Scientists discover shocking new details about the Earth’s core

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By News.com.au

February 22, 2023 | 1:02 p.m

The historical understanding of the Earth’s inner core has been called into question by a group of scientists from the Australian National University after analyzing earthquake data.

Seismologists from the university believe they have found evidence of a previously unknown layer within the Earth called the innermost inner core.

An article from ANU published on Wednesday said that the layer, according to the researchers, looks like a solid metal ball.

The researchers’ findings, published in the journal Nature Communications, confirm that there are five layers in the Earth’s core and there were not four similar layers as historically thought.

“The existence of an inner metallic sphere within the inner core, the innermost inner core, has been hypothesized for about 20 years,” said Dr. Thanh Son Phum, from the ANU Research College of Geosciences.

“We now provide another line of evidence to substantiate the hypothesis.”

The researchers analyzed seismic waves that travel directly through the center of the Earth and “spit” on the opposite side of the globe to where the earthquake occurred, also known as the antimatter.

The waves then travel back to the source of the earthquake in what scientists liken to a ping-pong ball bouncing back and forth.

The Earth’s structure was previously thought to consist of only four distinct layers: the crust, the mantle, the outer core, and the inner core.

But now, Professor Hrvoje Tkalic, also of the Australian National University, said new knowledge about Earth’s inner core could reveal more about the planet’s past and evolution.

“This inner core is like a time capsule of Earth’s evolutionary history – it’s a fossilized record that serves as a portal to the events of our planet’s past. Events that happened on Earth from hundreds of millions to billions of years ago,” he said.

One of the seismologists who studied grew up in Alaska where the seismic waves caused by the earthquake “bounced back” somewhere in the South Atlantic Ocean, before returning to Alaska.

They found that the seismic backscattered waves repeatedly searched for the spots near the center of the Earth from different angles.

By analyzing the variation of travel times of seismic waves for different earthquakes, the scientists believe that the crystallization structure within the inner region of the inner core is likely to be different from the outer layer.

They say it may explain why the waves speed up or slow down depending on their angle of entry as they penetrate the deeper inner core.

According to the ANU team, the findings indicate that there may have been a major global event at some point during Earth’s evolutionary timeline that led to a “significant” change in the crystal structure or texture of Earth’s inner core.

“There are still many unanswered questions about the innermost inner core of the Earth, which could hold the secrets to unlock the mystery of our planet’s formation,” said Professor Tkalčić.

The researchers analyzed data from nearly 200 earthquakes of magnitude 6 and above from the past decade.