Three minutes to the centre of the Earth | BBC Ideas


It’s 6,371 kilometres to the centre of the Earth.
Follow us down.
We’re going all the way to the heart of the planet.
Our world is made of layers, a bit like an onion,
and as far as we know, life only exists in the first layer –
the crust. In the crust, you’ll find the burrows of animals
such as moles and badgers.
The deepest are made by Nile crocodiles
and can reach depths of 12 metres.
The crust is also home to ancient underground cities
like Elengubu in Turkey,
an elaborate labyrinth capable of housing 20,000 people,
complete with schools and chapels.
It is thought to have been built around 370 years BC.
The world’s deepest mines can go down to around four kilometres.
South African gold miners have found worms two kilometres down,
but all life stops before three kilometres.
Then there’s the deepest hole ever drilled –
the Kola Superdeep Borehole in Russia.
Some call it the gateway to hell,
with locals claiming to hear the screams of tortured souls.
At around 30 to 50 kilometres depth,
we reach the next layer – the mantle.
It’s made of hot rock, which appears solid to us
but actually flows very slowly, just a few centimetres a year.
These delicate shifts below can give rise to earthquakes above.
In the 1960s, a group of scientists attempted to drill
into the Earth’s mantle.
Although unsuccessful, new efforts are afoot with a plan to drill
deep below the Indian Ocean.
As we descend, the increasing pressure
means that atoms become warped,
and even the most familiar materials behave bizarrely.
Crystals change from green to blue to brown,
and rock becomes as malleable as plastic.
2,900 kilometres down, we reach the bottom of the mantle.
See those two giant blobs?
They’re the size of continents.
Scientists aren’t sure how they were formed or what they’re made of.
They cradle the next layer – the outer core.
In Jules Verne’s classic novel, Journey to the Center of the Earth,
Professor Otto Lidenbrock encounters an entire underground world,
replete with prehistoric creatures and a subterranean ocean.
While the dinosaurs might have been a bit of a stretch,
there is an ocean of sorts,
but this one consists of flowing red-hot iron and nickel,
a sunless sea with its own currents and jet streams.
This motion creates a magnetic field that protects the Earth
from dangerous solar rays.
The final layer is known as the inner core.
It’s 6,000 degrees in here.
The pressure is so intense that the metals here
have crystallised, forming a solid sphere
at the very centre of our planet.
In reality, our little vehicle would have been crushed
and melted long ago.
And as for our driver, I think she better head back to the surface.
It’s a long way to go.
Good luck!
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