People get out of bed every day and go to work or school. The ground we walk on feels very natural to everyone and as it should be. But there is one fact that we do not always realize or think of. Earth moves through the vacuum of space and our planet is made up of layers, just like the pages of a book. A new study could change the number of layers we know.Research shows that little known episodes exist deep in Earth’s past. Modern research suggests that the Earth’s inner core has even more inner cores inside it. The new study reveals the first signs of this.
The veil of mystery in Earth’s inner core is being lifted
“We have traditionally been taught that the Earth has four main layers: crust, mantle, outer core and inner core,” said Australian National University geophysicist Joanne Stephenson. Our knowledge of what lies beneath the earth’s crust consists mostly of what volcanoes reveal and the whispers of seismic waves. Based on these indirect observations, scientists have calculated that with temperatures in excess of 5,000 degrees Celsius, the scorching hot inner core makes up only 1 percent of Earth’s total volume. But a few years ago, Stephenson and colleagues found evidence that Earth’s inner core may actually have two separate layers.
The team used an algorithm to scan thousands of models of the inner core and match decades of observed data on how long it takes seismic waves to travel through the Earth. Some models suggested that there are different layers of the inner core. This difference is due to material differences in the inner core.Stephenson believes that although this new layer is difficult to observe, its distinctive features may indicate an unknown, dramatic event in Earth’s history. “We found evidence that could indicate a change in the structure of iron, which suggests that perhaps two separate cooling events occurred in Earth’s history. The details of this major event are still a bit of a mystery, but when it comes to our knowledge of the Earth’s inner core, we’ve added another piece of the puzzle,” Stephenson said.
We still don’t know enough about what’s going on at the center of the Earth. Data deficiencies limit the scope of studies. Future research may fill some of these data gaps. Future studies can tell us older stories written in this early layer of Earth’s history.
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