Geologists have used earthquakes to study the interior of the Earth’s core
- Half of the 750 mile wide inner core appears to have a different structure
- Scientists believed the inner core was thought to be a solid lump of iron
- The new findings will mean that school textbooks may need to be rewritten
- The iron crystals in the outer half of the inner core are aligned north south
- Those in the innermost portion of the core point in a east/west direction
- Scientists believe the inner core could tell us about how the Earth formed
While there’s no prehistoric land hidden at the centre of our planet, as author Jules Verne imagined, the Earth’s core may not at all be like what scientists have led us to believe.
Geologists have discovered that the Earth’s inner core – previously thought to be a solid lump of iron – may in fact have its own even smaller core within it.
Using the seismic waves that reverberate across the planet after earthquakes, researchers have been able to gain new insight into what lies at the centre of our world.
The findings could mean that our understanding of Earth’s interior, and its history, will need to be rewritten.
Scientists found that rather than a solid ball of iron lying within the molten mass of the outer core, the inner core changes in structure about half way through.
They discovered a distinct inner inner core that is about half the diameter of what was believed to be the solid inner core, which is about the size of the moon.
Professor Xianodong Song, a geologist at the University of Illinois, said the structure of two inner cores could help reveal new details about how the Earth first formed.
He said: ‘Even though the inner core is small – smaller than the moon – it has some really interesting features.
‘The fact that we have two regions that are distinctly different may tell us something about how the inner core has been evolving.
Magma bursting to the surface like in the lava fountain above on Erta Ale, Ethiopia is from only the second layer of the Earth’s interior but the planet has a complex structure with a solid metal core at its very centre
Rotating liquid and solid cores at the centre of the Earth create the planets magnetic field, illustrated above