CANBERRA, Australia — It appears that Jules Verne’s classic “Journey to the Center of the Earth” may need a few more chapters added to it. Researchers in Australia say they’ve confirmed the existence of an extra, mysterious layer at the planet’s core.
A team from The Australian National University (ANU) is calling it the “innermost inner core” of the Earth. Their findings reveal it has distinct geological properties pointing to a yet-unknown event in the planet’s past.
“We found evidence that may indicate a change in the structure of iron, which suggests perhaps two separate cooling events in Earth’s history,” PhD researcher Joanne Stephenson says in a university release.
“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.”
Earth is about 4.5 billion years-old. Although this new layer is difficult to detect, researchers say learning more about it will help scientists understand how the planet formed and evolved over time.
“Traditionally we’ve been taught the Earth has four main layers: the crust, the mantle, the outer core and the inner core,” the lead author explains. “The idea of another distinct layer was proposed a couple of decades ago, but the data has been very unclear.”
Stephenson says the team was able to make the breakthrough using “a very clever search algorithm.” This allowed them to sift through thousands of planetary models examining the inner core.
“It’s very exciting – and might mean we have to re-write the textbooks!”
The study appears in the Journal of Geophysical Research: Solid Earth.