The research into what lies deep, deep beneath our feet has yielded precious few details over the past few decades. We all grew up learning that we live on the Earth’s crust, which is just a thin layer above the mantle. Beneath that, the outer core surrounds the inner core, and… well, that’s it, or so we thought. Now, scientists have offered us an update to this model, and they believe the discovery may be concrete enough to warrant the rewriting of textbooks.
In a new paper published in the Journal of Geophysical Research, a small team of scientists says that the most widely accepted model of the interior of the Earth doesn’t necessarily jive with the data that is available. In its place, the researchers propose a new model that includes a new layer within the inner core, and they say that, based on the data, it may be evidence of a “traumatic event” somewhere in Earth’s history.
The new layer the researchers are said to have confirmed is distinct from the inner core and would represent a new “central inner core,” for lack of a better term. To do this, the team collected a massive amount of data from seismic events over decades, then tested them against models of the Earth’s interior. What they found was that the notion of a new core layer was the best way to match the data with a model.
“Traditionally we’ve been taught the Earth has four main layers: the crust, the mantle, the outer core and the inner core,” Joanne Stephenson, lead author of the work, said in a statement. “The idea of another distinct layer was proposed a couple of decades ago, but the data has been very unclear. We got around this by using a very clever search algorithm to trawl through thousands of the models of the inner core.”
How exactly this newly-identified layer formed is anyone’s guess, but it may point to a more complex story of early Earth formation than was previously accepted.
“We found evidence that may indicate a change in the structure of iron, which suggests perhaps two separate cooling events in Earth’s history. The details of this big event are still a bit of a mystery, but we’ve added another piece of the puzzle when it comes to our knowledge of the Earths’ inner core.”
The discovery of a new core layer may not change much when it comes to our daily lives, but it’s a big step toward better understanding how our planets and others like it form. If we hope to have a solid understanding of the nature of planets, figuring out what is hiding deep within them is a prerequisite and a pretty big one.