Earth’s mysterious core is much stranger than you think

Illustration of the Earth’s core.
iStock/Getty Images Plus

  • The Earth’s core has puzzled researchers for decades, and it still contains many secrets.
  • Recent studies show that this hot furnace buried deep beneath our feet is stranger than we think.
  • The inner core may be rotating, and scientists believe it is covered by an ancient ocean floor.

Earth’s mysterious core is crucial to every part of life on our planet.

This furnace of molten metal, located approximately 1,800 miles beneath our feet, keeps our atmosphere intact and protects us from exposure to solar radiation.

But scientists still don’t understand exactly how it works. We can’t go down there for obvious reasons, so researchers have to rely on shock waves traveling through Earth to give us clues about what’s really going on at the core of our planet.

Recent studies have revealed a series of amazing discoveries about the planet’s core, and scientists now say they are beginning to uncover its secrets.

There is a significant deviation in the Earth’s magnetic field over South America, and the core may be the cause

Although the Earth may appear static to us, there is a lot going on inside our planet. Beneath the Earth’s cold, brittle crust and its blanket of molten rock lies the Earth’s core.

Inside the core, temperatures are so hot that the metal oozes out like a vigorously churning liquid.

The diagram explains how the Earth’s core can act as a giant dynamo, creating our planet’s magnetic fields.
NASA/Andrew Z. Colvin, CC BY-SA 4.0

This is extremely important for all life on Earth: when this metal rotates, it creates powerful magnetic fields that radiate from the Earth’s poles.

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These magnetic fields, in turn, act as a shield for our planet, keeping our atmosphere in place and reflecting the worst of the solar radiation that constantly bathes the Earth.

That’s why scientists are so puzzled by how much of Earth’s magnetic field has become weaker over the past 50 years.

The South Atlantic Anomaly is located over the middle of the South American continent, an area where a slightly greater amount of solar radiation is thought to penetrate Earth’s protection.

People on Earth are still safe from this radiation. But satellites and spacecraft could sustain more damage as they sail through this region, Insider reported in 2020.

The strength of Earth’s magnetic field in 2020, as measured by the European Space Agency’s SWARM satellites. In blue is a weaker area of ​​the field.
Wikimedia Commons/Christopher C. Finley et al.

This anomaly has become larger over the past 50 years, and has also begun to split into two points, which has baffled scientists.

“The challenge now is to understand the processes occurring in the Earth’s core that are driving these changes,” Jürgen Matzka, of the German Research Center for Geosciences, said in an ESA statement accompanying the results in May 2020.

Giant mountains five times taller than Everest can keep her heart warm

The mantle is much cooler than the core, and it follows that the outer edge of the core must get progressively cooler to match the temperature of the layer above it.

But this does not happen, as the temperature rises at the boundary between the mantle and the core.

This has led experts to believe that an unknown layer or phenomenon may exist at the core boundary of the mantle to keep our planet’s core warm. a A study published in April Provides a potential solution.

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Scientists studying how shock waves from earthquakes bounce off the Earth’s core have suggested they may be wrapped in parts of ancient ocean floors that were “recycled” over millions of years when they were compressed back into Earth by continents colliding with each other.

A conceptual illustration of what the structure around the core would look like is next to a photo of scientists placing seismic equipment in Antarctica.
Edward Garnero and Mingming Li at Arizona State University/Lindsay Kenyon

The floor of ancient oceans would be the perfect candidate to explain the stark temperature change: It is so dense that it could easily sink to the bottom of the mantle, and it is quite heat-resistant, says Samantha Hansen, the study’s lead author and a professor of geological sciences at the university. From Alabama, he previously told Insider.

Looking at seismic data, scientists found that this layer, which would serve as a lid for the core, could feature peaks five times the size of Mount Everest, one of the study’s authors said in a press release.

The Earth’s inner core may be rotating and sometimes flipped backwards

The kernel itself is not uniform. At the core of our planet, the pressure becomes so intense that the metal can no longer liquefy. Instead, it behaves like a huge ball of solid metal, which is called an inner core.

An artistic visualization of the different layers of our planet, including the crust, mantle, inner and outer cores.
GT

Because it floats in a pool of molten metal, our inner core does not necessarily rotate at the same speed as the planet. In fact, A Recent study It found that the inner core may have recently stopped rotating and could start turning in the other direction.

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The theory is that the magnetic field pulling on Earth’s inner core competes with a strong gravitational field from the mantle, a huge mass of rock located directly above the core.

Every few decades or so, one force might triumph over the other, Insider’s Morgan McFall-Johnson and Chris Panella previously reported.

This is nothing to panic about. In fact, the same thing appears to have happened around 1971, the study found. The world did not stop turning then.

John Fidell, a geophysicist at the University of Southern California, said that although the phenomenon is “likely benign,” scientists will want to know more about it. Washington Post In January.

“We don’t want to have things we don’t understand deep in the ground,” he told The Post.

The heart may grow unevenly

The core is always growing. Each year, more of the iron in the inner core crystallizes, adding about one millimeter to its radius.

We’ve known this for some time. but Study 2021 This has raised astonishment among scholars.

The study found that the eastern part of the sphere, which lies beneath Indonesia’s Banda Sea, appears to have about 60% more iron crystals than the other side.

In short, our Earth’s inner core grows sideways, according to the study.

However, this does not mean that the inner core grows into a football. Scientists believe that although the crystals appear on one side of the inner core, they are redistributed on the other side so that it can maintain its spherical shape, Insider previously reported.

A diagram showing how iron crystals are distributed and move around the Earth’s inner core.
Marine Lasplace

This new information may tell us just as much about the mantle above the core: This side of the mantle is likely to be slightly cooler than its western counterpart, the scientists said.

The question then, as Daniel Frost, a co-author of the study and a seismologist at the University of California, Berkeley, told LiveScience at the time, is, “Does this change the strength of the magnetic field?”

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