The Yellowstone supervolcano represents an immense geological force with the potential to cause catastrophic global consequences, including an existential threat to humanity, due to its massive magma chamber and historical eruption patterns.
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The 21st [music]
century started off with a bank as
volcanoes erupted all over the world.
Iceland, the Canary Islands, southern
Japan, and [music] off the coast of
Tonga, blasted by the most powerful
eruption of the century so far. While
these volcanoes can cause death and
mayhem, they pale in comparison to the
super volcanoes that some believe drove
some of the Earth's mass extinctions and
could [music] happen again. The worst
possible consequences of a super
eruption would be an existential [music]
threat to human beings.
>> We are nothing in comparison to that.
>> One of the most powerful [music] super
volcanoes on Earth sleeps in the very
heart of the United States in
Yellowstone National Park. [music] Its
origin dates back some 2 billion years.
So far, it has detonated three super
[music] eruptions around 700,000 years
apart, and it's about due for the next one.
one.
>> Yellowstone is definitely a big system.
It is really massive. The caldera
[music] is is huge. It's tens of
kilometers across. But also in terms of
of its depth,
>> the Yellowstone super volcano churns
with the largest reservoir of magma on
Earth. That has scientists [music]
concerned. Its seismic and geothermal
activity have been rumbling for the last
10 years. Does that mean the giant is
beginning to stir? If Yellowstone does
erupt, what would happen? The answer is
indisputable and inconceivable.
If the super volcano exploded today,
[music] it would destroy a huge part of
North America and disrupt life on Earth
for centuries.
>> Chaos. It would be a major ecological
and human disaster.
>> What would the end of the world as we
know it look like?
Pyrolastic flows [music] breaking at
hundreds of kilome hour, annihilating
everything in their path.
Huge amounts of ash [music] smothering
thousands of square kilometers across
the North American continent
and then magmatic [music]
gases triggering volcanic winter around
the world for decades to come.
>> Basically, there's no escape. [music]
>> There's no way of preventing it. You
just got to kind of prepare for it.
>> Preparation is easier said than done.
Yellowstone is the most powerful and
potentially the most dangerous super
volcano on Earth. An eruption would be a
million times more [music] cataclysmic
than the bombing of Hiroshima. Would
humanity survive it? Would we even want
to? After the apocalypse, what [music]
kind of world would be left?
Volcanologists agree the question
[music] is not whether the Yellowstone
volcano will awaken,
It is one of the most beautiful and
[music] best preserved natural sites in
the world, but potentially one of the
most dangerous. Yellowstone [music]
National Park straddling the states of
Wyoming, Idaho, and Montana. Its
sumptuous landscape covers more than a
million hectares over an area 88 km long
and 95 km wide.
>> There are lots of special places on
Earth, and Yellowstone, [music] I think,
is one of those.
>> It hasn't been altered as strongly as
most areas of the world.
>> It's wonderland on its own. It It's
almost impossible to believe.
Yellowstone National Park is the oldest
national park in the world and the most
visited in the United States. After
being [music] discovered by a member of
the famous Louiswis and Clark expedition
in 1806, President Grant signed a
[music] protection order in 1872. It was
listed as a UNESCO World Heritage site
in 1979. Here the wildlife roams freely
across [music] more than 9,000 km of
vast plains amid picture postcard
landscapes located at an average of 2400
m above sea level. It is home to more
than half of the world's geothermal
phenomena producing energy below the
surface [music] of the earth. For many
millennia before becoming a park, this
vast territory was already inhabited by
Native Americans. The Nesper or
Blackfeat tribes [music]
gathered around geysers and collected
obsidian stones from ancient lava flows.
Being very much in touch with nature,
they [music] could sense the stirrings
in the depths of Yellowstone.
It was known to be a volcanic system
[music] because even some of the early
explorers had learned from some of the
indigenous peoples [music] of the area
that there was perhaps a volcano
somewhere up near the headarters of the
Yellowstone River.
They recognized that there were a lot of
volcanic deposits uh in the area. So
they kind of had a inkling of it was a
large volcanic system.
>> While the Native Americans were aware of
living in a sometimes hostile natural
environment, Yellowstone Park was
initially not regarded as an area of
interest to geologists. But a tragic
event awakened the attention of
scientists around the world. It all
began with a deadly earthquake in the
There was a magnitude 7.3 earthquake. We
call that the Hebggman Lake earthquake.
And that happened just west of the park,
just outside of the park. [music] That's
the largest earthquake that has ever
been recorded in the inner mountain west
of the United States. [music]
>> The biggest effects of course were out
where the earthquake occurred out by
Hebin Lake where you had a lot of
damaged roads where roads were blocked,
people were were trapped. Um then it
caused a big uh landslide to occur [music]
[music]
and that landslide came down on a
campground and buried 28 people.
>> Uh it killed a large number of people.
It damned a river and created [music] a
brand new lake that created all kinds of
damage in Yellowstone National Park as
well. Damage to roads with landslides
and the shaking from that event caused a
large number of [music]
new geyers to form and existing geysers
to change their behavior.
The following day in the park, just a
few kilometers away. To the astonishment
of all, 289 hot springs exploded into
the sky [music] in the form of geysers.
Later, cracks in the ground appeared,
releasing plumes of toxic gases. There
could be no doubt that the earthquake at
Lake Hebin had triggered a great deal of
underground activity in Yellowstone. And
yet, the area is not located on the edge
[music] of a tectonic plate. What
exactly was going on in the heart of the
United States?
There were a lot of seismometers that
were put in the area, a lot of research
that was done into earthquake activity.
And it was found that Yellowstone is
actually one of the most seismically
active areas in the United States.
These earthquakes were of volcanic
origin triggered by an accumulation of
underground magma.
Scientists also discovered that the
region is active because it is located
on a hot line. It is a thermal anomaly.
Starting some 2900 km below the surface,
a hot spot brings up fragments of magma,
producing the volcanic and seismic
activity seen at ground level. And you
can imagine this as a bit of a torch
that is fixed. The North American
continent is moving, is drifting toward
the west.
>> And so [music] you'll get little
volcanoes. The blow torch pops through
every now and then, and you'll get a
chain of these volcanoes.
>> Volcanoes kind of pimple upward along
the Snake River plane. in southern
Idaho. If you go to the most western
side of Idaho, you get to the oldest
vcanism and then it gets younger and
younger as you progress up towards
Yellowstone today.
The 3 million plus tourists who come
here every year are blissfully unaware
that they are walking [music] across a
ticking time bomb of unimaginable power.
Visitors are [music] oblivious to the
secret that lurks beneath Yellowstone
Park, the invisible volcano that may one
day erupt and in doing so profoundly
>> We have to bear in mind that what we
call super volcanoes can also produce
small eruptions.
>> Yellowstone is an example. Most of the
eruptions are actually very small and
there were three large eruptions.
>> Yellowstone has experienced [music]
three major volcanic eruptions. The
oldest and most powerful occurred some
2.1 million years ago at Huckleberry Ridge.
Ridge.
It would have covered Texas with 4.5 m
of volcanic ash. The second 1.3 million
years ago was at Mesa Falls. Finally
came the third eruption at Lava Creek
some 640,000 years ago. These events
produced astonishing quantities of magma
[music] up to 2,450 cubic kilm in each
case. These extraordinary magma flows
and the violence of the explosions
[music] make Yellowstone a super volcano.
volcano.
>> A super volcano is really a volcano
which has been able to produce an
unusually large eruption. Unusually
large in this case means several hundred
maybe a thousand times larger than a
common eruption that we've seen in
historical time. The VI volcanic
explosivity index is a scale that
[music] volcanologists use to measure
the explosiveness of an eruption. So a
super eruption has a VI8.
>> On a planetary scale, these eruptions
have a huge impact on the ecosystem and
on humanity.
>> The number of super volcanoes can be
counted on the fingers of one hand. Over
the past 2 million years, there have
been about 15 super eruptions worldwide.
Today, most of these super volcanoes are
dormant. But for how long? The
Yellowstone super volcano was formed
during its last super eruption. Its
collapse created the current caldera, a
crater which today extends over 65 km or
1/3 of the national park.
>> A caldera is a large depression that has
formed because of the collapse of a
magma chamber.
>> Yellowstone Park is actually in the
caldera. This caldera is so huge that
cannot be seen in the landscape.
>> The corderas can be so large that you
can build entire towns and cities inside them.
them.
>> They can have diameters of between one
and and 100 km.
>> It's not recognized that you're actually
inside a volcano. This is why trying to
raise awareness of the what a super
volcano is or a large cord era is can be
very difficult because they don't look
like a stereotypical volcano that you
would see in uh say a film from Hollywood.
Hollywood.
At first sight, the uniform nature of
the landscape offers few clues. So what
does an exploding caldera look like and
what exactly happened? The series of
events leading to a super volcano
eruption is always the same. Several
kilometers below the Earth, the magma
chamber begins to liquefy under the
effect of very high heat. The magma then
fragments and rises a few dozen meters
toward the surface. The pressure from
the chamber eventually weakens the
Earth's crust, splitting it open.
The immense pressure and very high
temperatures produce [music] an
explosion, causing the volcano to
collapse in on itself, giving rise to a
4,000 km cala.
And when that magma chamber emptied, the
surface fell into the space that was
created, the space that was vacated by
all of that that magma that erupted. And
that left this structure that we call a
caldera, kind of like a piston cylinder
plummeting down into a liquid, which
then pushes more material outward and
makes this very flat surface.
>> The area of the caldera give us some
idea of the surface occupied by the
magma reservoir that is at the base of
this [music] volcanic system.
A lot of that hole that was created by
the big explosion has been filled
[music] by lava flows and by glacial
debris and by lake sediment. It's not
necessarily clear you're looking at a
volcanic area unless you know uh the
features that you're that you're looking at.
at.
>> After each super eruption, the magma
chambers fill up again and the
Yellowstone caldera now has the largest
amount of magma of any in the world.
For scientists, the threat is ongoing
and a constant worry. But volcanologists
have another cause for concern. If we
take the dates [music] of the past three
super eruptions, the calculation is
simple. The park's dormant volcanic
system seems to wake up every 700,000
years or so. Given that the last super
eruption took place 640,000 years ago,
another is due. Scientists now
anticipate another major eruption. But
the question is when? and what will be
its magnitude?
>> Yellowstone's three previous super
eruptions are huge indications of what
might happen in the case of a fourth. We
know the volume. We know the surface
areas. We know the quantities. [snorts]
[snorts]
>> The signs are clearly visible in the
heart of the caldera. The impressive
forest [music] of dead trees testifies
to the presence of sulfur in the soil
and in the streams. Scientists at the
Yellowstone Volcano Observatory [music]
closely monitor the caldera.
The slightest variation or change in
physomy is a warning sign of a potential eruption.
eruption.
>> As that pressure increases, it causes
the ground to move. Now, the the
movement may be just a few cm, but we
can detect that with satellite
measurements, global GPS measurements,
but also from traditional surveying technique.
technique.
>> In the 1970s, while hiking through the
park, a seismologist noticed that the
landscape had changed.
On the southshore of the lake, the bases
of tree trunks had become submerged in
water. The only explanation was that the
opposite bank had risen and the slope
had changed. Between the 1920s and the
1970s, it was seen that the land
actually rose in Yellowstone Caldera by
over 70 cm. And Yellowstone sort of goes
up and down all the time on its own,
typically at a rate of 2 to 3 cm a year
or so. Now, before an eruption, we might
expect to see very dramatic uplift.
>> When the magma rises, when an eruption
is imminent, tiny earthquakes occur,
micro earthquakes have a magnitude of
only one or two, which is very weak.
They barely register, but there are
hundreds or even thousands of them every day.
day.
>> Is the local very localized uh [music]
breaking of rock as uh pressure builds
up underneath the volcano.
>> The classic sign of an imminent eruption
is a combination of swelling and
microismicity. If we have between 100
and 1,000 micro earthquakes per day
allied to swelling of just a few
millimeters or a few centimeters, the
signs are worrying. The magma is moving
and swelling. The situation then becomes critical.
critical.
>> We record on average about 1500 to 2500
earthquakes a year. So, it's a very
seismically active area. They don't
always happen on a regular basis either.
We get what we call swarms of
earthquakes. For example, there's kind
of an east west band of seismicity
between the Hebggan Lake area and Norris
Geyser Basin where we see most of the
earthquakes uh in Yellowstone. [music]
The Norris Geyser Basin is the park's
most dynamic geothermal area. This is
the visible part of 115,000 years of
seismic activity. [music] It is the
oldest and the hottest spot with
temperatures hitting 237° C [music] in
some springs. The water here is acidic
and in this postapocalyptic landscape,
you get a sense of the volcano
breathing, swelling, and purging itself
of the pressure just below the surface.
>> There's always kind of weird things
going on there that we're that we're
learning how hydrothermal systems work.
>> Sometimes I I like to think of geyser
plumbing systems as like the plumbing
[music] in an old house. You know, maybe
the plumbing is sort of rotting away.
the the plumbing uh is is very tight
because [music] of all the minerals that
have precipitated around the the the
plumbing on the on the inside of the
pipes. And if you shake that, pipes are
going to break here and there and and
things just [music] aren't going to work
very well, right? That's sort of what
Yellowstone is like. And so when you
have these large earthquakes shaking the
plumbing system, it's going to break and
you'll see geysers doing all kinds of of
weird things. So that's really the the
hazard that I think will impact this
area on [music] a human time scale.
Scientists are acutely aware of the
threat posed by the Yellowstone super
[music] volcano. Since the installation
of seismographs in the caldera,
volcanologists have been scrutinizing
seismic [music] disturbances, and their
intensity has increased sharply since
the turn of the century. Correct
interpretation of these seismic [music]
phenomena makes it possible to better
predict eruptions and thus save precious
time in evacuating [music] the area.
Everyone remembers what happened at
Mount St. Helens. After several weeks of
seismic disturbances, fractures, and
deformation, on May [music] 18th, 1980,
at 8:32 a.m., the volcano erupted. It
was the most traumatic [music] in the
history of the United States.
>> The 1980
eruption of Mount Senance is the most
catastrophic eruption in the United States.
It began with a kind of landslide. The
summit of a volcano collapsed and it
decapitated itself, releasing the magma
below, which gushed out in the form of
fastmoving pyrolastic flows in a mixture
Then a column rose up into the
In just a few minutes, this vertical
column developed into a huge 25 km wide
>> The winds coming in from the Pacific
pushed the voluminous cloud of ash
towards the east of the United [music]
States at a speed of 100 kmh.
11 states were affected by the ash,
which even fell on Oklahoma, some 2,000
km away. It killed [music] about 60
people, but it also destroyed hundreds
of houses, hundreds of kilometers of
roads, let's say infrastructure.
>> The eruption of Mount St. Helens is
actually a huge revolution for the field
of volcanology. It really changed our
whole perspective on how volcanoes work.
>> It's a reference point. It happened in a
technologically advanced country with
lots of data
>> that taught us also many lessons uh in
terms of prevention, in terms of
monitoring volcanoes, in terms of uh
emergency crisis. We always have
something to learn from volcanic
eruptions. So we build our knowledge on
studying uh new eruptions.
[music] Scientific studies around this
previous eruption still serve as a solid
working basis for volcanologists. But
the explosion of gas and rock, the
volcanic purge that occurred at St.
Helens pales in comparison to the volume
that could potentially erupt from
Yellowstone. A few km were released. So
compared to a super eruption, the ratio
is something like 1 to 500 or 1 to 10,000.
10,000.
>> Yellowstone volcano is about 2,500 times
larger than Mount St. Helens.
Sometimes the imminence of eruptive
events becomes clear within a few months
as in Mount St. Helens, but sometimes
it's just a few days. That's the
worrying aspect of the Yellowstone
Caldera. What if the time elapsing
between eruptions is shorter than
expected? It is a vital question in
anticipating possible disasters because
the Yellowstone caldera has the largest
magma chamber on Earth.
If Yellowstone is reawaking now, [music]
is it how long is going to take? How
much time do we have before we need to
take some sort of [music] action?
For this, we rely on on crystals that
are contained inside the magma.
>> It is vitally important to understand
the warning signs of an imminent and
massive eruption. The information
[music] locked in the crystals of
Yellowstone's ancient lava flows provide
clues about the conditions and [music]
processes that preceded the eruptions.
Crystals are taken from the magma of the
super eruption that occurred [music] 2.2
million years ago. An eruption described
as apocalyptic. If such an event were to
be repeated in Yellowstone today, it
would cover 2/3 of the United States in
ash and kill millions of people within
minutes. the explosive energy would be
22 times greater than that of the Hbomb.
The objective of these analyses [music]
is to determine the time elapsing
between the first signs of an eruption
and the caldera exploding.
>> When magma cools, it generates crystals.
Crystals are small particles inside the
the magma. So what we need to do, we go
in the field, we collect a rock that is
cooled magma that has been erupted
>> and then we break them apart and look at
the crystals and see well what did they
record? And so essentially crystals um
can record all sorts of changes that
happen within magma. So essentially
they're like little recorders of the
processes that are happening within the
magma chamber. [music]
This is important because it tell us
something about how much magma was
coming into the system before the
eruption occurred.
>> Crystals ejected during a past super
eruption allow scientists to establish
the chronology of an explosion and
define the time that elapsed between the
fusion of magma in the chamber and its eruption.
eruption.
Using these direct witnesses to the
cataclysm, scientists then attempt to
predict the next awakening of Yellowstone.
Yellowstone.
The rock record is our best
understanding of really what happened,
especially for historic eruptions where
we don't get to see them in real time.
>> It's a little bit like looking at what
happened in the past to try to
understand what will happen in in the
future. These sort of studies have been
done for Yellowstone and some a part of
the community speaks about reactivation
For now, measurements show that the
caldera remains stable. But what happens
when the pressure generated [music] by
the magma beneath the caldera reaches a
>> Magma is a thick liquid that forms at a
depth of less than 100 km. It then rises
to a depth of less than 5 km and forms a
magma chamber.
>> We call a magma chamber that last
[music] stage of storage. That's the
place where the magma was immediately
before the eruption. At the moment under
Yellowstone, the geohysical surveys
suggest that there's something like 15,000
15,000
cubic kilm of molten rock.
>> The top part of this chamber is probably
around 4 km at depth and it can extend
up to maybe 8 or 10.
>> It's what's providing all the heat um
energy that's fueling the hydrothermal
system. Most of that magma chamber is
actually solid. It's hot, but it's
solid. Typically, to get magma to
mobilize and to move, um, it has to be
at least 50% melt, and we're only at
about 15 [music] to 20% melt. That's not
to say that there might be small pockets
within there that have a higher
percentage of melt. So, that's kind of
one thing that we're looking at if we
can get better resolution images [music]
of of part of the mag reservoir. Um, but
right now, we have kind of a overall
kind of average over the whole thing.
Its presence just a few kilometers from
the surface [music] may be cause for
concern. Scientists are closely
monitoring any possible change in the
state of the magma in the chamber. The
more it [music] liquefies, the more
dangerous it becomes. The discovery of a
new model of the interior of the magma
chamber [music] is precisely what now
worries volcanologists.
>> The change from a quescent state to an
eruptive state implies the migration of
magma from depth to the surface.
So for a long time we have imagined a
magma chamber, a volume filled with magma.
magma.
This this magma chamber we we conceive
it as embedded in an elastic medium. So
it's like blowing into a balloon that is
inside a wood box. When you blow inside,
you feel the pressure increasing. And we
thought that the injection of magma was
the parallel for blowing inside the
balloon. The pressure would increase and
then the eruption occur.
As we see today at Yellowstone, [music]
we think that there are little pockets
or smaller pockets of magma embedded in
a in a system that is a bit like a sponge.
sponge.
When this system are [music] separated,
the pressure inside is not sufficient to
feed an eruption.
Now, we think that if each of these
pockets the magma tends to go up, this
may lead to these pockets getting
connected. And if these pockets get
connected, the pressure inside a
connected [music] system increases a lot.
lot.
>> The conclusions of this model of the
magma chamber are crucial because these
connections of magmatic pockets would
generate zero or very few signs of seismicity.
seismicity.
The magma would penetrate silently from
one pocket to another, increasing the
pressure before triggering a gigantic eruption.
We think that this process of connecting
the various pockets could be itself the
process that triggered the eruption. And
I think one of the biggest question is
how big the next eruption will be in in
in a sort of system like Yellowstone.
>> While seismic activity may not be the
most reliable clue preceding an
eruption, others need to be studied
closely. Geysers, pools, hot [music]
springs, boiling mud, fummeralss, all as
spectacular as they are potentially
dangerous, are [music] in fact
indicators of underground activity
constantly being monitored by scientists.
scientists.
>> We like to say that there's 10,000
thermal features in Yellowstone.
>> Yellowstone has half of the world's
hydrothermal features or geysers in the world.
world.
>> The best known in the caldera is the
geyser known as Old Faithful.
For more than a century, it has been
spurting out [music] eruptions more than
40 meters high every 90 minutes or so.
It is the park's star attraction. These
geothermal phenomena act as a
thermometer for the rise in heat within
the magma chamber when the underground
hot [music] water source reaches 100° C.
A gas bubble forms and expels the hot
water in the form of a column tens of
meters high. But if the temperature
rises excessively, the geyser could
change its cycle and sound the alarm.
This is precisely what happened in the
Norris Bass and Geyser area with
Skiboat, [music]
the world's largest geyser with
unpredictable eruptions. It suddenly
woke up in 2018 after 8 years of
inactivity [music]
triggering a 120 m high column of water.
>> These volcanoes are active. They always
[music] do something. They always
inflate, deflate, they emit gas, they
have earthquakes continuously. So one of
the bigger problem is to to understand
at which time do we have to start worrying.
worrying. >> [music]
>> [music]
>> One striking feature of the landscape
around the Yellowstone hydrothermal
system is the forests of dead trees,
collateral victims of [music] degassing,
and real sources of danger. Grand
Prismatic is the largest hotring in
America, the size of a football field
and is deep as [music] a 10-story
building. The pool is composed of sulfur
and iron dioxide, and its temperature
[music] rises to 70° C. The hydrothermal
explosions associated with these [music]
basins caused by underground water
suddenly turning into steam represent a
threat. When water [music] transforms,
it expands rapidly, creating a very
large volume that needs to escape. If
These sorts of hydrothermal explosions
could happen just about anywhere uh that
there's hot water moving around beneath
the surface. In fact, in 2018, there was
a small pool called Ear [music] Spring,
and it suddenly started erupting as a
geyser. Uh, it hadn't done that since, I
think, at least the 1950s.
Why did that happen in 2018? We don't
know the answer to that. And that's
something that we're really [music]
trying to focus on to understand these
small changes.
ground movement, earthquakes, the
arrival of magnetic gas. Those are
really the three components or the three
factors that we will rely on most for
[music] deciding whether or not eruption
is likely.
>> The unpredictable and uncontrollable
nature of these gigantic volcanic
systems is a source of great anxiety for
scientists. Seismic alerts and
geothermal thrusts are not enough to
flag a catastrophic eruption.
The intervals between explosions need to
be closely examined, too. The past three
super eruptions at Yellowstone suggest
that the rate of recurrence is
approximately [music]
once every 700,000 years. So, are we
dangerously close to the end of a cycle?
There seem to be periodicity, but a
statistic based on just three eruptions
has no real value. What we can say,
though, is that a super eruption is
possible sometime in the millennia to
come or within the next 300,000 years.
The cycle nature of these systems is so
challenging because I think in every
system where you have these periods
where you have more volcanism and then
less vulcanism, you're always trying to
figure out are you at the end of a
cycle, at the beginning of a new cycle,
like where are you in the cycle?
It's entirely possible that we're not
only at the end of the current cycle of
Yellowstone activity, but there may not
be that much in the future. That's a
possibility. Unfortunately, I suppose we
won't ever be able to answer that
question because we're we're never going
to see it.
>> The caldera's huge dimensions, plus the
danger lurking within Yellowstone's
active magma chamber, allied to the
resurgence of earthquakes beneath the
[music] park, are all alarming
indicators. The real question being
asked by scientists around the world is
not whether or not the eruption will
take place, but what the nature of the
event will be when it does. As with many
alarming possibilities, scientists
[music] may be unable to provide an
accurate timeline, but they can imagine
the potential consequences of an [music]
eruption. But will they be able to give
the alert in time?
The prospect is undoubtedly a
frightening one. A super eruption at
Yellowstone would quite simply be a
geological event that disrupts social
organization throughout the northern
hemisphere and in the worst case
scenario, wipe out the entire human race.
race.
The major danger of this type of
explosive eruption is the phenomenal
amount of energy expelled by the volcano
The most [music] important factor is the
volume emitted. 1 cubic km of magma
ejected during a regular eruption would
bury [music] the entire Paris region
beneath its ashes. In the case of
Yellowstone, we are talking about 1,000
c km of magma or a thousand times more energy.
energy.
>> It's all about scale. As I tell my
students, an eruption of 1 cubic km
already has a huge impact. Increase that
100fold, a thousandfold, up to a
thousand or even 10,000 cubic km and the
event becomes absolutely catastrophic.
The energy that the [music] Yellowstone
caldera could potentially generate in
the event of an explosion is simply unimaginable.
unimaginable.
Predictive models show that a super
eruption at Yellowstone would be of
It starts with a normal eruption
shooting a plume of ash and fragments
into the air. Then as the eruptive
conduit widens, so the magnetic flow
increases and all of a sudden the magma
projections increase dramatically and
you have what are called ignimbrites
coming from the Latin word meaning fire ring.
ring.
These eruptions expel clouds of gas and
fragments of broken up magma. Some of
these clouds and fragments, they spread
out over the ground and they can travel
at huracan speeds up to well tens of
kilometers away from the volcano.
>> It's actually a burning cloud of ash,
gas, and fragments traveling at 600 km
an hour at temperatures of 600 to 700°,
hot enough to immediately fuse into
rocks. The curls of ash unleashed with
lightning in the plumes are like the
wrath of the gods, the fury of Zeus or Jupiter.
Jupiter.
>> The super eruption could cover several
thousand square kilm.
>> And because the pressure decrease in the
reservoir, this becomes a sort of vacuum
cleaner that is sucking new magma coming
in. And if this process is keep going,
eventually a caldera collapse can start.
And when the roof of the caldera pushes
on the reservoir, it makes the magma
come out from the fractures around the
caldera. And then these especially
produce [music] pyrolastic flows.
>> Gigantic, extremely high temperature
fiery clouds composed of ash, gas, and
rocks roll down the slopes of a volcano, [music]
[music]
seeping into the surrounding terrain,
petrifying the landscape.
Pyrolastic flows destroy everything that
is on their way. there can reach 500
600° centigrades.
>> For sure. Pyrolastic flows would be
[music] the most devastating phenomenon
associated with the super eruption.
Basically, there's no escape from
pyrolastic flows.
>> Life on the ground then would be
sacrificed. But there is no escape in
the skies above either. Without
evacuation, the explosion would
instantly kill any sensient being within
1600 km around the caldera as it expels
1,000 billion tons of [music] matter
into the atmosphere. Then, a few days
after the explosion comes the most
formidable enemy of all, volcanic ash.
Volcanic ash is is glass. It's like if
you take your window glass, you break it
with a hammer, you make a little powder,
[music] and then you throw it into the atmosphere.
atmosphere.
Previous eruption of Yellowstone have
covered in ash essentially the entire uh
North American region.
>> In the immediate vicinity around
Yellowstone, for instance, we're
supposed to get over a meter of ash and
that goes all the way down to Salt Lake
City over to Billings, Montana. It's a
huge extent of a meter of ash, which is
a crazy amount of material. But most of
the death associated with volcanic ash
is related to the collapse of buildings
because you can accumulate uh a lot of
ash on the roof of a building that can collapse.
collapse.
>> In addition to destroying cities, the
ash mantle contains still glowing
residues of magma, causing forest fires
and destroying crops and herds as it
falls to the ground.
The ecosystem necessary for human life
is swept away. Wildlife is threatened.
North America would then be plunged into
darkness. No more electricity. No more
drinking water. Particles of volcanic
gases then escape.
As they reach the stratosphere, they
threaten the entire planet.
These gases are liberated into the
atmosphere. And um sulfur for example
can produce aerosols [music] in the atmosphere.
atmosphere.
>> These sprays filter the sun's rays
meaning fewer solar rays reach the
surface of the earth. They form an
opaque veil triggering cooling on the
ground of anything from a few ten of a
degree to a few degrees in the case of
the very strong eruptions.
>> This is what generate volcanic winters.
>> A volcanic winter is a significant drop
in temperature following a major
eruption, a super eruption which
radically disrupts the climate.
modeling suggests that a super eruption
could cause cooling of several degrees
centigrade and certainly enough to
disrupt growing seasons for several
years and that [music] in turn can lead
to global famine. So this is the real uh
perhaps the even greater problem about
super eruption.
>> It's chaos, a major ecological and human disaster.
disaster.
Far from fantasy, volcanology
researchers are [music] constantly
studying every eruptive event on the
planet in an attempt to anticipate any
looming crisis at Yellowstone. The study
of previous explosions can help produce
predictive models. But the problem with
[music] Yellowstone is the scale.
Compared to the eruptions in Iceland or
the Philippines, the effects would
There was a famous eruption in Iceland
in the spring of 2010 when the AFL
volcano erupted. [music]
>> It was a moderate eruption, had a
volcanic explosivity index of three.
>> Then in April, the magma migrated to
another place beneath a glacier. From
that moment on, everything changed.
The hot lava coming into contact with
the frozen glacier caused a huge plume
of steam to rise 10 km [music] into the atmosphere.
atmosphere.
At the same time, an anticcyclone in the
north of Iceland pushed the plume right
across Europe.
European airspaces were closed down,
[music] costing billions of euros in
just a few days. Iceland isolated
itself. This major eruption went on for
2 weeks with no deaths or injuries. But
this ordinary event coupled with
unfavorable [music] winds showed the
>> Demonstrated how vulnerable we are even
to a small eruption
>> compared to a super eruption in the
Yellowstone. What happened in Iceland in
2010 is a ratio of 1 to a,000.
>> So if VI7 had to happen now in the world
as we have [music] it now, the impact
will be devastating.
What's in store for [music] Yellowstone
and the surrounding area is far worse.
The Icelandic eruption was [music] not
from a super volcano and had no impact
on the climate. The same was true of the
dramatic eruption at Pinatubo in [music]
the Philippines, the most significant
disaster of the 20th century. [music]
So if we want to have sort of some idea
of what might happen after super
eruption, we could think what were the
consequences of one of the biggest
explosive [music] eruptions of the 20th
century. And by that I mean the eruption
of Pinatubo in 1991.
>> The terrible rumbling from Mount
Pinatubo has been going on for 6 days
now. A new 3 km long crack has appeared
on the southern slope.
In late 1991, [music] having been
dormant for 500 years, the Mount
Pinatubo volcano exploded. The
consequences were catastrophic [music]
and affected the entire planet. The
explosions sent fine particles of magma,
ash, and [music] sulfur rich gases into
the stratosphere.
>> All life was wiped out in [music] a 14
km radius around Mount Pinatubo.
Collapsed roofs claimed many victims.
[music] 300,000 people were evacuated
and nearly 900 people died.
Infrastructures broke down [music] and
looting became commonplace. Nearby
villages suffered mudslides for many
[music] years afterwards. The
surrounding soils became contaminated.
It was a gigantic human and ecological disaster.
disaster.
And it did lead to cooling [music] at a
global scale of a fraction of a degree
centigrade over the following few years.
So this gives us an idea [music] that
such a small eruption can have an impact
on climates.
Luminosity was reduced by 10% [music]
across the surface of the Earth. A
colossal figure. The ash circulated
around the globe for three whole years,
resulting in torrential rains and
unusual flooding in the United States.
The subsequent hole created in the ozone
layer took 30 years to fill.
This erupted a few cubic kilm of magma.
So already [music]
several hundred times, if not thousand
times smaller than a super eruption. So
for eruption like the the size of
Yellowstone, the this could have an
impact and generate few years of
volcanic winters. At least what we think.
think.
>> Learning from previous disasters is one
way for volcanologists to anticipate and
better prepare populations in the event
of an eruption.
But some visionary scientists are
playing the sorcerer's apprentice and
trying to find other preemptive
NASA, for example, decided to take
things further. After the eruption at
Mount Pinatubo in 1991, they began
working on a plan of action that could
Given that a volcanic eruption is a way
of purging [music] the pressure that
builds up in the magma reservoir, the
engineer's idea was to schedule regular
Let's just take it seriously for a
minute. Okay. So, the idea would be
could we is it possible [music] for
example to put a a a drill hole down
towards the magma body and maybe allow
gases to escape gently so you reduce the
pressure and prevent the the the molten
rock in fact eventually coming [music]
to the surface. Um that really is still
in the realms of science fiction. I'm afraid
afraid
>> the NASA study to drill the volcano and
cool it down uh was not realistic. It
was it was basically a calculation. It
was sort of the thing you do on the back
of a napkin in a bar.
>> And this will take tens of thousands of
years and uh even with the risk that of
generating friatic eruption.
>> But it didn't account for the fact that
there's always more heat coming in.
Once you start to trigger the formation
of gases, there is a risk that it's a
self-feeding process and once you start
it, you won't just control the the
creation, the release of gas, which then
increases the pressure, which then leads
to an eruption.
>> Yellowstone is already water cooled.
This is why there is a there is a geyser
system that [music] is continuously
releasing heat from this system.
>> We can't even essentially make a lava
flow go into a different direction. many
[music] times. There's no way we're
going to stop a super eruption from
going if it wants to go.
>> There's no way of preventing it. You
just got to kind of prepare for it.
>> So our scientific [music]
responsibility is to mitigate the
impact, not to change nature.
>> Our responsibility is to avoid that this
natural phenomena becomes an impact on
the population. We just have to monitor
it, understand [music] the system, how
it works, what we might expect to see in
terms of hazards, and then essentially
make a response plan based on that information.
information.
>> Volcanologists [music] around the world
collaborate with each other, depending
on their various areas of research and
expertise. [music] They pull their work
to better understand what is happening
at the center of the Earth. The
challenge for crisis [music] cells all
over the world is to ensure the earliest
possible evacuation of populations
around volcanic areas. There are more
than 800 million people living around 10
kilometer of an active volcano. [music]
So it's a big part of the the global
population. So we need to take care
about this.
>> A volcano is goes through cycles. [music]
[music]
Sometimes we can think that uh a volcano
is extinct because it hasn't shown any
sign for many [music] years. people get
used to it and and can start also
building houses close to volcanoes
[music] and then all of a sudden a
volcano can reawake after [music]
hundreds of years and this is why these
type of volcanoes can be particularly
dangerous for people. [music]
[music]
>> The most worrying and the most boring
result for a volcanologist is a non-
eruption. It's already happened. All the
signs are red. An eruption seems
imminent. The area is evacuated and
nothing happens. Yeah, there are an
awful lot of examples >> [music]
>> [music]
>> um of uh uh volcanic crises where
populations were evacuated and nothing
happened and then you know the
population tends to lose trust in the
scientists. [music]
>> If they lo lose the trust this could be
very dangerous because perhaps then
something happened 2 years after when
everybody's back.
>> We vulcanologists are spectators. We try
to understand what the volcano decides.
Volcanologists know that the only
solution [music] is increased monitoring
In 2015, [music]
researchers from the University of Utah
made a discovery as spectacular as it
was unexpected [music] when they located
a gigantic undetected magmatic reservoir,
reservoir,
the Yellowstone [music] plumbing system.
It was not limited to to the very large
10,000 cubic km reservoir that is
somewhere in the upper crust in the
first 10 km, but there was a much deeper
reservoir where about 46,000 cubic km of
magma are stored.
>> Lying beneath the already known magma
chamber at a depth of some 45 km, this
reservoir is an alarming discovery. 19
km [music] high, 64 km long, and 40 km
wide. It contains 46,000 cubic kilm of
magma. Enough to bury an area the size
of Texas beneath 15 m of material. It is
currently the largest magma chamber on Earth.
Earth.
>> That's a place where magma can reside
for much much greater intervals of time,
much longer than for a single eruption.
So So that's really the reservoir that
that can last the lifetime of the
volcano. While the rocks are not
completely melted, most are in a solid
spongy state and they are extremely hot
with pockets of liquid.
Scientists have calculated that on
average 9% of the magma in the known
chamber is molten with a further 2% in
this new reservoir below. [music] From
this place, there are little volumes of
magma that keep the system that is in
the last 10 kilometer alive.
And it is possible at some point that it
might inject some of that lower
viscosity magma into the upper magma
chamber. That may be the kind of thing
[music] that would cause a rejuvenation.
It might be able to melt some of that
stagnant upper magma chamber.
>> So the thing that this show us is that
even if Yellowstone is is not erupting
[music] now, it's an active system.
The discovery of this reservoir helps
explain why the carbon dioxide emitted
by Yellowstone soil and geothermal
springs exceeds [music] the volume that
the only known chamber could be expected
to produce.
Scientists now have a better
understanding of [music] the complexity
of the Yellowstone magmatic system.
Yellowstone is definitely a big system.
[music] It is really massive, not only
in terms of its aerial extent, right?
The caldera is is huge. It's tens of
kilometers across, but also in terms of
of its depth and uh and the evidence for
that is is all around us, not only in
the geysers and the hot springs, but in
all of the volcanic rocks we see, not
just here, but trending all the way
across southern Idaho. Um, this has been
a longived and and and very large
volcanic system.
On a human time scale, the eruption of
the Yellowstone caldera remains a very
rare occurrence. The risk is comparable
[music] with that of the Earth colliding
with a meteorite.
The super eruption fantasy is part of an
irrational fear particular to the human
race. The only species aware of its own death.
death.
>> You don't necessarily like live in fear
from these things cuz what can you do
[music] about it, right? It's it's just
part of the way the earth works.
>> The earth is neither nice or nasty. The
same is true of volcanoes. Humans are of
course dependent on nature. So you can
plan on it, you can model, you can
prepare and you can gain knowledge on
the system so we can better uh
disseminate that knowledge to people who
live in the area and and and be well
prepared for uh certain events.
>> If NASA's purge technique or some other
as yet unknown solution fails to [music]
work, it is likely that a super volcano
such as Yellowstone will one day wake up
and trigger a mega explosion [music] and
The worst possible consequences of a
super eruption might actually get close
[music] to uh those that we might
imagine Hollywood would come up with and
that would [music] be an existential
threat to human beings mainly because of
continued [music] famine. So there are
have been uh ideas that it could lead to
the uh uh end of the our species
but that really is an extreme [music]
case. It will certainly end up with the
the the a complete change in our
civilization. That is for sure.
>> I'm a I'm optimist in this case. I don't
think a super eruption will cancel us
from uh I think we are much more capable
to do that by oursel than than an
eruption. But the um obviously will have
an impact.
>> While the Yellowstone super volcano is
one [music] of the most beautiful
representations of nature, it is perhaps
also its most remarkable paradox. The
raw beauty [music] of the landscapes,
the geothermal diversity, and the purity
of its colors conceal a frightening reality.
reality.
Here, many kilome below [music] one of
the Earth's rarest and best preserves
ecosystems, lurks a volcanic complex,
which [music] should it ever erupt,
would completely reshuffle the cards of
human activity. We're making progress in
[music] forecasting when an eruption
will occur, but we're a long way behind
in forecasting how it will occur and how
big [music] it will be.
>> This these are the big questions we ask
ourself for any volcano on Earth. [music]
[music]
>> In Yellowstone, the paradise visible on
the surface exists alongside and above
the hell down below. This unique [music]
system forged by fire and water over
many millions of years allows
researchers to observe, study, and
understand [music] the evolution of our planet.
planet.
>> The scientific opportunities here are
amazing. And the lessons we learn at
Yellowstone, even if it's not going to
erupt, we can apply [music] to other
caldera systems around the world.
There's always something new. It's such
a dynamic place. It's always changing.
Every year, something happens. All of it
integrated together gives us a better
idea of how the earth works.
>> The long history [music] of the universe
is littered with examples of physical
phenomena such as extinction, climate
change, cosmic collisions, and dead
[music] planets. The disasters of the
past are etched into our DNA and maybe
as some believe in a collective
ancestral memory.
>> Any eruption teaches us that we are very
small in front of nature. [music] So we
think that we are in control but we are
not in control. We can study as much as
we can but at the end we need to study
to be able to respect [music] nature not
to control it.
>> So this is why we should take care and
[music] use super eruption as a
demonstration of the supreme power of
nature. We are nothing in comparison to
that. So we should have a little bit
more respect for measure than what we do now.
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