By studying the structure of the Earth’s inner core, researchers will be able to better understand the history and evolution of our planet.
While most of us take the Earth under our feet for granted, the history of our planet is painted within its complex layers. Science Alert.
“Traditionally, the Earth was thought to have four main layers: the crust, the mantle, the outer core and the inner core. But in reality, its structure can be much more complex,” – explained Australian National University geophysicist Joan Stevenson.
Our knowledge of what lies beneath the earth’s crust is based primarily on observations of volcanoes and seismic waves. Based on the data obtained, scientists have calculated that the incandescent inner core, with temperatures in excess of 5000 ° C, is only one percent of the total volume of the Earth.
Now Stevenson and her colleagues have found even more evidence that the Earth’s inner core can have two different layers.
“This is very interesting and may mean that we will have to rewrite the textbooks,” said Stevenson.
The team used a smart search algorithm, matching thousands of inner core models with observations of how long seismic waves travel through the Earth. She also studied some models of the anisotropy of the inner core, namely how differences in the composition of its material change the properties of seismic waves, and found that some of them are more likely than others.
While some models believe that the material of the inner core directs seismic waves parallel to the equator, others argue that the mixture of materials allows for faster waves to propagate along the axis of rotation of the Earth.
The new study showed no significant changes in depth in the inner core, but found a 54-degree change in seismic direction. The faster direction of the waves was parallel to the axis.
“We found evidence that could point to a change in the structure of iron, which suggests perhaps two separate cooling periods in Earth’s history. The details of this big event are still a mystery, but we have completed another piece of the puzzle about exploring the Earth’s inner core.” Stevenson said.
The researchers note that these new discoveries may explain why some experimental data do not correspond to their current models of the structure of the Earth.
Experts have long suspected the presence of an additional inner layer, indicating that the iron crystals in the core have different structural arrangements in two different layers.
A new method currently being developed may soon fill some of these gaps and allow scientists to confirm or disprove their findings. In addition, studying the structure of the inner core can help researchers better understand the history and evolution of the Earth.