Yellowstone, a ticking time bomb we can't defuse
A slumbering giant nests in the western part of the United States. Though it stirs
from time to time, it has not awakened from its sleep for nearly 70,000 years.
But when it finally does stir, it could roar and rise with unprecedented force.
This giant is the "supervolcano" lying beneath Yellowstone National Park, the natural reserve
sprawled across the states of Wyoming, Idaho, and Montana. The volcano itself lies in northwestern
Wyoming, where much of Yellowstone is contained. According to vulcanologists, a possible eruption
could blanket entire regions under several meters of ash, while emitted gases could spread
worldwide, blocking sunlight and significantly lowering temperatures for several years. Are
these just hypothetical scenarios, or will it truly happen someday? And when?
This video, beautifully crafted by Insane Curiosity Channel, seeks to answer these
and other questions as best as possible. But, folks, heed this warning... Yellowstone
is one of the six "supervolcanoes" in the world. It erupts in its wildest manner
roughly every 650,000 years. And the last major eruption occurred just 650,000 years ago...
In our view, there's little room for jest. What poses the greatest threat to life on
our planet? Surely, the ongoing climate crisis is a prime candidate. Nor can we underestimate
the dangers posed by a potential nuclear war or the spread of some bioweapon capable of
swiftly decimating the population. Yet, not all existential threats we
must worry about are man-made; some of them are entirely beyond our control.
The asteroids that regularly graze Earth (relatively speaking,
in cosmic terms) serve as a constant reminder that the event 66 million years ago, which caused the
extinction of the dinosaurs (and 99% of living species), could happen again sooner or later.
Oddly enough, much less concern is raised about the supervolcanoes scattered worldwide,
which could catch us off guard at any moment, jeopardizing our very existence.
Are we exaggerating? Well, consider that it's already happened once that a volcanic eruption
threatened the survival of our species. Though it can't be precisely dated, about
70,000 years ago, the terrifying eruption of the supervolcano beneath Lake Toba (near present-day
Sumatra) occurred. The explosion rendered the planet's climate almost uninhabitable,
filling the atmosphere with 2,800 cubic kilometers of ash and dust... Thinking of another Pompeii?
Well, you're way off... the eruption that caused the end of Pompeii produced
only a thousandth of that dust! The consequences were dramatic:
in some areas, temperatures dropped by as much as 20 degrees, and it seems that of all the humans
on Earth at the time, only tens of thousands survived; an evolutionary bottleneck that,
incidentally, could also be at the root of our limited genetic diversity.
Humanity, according to experts, came perilously close to extinction on that occasion. Today,
of course, we are immensely more numerous and scattered in every corner of the Earth.
This makes it unlikely that an eruption of this magnitude could wipe out humanity. But it could
certainly change human life as we know it today. Across the globe, numerous volcanoes could give
rise to apocalyptic scenarios (including Vesuvius, Novarupta in Alaska, Pinatubo in the Philippines,
Agung and Merapi in Indonesia, Nyiragongo in the Democratic Republic of Congo, and others). But
those whose eruption could radically change the landscape for hundreds of kilometers and influence
the climate globally, with potentially cataclysmic effects, are said by experts to be only six,
and they are defined as "Supervolcanoes": imposing volcanic structures characterized by
calderas that can have diameters ranging from a few kilometers to hundreds of kilometers.
These calderas can fill with water, creating lakes, or with lava, forming shield volcanoes.
But what exactly is a supervolcano? Supervolcanoes typically form in
areas where enormous quantities of magma rise from the Earth's mantle towards the surface,
such as hotspots or subduction zones, and then become trapped and accumulate in the crust. Today,
on a global scale, we know of six still dangerously active ones: Yellowstone,
Long Valley Caldera (California), Lake Taupō (New Zealand), Lake Toba (Sumatra), La Pacana
Caldera (Chile), and the Campi Flegrei (Italy). In the common imagination, a supervolcano is
considered a volcanic edifice of considerable size, whose eruption could push our species to
the brink of extinction. However, this perception, fueled over the years by journalism, literature,
and cinema, deviates somewhat from its scientific definition.
Between the late '90s and the beginning of the new millennium, the term supervolcano
took on a different connotation, one to which the scientific community now refers:
the supervolcano is essentially a volcano that, throughout its history,
has experienced at least one eruption with a volcanic explosivity index (VEI) of 8 or higher.
The VEI, or Volcanic Explosivity Index, is a scale used to describe eruptions based on
their size and intensity, taking into account two main parameters: the volume of emitted pyroclastic
material and the height of the eruptive column. The explosivity index is constructed on a
logarithmic basis and can range from a minimum value of 0 to maximum values exceeding 8. It
operates similarly to the Richter scale, which many of you already know for measuring earthquake
intensity. Each step on the VEI scale defines an eruption ten times larger than the previous step.
At the top of the VEI scale, with values equal to or greater than 8,
are those eruptions capable of emitting over 1,000 cubic kilometers of material, often referred to
as "super-eruptions," which, as we have seen, define the characteristics of a supervolcano.
These events can drastically transform the landscape and alter the climate globally for
extended periods. Furthermore, the expulsion of huge volumes of magma and the emptying
of the magma chamber often result in the collapse of the overlying crust,
including the volcanic edifice, and the formation of large circular depressions called calderas.
So, the term supervolcano is not linked to the size of the volcanic edifice itself but
to the size of its historical eruptions. Apparently, in the last 36 million years,
only 42 super-eruptions have occurred. Modern humans have no memory of any of them. In fact,
the most recent one is that of the Taupō volcano in New Zealand, which occurred
about 26,500 years ago. For comparison, the 1991 eruption of Mount Pinatubo in the Philippines,
one of the largest of the 20th century, only rates level 6 on the VEI scale...
indicating that it was at least 100 times weaker than a supervolcano eruption.
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OK…After all these interesting and necessary clarifications, we have now arrived at the true
and absolute protagonist of this splendid video: Yellowstone volcano, undoubtedly
the most famous among existing supervolcanoes. Yellowstone, it's almost needless to say, is one
of the most famous and sought-after national parks in the world, located in the northwest United
States, spanning the territories of Wyoming, Montana, and Idaho. Every year, millions of
tourists flock to this enchanting place to admire its natural wonders, including geysers, hot
springs, waterfalls, canyons, lakes, rivers, and a rich variety of wildlife. However, beneath this
idyllic surface lurks an unimaginable danger: a supervolcano that could erupt at any moment, with
catastrophic consequences for the entire planet. Volcanism in the region is linked to a hotspot
present for over 16.5 million years, with the original eruptive center situated between the
states of Nevada and Oregon. In recent geological times, volcanic activity in
the Yellowstone supervolcano area has produced three large calderas. The first super-eruption,
and also the most intense, occurred 2.1 million years ago, producing an eruptive explosion that
removed so much magma from its underground storage reservoir that the ground above it
collapsed into the magma chamber, leaving a gigantic depression in the terrain, practically
a hole larger than the state of Rhode Island. The enormous caldera was estimated to measure
up to 80 kilometers in length, 65 kilometers in width, and hundreds of meters in depth.
Subsequently, due to the shifting of tectonic plates, magmatic activity migrated to a smaller
region within the Island Park area in eastern Idaho, just southwest of Yellowstone National
Park, and produced another major eruption that formed a caldera 1.3 million years
ago. Subsequent activity focused on the area of the National Park, and another enormous
eruption that occurred 631,000 years ago formed the Yellowstone Caldera as we see it today.
It's worth noting that these three super-eruptions were respectively 6,000,
700, and 2,500 times more powerful than the eruption of Mount St. Helens on May 18, 1980, in
the state of Washington. Together, they expelled enough ash and lava to fill the Grand Canyon.
In addition to the three climactic eruptions, the activity associated with each of the
three caldera cycles produced dozens or even hundreds of smaller eruptions that produced
both lava and pyroclastic materials. But what would happen if something
like this were to occur today? Vulcanologists believe that an
eruption at Yellowstone would bury entire areas of Colorado, Wyoming, and Utah under about a
meter of volcanic ash. Depending on the weather patterns, a significant portion of the Midwest
would still receive some centimeters, plunging the entire region into darkness. Even on the coasts,
where most Americans reside, there would be a dusting of ash due to the spread of the ash. Crops
would be destroyed, pastures contaminated, and power lines compromised, potentially
knocking out a large portion of the grid. Lastly, the eruption would unleash a chain
of secondary events such as earthquakes, landslides, floods, and tsunamis. Crustal
displacement would cause tremors, which in turn could trigger landslides burying entire areas or
blocking waterways. Floods would result from the melting of glaciers and snow, causing rivers and
lakes to rise. And tsunamis could be generated by the impact of lava or debris on the ocean,
creating abnormal waves that would propagate toward the coasts of other continents,
causing further damage and casualties. Simulations predict 25 million deaths in the
first week, 80% of the USA covered in volcanic ash, and 20% becoming uninhabitable. Sulfur
and ash in the atmosphere would lower global temperatures by 5 or even 15 degrees Celsius,
blocking Asian monsoons and causing millions of deaths from famine. Precipitation would plummet,
leading to a die-off of tropical forests. The victims of such an apocalyptic scenario could
reach up to 10% of the population (that is, 750 million people, over ten times the deaths caused
by World War II): a catastrophe on a completely different scale than any disaster—natural or
otherwise—that humanity has ever faced. Recently, furthermore, new measurements
have considerably modified the known dimensions of the caldera beneath Yellowstone. While previously
there were thought to be several unconnected calderas, the new research conducted by the
University of Utah researchers has shown that beneath the eponymous park lies a
massive caldera with numerous branches, as if it were a single magma chamber. Additionally,
by studying the newly collected data, it was possible to increase the previously hypothesized
dimensions by a whopping 50%, bringing the caldera to a length of 60 km, a width of 30 km,
and a depth between 5 and 12 km below the surface. The news of this new measurement has once again
ignited the fears of doomsayers; never quelled since 2012, the year of the
messianic anticipation of the end of the world dramatized in the eponymous movie.
The fact that the three super-eruptions of the Yellowstone caldera occurred with
an approximate interval of 650,000 years and that the last one occurred, precisely,
about 650,000 years ago might seem like the universe is sending us a giant WARNING...
But is there a possibility that what has happened three times in the span
of two million years could happen again soon? Can we make predictions about when?
The short answer would be NO, but although it is a complex and unpredictable phenomenon
that eludes human control, we can draw on scientific knowledge and technological
advancements to make some considerations. Continuous monitoring of volcanic activity is
crucial for predicting potential eruptions. Various signals, such as seismicity,
ground deformation, temperature, composition and flow of geothermal fluids, volcanic gas emissions,
and variations in the magnetic field, can provide valuable clues about the state of
the magma chamber and the likelihood of an eruption. However, these signals are
not always clear and can be influenced by other factors, such as weather changes,
precipitation, landslides, and human activities. Furthermore, even if an increase in volcanic
activity is detected, this may not be sufficient to determine the timing, extent, duration,
and direction of an eruption, which depend on numerous other parameters such as magma viscosity,
pressure, temperature, quantity, and distribution, as well as crust geometry and resistance,
interactions with faults and tectonic plates, and atmospheric conditions.
Therefore, even with advanced monitoring technology, predicting volcanic eruptions
remains a complex and uncertain task. However, officials from the United States
Geological Survey state that a massive eruption like the last one is an unlikely scenario. At
most, future eruptions could involve steam and hot water rather than molten rock,
or lava flows. Additionally, experts estimate that the probability of Yellowstone erupting in any
given year is 0.00014%, lower than the chances of being hit by a 400-meter diameter asteroid.
To fear an imminent eruption, other circumstances should occur simultaneously, such as ground
deformation and changes in hydrothermal features or gas emissions. That's why the
presence of only seismic events - albeit closely monitored - does not raise significant concerns.
It goes without saying that Yellowstone remains one of the most dangerous volcanoes in the world,
but this doesn't necessarily mean we're on the brink of imminent danger... It could happen in
a century, in a thousand years, or even never. At the moment, our technology doesn't allow us
to hypothesize any form of control when the first signs of collapse appear. In short,
as it used to be said, for all these things, we can only say we are in the hands of the Lord.
Humanity might develop a way to alter the trajectory of an asteroid, but we
will never find a way to stop the eruption of a supervolcano. The only path is damage containment.