Geophysicists from Australia have discovered an unusual structure in the Earth’s liquid core that could improve understanding of the dynamics of the planet’s magnetic field.
The Earth has a complex internal structure consisting of several layers. In the center of the planet is the core, which is divided into two parts: the solid inner and the liquid outer. Above the core is the mantle, and the outer layer is formed by the Earth’s crust. Recently, a team of researchers from the Australian National University made an important discovery. They have discovered a hitherto unknown structure in the Earth’s outer core, near the border with the mantle.
Professor Hrvoje Tkalčić, co-author of the study, explains that the new structure was discovered by slowing down seismic waves. According to him, it resembles a donut shape and extends for the first hundreds of kilometers below the mantle-core boundary.
To study the internal structure of the Earth, scientists used the method of seismic tomography. This approach makes it possible to measure the speed of seismic waves after earthquakes, the centers of which can reach a depth of 700 kilometers. Unlike previous studies, which usually recorded signals within the first hour after an earthquake, Tkalčič’s team collected data for several hours.
The discovery by Australian geophysicists opens up new perspectives for understanding the dynamics of the Earth’s magnetic field. Xiaolong Ma, a co-author of the paper, emphasizes the importance of an interdisciplinary approach to further study the outer core, which is still a mystery to scientists.
The Earth’s outer core is composed mostly of molten iron and nickel. The movements of this electrically conductive mass create a magnetic field that protects the planet from cosmic radiation. Prof. Tkalcic suggests that the discovered structure is enriched with light chemical elements, which enhances mixing in the outer core.
The geophysicist also notes that this discovery may be important not only for the study of the Earth. New knowledge about the structure of the Earth’s core and its influence on the planet’s magnetic field can be useful for studying the magnetic fields of other planets.
Results of the study published in Science Advances.
Source: Sciencealert, Phys
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