Arwen deuss biography of donald

The Earth's core

Take a trip with Rob and Alice to find out about the Earth's core. They'll discuss how hot it is and what it's made of – and whether there are any dinosaurs living there! – as well as teaching some related vocabulary.

This week's question

how big do you think the inner core is? Is it the size of …

a) the Moon?

b) Jupiter?

c) Mars?

You can hear the right answer at the end of the programme.

Vocabulary

core
(here) the Earth’s centre

dense
something which is heavy in relation to its size

crust
the Earth's outer layer (where we live)

mantle
the Earth's layer beneath the ocean floors

silicate
material that glass is made of

molten
liquid

magnetosphere
area around the Earth in which the Earth's magnetic field is felt

strip away
remove

radiation
heat or energy or particles in the form of rays, e.g. the Sun's rays

deflect
make something change direction

Transcript

Note: This is not a word-for-word transcript

Rob
Hello and welcome to 6 Minute English. I'm Rob…

Alice
… and I'm Alice. Hello.

Rob
Hi there, Alice! Now, have you read any books by Jules Verne?

Alice
Yes, I have. Journey to the Centre of the Earth was my favourite book as a child! A German Professor and his two companions climb down a volcano in search of the Earth’s centre – or core. They visit strange lands inhabited by dinosaurs and giant prehistoric humans, and sail across an underground ocean.

Rob
Hmm. Very exciting but it doesn’t sound very realistic. How do they get out again?

Alice
Well, they shoot to the surface from the mouth of Mount Etna during a volcanic eruption.

Rob
Wow! That sounds very uncomfortable! Well, on today's show we're going to discuss what scientists really know about the Earth's core.

Alice
Yes. The Earth has a dense inner core surrounded by a fluid outer core. Dense, by the way, means heavy in relation to its size. But, Rob, I've

They make Mount Everest look like an anthill.

Scientists in the Netherlands have shed new light on two mountains that are taller than Mount Everest by hundreds of miles, suggesting that they’re potentially much older than once thought. The literal groundbreaking research was published recently in the journal Nature.

“Nobody knows what they are, and whether they are only a temporary phenomenon, or if they have been sitting there for millions or perhaps even billions of years,” said head researcher Dr. Arwen Deuss, a seismologist and professor of Structure and composition of Earth’s deep interior at Utrecht University.

At around 620 miles high, these subsurface “islands of rock” stand more than 100 times higher than Mount Everest’s summit of around 5.5 miles, and pretty much dwarf everything else on the planet as well.

But don’t think of trying trying to climb them.

The two “supercontinents” are located some 1,200 miles beneath the surface of the Earth at the intersection of the planet’s core and the mantle, the semi-solid area beneath the crust. One is situated under Africa while the other lies beneath the Pacific Ocean.

They’re also surrounded by a massive “graveyard of tectonic plates which have been transported there by a process called ‘subduction,’ where one tectonic plate dives below another plate and sinks all the way from the Earth’s surface down to a depth of almost three thousand kilometers (1,200 miles),” said Deuss.

Despite being part of the literal underground, researchers have known about the formations since the turn of last century thanks to seismic shockwaves rippling through the Earth’s interior.

Large earthquakes cause the planet to ring like a bell, and it will sound “out of tune” when it hits anomalous o

Chris- I'm Chris Smith and we are talking extreme geology this week, as we're joined by three esteemed guests from the Department of Earth Sciences at Cambridge University - James Jackson, Tehnuka Ilanko, and Arwen Deuss, who - you're a seismologist, Arwen. So, let's shake up the world of geology a bit and tell us what you do.

Arwen -  Well, we've heard about earthquakes and volcanoes from the other two people here. That's the main thing you'll see, the main thing you'll hear about on the news. But all these things that happen at the surface of the Earth, they're driven by processes deeper in our planet. If you want to understand them then we need to know what's happening in the deeper parts of the Earth.

The way we look at that is by using seismic waves. So, we can look at the earthquake itself, but these earthquakes, they generate waves. They travel all the way through the Earth. They don't only travel along the surface. They go right through its centre. So, an earthquake that would happen in New Zealand, we can pick that up here in the UK. We wouldn't feel it as human beings, but our seismometers, they're very sensitive instruments that can feel these waves. They make recordings of those, so we can make pictures of what the deeper parts of our planet looks like. This is a very, very nice way to understand the tectonics, the movement of plates, the generation of earthquakes, the reasons why there are volcanoes in some places. We can link those to the deeper parts of our planet and we make pictures, just like making a brain scan and our pictures look very similar. Give them colours, red and blue, they relate to regions in the Earth where the velocity is slightly or slightly lower, and we think we can link those to regions in the Earth where the temperature is slightly higher or slightly lower.

Now, volcanoes, they need higher temperatures and we would see them in our models, places where the temperature's probably h

Deeply hidden in Earth's mantle there are two huge "islands" the size of a continent. New research from Utrecht University shows that these regions are not only hotter than the surrounding graveyard of cold sunken tectonic plates, but also that they must be ancient: at least half a billion years old, perhaps even older.

These observations contradict the idea of a well-mixed and fast-flowing Earth's mantle, a theory that is becoming more and more questioned. "There is less flow in Earth's mantle than is commonly thought." This research was published on January 22, 2025 in Nature.

Large earthquakes make the whole Earth ring like a bell with different tones, just like a musical instrument. Seismologists study Earth's deep interior by investigating how much these tones are "out of tune," because whole Earth oscillations will sound out of tune or less loud when they encounter anomalies.

This way, seismologists will be able to make images of the interior of our planet, just like a hospital doctor can "see" through your body with X-rays.

At the end of the last century, an analysis of these oscillations showed the existence of two subsurface "super-continents": one under Africa and the other one under the Pacific Ocean, both hidden more than two thousand kilometers below the Earth's surface.

"Nobody knows what they are, and whether they are only a temporary phenomenon, or if they have been sitting there for millions or perhaps even billions of years," says Arwen Deuss, seismologist and professor of Structure and composition of Earth's deep interior at Utrecht University in the Netherlands.

"These two large islands are surrounded by a graveyard of tectonic plates which have been transported there by a process called 'subduction,' where one tectonic plate dives below another plate and sinks all the way from the Earth's surface down to a depth of almost three thousand kilometers."

"We have known for years that these islands are located at the boundary between t