Tokyo, Japan – A team of scientists at Ehime University in Japan has made a significant scientific discovery: the presence of supercharged liquid hydrogen deep within the Earth, in an unusual and advanced physical state. Details of this recent study were published in the journal Proceedings of the National Academy of Sciences. Moreover, the study highlighted the thermodynamic modeling that helped decipher the behavior of this material under extreme temperatures and pressures.
Quantum simulation for exploring the Earth’s center
Because it is physically impossible to study the Earth’s core directly, geophysicists rely primarily on advanced computer simulations. In this study, researchers focused on hydrogen at extremely high temperatures, which make it electrically conductive and give it unique liquid-like properties. To analyze this complex phenomenon, scientists developed precise quantum models of iron-hydrogen alloys. These models included different crystalline structures.
The results of tests on the two crystal structures—the body-centered cubic and the hexagonal compact—showed that the former possesses excess free energy, making it chemically active. However, it melts under high temperatures, transforming into a homogeneous mass. According to quantum mechanical calculations, the hexagonal compact structure predominates in the Earth’s inner core. It maintains its thermodynamic stability at an immense pressure of approximately 3.5 million times atmospheric pressure. Additionally, it remains stable at temperatures exceeding 6000 Kelvin (around 5727 degrees Celsius). This temperature is comparable to that of the Sun’s surface.
Cycle of elements and generation of magnetic field
The researchers also identified a precise radial gradient in the distribution of hydrogen within the planet. The concentration of this light element decreases as you move from the outer core to the inner core. As a result, this gradient pushes highly ionized hydrogen outward to mix with the molten rock. The scientific team explained that this cycle of light and heavy elements provides the “chemical buoyancy” necessary for the Earth’s internal dynamics. Indeed, this is the fundamental process responsible for generating the Earth’s magnetic field.
Furthermore, the heterogeneous distribution of elements and pressure influences the thermodynamic processes. This allows the inner iron core to grow at a rate of approximately one millimeter per year. These groundbreaking results expand our understanding of the deep processes that shaped Earth. On the other hand, they open new avenues for improving the prediction of geomagnetic variations. Finally, the team intends to expand their mathematical models to explore the behavior of oxygen and carbon in the core in the future.
