On Earth, there are four layers: the crust, the mantle, the outer core, and the inner core. This is what people have been told for decades. In scientific settings, this assumption is generally thought to be true. An Australian National University study now shows a fifth layer, a huge metal ball or the “innermost inner core.” The fifth layer actually consists of two layers itself, referred to as the inner core and the innermost inner core.
Many people are surprised by this, but some experts are not. “About 20 years ago, it was thought that there might be an internal metallic ball within the inner core, the innermost inner core. Now, we have more evidence to support that idea,” said Dr. Thanh-Son Phạm from ANU’s Research School of Earth Sciences.
To come to their opinion, the experts looked at the seismic activity caused by 200 earthquakes and tremors in the last ten years. They were especially interested in how fast the earthquake waves moved through the earth’s core.
These waves go straight through the middle of the Earth and emerge on the other side of the earthquake’s trigger point, which is also called the antipode. They then go back to the earthquake’s place of origin.
“By coming up with a way to boost the signals picked up by networks of many seismographs, we were able to see for the first time seismic waves that bounce back and forth up to five times along the Earth’s diameter.” “Studies from the past have only found one antipodal bounce,” Dr. Pham said.
Unlocking Earth’s Time Capsule
This new technology will not only help us understand Earth better in its present state, but it also has a lot of promise to help researchers learn more about Earth’s past and future.
Professor Hrvoje Tkalčić, who worked on the study, says that the results are interesting because they give us a new way to look into the Earth’s center and inner core. Prof. Tkalčić said, “This inner core is like a time capsule of Earth’s evolutionary history.” As a way to learn about what happened on Earth in the past, this preserved record can be used. Something that took place on Earth hundreds of millions to billions of years ago.
In particular, some researchers are interested in what the very core’s makeup might tell us about a big global event that hasn’t been studied yet. Scientists have found that the deepest core of the planet has a crystalline alloy structure that is very different from the outer sections. This means that they have a whole new part of the history of the planet to study. Professor Tkalčić said, “There are still many unanswered questions about the Earth’s innermost core, which could hold the keys to solving the mystery of how our planet came to be.”