Yellowstone Supervolcano (2015) - full transcript

It's nature at

its most savage and fearsome...

Volcanic blasts,

spewing pillars

of superhot clouds skyward,

unleashing hurricanes

of molten rock and fire.

But as awesome

as past eruptions have been,

one coming eruption is destined

to change life on our planet...

Killing millions of people,

altering the earth's climate,

creating world-wide famine.

It would be so massive.

It would have such impacts.

It's hard to fathom.

This would truly be a catastrophic event

on a global scale.

And the source

of this monstrous devastation

lurks just miles below the surface

of america's first national park.

We are directly over

mt. St. Helens right now,

and there is no question at all

that the volcanic activity has begun.

May 18, 1980.

8:32 A.M.

A 5.1 magnitude earthquake

rocks mt. St. Helens

in southwestern Washington State

and triggers

the deadliest volcanic eruption

in U.S. history.

Northwest side is sliding down.

All right, we got it, boys.

The whole northwest section.

In minutes, a mushroom-shaped cloud

shoots up ten miles high.

Below the cloud,

superheated flows of rock and debris

surge out of the crater,

racing over the land,

incinerating everything in its path.

No one is prepared for the chaos.

Get off the bridge!

A river, swollen with mud and debris,

rages out of control.

The devastation is immense.

Everything within a 230-square-mile area

of the mountain is obliterated.

57 people are killed,

and thousands of acres destroyed.

By midday, the eruption ends,

leaving a once serene and

beautiful region a wasteland.

A graceful cone-shaped volcano

is now a blasted stump,

and a nation is in awe

of nature's destructive power.

But there's

one volcano in the U.S.

With the potential to wreak devastation

on a far greater scale.

It's located 575 miles away

from mt. St. Helens,

in the northwest corner of Wyoming.

For over a century,

tens of millions of visitors

have marveled at Yellowstone's

breathtaking scenery.

But beneath this spectacular

beauty lies a ticking time bomb.

We get a glimpse of it each day

from old faithful.

Every 90 minutes, this famous geyser

shoots over 8,000 gallons of

boiling water 18 stories high.

A tourist attraction, but far from benign.

Yellowstone is one

of the largest volcanic systems on earth.

Scientists call it a supervolcano

because of the size of past explosions.

The criteria that we use

to decide whether

an eruption is a super-eruption

is essentially the volume of the eruption,

and that is, if an eruption

has more than 240 cubic miles,

or 1,000 cubic kilometers

of pumice and ash

that came out in that one event,

then it's a super-eruption.

There have been three super-eruptions

at Yellowstone

over the last 2.1 million years.

The last big one was 640,000 years ago;

the one before that, 666,000 years prior.

Which leaves many to wonder what's next.

There have been signs

that something unusual

may be happening in the park.

In 2004, five bison were

found dead in a geyser basin.

They weren't in a typical death pose,

kind of like a cat that's curled up.

It looks like they'd just fallen over.

We think it was just a very cold

night, a very still night.

The geothermal gases accumulated,

and the bison just basically

dropped where they stood.

The gases were identified

as hydrogen sulfide and carbon dioxide,

two components of what's found

just below the ground

at Yellowstone...

Boiling-hot magma.

The Yellowstone supervolcano

sits on what geologists call a hot spot.

Unlike other volcanoes in the world,

Yellowstone isn't cone-shaped

with a crater at the top.

Instead, it's a caldera,

a large depression in the earth

50 miles long by 30 miles wide,

formed during its last major eruption.

You can be standing on the caldera

without realizing you're standing

in the crater of an active volcano,

one that's erupted over 25 times

since its last super-blast.

Yellowstone is most famous

for its very large super-eruptions.

However, there have been

a series of other eruptions.

These are smaller than super-eruptions,

but they're still enormous events,

50 or so times as big

as mt. St. Helens.

Given its past, the

next Yellowstone super-eruption

could be the largest natural

disaster in recorded history.

In our lifetime, we have nothing

to compare it with.

The Icelandic volcanic eruption in 2010

grounded flights

around the world for a week,

causing the biggest air travel

shutdown since world war ii,

but it doesn't come close to

what Yellowstone's capable of.

A Yellowstone super-eruption

would eject over 1,000 cubic kilometers,

240 cubic miles,

of pumice and ash

from deep within the earth.

Which would come out of the volcano

and destroy all...

Everything in its path.

1,000 cubic kilometers is enough

to Bury the state of Texas

about five feet deep.

It would be roughly the equivalent volume

of the size of the Grand Canyon twice.

The explosion would also release

ferocious avalanches

of hot ash, pumice, and gas,

called pyroclastic flows.

They are essentially

like super-heated sandblasting clouds

that can destroy pretty much

everything in their path

through either knocking it down

or sandblasting it to bits

or setting the resulting debris on fire.

Case in point...

The 1995 volcanic eruption

on the Caribbean island of Montserrat.

Pyroclastic flows surged down the mountain

and into the capital city of Plymouth,

burying it under more than

30 feet of mud and ash,

rendering it uninhabitable.

While pyroclastic flows sear the land,

the volcanic ash in the air is deadly.

This is a bomb.

This is a bomb actually from

mt. St. Helens, 1980 eruption,

and when you're fairly close

to the volcano

and you get big glops of magma

and lava that end up in the air,

then they cool, literally, in the air

and then come down

as a big, heavy, solid chunk.

In the case

of mt. St. Helens,

some of these bombs

were this big or this big,

but we've certainly seen, in other places,

bombs that are as large as a house.

These bombs are mixed

with tons of volcanic ash,

but it's not the powdery residue

you see in your fireplace.

Smithsonian institution

geologist Ben Andrews

is an expert on explosive eruptions.

Fireplace ash

is essentially just burned wood.

Volcanic ash

is pulverized pumice and rock,

smaller than two millimeters,

and if we look at it with a microscope,

we see that's it's essentially

little bits of broken crystals,

little bits of broken rock,

and bits of broken pumice,

and if we look at that pumice,

we see that it's glass.

A petrographic optical

microscope reveals some details,

but it's not until you see volcanic ash

with a scanning electron microscope

that you learn how dangerous it is.

So, we're looking at a sample of ash

from the 1980 eruption

of mt. St. Helens here,

and as we look at this,

we can see right now

that it's much more

than just fine-grained dust.

We have a piece of glass

that then has some very sharp

features to it.

We see that it has these points

and sharp edges around it,

and each one of these particles,

in this particular field of view,

each one of the big particles

is about half the size of a human hair.

In the case of volcanic ash,

you're inhaling bits of broken glass,

which effectively can lacerate

your entire respiratory system.

If you're close to a super-eruption,

inhaling large amounts of volcanic ash

can burn the lining of

your lungs, causing rapid death.

But further away,

airborne ash will

make it difficult to breathe,

and that can kill you, too.

Project managers at the federal

emergency management agency

take the threat

of a Yellowstone super-eruption seriously,

mapping out six danger zones.

Following an eruption, zone 1,

closest to Yellowstone,

would be suffocated

by up to six feet of ash.

70,000 people are at risk here.

The ash cloud

would reach nearby communities

in a matter of minutes,

leaving little chance

for residents to escape.

This is as far east as you can go.

Travel 60 miles further to zone 2,

and another 400,000 people

are at risk from over three feet of ash.

There would be severe health problems

on a scale that would overwhelm

local hospitals and clinics.

The deadly ash would spread quickly

as it rises into the atmosphere.

In zone 3, more than a million

people would be exposed.

In zone 4, salt lake city and Denver

would be crushed

by a foot and a half of ash,

twice the amount needed

to collapse a building.

Nothing short of a concrete bunker

would support the weight.

In zone 5, cities as far away

as Kansas City and St. Louis

would see nearly a half-foot of ash.

Even that amount

can cause roofs to collapse.

By the time the ash covers

zone 6, it would blanket an area

from San Francisco to New York,

from Dallas to Detroit,

dumping about a half an inch,

still enough to irritate lungs and eyes.

In total, at least 200 million

people would be affected

by the ash fallout

from the Yellowstone volcano.

If the super-eruption

occurs without any warning,

the human toll would be unimaginable.

Even with warning, the impact

would be catastrophic,

with deaths in the millions.

As for those who survive the blast,

they would face a world

of desperation and turmoil,

caused by gritty, abrasive fragments

raining down on them from the sky.

The ashfall resulting

from a supervolcanic eruption

at Yellowstone

would endanger the food chain.

Crops in the heartland of america

would be severely damaged,

if not destroyed.

Well, the problem is

that the bread basket of North America

is downwind from the Yellowstone volcano,

and the ash that would

cover the ground surface

would destroy the growing season

in the U.S. and Canada,

and the world supply of grain

would be in trouble.

Even if food were available,

distributing it throughout North America

would be next to impossible.

Aircraft wouldn't be able to fly

because of ash in the stratosphere.

It's why planes were grounded for days

after the 2010 Icelandic eruption.

Flying through volcanic ash

is like flying through clouds of sand.

The small, gritty particles can

damage jet aircraft blades,

affecting the engine's performance.

This simulation shows what ash

can do within a jet turbine

when it strikes an engine blade

made of titanium.

Close the unit up.

In just five minutes,

the ash blasts a hole through the blade,

which could lead to catastrophic

engine failure in midflight.

While not as dramatic,

ash can also disable

ground-based vehicles.

Automobiles,

their engines would get clogged

with the volcanic ash,

so there'd be no trucks.

In the middle of North America,

there'd be no way to get food

in or out of that zone.

The volume of ash

would pose the most serious

threat to human health.

Canadian rahul Singh has responded

to natural disasters around the world.

As a paramedic and director

of the charity global medic,

he's seen the effect

volcanic ash can have firsthand.

You know that people are going to need

food, water, shelter,

access to primary healthcare.

The main difference with a volcano?

The ash.

The ash is the killer.

There's evidence of ash's deadly effects

from 12 million years ago

in northeast Nebraska.

Here, at the university of Nebraska's

ashfall fossil beds site

are the skeletons

of over 200 prehistoric animals

that died from exposure to volcanic ash.

The ash came from a volcano

that erupted over 1,000 miles

away in what is now Idaho.

Researchers at the site

scrape away layers of soil and sediment,

revealing a scene reminiscent

of the human tragedy at Pompeii.

These animals survived

the initial ashfall,

but over time, as they grazed

on ash-covered grasses,

they breathed in the powdery glass dust,

which shredded their lungs,

and here, at what

was an ancient waterhole,

they suffocated to death.

If you don't die from

inhaling ash after an eruption,

your next concern

would be clean drinking water.

Falling ash would contaminate

rivers and lakes.

Water like this would have to be filtered,

and rahul Singh knows about

the consequences if it isn't.

Our teams are

specialty in providing people

with access to clean drinking water

and access to primary healthcare.

The ash is going to give us

tons of patients,

but in two or three days,

that ash is also going to wreck

the water source of all those people,

so that same patient you may have treated

on the first day of an event,

because the ash is what he inhaled

and it made him short of breath

and it's caused all kinds of problems,

in two or three days,

if you don't get

clean water up and running,

they're going to be a patient again.

The effects of

a Yellowstone super-eruption

wouldn't be confined to North America.

They would be global,

triggering catastrophic climate change.

It's happened before.

Scientists use a numeric scale

to measure the magnitude

of a volcanic eruption.

So the volcanic explosivity index, or vei,

is a way for scientists

to measure how big an eruption is.

It's similar to

the Richter scale of magnitude

for earthquakes

in the fact that it's a logarithmic scale,

so a vei 6 is going to be

10 times bigger than a vei 5,

and 100 times bigger than a vei 4,

so the purpose of the vei scale

is to get scientists on

the same page about an eruption,

you know, so when you say vei 5,

that has some meaning about

how much volume was erupted,

how high an ash plume went.

May 18, 1980 eruption

of mt. St. Helens, for instance,

was barely a vei 5,

which is considered very large.

Mt. Pinatubo and krakatau

were both vei 6.

A super-eruption would be a vei 8,

or 1,000 times greater than

the mt. St. Helens eruption.

While the largest eruption

in the continental United States,

mt. St. Helens is not

the biggest in human history.

The biggest volcanic

eruption in historic times

is the Tambora event of 1815 in Indonesia,

and that was followed

by global climatic cooling

and failure of the crops

in North America and in Europe.

There was a famine in Western Europe.

1816 has been called

the year without a summer.

Now, Yellowstone is hundreds

of times bigger than Tambora,

and the effect would be global.

There would just be wet and cold

weather all over the world.

We coined the term "volcanic winter"

to cover what would happen

after a major supervolcano

like Yellowstone.

Professor rampino has

studied slices of volcanic rock

to learn how previous volcanoes

have changed the earth.

He paints a grim view of life

after a super-eruption.

Temperatures would drop, on average,

around the world about 10 degrees celsius,

and in parts of the world,

including Africa, for example,

in the Equatorial regions,

the temperature effect

would be even greater,

20 degrees celsius in change.

Tropical vegetation could not cope

with these freezing temperatures.

All aboveground vegetation

could be killed off.

There'd be a 50 percent die-off

of temperate forests.

There might be a 100 percent die-off

in tropical rain forests.

This would truly be a catastrophic event

on a global scale.

The lungs of the world

would be in jeopardy,

but not just from ash.

A supervolcanic eruption in Yellowstone

would release sulfur dioxide

up into the stratosphere.

In combination with water vapor,

it would form aerosols

that could block the sun

from reaching earth.

The indications are

that the ash and the aerosols

that are formed

would stay in the upper atmosphere

for five or six years,

so imagine the rice production in Asia.

Five or six years

of little or no growing season

would clearly cause a worldwide famine.

And in the wake of worldwide famine

would come a barren and desolate world.

Yellowstone's supervolcano is home

to the largest concentration

of hot springs,

geysers, and bubbling mud pots

in the world.

It doesn't have the cone shape

of other volcanoes,

but below the surface,

there's an extinction-level

event waiting to happen.

It's just a matter of time.

A super-eruption exploding

from this restless caldera

would devastate the immediate area.

The pyroclastic flow

could spread from the site

in all directions,

smothering people, animals, and vegetation

in up to six feet of ash and debris.

Seismic activity doesn't

necessarily foreshadow

a major volcanic eruption,

but geologists sometimes see

a link between the two.

There's no way a supervolcano,

or really any volcano, for that matter,

can erupt without causing earthquakes.

Conversely, when you have

very large earthquakes,

you tend to affect the plumbing systems

of volcanoes that are nearby.

Martin stryker of Berkeley, California,

knows all too well the

seismic dangers of Yellowstone.

One of america's worst series

of earthquakes in this century,

felt throughout the northwest.

In 1959, Martin was 15 years old,

on a family camping trip near Yellowstone.

Late one evening, he was startled awake.

His two younger brothers

were reading comic books by flashlight.

And I said, you know, "what's going on?

Is this a thunderstorm?"

And they said,

"yeah, we think so."

And they just went back

to what they were doing,

but, to me, it didn't feel right,

so I got up, and I went outside the tent,

and I looked right in front of me,

and ten feet away was our car,

and on top of the car were two pine trees

that had snapped off and were broken.

Martin's dad and his stepmom

were sleeping in a tent nearby.

I saw that a Boulder

was sitting right on top of their tent,

and the tent was

totally covered by this Boulder.

I realized then that they'd been killed.

In Madison river canyon,

50 million tons of earth and rock,

the top of an 8,000-foot mountain

thundered across a forest campground

in one of the biggest landslides.

The landslide was the result

of a magnitude 7.5 quake

that killed 28 people.

It shows the power of the initial quake

because this rock had been

jarred loose on the hillside,

had jumped...

Run down the hill,

jumped over the picnic table,

and landed on top of their tent

in, like, nothing flat.

My instinct was to protect my brothers.

Then when I took them outside

and told them that

dad and ethyl had been killed,

I mean, that was a heck of a shock.

The next day, a sheriff and

a ranger and a farmer came by,

and they got a winch,

and they pulled the rocks back,

and that was fairly

traumatic to me, you know.

The hebgen lake

earthquake is a deadly reminder

of the geologic forces at work

in Yellowstone.

Deep beneath the surface,

magma will try to make its way to the top.

It will push and shove the rock

around, producing earthquakes.

It's normal for Yellowstone

to have 3,000 earthquakes a year,

but 2008 saw an alarming increase.

In just two weeks, thousands

of quakes, an earthquake swarm,

rocked the area and put

geophysicist Bob Smith on alert.

The front of the earthquake swarm

was moving from south to north

at about a kilometer a day,

which is a very high rate.

The earthquakes were underneath a lake,

and so that always

kind of raises a red flag

with the public is because it's

a little bit more mysterious

when something's happening

beneath a body of water.

In addition, we could

see that the earthquakes

did migrate over time,

and so that implies

that maybe something's moving,

maybe some fluid, maybe even some magma.

Whatever it did, it stopped.

I was concerned that it was

a failed earthquake sequence,

and we're building up

this long fracture zone,

get enough stress,

we can have a much larger

earthquake nucleating.

Then, in 2010, another alarm goes off.

Earthquakes have been rocking

Yellowstone national park all day.

Researchers at the university of Utah

say the park's in the middle

of a swarm of quakes

that started Sunday night.

Since yesterday, seismologists say

they've recorded more than 200 quakes.

This time, the earthquake swarm

lasted a month before it stopped.

You know, geologically,

everyone gets excited

about things that start rapidly,

but we never talk about

things that stop rapidly,

and it's the stopping phase

that we need to understand.

Recently, scientists

have collected new data,

giving them a better picture

of Yellowstone's underground plumbing.

Right beneath the caldera,

from the last eruption,

sits the magma chamber.

And it's fed by a plume of magma

stretching down 465 miles

northwest into Montana.

It's mostly solid rock,

with the potential to liquefy,

and scientists are closely monitoring it.

Magma, or molten rock,

is rising through the plume

into the magma chamber

at two inches a year.

There's no reason for it to stop.

Although it might come in spurts,

our images show

wider parts and narrower parts,

so it's like slugs of material

that are flowing in a sewer line,

and this restless Yellowstone caldera

is truly living, breathing,

and every once in a while, it burps.

The danger is

if the plume starts liquefying

and moving up at a faster rate.

Natural systems can

throw us a lot of curveballs.

A lot of things can happen

that we're not really ready for.

Scientist Jake Lowenstern

is looking for a pattern

connecting the supervolcano today

and its three prior major eruptions...

2.1 million years ago,

1.3 million years ago,

and 640,000 years ago.

In two of the really

large eruptions at Yellowstone,

so much material comes out,

entire mountain ranges end up

falling into the ground

and, essentially, disappearing.

One 50-mile stretch of mountains

simply disappeared by collapsing

into the magma chamber.

University of Toronto geologist

John Westgate

has tracked the ash from

Yellowstone's prior eruptions.

It covered much of the United States.

It occurs right out in the pacific ocean.

It's even found in the Gulf of Mexico.

Up in northeast Montana, there's

a site that we're working on.

The tephra's over 7 meters thick.

These eruptions are enormous.

The amount of material

erupted from them, huge.

When mt. St. Helens

erupted in may 1980,

it blew off one side of the mountain

and triggered an avalanche

of snow, mud, ash, and rock.

Driven by the wind,

the ash landed in 11 states

and up into Canada,

but that's nothing

compared to the amount of ash

from Yellowstone's

last three major eruptions.

In magnitude and volume,

each one was far greater

than mt. St. Helens.

Today there's little evidence of

the supervolcano's violent past.

The 50-by-30-mile caldera

from the last eruption

was covered by lava and ash

and smoothed over by glaciers.

Forests now conceal the scars.

But this pastoral image of Yellowstone

doesn't fool geophysicist Bob Smith.

He's been watching the volcano

for his entire career.

This thing's been active

for 17 million years,

and as we see it today, it's very dynamic.

When you drive to Yellowstone

from anywhere,

you drive uphill onto this high plateau,

and the plateau's essentially

the top of the hot spot.

It includes the earthquakes,

it includes the concept of heat flow

that's driving the geysers

and hot springs,

but it has its source deeper

in the earth's upper mantle.

It's that mysterious

heat source deep in the earth

that's fueling Yellowstone.

North America is a tectonic plate

moving at about an inch per year

in a southwesterly direction.

As the plate moves, cracks and fractures

allow magma to make its way

to the earth's surface

and sometimes punch through

as an eruption.

This plate movement has

left behind a trail of calderas

from past volcanic eruptions,

called a hot spot track.

From Yellowstone, it stretches

nearly 500 miles to the southwest,

signs of a violent past.

All we see is what happens at the surface,

but we don't know

the actual players in detail

of what's happening down below.

Geologist Hank Heasler,

armed with an infrared camera,

monitors heat levels

at Yellowstone's Norris Geyser basin,

even in the dead of winter.

Right here, much of Norris

is at boiling temperatures,

so a lot of heat,

a lot of thermal energy

coming from the molten rock

that's right here beneath our feet.

187 feet underground, the temperature

can reach over 460 degrees fahrenheit.

Yellowstone is

still a tremendous heat source,

and it's really a globally

significant volcanic system.

There is no place on earth

quite like Yellowstone.

And there's no place

more likely to produce

an earth-shattering eruption than here.

Geologists who got a closer view

of the volcano,

flying right into the crater,

called the scene

"spooky" and "scary."

Other scientists reported new rumblings

from the mountain today.

They aren't sure what that portends.

The 1980

mt. St. Helens volcanic eruption

was the deadliest

in U.S. history.

We had a major eruption

occurring at 8:32...

The first to occur

in the era of live television.

Northwest flank of

the mountain seems to be gone.

Never before had the world witnessed

a volcano's destructive power

in real time,

but while a media event,

it was also an unprecedented

opportunity for scientists.

The 1980 eruption was the first

to be thoroughly monitored

with a variety of geophysical instruments,

observing and measuring the processes

that produced such an explosive fury.

845.

Since then,

scientists have kept a close eye

on the Yellowstone caldera,

watching for unusual activity.

Geophysicist David Mencin

is trying to decipher

strange signals

coming from Yellowstone lake.

These signals are picked up by instruments

buried under the lake,

far beneath the earth's crust.

Mencin and his team couldn't

believe the readings they got...

Mysterious messages from the deep.

We thought the

instrument was malfunctioning

until we noticed they were showing up

on all the instruments simultaneously.

They realized the lake was making waves,

undetectable to the eye, but

registering on the instruments.

Water moving back and forth,

like water displaced in a bathtub.

This water, this big weight of water

going back and forth

is essentially pushing down

on the crust on top of the caldera,

and it's reacting differently

because the layer underneath

is more like a fluid than it is a solid,

and we don't understand

what's forcing this to happen.

And it's not just the water making waves.

The ground itself is moving.

Beginning in 2004, scientists discovered

a quarter of the Yellowstone

caldera was rising

nearly three inches a year

right over the magma chamber.

It was about 25 centimeters

over that entire four-to-six-year period.

Then in 2010,

the earth slowly started going back down.

No one's quite sure what's

causing this rise and fall.

People still argue

about exactly what it means.

The meaning of these geologic clues

may be up for debate,

but there's little doubt

about the economic costs

of a Yellowstone super-eruption.

According to FEMA, the estimated

economic losses in the U.S.

Could run to up to $3 trillion.

The effects on the world economy

would be equally catastrophic

if a global volcanic winter resulted.

So are we prepared for this event?

Probably not.

While there's no way

to prevent a super-eruption,

there may be ways to mitigate its impact,

if there are early warning signs.

It's feasible to keep

everybody out of the park.

Not an easy thing to do,

but that's something they can plan for.

That's a big evacuation plan,

and certainly

things are going to go wrong.

People are going to be killed

in car accidents, for example,

in the rush to get away from the volcano.

For people living in zones

further away from the eruption,

survival would depend

on preparing for the worst.

But how bad would the worst be?

And I would say that the example of Japan

has a number of

very important lessons for us.

They were not prepared for it.

The earthquake was bigger.

The tsunami was bigger.

Based on the historic earthquake activity,

they thought they really

had a pretty good understanding

of how things moved,

and when they got a 9,

the overwhelming majority

of seismologists, engineers

were really, really surprised.

We really do have to consider

that the event may exceed our parameters.

In america, hurricane Katrina

revealed how vulnerable

people and property are

in the face of massive natural disasters.

But while evacuation for a hurricane

may move people away from impact zones

for a period of days or a week,

a super-eruption's destructive

power would be far greater

and last far longer.

For individuals

to survive a super-eruption,

it may take a new mind-set.

Developing a culture of preparedness.

It's not paranoia.

It's not constantly thinking

that something's going to happen,

but simple things like having the ability

to last on your own for a week,

having food and supplies,

having a kit in your car.

For a community

to survive a super-eruption,

it requires planning

and preparedness on a vast scale

and begins

with stockpiling the essentials,

starting with water.

Just what we keep

in stock is enough to purify

about 150 million liters

of clean drinking water.

You don't get folks

clean water, people die,

and it's as simple as that.

The Canadian charity global medic

has responded to 60 natural disasters

in 35 different countries

around the world.

And one thing I can tell you

as a uniform rule

is no one's prepared enough.

You and your family should be

stockpiled for about three days

because that's probably

what it's going to take

the rest of our society

to come and provide you

with supplemental aid.

There's the likelihood that food security

will become a concern

once initial supplies run out.

Food's tough to distribute at any time.

I think back to Haiti,

where we had to use u.N. Troops

to roll down the streets

just to protect our convoys of food,

just so we could get them

into community centers

of makeshift cities.

Some scientists advocate

governments taking measures now

to guard against eventual shortages.

One of the things you might want to do

if you're waiting

for a supervolcanic eruption

is to be able to store enough food

to get you through the five or six years

when there's going to be

no growing season,

but when the yields are high,

we only have about two month's

worth of grain in storage

in the United States,

so we really have to make a major effort

to stockpile enough foods

and other materials.

The challenge may seem insurmountable,

the consequences inevitable,

but with a disaster so great

looming in the future,

the question becomes when will it happen?

As scientists learn more

about how volcanoes behave,

they search for clues

that may help pinpoint

the next Yellowstone super-eruption,

but forecasting when it will

happen is tricky business.

Some volcanoes erupt with more regularity,

and are a little bit easier to predict,

and some aren't,

and Yellowstone, you know,

it's a dynamic system,

and so a dynamic system like

that is difficult to predict.

We know a major eruption

will occur in the future,

but exactly when, we don't know.

I do know that there will be

volcanic eruptions again at Yellowstone.

I don't think

they're very likely to happen

within my lifetime.

The scientists agree

it's hard to predict the timing

of Yellowstone's next major eruption.

So will that be in our lifetime,

our children's lifetime,

our grandchildren's?

We can't say for sure

because we've never experienced

in historic times

an eruption that big.

When the eruption comes,

scientists agree

there will be warning signs,

weeks, if not months, in advance.

We're going to see

at least six weeks of re-awakening...

Increased earthquake activity,

increased small-scale steam eruptions,

ground swelling, gas emissions

because that's certainly what we saw

in the case of St. Helens and Pinatubo.

But has the re-awakening begun?

The difficult thing is always going to be

understanding how big is this

going to be, how big can it get?

And that's not something

that we really have

that much experience with

because we haven't had

any eruptions in historic time

that are of that kind of scale.

There's good reason

why scientists and officials

are hesitant to sound the alarm.

When you start to make comments

about potential eruptions or,

indeed, potential earthquakes,

local administrative bodies

get very, very upset.

Real estate values drop.

Tourism decreases.

I mean, you have real issues there.

I don't make the decisions to evacuate.

I just tell the managers,

"here are the possibilities,

and here's the likelihood.

It's up to you."

But what happens when scientists

fail to warn the public?

In 2009, in L'Aquila, Italy,

a series of earthquake swarms

were recorded in the months

before a 6.3 earthquake shook the city.

No evacuation was ordered.

More than 300 people were killed.

Six seismologists and a government official

were charged with manslaughter

for failing to warn people

about the coming earthquake.

We don't know enough

about the warning signs

of an impending eruption

to be able to say, "okay,

now is the time to evacuate."

If you make a mistake

and the volcano doesn't go off,

then you've moved

hundreds of thousands of people

for no reason whatsoever,

so, politically, it might be a problem

of who is going to make the call?

The governor, the president,

the local mayors?

Who's going to make the call

to begin to evacuate?

It's a tough call to make

because, even if you know the date,

how do you evacuate

most of the United States

west of the Mississippi?

I always worry about how

much error we have in our data.

What's the variability in an answer?

I could answer you, I could say,

"50 percent chance in 10 days,"

but what if I'm off by 1,000 percent?

In my view, there will be

another super-eruption from Yellowstone,

but it's almost certainly

not going to happen

for many thousands of years.

People want to

put their heads in the sand.

They don't want to think

about these super-eruptions

happening again,

and we know for sure that

that volcano is going to go off.

Today, Yellowstone's old faithful

erupts predictably every 90 minutes or so.

But as for exactly

when Yellowstone will unleash

its inevitable catastrophic fury,

whether tomorrow or

many thousand of years from now,

the answer lies buried

deep within the earth.