US, WASHINGTON (ORDO NEWS) — Today, our Earth has two cores: a liquid external and a solid internal . The processes taking place at their boundary cause melt mixing in the outer core, leading to the appearance of the global magnetic field of the planet. They are investigated using elastic seismic waves that pass through the core, reflecting and refracting from different layers in different ways.
However, many details of what is happening here remain incomprehensible.
So, back in the 1990s, some waves revealed strange anomalies that could indicate that the inner core rotates slightly faster than the surface of the Earth. However, many experts explained them differently, linking them to slow but constant changes on the border between the outer and inner core, which, according to Xiaodong Song, a geologist at Peking University, resembles the growing mountains and canyons that open between them.
However, in a new article published in the journal Earth and Planetary Science Letters , Professor Sun and his colleagues refuted this interpretation, confirming the super-rotation of the Earth’s inner core. To do this, scientists used the latest seismic technology, which made it possible to synchronize with high accuracy the operation of sensors located in different parts of the earth’s surface.
Observations showed that some seismic waves passing through a solid inner core are refracted, indicating its super-rotation. “The work confirms that the changes occur mainly, if not completely, in the depths of the inner core,” adds Xiaodong Song. “The hypothesis of changes in the surface of the inner core – as the main source of anomalies in the signal – can be rejected.”
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