A new study the inner core of the Earth is not a "solid mass of iron"

A deeper understanding of the Earth's inner core will help scientists understand the relationship between the planet's interior and its magnetic activity.

For more than half a century, the scientific community has believed the Earth's inner core to be a solid, compressed ball of iron surrounded by a liquid outer core, but new research indicates that it is made up in parts of solid, semi-solid, and liquid metal.

Non solid core

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Jessica Irving says -aalmh earthquakes at the University of "Bristol" (University of Bristol) in England that did not participate in Aldrash- site "Life Science " (Live Science) in a report published on October 26 / October last "Whenever we look at it, we realized it It's not a solid ball of iron, we're discovering a whole new hidden world."

In fact, the Earth's inner core remains as mysterious as it was when Jules Verne published his book A Journey to the Center of the Earth in 1864. Although scientists have known since the 1950s that our planet is not as hollow as Verne predicted, the planet's interior remains unexplored; The enormous heat and pressure are simply too great for any probe to sink there.

"Unless something catastrophic happens to our planet, we will never have a direct view of the Earth's core," says Irving.

Instead, geophysicists rely on seismic waves produced by earthquakes. By measuring these massive vibrations, scientists can reconstruct a visualization of the planet's internal structure in a "like tomography" way, Irving says. These waves come in two main forms: straight pressure waves and shear waves. undulating, where each wave can accelerate, decelerate, or bounce off different media as it travels through the Earth.

Accidental discovery

Rhett Butler, a geophysicist at the Hawaii'i Institute of Geophysics and Planetology and one of the authors of the study, which was published in Physics of the Earth and Planetary Interiors, began the study. In the form of a question about inconsistent numbers, Butler was looking at how seismic waves caused by large earthquakes in 5 different locations travel through the Earth's core to the opposite side of the globe.

But something was not right; The seismic shear waves that were supposed to pass through a solid ball of metal were instead deflected in certain areas. These numbers surprised Butler, who knew that the calculations of seismic waves were correct, which could only mean one thing. Scientists are wrong about the structure of the Earth's core.

“When you work in this field, you have to match the data,” Butler says. So Butler and his colleague reevaluated their basic assumption that the Earth's inner core was all solid, and discovered that the waves they observed would be true if the core contained pockets of semi-soft and liquid iron. steel near its surface.

A revolution in understanding

Iron's viscosity range was particularly remarkable, according to Butler. "We've seen evidence that it is not only completely soft, but hard in some places. It has hard surfaces corresponding to molten or soft iron. So, we see a lot of detail in the inner core that is not We've seen it before."

This research could revolutionize our understanding of the Earth's magnetic field. While the outer core (which is made up of swirling fluid) drives our planet's magnetic field, the inner core helps modulate the field, according to 2019 research published in Science Advances.

Other planets, such as Mars, have a liquid center, but lack both an inner core and a magnetic field, according to research by NASA. Therefore, Butler and Irving believe that a deeper understanding of the inner core will help scientists understand the relationship between the planet's interior and its magnetic activity.