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Scientists found a doughnut-like area at the upper boundary of the outer core.
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This less dense area aids in agitating the molten metal, thereby producing the magnetic field.
Researchers have discovered an enormous ring-like formation hidden deep below the surface.
Scientists from the Australian National University utilized seismic waves produced by
earthquakes
to gaze into the Earth’s enigmatic liquid center.
By following the journey of these waves through the Earth, scientists discovered a layer approximately hundreds of kilometers thick where their speed was 2% below average.
This doughnut-shaped formation circles the Earth’s liquid outer core along a path parallel to the equator, potentially playing a key role in generating our planet’s shielding magnetic field.
Professor Hrvoje Tkalčić, who led the research, states: “The magnetic field is an essential component required to maintain life on Earth’s surface.”
Our planet consists of four primary layers.
the exterior crust, the partially molten mantle, a liquefied metallic outer core, and a solid metallic inner core.
As tectonic plates shift within the Earth’s crust, they trigger earthquakes, which generate seismic waves that propagate throughout the planet’s various layers.
Leveraging the global network of seismic monitoring stations,
Researchers can observe how the waves propagate and use this information to forecast the circumstances beneath the water’s surface.
Researchers typically focus on the large, strong wavefronts that circulate globally within the initial hour following an earthquake.
Nevertheless, Professor Tkalčić and his co-author Dr Xiaolong Ma managed to identify this pattern by examining the subtle remnants of waves that persisted for several hours following the original seismic activity.
The technique demonstrated that seismic waves propagating close to the poles were traveling at a quicker speed compared to those nearer to the equator.
When they compared their findings with various models of the Earth’s interior, Professor Tkalčić and Dr Ma discovered that this phenomenon could be most effectively accounted for by the existence of an extensive subterranean ‘ring’ or torus-like area.
They forecast that this area is present solely at low latitudes and aligns with the equator close to the upper boundary of the outer core, where the liquid part interfaces with the mantle.
“We aren’t certain about the precise thickness of the doughnut, but we deduced that it extends several hundred kilometers below the core-mantle boundary,” states Professor Tkalčić.
Due to the significance of this area, their discovery could also have deep repercussions for understanding life on our planet and beyond.
The Earth’s outer core extends about 2,160 miles (3,480 km), which is somewhat bigger than the size of Mars.
Primarily composed of molten nickel and iron, the movement within this layer is driven by convection currents combined with the planet’s spin, which twists the liquid metals into elongated vertical whirls stretching from north to south, much like enormous water tornadoes.
The rotating flows within these molten metals function akin to a dynamo, generating the Earth’s magnetic field.
As this donut-shaped area has risen to the upper part of the liquid outer core, it implies that it might contain an abundance of lighter elements such as silicon, sulfur, oxygen, hydrogen, or carbon.
Professor Tkalčić states: “Our discoveries are intriguing as this reduced speed within the liquid core suggests a significant presence of lightweight chemical elements in those areas, which would consequently decelerate the seismic waves.”
These lightweight components, along with variations in temperature, aid in circulating the fluid within the outer core.
Without that vigorous movement to power the planet’s internal dynamo, Earth’s magnetic field may not have come into existence.
In the absence of the magnetic field, the planet’s surface would face an unrelenting assault from charged particles.
From the sun, which has the power to damage the genetic material of living organisms.
Hence, this ring-like area could be an essential clue in understanding how life emerged on Earth and what we should search for when identifying habitable exoplanets.
Dr. Tkalčić concludes: “Our findings might encourage further investigation into the magnetic fields of both our planet and others.”
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