Right now, in the United States,
one of the world's largest volcanoes
is gearing up to explode.
It's known as the Yellowstone Volcano,
and it's not just any regular volcano.
Nope.
It's a supervolcano!
If Yellowstone decided to erupt,
the results would be devastating.
But just how bad would they be?
Located in Wyoming, United States,
Yellowstone has erupted three times
in the past 2 million years.
This has led some people to wonder whether
we should be worried about another Yellowstone eruption
in the near future.
And by "near future,"
we mean probably in another
couple hundred thousand years.
But instead of waiting so long,
why don't we find out,
what would happen
if the eruption took place tomorrow?
If you live in North America,
there would be virtually nothing you could do to prepare.
Now that this supervolcano has exploded...
Well first,
what makes Yellowstone a supervolcano anyway?
Apart from it being larger in size,
a supervolcano also produces
a much more massive explosion.
Most of the time,
when we think of a volcanic eruption,
we think of the hot,
molten lava spewing down,
covering the surrounding area.
While that would happen at Yellowstone,
and it is something you'd need to worry about,
it wouldn't be the only thing.
In fact, the lava pouring out of the volcano
might be the least of your worries.
Surprisingly, there wouldn't be much of it,
at least not as much as you'd expect
from a supervolcano.
That's because before lava leaves a volcano,
it's first known as magma.
But in this case,
a lot of Yellowstone's magma
won't be able to become lava.
That's because it will be shot up into the sky,
becoming airborne ash particles.
And it won't just be any type of ash.
These will be tiny, scorching particles of jagged rock.
This would affect nearly the entire United States
and Canada.
Tens of millions of people
within 1,000 km (621 mi) of the eruption would die.
If you breathed the ash,
which would be inevitable in a scenario like this,
it would form a cement-like mixture in your lungs,
causing you to suffocate.
Buildings would collapse,
as just 30 cm (12 in) of ash
is enough to cave roofs in.
And you'd still be in trouble
even if you were outside that 1,000 km (621 mi) range.
Experts say that
even the east coast of the United States
would be covered in 1 cm (0.4 in) of ash,
which would still be incredibly dangerous
to our human lungs.
Even parts of Europe would see some ash,
maybe a light dusting.
And that wouldn't be the only effect they'd experience.
Apart from the deadly ash everywhere,
the entire world would experience a temperature drop.
The ash lingering in the air
would block out the Sun,
resulting in significant weather changes.
The global temperature would drop by 10 degrees,
an effect which could last as long as a decade.
The ash would also affect crops,
water supply, and
virtually everything else in the western part of the world.
So although you'd probably survive
the initial explosion,
you'd eventually suffer the consequences of the ash,
whether that means dying relatively quickly,
or living long enough to experience
a colder, harsher world.
Luckily, you can take a deep breath of
ashless oxygen, knowing that something like this will
probably never happen,
at least not in our lifetime.
An eruption like this at Yellowstone
would be known as a supervolcanic eruption.
A more likely explosion at Yellowstone
would be a hydrothermal eruption.
This mainly involves a lot of steam,
and some rocks hurling through the air.
Although something like this would be bad,
it wouldn't be nearly as scary as
what we're getting here.
And an even more likely eruption at Yellowstone
would be a relatively simple lava flow.
In fact, since the last major explosion
600,000 years ago,
we've had nearly 50 of these eruptions
and 0 casualties.
We know one way to almost certainly get killed by lava
and it involves dropping your trash into it.
But that's a story for another WHAT IF.