Scientists are one step closer to solving one of the greatest mysteries in geophysics: how the Earth powers its magnetic field. The research team from the University of Texas at Austin and colleagues from Sichuan and Nanjing Universities in China believe their discovery provides a basic mechanism that will help explain the surprisingly “soft” physical properties of the Earth’s core.
About 1,800 miles deep beneath the Earth’s crust is a ball-shaped core made mostly of iron and nickel. The core is very hot, with temperatures ranging from approximately 8,000 to 10,800 °F (4,426 to 5,982 °C), and consists of two parts: Liquid outer core And the Dense and solid inner core.
the Movement of iron atoms In this heart it is known that power Earth’s magnetic fieldWhich is believed to play an important role in the continuity of life on this planet. Not only is it responsible for determining compass directions, but it also acts as a shield around the planet, deflecting powerful radiation from solar storms.
The Earth’s magnetic field is produced primarily in the liquid outer core by A The “ocean” of super-hot, swirling metalBut the role of the solid inner core in this is called Geodynamo It remains a mystery to this day.
“The Earth’s core is under such intense pressures, about 3.5 millibars, that you would expect the iron atoms to be confined to their positions and not have much room to move.Jong-Fu Lin, a professor at the University of Texas Jackson School of Geosciences and one of the study’s lead authors, told Newsweek. “What we found was completely contrary to this traditional view». “I was so excited for. We’ve just found the answer to the holy grail of geophysicsLin said.
“The iron atoms were moving so quickly that they moved to other locations in a fraction of a second». This movement, known in physics as mass motion, is similar to guests changing seats at a dinner party. The overall structure of the table remains the same, despite this internal movement.
By creating a miniature model of the Earth’s inner core in the laboratory, the research team was able to predict the properties and movement of these iron atoms. What the scientists found was very unusual: Instead of remaining fixed in their rigid lattice, the atoms moved quickly.
“[Αυτή η συλλογική κίνηση] This is due to the fact that iron atoms are in conditions so close to melting that they appear solid but behave like a liquid.Lin said. “In fact, this happens in many minerals that are close to melting and is a relatively well-understood physical phenomenon in condensed matter physics. But it is not known to happen in inner planets. We worked with physicists on this project, and it was as if they knew That this will happen.”
To confirm their models, the team also compared the results with studies of seismic waves of the Earth’s inner core. “We also performed shock wave experiments in the laboratory to measure the velocities of iron atoms at extreme pressures and temperatures where collective motion would be expectedLin said. “All this further confirms the prediction of the emergence of a mass movement in the “iron core” of the planet».
The team’s results were published in the journal With people on October 2, partly explains the mysterious “soft” properties of Earth’s inner core, while also offering possible readouts about heat production at the planet’s center. The study also helps us understand the processes that support the creation of Earth’s magnetic field, and perhaps the inner workings of other planets inside and outside our solar system.
“This discovery suggests that the same physics in mass motion occurs inside other planets, such as Mars, but also inside exoplanets.Lin said. “Exoplanets are subject to more extreme pressure and temperature conditions, so survey conditions must be expanded to see if this is the case. This will help us understand planetary systems in general».
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