All language subtitles for The Power Of Volcanoes Series 1 2of2 In The Shade Of Burning Mountains 1080p HDTV MVGroup

Volcanoes are sleeping giants.

Woe betide us should they awake.

Millions of people live in their shadows

and very close to a looming catastrophe.

But even giants far away and long forgotten

can suddenly come alive.

Looking at history, we come to understand

that active volcanoes also need to be

reckoned with in the future.

Volcanologists, climate
researchers, geologists.

They all want to learn
from previous catastrophes

in order to save lives in the future.

In a way, they're like
beauty and the beast.

Can we protect ourselves from this danger?

We can't always predict these events.

People will die.

The Ilopango Lake in El Salvador.

Few know that this huge lake was created

by the eruption of a volcano.

Archaeologist Payson Sheets
from the University of Colorado

is eager to find out how civilizations

can prepare for large volcanic eruptions.

In order to do that, he is
going to conduct research

on a dormant giant, a volcano
right directly beneath him.

1,500 years ago, this was,
much as it appears now,

beautiful, quiet,

but the magma pushed up through a vent

caused a colossal steam explosion

and volcanic ash blasted
all over the landscape

and changed El Salvador from
a lush, tropical paradise

it really was -

to a desert, a white desert, overnight.

Could the volcano erupt again today?

Let's go.

Its crater is 230 meters deep.

That is twice the height
of the Statue of Liberty.

Its sides are steep and are
strewn with hot springs.

There are indicators that new magma

continues to rise to the surface.

In some spots, it heats up
the water to 70 degrees.

The volcano is still active.

The majority of dormant
giants remain invisible,

sometimes for so long that
they fall into oblivion.

How do people react in view

of the possible sudden catastrophe?

Payson Sheets delves deep into the past

to answer this question.

The traces of this past catastrophe

can also tell us what the future holds.

It is the quest for the power
of the sleeping giants.

Robert Dull from the
University of Texas in Austin

has researched the scope of
the last great eruption.

There is a very large magma chamber

that sits under Lake Ilopango

and one of the wonderful
things about a caldera lake

is that, unlike the more
conical strata volcanoes

that we are used to seeing,

the magma chamber down below,

the lake itself is showing really almost

the entire size of the magma chamber.

I expect that an eruption
will happen from Ilopango

at some time in the future.

It's happened over and
over again in the past

and it's likely to happen again.

This is the place you need to research

if you want to know how
civilizations react to the threat,

because El Salvador hasn't just been

destroyed several times by volcanoes,

the area has also been
populated since millennia.

Joya de Ceren is located 35
kilometers from the Ilopango.

The small Mayan town
provides important clues

as to how people have led their
lives in the face of danger.

For one thing, the village isn't located

under the ash layer of the Ilopango.

It is actually constructed on top of it.

The results of his excavations here

made Payson Sheets believe to have found

what a life with a sleeping
giant has been like

up until today.

More than 1,000 years ago,

only a few hundred people lived in Ceren.

Their village was destroyed
by a volcanic eruption.

If you dig here, you dig
through several ash layers

that were produced by the sleeping giants.

Volcanoes in a place like this

have some very beneficial aspects

and some very detrimental aspects.

The beneficial ones are
creating rain up high

and volcanic ash weathering
into very fertile soil.

In this case, the soils
recovered, people came in,

started this small community of Ceren

200, maybe 300 people.

But look what they did,
they built this gorgeous,

delicate, very religious
building for a diviner.

The shaman is an intermediary

between the people and their environment.

She is asking for good harvests

and safety from nature's perils.

The shaman here can handle

these everyday kinds of anxieties,

but when the eruption occurred,

she could not do anything to help.

The problem is that if you're standing

this far away from me
shouting, you cannot hear.

The sound from the steam emissions

from the very beginning of the
eruption is way too loud.

It's the loudest sound they
ever heard in their lives.

And they inhaled that cloud

that is following them, catches up to them.

It coats the inside of their
lungs with volcanic ash

and they have about a minute
or a minute and a half

to keep living.

No more oxygen gets to them.

It is a very painful death.

This story illustrates

feeling safe is the biggest danger.

But Payson Sheets believes
that the giant's power

reaches far beyond its ash.

In Mexico, 12,000 kilometers away,

there is a mysterious place.

Whereas villages have been built

on the ashes of the Ilopango
in very close vicinity,

life here seems to have
come to a halt forever.

Today, the city in Mexico's high plateau

is called Teotihuacan,

the place where humans become gods.

The only thing that this high
culture left behind are ruins,

but the most monumental on the
American continent at that.

The pyramid here measures 65 meters.

It is the third tallest in the world.

This huge city is considered
to be the precursor

of many of Mexico's civilizations,

but its downfall remains a mystery.

Above ground, no stone is left unturned.

So the secret of the former
metropolis must lie elsewhere.

The exploration of
Teotihuacan is difficult.

There are neither decipherable
scripts nor other accounts,

nothing that explains its downfall.

Archaeologist Sergio Gomez
is hoping to find out more

about the former high culture's fate

14 meters below one of the pyramids.

He follows a tunnel that the
inhabitants constructed

under the Temple of the Feathered Snake,

the pyramid devoted to one of
their most important gods.

It's a rare find.

In 2003, Gomez discovered a shaft

100 meters away from the pyramid center.

Since then, he's been trying to advance

further into the tunnel.

Camera robots give the
researchers a first impression

of what awaits them on
the inside of the shaft.

Not only did the inhabitants
dig this tunnel,

but they also sealed it with tons of earth

after its construction.

Without pack animals and wagons,

they put a tremendous effort
into hiding a construction

that was supposed to remain hidden forever.

After a few attempts, the robot succeeds

and advances into the first
segment of the tunnel.

The images show that the tunnel

wasn't constructed to serve an earthly use.

It is part of a type of underworld

that existed underneath the bustling city.

Its purpose, however,
still puzzles scientists.

At the moment, we're still
working on the tunnel

to better understand their
system of government.

One of the main theses that I set up

is that we will find the
grave or the human remains

of those that stood in close
relation to the government

or political system of Teotihuacan.

Meanwhile, the team has uncovered

several meters of the tunnel.

An imperial grave, however,
has not yet been discovered.

But the tunnel contains countless clues.

75,000 objects have been recovered

and they can be read like a book.

Caribbean conches, statues,
masks, and sacrificial vessels.

Mysterious cultures with ornaments showing

a high level of craftsmanship.

The inhabitants must have been in contact

with several different cultures.

But few of the found objects
were of practical use.

The most bizarre find:
Ritualistic knives made of glass

and a piece of human skin.

Teotihuacan was the most important

and influential city of its time.

In between 100 and 500 CE it was the center

of a huge, complex empire

that was governed from Teotihuacan.

Furthermore, Teotihuacan
was, symbolically speaking,

the most important holy city that existed,

that had ever been constructed until then.

Teotihuacan is located in central Mexico,

just 45 kilometers from the capital.

It is known to have served as a model

for the construction of Mexico City.

Today, over 20,000,000 people live

in the environs of the city,

one of the world's largest.

It is the economic, cultural,

and social epicenter of the country,

and it continues to grow.

Especially in its wealthy center,

one can easily forget the
danger of a volcanic eruption.

It's a normal day like in
any other megalopolis.

Everything seems to be more important

than a preparation for
a disaster situation.

Modern symbols of wealth and
power rule the skyline,

even though both Teotihuacan
and Mexico City

are surrounded by volcanoes.

The pyramids and towers of
glass rest on troubled ground.

Mexico is in the hands
of the sleeping giants.

Craters rise up everywhere.

In some areas, they protrude
out of a sea of houses.

This volcano named Xico is
considered to be dormant,

but magma is seething underneath it.

It can find its way to the
surface at any given moment.

This is the largest daisy chain
of volcanoes on the planet.

The country lies on the
so-called Pacific Ring of Fire,

a fissure line of the tectonic plates

around the Pacific Ocean.

Nowhere are there more volcanoes,

and there are 40 of them in Mexico alone.

Only 50 kilometers from Mexico City,

one of the most dangerous volcanoes,

the Popocatépetl, lies dormant.

Its active signs are constantly monitored.

Seismic waves, elevations
of the ground, gases.

It became active again in the 1990s.

Currently, a so-called
lava dome seals its shaft.

Should the volcano stir,

the instruments will raise the alarm.

Ramon Espinasa is the vice director

of the Popocatépetl Observatory.

He tries to foresee the
time of a future eruption.

Once lava is spewed out,
it collects at first.

Because it's very slow-flowing lava,

it doesn't flow downhill
but stays in the area

of the volcano's opening instead,

forming a hill in the
exact shape of a dome.

This dome seals the shaft and prevents

not only gases from leaking but
also the release of energy.

That's why this energy is
then collected underneath it

until it reaches a
sufficient amount to explode

and to catapult the dome into the air.

Any movement of the volcano

could be the start of a large eruption.

In 2000, a big eruption announces itself.

The formerly peaceful,
sleeping neighbor awakens

and instantly becomes a threat.

The residents of the surrounding
villages are evacuated,

even against their own will.

But El Popo quiets down again,

only to awaken shortly thereafter.

The constant to and fro
deadens the residents' fear.

Once the alarm sounds again,

many refuse to leave their houses.

Psychologist Esperanza
Vazquez is a researcher

for the Mexican Ministry
of Health, among others.

It is her goal to make the population

aware of the seriousness of the warnings

given by geologists.

To this end, she examines the
relationship of the residents

to their mountain.

They look at it and say "Oh, he's happy.

"He's coughing."

And even if they're not thinking this way,

the volcano still plays a
central role in their lives

and some studies that I've conducted show

that the people living here

see the volcano more as a legend,

as a part of the landscape.

Their image is a lot more positive

than that of scientists from abroad,

who see it as a threat from
an objective point of view.

The locals see it as a
part of their identity.

The volcano is like a relative to them.

How do the residents

in the immediate surrounding
area of the volcano

cope with the threat of an eruption?

Is the threat even taken seriously?

Those are questions that Esperanza Vazquez

wants to find answers to.

They are important to
determine the best way

to communicate with the people

so they can be evacuated in
the event of an emergency.

The psychologist especially
wants to communicate

with the new generation.

Shut off the water, turn off the gas,

and switch off all electrical devices,

and put on protective
glasses and a face mask

so I won't breathe in any
ashes that could hurt me.

I think it's better to be
close to an active volcano.

A dormant one can also erupt at any time,

but with an active one, at
least you know about it

and you can prepare better for it.

People all over Mexico

are aware of the volcano's untamed powers.

Just 230 kilometers from the capital,

there is a village church embedded in lava.

Its history shows just how fragile

the Earth's crust in Mexico really is.

In February 1943, in the
middle of a corn field,

the ground starts to rise and then burst.

A new volcano is formed right in front

of the eyes of the farmers.

Within two days, its constant eruptions

produce so much lava

that it rises up to a height of 50 meters.

A year later, it is 336 meters high.

The lava destroys everything in its path,

except for the church.

10 years later, the volcano falls silent,

but only after a very long eruption.

These past eruptions help to understand

recurring events in the
course of Mexico's history.

In the fourth century, for example,

the shaft of the Xitle
covered the world in ash

with a single long-lasting eruption

without a previous warning.

Eruptions such as these can
reach gigantic dimensions.

The Xitle lets an area
of 70 square kilometers

disappear under its ash and lava.

The city of Cuicuilco is
completely destroyed.

The residents have to leave their land,

taking only meager belongings
that can be saved.

Only the pyramid defies destruction.

Today, it is located in
the middle of Mexico City

in between the university
and residential areas.

Entire districts of the modern metropolis

were constructed on top of lava fields.

Where did all these people go back then?

Sergio Gomez has traced
the path of the refugees

and came to a surprising conclusion.

What is remarkable is that all of them fled

into the same direction.

Their path leads directly to Teotihuacan.

This has widespread consequences.

The eruption of the Xitle volcano

has dramatically changed the
history of the Mexican basin.

The social and economic
history of both places,

Cuicuilco and the rising
city of Teotihuacan,

was rewritten.

Teotihuacan has therefore
never had any rivals,

and could establish a wide-reaching network

of economic and social connections.

It was able to spread its rule

of the entire Mesoamerican region.

Several volcanic eruptions

are the cause of mass migrations.

With the arrival of the refugees,

Teotihuacan gains importance

as more and more people
are drawn to the city.

But what makes the city so attractive?

One of the reasons is its religious system.

In Teotihuacan, the people
make a pact with the gods.

The residents carry the
occult to an extreme,

as if they wanted to
confront the force of nature

with everything humanly possible.

The priests don't even shy
away from human sacrifice,

meant to protect the
city from catastrophes.

But the idea that nature can be

kept under control by performing rituals

will soon be proven wrong.

Even today, the danger is far from over.

The giant can awaken at any moment.

How do you live with a
dangerous volcano close by?

How do you cope with its constant threat?

No one trusts the official
institutions anymore.

Too often, they warn the
population of an eruption

that didn't happen in the end.

Therefore, many turn to ancient knowledge.

For shaman Epifanio Alonso,
faith is the only way to cope

with living in the volcano's shadows.

We always trust in God first, always.

The volcano is the place
to ask for what we need.

It is the place of the
descent of God's spirit.

Here, we pray to receive
everything we need to live,

everything we need.

Volcanoes represent the
primal forces of nature.

Their power reaches beyond human control.

That is why they continue
to be seen as home

of holy beings until today.

For me, it is a church,

a church into which you
can't just look into.

I'm telling you this because in my dreams,

I have seen what it looks like from inside.

That's how it is.

And we climb up there to
pray for enough food,

because the volcano protects the seed.

Even today, people try

to control the Popocatépetl
by performing rituals.

Prayers and offerings
are seen as guarantors

for security and prosperity.

And there is indeed a bit
of truth in this belief,

because earth of volcanic origin

is very loose and full of minerals.

These are ideal conditions for plants

and thereby for agriculture

as well as livestock farming.

In the area surrounding the volcano,

a few centimeters underneath the soil

lies the ash of its eruptions.

As soon as the giant sleeps,

the ash turns into the most
fertile soil on the planet,

but the price is high.

The Popocatépetl has catapulted
stones all the way to here,

several kilometers away.

In case of a big eruption,

there would be an ash column

reaching all the way into the stratosphere,

15, 20 kilometers high.

All of this material would
then fall back into itself

and cause pyroclastic flows

that would cascade down
the sides of the volcano

towards the surrounding villages.

These pyroclastic flows

are the biggest and most treacherous

dangers of a volcano,

barely noticeable at first
because they are so quiet.

But they soon pick up speed and spew over

everything in their way

at up to 400 kilometers per hour.

It is highly dangerous to
conduct research on them.

In the 1970s, Katia and Maurice Krafft

were real celebrities
in the geologist scene.

Risking their lives, they got closer

and closer to the crater.

Even today, this is still the only way

to learn more about volcanoes.

How exactly do pyroclastic flows behave?

What makes them so dangerous?

In 1991, the Unzen in Japan
shows increased activity.

It is one of the most dangerous
volcanoes in the country.

The Kraffts are just a few meters

above the valley floor on the hillside

when the pyroclastic flow reaches them.

Both lose their lives.

At the Smithsonian Institute in Washington,

one scientist has managed to create

pyroclastic flows in the laboratory

at a safe distance.

Benjamin Andrews didn't have
to risk his life for this.

He creates artificial ash
clouds on a smaller scale.

They behave just like real flows
but they're a lot smaller.

This is just a mineral talc,

and it's been smashed and sorted

so that it's all the same size.

So it really is like using
baby powder without the scent,

except that we buy this baby
powder in 40 kilogram drums

instead of 800 gram bottles.

The size of the particles, their weight,

everything is precisely calculated.

Here in the laboratory,
the scientist can safely

examine several scenarios.

He creates obstacles on a miniature scale,

like small mountains.

What makes the flow so
dangerous in real life?

Pyroclastic flows are very dangerous

because they move very fast,

they're very thick, and they're very hot.

And these currents, they look fluffy

but they're not fluffy at all.

Instead, they're a very fast-moving mixture

of ash, and rocks, and pumice,

and all of this has the
effect of destroying

pretty much anything and
everything in its path.

A laser light makes visible

the behavior of the flows.

If they are relatively cool,

they can easily overcome the obstacle.

Benjamin Andrews heats up
the ash using a toaster.

He wants to know whether

extremely hot ash behaves differently.

And indeed, once a hot pyroclastic
stream hits an obstacle,

it can't overcome it.

Instead, ash and gases
rise into the atmosphere.

One thing that our experiments here can do

is ultimately help develop better
or more informed risk maps

based upon how far do we think
pyroclastic flows might go,

how might those pyroclastic
flows interact with topography

or interact with a river valley.

The local authorities close to Popocatépetl

are trying to find safe
ways out of the danger zone

using these investigations.

It's been 2,000 years since
the last big eruption.

It would be negligent to forget about it.

On the contrary, the more
time that has passed

since its last eruption,

the more likely a new one is to occur.

Tension increases with the
mountain's every move.

Once the instruments sound the alarm,

20,000,000 people are in immediate danger.

CENAPRED to El Popo, CENAPRED
to El Popo, do you read?

Smaller explosions and
earthquakes like these

can always be the beginning
of a larger eruption.

This is Popo calling CENAPRED.

I can read you loud and clear, over.

The preparations for an
emergency are meticulous.

Nonetheless, it is almost
impossible to evacuate

a city with millions of residents.

German volcanologist Claus Siebe has been

working in Mexico City for 20 years.

He is trying to determine the
consequences of an eruption.

What would the ash do to the city?

Its dense population, location,

and the ailing infrastructure

would seal the city's fate.

Mexico City certainly is a special case

because it's a metropolis, a megacity

that isn't located next
to a river or the ocean.

The city's sewer system is
already quite strained.

A case like this would lead to plagues

and even bigger problems.

And the sewers aren't the only concern.

The ash can get anywhere.

It can contaminate the drinking water,

rupture the power supply
through short circuits,

and impair car and air traffic
by limiting visibility.

It is hard to believe
that more and more people

want to move here.

But life with a fire-spitting giant

can also have its benefits,

benefits that were also valuable
to Teotihuacan back then.

Volcanoes create fertile soil.

They seem to intensify the
need for rites and culture.

The pact with the gods promises
people a life and safety.

But for Teotihuacan, these
are not the only advantages.

Imagine, it is the most
successful civilization

that had ever existed in Mesoamerica

in political, and economic,
and religious terms,

no doubt about it.

Just like Mexico City,

Teotihuacan lies on a high
plateau, far away from the ocean.

Nevertheless, the residents
have access to plenty of food.

There is prosperity, and not
only in the upper class.

Soon, the city becomes larger
than the ancient Rome.

At Teotihuacan, you have to imagine

a city of over 100,000 people,
beautiful gridded streets

and residential compounds,
apartment buildings,

and the agricultural
system works very well.

Trade routes are all the way down

into what's now Guatemala,
and Belize, and El Salvador,

all the way up into New Mexico.

Volcanoes supply the crude material

for the city's wealth.

The alleys are full of obsidian workshops.

The volcanic glass is
used to create jewelry,

cult objects, and tools.

And Teotihuacan exports weapons
to all of Central America,

one of the most important
commodities of the time

that could be exchanged for food,

cosmetics, and luxury goods.

Obsidian is created when
lava cools down so quickly

that it cannot form any crystals.

The volcanic glass has helped Teotihuacan

to become the first trade
city in Central America.

We have proof of Teotihuacan
presence in Guatemala,

Honduras, even in El Salvador,

places and people the city must have had

some sort of contact with.

Volcanoes let the city flourish.

Remarkably, its residents
left shortly after

the eruption of the Ilopango
in the 6th century.

Is this where the secret of the city's

downfall can be found?

1,200 kilometers away?

Payson Sheets is sure that the Ilopango

is responsible for the fall of Teotihuacan.

But after several centuries, it
is hard to prove his theory.

Humans were also sacrificed here

to appease the giant,
just like in the city.

Figurines of Christian
saints that have been

brought up here by later generations

testify to this.

And yet, the danger seems
to have been forgotten.

And people would like
to believe in this area

that that's it, it won't erupt again.

Sorry.

Sorry, this is not a good place

for long-term land investment.

Over here you see 540, over here you see...

Robert Dull has managed

to date Ilopango's eruption.

This offers a decisive clue.

This is a massive amount of information

that you're putting together.

This is ice cores and tree rings.

Here's 1257, that's the Samalas event.

In a sense, in kind of a selfish

archaeological sense as a researcher,

I know that there are
hundreds, literally hundreds,

of archaeological sites buried

by the volcanic ash from Ilopango.

They all date of course
to the same timeframe.

Today, the villagers that
were suffocated under the ash

are the only witnesses.

They reveal how massive the
eruption of Ilopango was.

Judging by the measurements
of the ash's dispersion,

it must have spewed out up
to 160 megatons of sulfur.

Sulfuric acid clouds circle
the globe for several years.

The climate is out of control.

That means that the
eruption didn't only happen

in the time in question,

but that it was big enough
to influence the climate

even in places very far away.

They got hit by this
dramatic downturn in climate

that was both a long-term,
more than a decade

of cold temperatures and drought.

Both of those caused in Teotihuacan

a failure of confidence in the system.

The city faces the consequences

of the largest volcanic
eruption in 2,000 years.

For 500 years, the pact with the gods

and the omnipotence of the priests

have kept the volcano in check.

The human sacrifices seem to
have silenced the volcanoes.

They had ensured rain, and with it,

fruitfulness and prosperity.

But suddenly, there is
no more rain for years.

The gods seemed to have
forgotten the holy city.

There was a fire that ran
along the street of the dead

and burned the temples.

Early, people thought it was a huge fire

that ran through the city.

No, it was set.

The enraged residents set fire

to the symbols of the gods

that no longer provide them with shelter.

The city was largely abandoned

and it never regained
that kind of political,

economic, religious power.

That was it.

History shows that even

highly developed civilizations

cannot oppose the force of volcanoes.

1,500 years after the
catastrophe of the Ilopango,

in 2008, the Chaiten in
southern Chile erupts,

almost without any prior warning.

Its eruption catches the
population off guard,

and it can barely flee to safety.

Shortly after, the
eruption column collapses

and pyroclastic flows gush down
the sides of the mountain.

The Chaiten has proven how difficult it is

to predict a dangerous eruption.

For centuries, the volcano was
considered to be dormant.

The city of Chaiten is
completely destroyed.

Due to the destruction and the
constant volcanic activity,

the government decides to
abandon the place completely.

Villages and people within
the radius of volcanoes

can be led to safety,

but the history of Teotihuacan indicates

that the giants pose a threat

that can even reach
cities that are far away.

These are especially vulnerable.

In 2010, the eruption of Eyjafjallajökull

gives us an inkling of how
vulnerable even modern

and technologically advanced
societies can be today.

Exactly what volcanologists
fear the most takes place.

Magma comes into contact with glacier ice.

The steam explosions rip
apart the molten rock

into tiny ash particles.

Poisonous fluorine and ash
spreads over the landscape.

500 people have to be evacuated
from around the volcano.

The farmers that work the
area are hit especially hard,

but the consequences spread further.

The wind continuously pushes the ash clouds

into higher air layers

and sends them across the North Sea

over to central Europe.

In April 2010, they reached Germany.

All air traffic is grounded.

Europe is at a standstill.

100,000 passengers are stranded

and cargo flights are canceled.

And yet, the eruption
of the Eyjafjallajökull

isn't even the biggest one.

The volcano ejects only
about 0.14 cubic kilometers

of material into the air.

The eruption of Mount St.
Helens is 10 times bigger,

and the Ilopango's 100 times as big.

The eruption of a super
volcano could release

more than 1,000 times that amount.

So, we cannot fathom,

I cannot fathom,

the enormity, the massive
scale of an eruption

of Yellowstone should it occur again today.

This volcano is almost unrecognizable,

simply because of its enormous size.

The Yellowstone super volcano
is one of the world's biggest.

It lies dormant in the middle

of the Rocky Mountains in Wyoming.

Henry Heasler is a geologist working

for the Yellowstone National Park.

He monitors the numerous geysers,

visible signs of the sleeping super giant.

Go ahead and pan it out towards...

This is the largest collection

of hot springs in existence.

3,000,000 visitors come
to see them every year.

In a way, they're like beauty and the beast

at the same time.

They look gorgeous but you can have

above boiling temperature waters,

you can have acidic conditions, pH 1 and 2,

the pH of battery acids,

you can have dangerous
geothermal gases in low areas.

So how do we choose where to
safely put these boardwalks

so visitors can experience the
sights, sounds, and smells

of a hydrothermal area safely?

It is invisible to the visitors,

but the American continent
is pushing itself

very slowly over a huge magma bubble.

The tourists deem themselves in safety

while contemplating the natural spectacle

above the super volcano.

Every year, 2,000 small earthquakes

and recurring elevations of the ground

reveal that the giant is alive.

Only as recently as 2014,

the biggest seismic shock
in 30 years hit the area,

thankfully without causing
any serious damage.

No scientist can predict when
the volcano will awaken again.

The only thing we can do
is to monitor the giant.

One look into the
Yellowstone's history shows

that the volcano has erupted several times.

These eruptions put out
so much volcanic material

as a fine ash, it was jetting it out.

It wasn't a big explosion,
it was jetting it out

much like when an apple pie starts to break

and you get steam coming out

that the ground then subsided.

Just a few kilometers
underneath the surface,

magma eats its way through
the Earth's crust

like a welding torch.

Only since 2015 do we know that the bubble

is incredibly large,
46,000 cubic kilometers.

The last eruption of the Yellowstone

was 630,000 year ago.

It destroyed everything within
a radius of 100 kilometers.

Ash rains down even 1,500 kilometers away.

The rest of the world
disappears into darkness

for over decades.

You got these big, dense populations.

Try to have them handle a big eruption?

They don't.

They become archaeologically
important material, thank you.

But they did not do well at that time.

The cloud of the Yellowstone

could well introduce a new, small Ice Age.

Under a veil of ash and sulfur,

the tropical rainforests would freeze.

Supplying cities with over
a million inhabitants

would become impossible to handle.

These huge eruptions are extremely rare.

They occur only once every 100,000 years.

However, the giants are still just asleep

and lure us into believing we are in safety

by overwhelming us with their beauty.