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Scientists discovered Earth's core and mantle misaligned in an 8.5-year wobble

Thursday, 21/12/2023, 11:56 (GMT+7)

Researchers have discovered Earth's Core Wobble, a cyclical oscillation with a periodicity of 8.5 years. This discovery has implications for polar motion and day length and could unlock new insights into Earth's geological processes.

China scientists discovered Earth's core and mantle are not aligned, causing an 8.5-year-long Inner Core Wobble (ICW)

Scientists from China have made a significant discovery regarding the Earth's structure, revealing that the core and mantle are not aligned and undergo an 8.5-year-long wobbling motion. 

Scientists discovered Earth's core and mantle misaligned in an 8.5-year wobble 1
Chinese scientists have discovered Earth's core wobbles, revealing a significant seismic revelation. Image Credit: Getty

The researchers have named this phenomenon the Inner Core Wobble (ICW), which has implications for the Earth's poles and variations in the length of a day.

The ICW is characterized by a cyclic oscillation of the inner core's shape axis

The study reveals a significant misalignment of approximately 0.17 degrees between the inner core and the surrounding mantle, which starkly contradicts the previous assumption of a 10-degree misalignment.

This discovery suggests a more intricate relationship among Earth's various layers than previously understood.

Earth is a complicated object made up of various layers. The planet's core is made mostly of solid metal and is known as the inner core. 

The outer core, a layer of molten metal, envelops the inner core. Perched on the outer core is the lithosphere, or Earth's crust.

Scientists discovered Earth's core and mantle misaligned in an 8.5-year wobble 2
The study reveals a 0.17-degree misalignment between Earth's inner core and mantle, contradicting previous assumptions of a 10-degree misalignment, revealing a more complex Earth's layers. Image Credit: Getty

Researchers have not only established the ICW's existence but also discovered that it repeats itself in a regular cycle every 8.5 years

This rhythmic behavior is extremely important since Earth's structural dynamics are crucial in determining how events occur on its surface, including the duration of a day.

Professor Hao Ding, a collaborator in this research and the Director of the Department of Geophysics at Wuhan University, remarks, "The results from Earth's free oscillations reveal a highly heterogeneous density structure within the planet."

Scientists discovered Earth's core and mantle misaligned in an 8.5-year wobble 3
Professor Hao Ding at Wuhan University highlights Earth's structural dynamics, revealing a highly heterogeneous density structure due to its rhythmic behavior, which is crucial for day duration. Image Credit: Shutterstock

This discovery raises profound questions about the previously established understanding of Earth's geophysical processes

The study provides crucial constraints for 3D density models of the Earth's lithosphere and challenges conventional assumptions regarding the perfectly spherical shape of the fluid core.

The revelation follows another significant finding by seismologists at a university in Australia, who identified the existence of a "central innermost core" within Earth. 

This distinct region, considered separate from the rest of the inner core, is believed to be a solid metallic sphere about 400 miles wide.

Scientists discovered Earth's core and mantle misaligned in an 8.5-year wobble 4
A study challenges conventional Earth's fluid core assumptions, revealing a "central innermost core" in fact is a solid metallic sphere about 400 miles wide. Image Credit: Getty

As scientists delve deeper into the mysteries of Earth's core, the revelation of the Core Wobble marks a paradigm-shifting moment in our understanding of the planet's dynamic and intricate inner workings.

The implications of this discovery extend far beyond the realm of geophysics, shedding light on the fundamental forces that govern Earth's behavior and shaping our comprehension of the world we inhabit.