More mysteries of Earth’s core revealed in new research

10 Feb 2015

A team of researchers is claiming to have made a breakthrough in revealing more secrets of our planet’s inner core and, it’s safe to say, they have nothing to do with a mysterious Middle Earth.

The researchers, from the US and China, said it is quite likely Earth’s inner core may not be the inner-most layer of our planet but may in fact harbour another inner layer.

For decades, scientists have been trying to find answers about the deepest layers of the Earth but have been left wanting, given its density and the intense heat found the deeper you go into the planet. Much of what we know is based on estimations.

It is widely believed that the Earth’s core – which is about the size of our own moon – exists 5,000km beneath the Earth’s surface, having been solidified only 1bn years ago in the planet’s 4.5bn years of existence.

However, the researchers, who have published their findings in Nature Geoscience, said they came to their conclusions by monitoring the echoes created by earthquakes and measuring how the sound changes as it travels through the Earth’s different layers.


An illustration of the Earth’s second ‘inner-inner’ core. Image via Lachina Publishing Services

Cores have different polar axes

After they analysed the data, the researchers concluded this new inner core’s polar axis is different to its outer layer as it is aligned to a horizontal axis – much like east to west – compared with the outer layer, which is the more familiar vertical north to south axis, the BBC reported.

Research leader Xiaodong Song said this could explain more about how the planet has evolved throughout its history.

“The fact that we have two regions that are distinctly different may tell us something about how the inner core has been evolving,” Song said.

“For example, over the history of the Earth, the inner core might have had a very dramatic change in its deformation regime. It might hold the key to how the planet has evolved. We are right in the centre – literally, the centre of the Earth.”

Molten lava image via Shutterstock

Colm Gorey was a senior journalist with Silicon Republic