14 DAY TRIAL // As it turns out, our planet's anatomy is a tad more complex than previously assumed. Thus, in a paper published in yesterday's issue of the journal Nature Geoscience, researchers claim that our planet's inner core has an inner core of its own.
That's right, it looks like the old distinction between Earth's crust, mantle, outer core and inner core isn't exactly accurate. On the contrary, our planet has one other anatomical part: a so-called inner inner core. Pretty cool, right?
How the inner inner core was discovered
Writing in the journal Nature Geoscience, researcher Xiaodong Song with the University of Illinois in the US and his colleagues explain that, to document the presence of this inner inner core deep inside our planet, they looked at the movement of seismic waves through Earth's various layers.
More precisely, the scientists analyzed the properties of the waves that resonate following the initial shock of an earthquake. The data that they obtained led them to believe that our planet's inner core isn't just one big ball of iron, as previously argued.
As detailed by specialist Xiaodong Song and fellow researchers, their evidence indicates that Earth's inner core hosts one other ball-like structure inside it and that this so-called inner inner core is surprisingly different to the layer encompassing it.
So, what's the deal with this inner inner core?
The researchers behind this investigation explain that, as shown by previous studies, our planet's inner core is somewhat smaller than the moon. The inner inner core inside it, on the other hand, appears to have a diameter about half the one of the whole inner core.
Whereas the upper layer of the inner core comprises iron crystals arranged in a north-south direction, the inner inner core is made up of crystals that point east-west. Check out the image that the researchers released together with their paper to get a better idea of what this inner inner core looks like.
Interestingly enough, it appears that, apart from the fact that they look differently, the inner core and the inner inner core behave differently too. Researcher Xiaodong Song and colleagues expect that, by further studying these structures, they will gain a better understanding of how Earth formed and evolved.
“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 center – literally, the center of the Earth,” says specialist Xiaodong Song.
