Earth inner core not a solid state: study-Xinhua

Earth inner core not a solid state: study

Source: Xinhua

Editor: huaxia

2022-02-10 20:34:30

BEIJING, Feb. 10 (Xinhua) -- Chinese scientists revealed that the inner core of the Earth is not a normal solid state but a superionic state, said the Chinese Academy of Sciences Thursday.

The superionic state, an intermediate state between solid and liquid, is composed of solid iron and liquid-like light elements in the Earth's inner core, according to the study paper published in the journal, Nature, on Wednesday.

Besides iron, the existence of some light elements are long believed to be within the Earth's inner core due to its lower density than that of pure iron. Although silicon, hydrogen, carbon, and oxygen have been suggested to be the candidates, their state in the inner core is rarely considered.

A joint team of researchers from the Institute of Geochemistry under the Chinese Academy of Sciences and the Beijing-based Center for High Pressure Science & Technology Advanced Research conducted research on multiple iron-light-element alloys under simulative Earth's inner core conditions of high pressure and high temperature.

They found that the light elements of hydrogen, oxygen, and carbon in iron transformed to a superionic state under the inner core conditions, showing a high diffusion like liquid.

It reveals that the inner core of the Earth can be in a superionic state rather than a normal solid state, said the paper.