Mysterious &#39;Donut&#39; Structure Unveiled Deep Within Earth&#39;s Core

Scientists found a ring-like area at the upper boundary of the outer core.
This less dense area aids in agitating 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 produced by earthquakes to gaze into the Earth's enigmatic liquid center.

By following the course of these waves through the Earth, the scientists discovered a layer approximately hundreds of kilometers thick where their speed was 2% lower than usual.

This doughnut-shaped formation circles the Earth’s liquid outer core along a path that parallels the equator, potentially playing a key role in generating our planet's shield-like magnetic field.

Lead author Professor Hrvoje Tkalčić states: "The magnetic field is an essential component required to sustain life on Earth's surface."

Our planet consists of four primary layers. the exterior crust, the partly molten mantle, a liquid 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, Scientists can observe how the waves propagate and use this information to forecast the circumstances beneath the water.

Researchers typically focus on the large, dominant 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 primary 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 ‘torus,’ essentially a doughnut-shaped area.

They forecast that this area exists 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 certain about the precise thickness of the doughnut, but we deduced that it extends for several hundred kilometers below the core-mantle boundary," explains Professor Tkalčić.

Due to the importance of this area, uncovering it could significantly impact our understanding of life on both Earth and other planets.

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 Earth's rotation drive the movement of this liquid metal into elongated vertical whirls oriented from north to south, similar to massive water tornadoes.

The rotating flows within these liquid metals function similarly 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, assist in mixing the liquids within the outer core.

Without that intense movement to power the planet's inner dynamo, the 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 ability to damage the DNA of living organisms.

Hence, this toroidal area could be an essential component of the mystery explaining 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."