Scientists Confirm Earth’s Core Has Slowed Dramatically, Now Moving In Reverse

Deep within our planet lies a mysterious, solid metal ball that rotates independently of our spinning Earth, much like a top spinning inside a larger top. This inner core has long fascinated researchers, and its movement - including rotation speed and direction - has been the subject of a decades-long debate.

For years, scientists have been trying to understand the inner core’s spin, but it’s been a challenging task due to its remote location and limited data. Seismologists have gathered information by examining the behavior of waves from large earthquakes that reach this area. By analyzing these waves, they’ve been able to measure changes in the inner core’s position and calculate its spin.

Researchers have debated how to interpret these findings, with some suggesting that the core didn’t rotate at all. However, a promising model proposed in 2023 described an inner core that had previously spun faster than Earth but was now spinning slower. The core’s rotation even matched Earth’s spin for a period before slowing down further and eventually moving backwards relative to the fluid layers around it.

A new study published in the journal Nature on June 12 confirms the core’s slowdown and supports the 2023 proposal that this deceleration is part of a decades-long pattern of speed changes. The findings also reveal that the changes in rotational speed follow a 70-year cycle, according to Dr. John Vidale, a study co-author and Dean’s Professor of Earth Sciences at the University of Southern California’s Dornsife College of Letters, Arts and Sciences.

The inner core is buried about 3,220 miles deep inside Earth, surrounded by a liquid metal outer core. Composed mostly of iron and nickel, it’s estimated to be as hot as the surface of the sun - about 9,800 degrees Fahrenheit. Earth’s magnetic field pulls on this solid ball of hot metal, causing it to spin. Meanwhile, the gravity and flow of the fluid outer core and mantle exert a drag on the core, resulting in variations in the core’s rotational speed over many decades.

The movement of metal-rich fluid in the outer core generates electrical currents that power Earth’s magnetic field, which protects our planet from harmful solar radiation. Although the inner core’s direct influence on the magnetic field is not fully understood, scientists reported in 2023 that a slower-spinning core could potentially impact it and also slightly shorten the length of a day.

The implications of the inner core’s slowdown for our planet remain an open question, with some experts suggesting that Earth’s magnetic field could be affected. However, the new findings provide compelling evidence that the core’s slowdown is part of a decades-long pattern, and scientists are one step closer to understanding the mysteries of our planet’s inner workings.

Historical Context:

The study of the Earth’s core has been ongoing for decades, with scientists attempting to understand its rotation speed and direction. In 2023, a promising model was proposed that described an inner core that had previously spun faster than Earth but was now spinning slower. This model suggested that the core’s rotation even matched Earth’s spin for a period before slowing down further and eventually moving backwards relative to the fluid layers around it. The new study published in the journal Nature on June 12 confirms the core’s slowdown and supports this 2023 proposal.

Summary in Bullet Points:

• Scientists have confirmed that the Earth’s inner core has slowed down dramatically and is now moving in reverse. • The inner core is a solid metal ball that rotates independently of the Earth’s spin, located about 3,220 miles deep inside the planet. • The core’s rotation is influenced by the Earth’s magnetic field, which pulls on it, and the gravity and flow of the fluid outer core and mantle, which exert a drag on the core. • The movement of metal-rich fluid in the outer core generates electrical currents that power the Earth’s magnetic field, which protects the planet from harmful solar radiation. • The inner core’s slowdown could potentially impact the Earth’s magnetic field and slightly shorten the length of a day. • The study provides compelling evidence that the core’s slowdown is part of a decades-long pattern and scientists are one step closer to understanding the mysteries of the Earth’s inner workings. • The findings suggest that the changes in rotational speed follow a 70-year cycle, with the core slowing down and then speeding up again. • The implications of the inner core’s slowdown for the Earth’s magnetic field and the planet as a whole remain an open question and require further research.