Textbooks now say that the Earth’s structure has about four layers: the crust, the mantle, the outer core and the inner core. A new study has found that there is another layer inside the Earth’s core with a distinctive structure.
The study, done by the Australian National University (ANU), found that the Earth’s core turns out to be like a “nesting doll,” with another layer inside the uncovered layer. This innermost layer may have been caused by some extreme events in the early days of Earth’s formation.
Joanne Stephenson, the principal investigator, said, “We found evidence that the Earth may have experienced two very different cooling events (resulting in two iron cores with different characteristics) during its early Life.”
“The details of this important event are still a mystery, but at least our understanding of Earth’s core has improved one more step.”
“The idea that there is a completely different layer inside the Earth’s core was first proposed more than two decades ago, but the data were quite unclear at that Time. We solved this problem using a very clever algorithm that searches from within thousands of kernel model data.”
The study concluded that the inner core of this layer, tentatively called the “inner core,” is about half the diameter of the entire kernel. If you look down from the Earth’s North Pole, the iron crystals inside the inner core face east to west, while the iron crystals inside the core face north to south.
“This is so exciting, we may have to rewrite the textbook!” Stephenson said.
The study was published Dec. 7, 2020, in the Journal of Geophysical Research (JGR).
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