Can We Predict When Earth’s Core Will Stop Spinning?
Subterranean metal cannons churn away furiously beneath our planet’s crust towards earth’s core. Recent evidence indicates they may have stopped spinning in tandem with Earth and may even be changing course altogether. Scientists reported in Nature Geoscience about their research. That shows the inner core’s rotation slowing and switching directions on an 11-year cycle. Yet, currently doesn’t signal anything cataclysmic.
Seismic Waves
The Earth’s core is an immense ball of searing hot metal that makes up one-third of its mass. Although small in size, its fastest spinning part has become one of the planet’s key features. So, when scientists claim the core has abruptly stopped spinning. It’s an extraordinary development. But rather than fear that things may soon come to an end.
Let’s see why this might be occurring first. (follow up)
Researchers conducted studies using seismic waves generated from repeating earthquakes over the past six decades. To monitor inner core movement. Researchers discovered that the travel time of waves from the surface of the Earth to the center had changed slightly over this period. According to the report, this can be explained by changes in the inner core’s rotation. Which slows down and then speeds up relative to the rest of the planet.
In essence, acting like a pendulum swinging back and forth over a 70-year cycle.
As seismic waves travel through the mantle. They interact with its complex layers and processes. Dissipating energy to decrease their amplitude (how much they vibrate). When reaching outer core environments they experience changes that cause further attenuation. Which in turn contributes to an overall decline.
Attenuation plays an important role in this decline observed in new research.
Attenuation occurs as P-waves approach the inner core and encounter a layer of liquid iron and nickel. Creating magnetic forces which draw them in. When they hit this fluid layer, however, their momentum dissipates into an “attenuating zone” that prevents P-waves from progressing further. Similar results would occur with S-waves reaching this region of space. But this research is not the first time scientists have observed changes.
Other studies have proposed different oscillation periods. Yet much remains unknown regarding what goes on deep within our planet. Whatever its findings, this research adds another piece to the puzzle and shows us that our inner core may not be as steady as once believed.
Magnetic Fields of earth’s core
The outer iron core of Earth generates electromagnetic forces that give rise to its magnetic field. Which protects us from cosmic radiation and plays an essential role in life on this planet. Furthermore, these electromagnetic forces may even influence its rotation: seismic wave readings have revealed that Earth used to spin one-tenth of a degree faster each year. Suggestions are that the Earth’s inner core may be shifting its spin. The discovery was made after studying seismic waves generated by earthquakes.
Researchers noticed a difference in travel times for seismic waves traveling to both sides of the globe as well as slower rotational speeds for inner core rotations.
They were also able to observe changes in the speed of waves. Due to electromagnetic forces acting upon the liquid metal of Earth’s outer core, and their potential balance by gravitational effects. Researchers claim that Earth’s inner core was once spinning faster than its surface. But has recently slowed or reversed course, seemingly as a result of a change in balance between forces controlling its rotation. Believing this trend stems from changes in how these two forces control each other’s action and thus how rotation occurs in its core.
This conclusion was arrived at by studying differences in temporal shifts of repeated seismic waves.
Similar to banging on Earth pipes to see how waves changed over time. Over the past decade, scientists discovered that the inner core’s rotational speed had changed.Comparing this information with previous seismic data revealed that the inner core’s rotation had stopped outpacing that of Earth as a whole. An early sign that its speed has begun to diminish.
Pressure
Scientists recently released findings. One of them is that the inner core has significantly slowed its rotation, and may even reverse directions. The finding was supported by seismic waves recorded during earthquakes. With potential misreporting on the matter. The inner core is composed of solid iron and nickel metal.
Approximately the size of Pluto encased by a layer of liquid metal that allows it to rotate independently from its rocky outer layer.
Researchers studied seismic data from earthquakes around the world during the past decades. Specifically how the timing of seismic waves changed as time progressed. Before noticing that the inner core rotation increased or decreased according to changes in the length of days on Earth. Even over a seven-decade period, matching changes in length. They determined that the slowing inner core rotation was part of an underlying oscillation pattern.
Within this oscillation, the inner core spins faster than its outer core until slowing to match it.
After several decades have passed, the reverse occurs. Speeding back up until finally matching that of the outer core rotation speed again. This process is driven by forces acting upon the inner core from both electromagnetic and gravitational fields in its surroundings. While researchers believe that any imbalances among them could cause the core to slow or reverse its rotation. Potentially taking seventy years between cycles.
With predictions that the next reversal could take place around 2040.This research is significant because it provides answers to the idea that the inner core’s rotation does indeed shift on an irregular, yet subtle basis.
Temperature
The inner core of Earth consists of a dense ball of iron heated to temperatures comparable to that of the Sun. Separated from other parts by an outer core composed of liquid metal that allows its rotation at different speeds than those found at surface levels. This distinction between speeds is important since the inner core’s motion influences changes to Earth’s magnetic field. As well as slight variations in day length and contributes to seasonal variations on our planet. Scientists have been closely studying Earth’s movements deep inside, using seismic waves.
Vibrations caused by earthquakes that occur frequently – for some time now.
It may have been discovered that the inner core’s rotation has significantly slowed. Suggesting it may begin rotating slower than other parts of our planet in future years. Though scientists were shocked by this discovery. There was no call for this being a cause for concern. Researchers report that Earth’s inner core has seen a previous slowdown and reverse period before.
These cycles don’t signify that the inner core has stopped rotating or reversed its direction entirely.
Rather, their effects occur slowly over decades and can be difficult to notice from the outside. Research such as this represents another piece of the ever-evolving puzzle to better understand how our core works. While we cannot see directly into it. Seismic data and visualization techniques help visualize its situation inside. Once that has been accomplished.
Researchers may have to explore whether changes to the inner core are having any influence over factors like magnetic pole movements or variations in day lengths. For more on this subject check out this video
Provided by Antonio Westley
Disclaimer: This article is meant to be seen as an overview of this subject and not a reflection of viewpoints or opinions as nothing is definitive. So, make sure to do your research and feel free to use this information at your own discretion. For educational purposes only.
