- Scientists found a doughnut-like area at the upper boundary of the outer core.
- This less dense area aids in mixing the molten metal, thereby producing the magnetic field.
Researchers have discovered an enormous doughnut-like formation hidden deep within Earth’s interior.
Scientists from the Australian National University utilized seismic waves created by earthquakes to gaze into the Earth's enigmatic liquid center.
By following the trajectory of these waves across the Earth, scientists discovered a layer approximately hundreds of kilometers deep where their speed decreased by two percent compared to usual.
This doughnut-shaped formation circles the Earth’s liquid outer core along an equatorial path, 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 fluid metallic outer core, and a solid metallic inner core.
When the movement of tectonic plates in the crust creates earthquakes, these produce vibrations that spread out through all the other layers of the Earth.
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 shock.
The technique demonstrated that seismic waves propagating close to the poles moved at a quicker pace 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 these observations were most accurately described by the existence of an extensive subterranean ‘ring’ structure, akin to a doughnut shape.
They forecast that this area is located solely at low latitudes and aligns with the equator close to the upper boundary of the outer core, where the liquid portion interfaces with the mantle.
"We aren't sure 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 area's significant importance, finding these could greatly impact our understanding of life both on Earth and elsewhere in the universe.
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, convection currents combined with the planet’s spin cause the metallic fluid within this stratum to form elongated vertical whirls stretching from north to south, similar to immense 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 mixing the liquids within the outer core.
Without that vigorous movement to power the planet's inner dynamo, the Earth's magnetic field may not have developed.
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 DNA of living organisms.
Hence, this toroidal area could be an essential component of the mystery explaining how life evolved on Earth and what signs we should search for when looking at potentially habitable exoplanets.
Dr. Tkalčić concludes: "Our findings might encourage further investigation into the magnetic fields of both our planet and others."
Read more