huts,

the minoans build advanced cities.

But 200 years after the eruption,

the civilization declines and is conquered by invaders.

Is the eruption to blame?

Many archeologists believe

that the santorini eruption plays a role

in the great minoan collapse.

The explosion covers the land in ash, choking the vegetation,

and the tsunami destroys many of their fleets.

They become an open target for enemy attack.

It's the worst natural disaster in recorded history,

and the minoans pay for it.

Finding the tsunami evidence

from this far in the eastern mediterranean shows

that it was truly a massive, catastrophic event,

and makes us really understand what it meant for that time.

Narrator: But who are the people who live in ancient akrotiri?

Many scientists claim santorini is the lost island of atlantis.

Could a discovery on the sea floor

provide evidence of a submerged city?

Narrator: The eruption of santorini in 1650 b.C.

Decimates all life on the island

and erases an entire civilization

from the pages of history.

The mysterious lost people of ancient akrotiri

leave behind no written records of who they are.

Clues, however, can be found in the archeological evidence.

The ruins preserved by the volcanic ash

provide a glimpse of this advanced, lost civilization.

Through the front door,

a stone staircase leads up to the first floor.

The floors are paved with huge slabs of volcanic rock

with vibrant red detail.

Beautiful frescoes adorn the walls depicting local life

by the sea -- sailboats and fishermen with their catch.

Alongside an ancient bathroom with a magnificent clay bathtub

and one of the earliest toilets ever discovered, ingeniously

plumbed into the city's own sewer network.

It's evidence of a highly sophisticated

and cultured society.

What is this civilization, and who are its people?

Most of the people believe the lost atlantis city

was here -- was in santorini.

There was a huge city, a marvelous city

that has been destroyed completely

due to the eruption.

Narrator: In 360 b.C.,

the greek philosopher plato records the legend of atlantis,

the story of an advanced civilization

destroyed by the gods for their arrogance.

It's a story that's fascinated us for millennia.

People have searched for physical evidence

of plato's atlantis, but found nothing.

Could santorini be the lost island of atlantis?

Plato say that the civilization was very brilliant,

and we do know the people that they live in santorini

at that time, they were very clever.

That civilization was very sophisticated.

Narrator: But something doesn't stack up.

Plato's atlantis sinks into the ocean,

but santorini doesn't

could more evidence be submerged beneath the waves?

Evi uses her remote operated vehicle

to explore santorini's hidden depths.

She's looking for any evidence of ancient man-made structures.

Nomikou: I'm just wondering what will happen

if we map the area on the smallest dikes over there.

Narrator: In santorini's caldera

on the eastern edge of therasia island,

36-feet below the water,

evi makes an extraordinary discovery.

Yeah. What is this? Yeah, you see the structure

of the lava? -Yes.

It's very peculiar here.

Also, there is a line here. Wow.

So we have some kind of steps very close to the land.

Narrator: An ancient structure bears a striking resemblance

to a stone staircase.

But is it natural or man-made?

The step could be man-made, okay,

because of the shape, the geometry of the step,

they don't have this peculiar lava structure around.

This is completely flat and perpendicular.

Narrator: But why are these steps underwater?

Maybe this is a small part of the ancient port --

a submerged ancient port. -Amazing.

Narrator: An ancient port within the caldera

matches plato's description of atlantis.

Originally on dry land,

the port collapses into the caldera

during santorini's eruption. It suggests

the port sits right on top of the volcano's epicenter

when it erupts over 3,000 years ago.

If we found some remnants of the port within the caldera,

that means that something that was an ancient city

just in the middle of the caldera

like plato described.

Narrator: Evi will need future exploration

to confirm her findings

and reveal the true relationship between santorini and atlantis.

Nikomou: If you connect geography,

the history, and the catastrophic event

of the eruption, that means you have found

some evidence of the lost atlantis in santorini.

♪

narrator: Santorini is an island borne out of fire and brimstone.

Today, the ruins of akrotiri are all that remains

of the sophisticated civilization

that once thrives here.

Wiped from existence in the largest volcanic eruption

in human history.

By unearthing the remains and diving deep into the crater,

experts can piece together the true story of santorini's

mega volcano, and discover the real connection

between ancient akrotiri and the legend of atlantis.

♪

♪

♪