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The Earth’s inner core has started spinning in the opposite direction

This is according to a new study which probed the deepest reaches of our planet with seismic waves from earthquakes. The surprising finding might solve longstanding mysteries about the climate patterns that guide our local weather.  

According to a new study, the Earth’s inner core seems to have stopped spinning in the last decade and in even more surprising news, it may now be reversing the direction of its rotation.

The research, which was published in the journal Nature Geoscience, could reportedly lead to further understanding of how processes inside the planet could affect its surface, including the climate patterns that guide our local weather and the length of our days.

Before we get to that, however, let’s dive deeper (pun intended) into how exactly researchers managed to gather such mind-boggling results.

As explained by lead authors Yi Yang and Xiaodong Song, accessing a solid metal ball that is 75 per cent the size of the Moon, experiences intense heat on par with the surface of the Sun, and is located some 3,000 miles beneath us was no easy feat.

In fact, because it’s so remote and difficult to study, the inner core remains one of the least understood environments on Earth, though – and you may remember this from your school science lessons – it’s clear that it plays a role in many processes that make our world habitable to life.

Determined to further explore this untapped knowledge, Yang and Song probed through thick layers of solid granite and liquid iron with seismic waves made by earthquakes that occurred since the 60s.

In particular, they looked for ‘doublet’ events, which are ‘repeating earthquakes with nearly identical waveforms at common receivers.’

By analysing the slight temporal changes between these doublets, Yang and Song were successfully able to confirm that the Earth’s centre pauses and reverses direction on a periodic cycle lasting about 60 to 70 years.

This means that the rotation is a normal part of our planet’s behaviour and that we shouldn’t start panicking about a looming apocalypse any time soon.

‘We show surprising observations that indicate the inner core has nearly ceased its rotation in the recent decade and may be experiencing a turning-back,’ reads the study.

‘We believe the inner core rotates, relative to the Earth’s surface, back and forth, like a swing.’ What is revolutionary, is that the finding offers an unprecedented insight into a region that we still can’t really make sense of.

This is what has major implications for our comprehension of geological phenomena.

For example, the researchers note that the same multidecade cycle has been observed in the Earth’s climate system, as global mean temperatures and sea level rises appear to oscillate every 60 to 70 years.

Consequently, the discovery ‘may imply dynamic interactions between the deepest and shallowest layers of the solid Earth system.’

‘The gravitational coupling between the inner core and the mantle may cause deformation at the Earth’s surface, which would affect the sea level.’

‘The changes of the sea level and the Earth’s rotation may affect the global atmosphere circulation and temperature. The resonance of different systems may also amplify the mutual interactions.’

But we aren’t there just yet.

As Yang and Song stress, gaining more clarity about how the rotational cycles of the Earth’s inner core impact our very existence will require new models and a great deal more observation of the mysterious orb at our planet’s heart.

‘This multidecadal periodicity coincides with changes in several other geophysical observations, especially the length of day and magnetic field,’ they finish.

‘We hope to motivate researchers to build and test models which treat the whole Earth as an integrated dynamic system.’


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