Modern geology teaches that the Earth is made up of four main layers: crust, mantle, outer core, and inner core. But the new data obtained may force us to reconsider the usual state of affairs – scientists have received indirect evidence that the inner core can hide other objects.
Our knowledge of what is under the earth’s crust is based mainly on information received from seismographs and volcanic activity.
Scientists have roughly calculated that the scaldingly hot inner core, with temperatures exceeding 5,000 degrees Celsius, makes up only 1 percent of the Earth’s total volume.
But a few years ago, a series of measurements showed that the Earth’s inner core could consist of two separate layers.
The team of scientists used a search algorithm to review and match thousands of models of the inner core with many decades of observational data on how long seismic waves travel through the Earth, collected by the International Seismological Center.
The diagram below shows how the measurements are made. The wave must pass through the board. Extraneous objects and movement inside the planet can affect its exit point: just these are what scientists are trying to fix.
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| This is how geologists noticed that sometimes seismic waves travel faster parallel to the equator, while other times they accelerate along the Earth’s axis of rotation. |
“We have found evidence that may indicate a change in the structure of iron that deflects seismic waves at a certain point. This looks like a clear sign of the heterogeneity of the core structure, as if there is another object inside, ” said Joanna Stephenson from the Australian National University.
The new results may explain why some of the measurements are inconsistent with current models of the Earth’s structure.
The presence of another inner layer was assumed before, but was more of a conjecture. Now the hypothesis has become supported by statistics.
