Earth's inner core 'wobbles' every 8,5 years — Scientists now believe they know why

Earth’s inner core ‘wobbles’ every 8,5 years — Scientists now think they know why

Written by Fabio Lucas Carvalho

Published 07/12/2024 às 23:56

Researchers have discovered that Earth's inner core wobbles in mysterious ways every 8,5 years, and may be close to unlocking the reasons behind this puzzling phenomenon.

Earth's core, a dense mixture of iron and nickel, plays a key role in sustaining life by generating the Earth's magnetic field. planet. This field acts as a protective shield against harmful solar radiation. Despite its importance, the behavior of the core has puzzled scientists for decades, especially the slight but rhythmic movements of the inner core.

One of the most fascinating phenomena is the “Inner Core Wobble” (ICW), an oscillation of the inner core that occurs approximately every 8,5 years. A recent study from Wuhan University, published in the journal Nature Communications., brought new information about this mystery.

The wobble of the Earth's inner core

According to the study, the axis of the inner core is tilted 0,17 degrees relative to the axis of rotation of the Earth's mantle. This small misalignment has major implications for understanding how the core moves and interacts with the other layers of the planet.

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Understanding the mechanics

Hao Ding, a co-author of the study, explained that the findings suggest that the inner core may not be as perfectly spherical as previously thought. The misalignment of its tilt and rotation could indicate density differences both in the mantle and at the core-mantle boundary.

Ding first identified signs of this wobble in 2018 while studying Earth's polar motion. Now, the research suggests that the tilt of the inner core also influences the shape and behavior of the liquid outer core, which directly affects Earth's magnetic field.

Fluctuations in the geomagnetic field are fundamental to modern technology, which relies on magnetic orientations for navigation and communications. Thus, better understanding these internal movements is essential for the development of more accurate and reliable systems.

Alternative Theories and New Perspectives

While the Wuhan University study is a landmark, it does not completely solve the puzzle of the inner core's motion. Competing theories suggest that Earth's gravitational and magnetic forces may be in a constant tug-of-war, contributing to the core's complex movements.

Another hypothesis raises the possibility that the irregular shape of the inner core itself plays a crucial role in the observed wobble. Still, without physical access to the core, scientists rely on indirect methods, such as analyzing seismic waves and changes in the magnetic field, to build more accurate models.

Importance of continuous research

With so many variables involved, the core remains one of the greatest mysteries in science. Research like this is essential to refining our understanding of the inner workings of the Earth and how these processes affect the planet’s surface.

The inner core’s wobble, though subtle, is just one piece of a much larger puzzle. Future studies, combining interdisciplinary approaches and advanced technologies, promise to unlock more secrets about Earth’s internal structure.

By better understanding these phenomena, science can not only address fundamental questions about planetary dynamics, but also predict and mitigate the impacts these oscillations may have on life on the surface. The work continues, and with it, the hope of deciphering our planet’s deepest mysteries.

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Morvan

#92576

08/12/2024 20:07

Does it have anything to do with the earth's nutation? The standard deviations are pretty close.

Earth’s inner core ‘wobbles’ every 8,5 years — Scientists now think they know why