Richard Jenkins in The Core (Picture: Splash News)
The turn of the century was a high point in the history of Hollywood disaster films. Deep Impact. Armageddon. Volcano. The Core.
All classics.
Now, one of those is coming true. In a way.
Scientists from the US and China have discovered that the Earth’s inner core is slowing down – similar to the imaginatively titled ‘The Core’, in which it stops entirely, costing the planet its protective magnetic field.
Cue Hilary Swank, Stanley Tucci and Aaron Eckhart, who have a plan to restart it, saving everyone from being fried by the Sun’s radiation. With a nuke, obviously, because what else?
Phew.
In real life however, it seems not only is the core simply slowing, not stopping, but it also probably won’t have any extinction-level consequences. Just one – it could change the length of a day.
The speed of the inner core has been debated for decades, with some research suggesting that it rotates faster than the Earth’s surface.
Now however, using data from earthquakes, a team from the University of Southern California (USC) has found evidence that it actually began slowing down in 2010, and is now spinning slower than the surface, and everyone on it.
Co-author Professor John Vidale, from USC, said: ‘When I first saw the seismograms that hinted at this change, I was stumped. But when we found two dozen more observations signalling the same pattern, the result was inescapable.
‘The inner core had slowed down for the first time in many decades. Other scientists have recently argued for similar and different models, but our latest study provides the most convincing resolution.’
The Earth’s inner core is solid, while the outer core is liquid (Picture: USC/Edward Sotelo)
The inner core is a solid ball of iron-nickel about the size of the Moon. It is surrounded by the outer core, a churning layer of liquid iron-nickel – and it is this that is responsible for generating the planet’s magnetic field.
This means thankfully we won’t face the same fate as those in The Core, when the outer core ground to a halt, potentially exposing everyone and everything to deadly solar radiation.
And unlike in the film, scientists in real life can’t hop in ‘the Mole’, an iron drilling machine, and take a peek at what lies beneath.
Humans have yet to even drill all the way through the crust, never mind cross the mantle to drive a digger into the centre of the planet. Here the film goes way off what scientists suspect is down there – including weird empty spaces.
Hilary Swank in The Core (Picture: Rob Mcewan/Horsepower/Kobal/REX/Shutterstock)
Instead, Professor Vidale and other scientists rely on the waves generated by earthquakes to determine what’s in the core, and monitor any changes.
In the latest study, published in the journal Nature, the team used repeating earthquakes – seismic events that occur at the same location – between 1991 and 2023 to measure the core’s speed. They also used data from nuclear testing in the 1970s, which was picked up by seismographs.
But despite proving that the inner core is slowing down, they don’t know what the effects will be.
One could be longer or shorter days.
‘It’s very hard to notice, on the order of a thousandth of a second, almost lost in the noise of the churning oceans and atmosphere,’ said Professor Vidale.
The team is planning more research to try to discover why the speed is changing.
‘The dance of the inner core might be even more lively than we know so far,’ added Professor Vidale.