Our planet’s inner core is a solid ball of iron and nickel around the size of Mars. It’s always been there, but it recently paused and then shifted its course. We couldn’t detect the difference because it was so minor. But, it is sufficient to have an impact on our planet’s magnetic field, which might have catastrophic ramifications for life on Earth.
The Earth’s Inner Core is now spinning in the opposite direction that it was previously.
The Earth’s inner core rotates in the opposite direction as the remainder of the mantle and crust. This is due to the fact that it originated at substantially lower temperatures than the other layers. Nevertheless, scientists have discovered that this rotation has changed—and they have no idea why.
The inner core is approximately 2,400 kilometers (1,500 miles) deep and 870 kilometers in circumference (540 miles). It’s largely formed of iron and nickel. Scientists believe that its solid ball of iron and nickel is orientated in the same direction as the Earth’s magnetic field, but new study indicates that this is no longer the case.
How Did Scientists Discover It?
Researchers explain how they could identify this shift using seismic waves generated by earthquakes in a study published in Nature Geoscience on Monday. Scientists discovered that, whereas seismic waves travel faster through the outer core than through the mantle or crust, they travel slower through both regions of the inner core—a transition that occurred abruptly around 2002-2003. The experts believe this is due to a shift in the orientation of the Earth’s inner core. The solid ball of iron and nickel could have turned over, explaining why seismic waves now take longer to travel through both portions of the inner core.
“The evidence for the reversal since 2009 is rather strong—statistically over 95 percent confidence level,” the study’s authors said. “These results help us better understand how the inside of the Earth operates and how the many layers of the system interact as a whole. Similar multi-decadal oscillations exist in other Earth layers as well, including the outer core, mantle, and surface, indicating a hypothetical resonant Earth system.”
What caused it to flip?
So why would this occur? According to the researchers, there are two probable explanations: an increase in temperature or pressure within the inner core itself, or an increase in temperature or pressure outside of it (meaning closer to us). According to the researchers, the latter interpretation is more likely. They believe there is evidence that the Earth’s magnetic field reversed at some point in the recent past. This would have resulted in a shift in pressure or temperature outside of the inner core, making seismic waves travel more easily through both parts of it.
Some minerals identified within the inner core have been dated at around 1.5 billion years old, while others are only a few hundred million years old, according to the experts. This could imply that a reversal occurred at some point in Earth’s history, and that it occurred more recently than previously thought.
The inner core is thought to have developed nearly a billion years ago, but there is some indication that it may have formed recently. According to a study published in the journal Geophysical Research Letters, Earth has had at least two magnetic field reversals in the last 3 million years. This would be consistent with previous research that discovered evidence of magnetic fields reversing over short periods of time during Earth’s history.
What Impact Will This Have on Us?
So, what does this reversal signify for us? When this occurs, it could indicate that weather patterns or other natural occurrences on Earth are changing. Changes in the Earth’s magnetic field can interfere with satellites and communications equipment, as well as alter animal behavior and migration patterns. Yet, the reversal does not always imply that Earth will undergo significant changes. We don’t know if the reversal will be quick or take hundreds of thousands of years.
