While most of us take the ground beneath our feet for granted, within its complex layers, like the pages of a book, lies the story of Land. Our history.
Research shows that there are little-known chapters in that story, deep in the past of the Land. In fact, it seems that the inner core of the Land it has another even more internal core. “Traditionally we have been taught that the Land it has four main layers: the crust, the mantle, the outer core and the inner core,” geophysicist Joanne Stephenson of the Australian National University explained in 2021.
Our knowledge of what lies beneath the earth’s crust has been inferred mainly from what volcanoes have revealed and what seismic waves have whispered. From these indirect observations, scientists have calculated that the scorchingly hot inner core, with temperatures exceeding 5,000 degrees Celsius (9,000 degrees Fahrenheit), makes up just 1 percent of the Earth’s total volume. Land. But a few years ago, Stephenson and his colleagues found evidence that the inner core of the Land it may actually have two distinct layers.
“It’s very exciting, and it could mean we have to rewrite the textbooks!” Stephenson explained at the time. The team used a search algorithm to track down and match thousands of models of the inner core with data observed over many decades about the time it takes for seismic waves to travel through the Earth. Landcompiled by the International Seismological Center.
So what’s down there? The team examined some models of the inner core’s anisotropy, how differences in its material composition alter the properties of seismic waves, and found that some were more likely than others. While some models suggest that the inner core material channels seismic waves faster parallel to the equator, others suggest that the mix of materials allows for faster waves more parallel to the axis of rotation of the equator. Land. Even so, there are arguments about the exact degree of difference at certain angles.
The study here didn’t show much variation with depth in the inner core, but found that there was a change in the slow direction at an angle of 54 degrees, with the faster direction of the waves running parallel to the axis. “We found evidence that may indicate a change in the structure of the iron, suggesting perhaps two separate cooling events in the history of the LandStephenson said. “The details of this great event remain a bit of a mystery, but we have added another piece of the puzzle in regards to our knowledge of the inner core of the Land“.
Via: Science Natures
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