New Delhi, India

Scientists have been investigating the core of the Earth, which has become home to some of the most “extreme features" of a planet hidden deep in underground.

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Now new research has found that the mysterious zones, which are present in the deep mantle underneath some places where earthquake waves have slowly moved, may actually have been spread across the entire planet.

The existence of these zones in the Earth's lower mantle, which are ultra-low velocity zones (ULVZs), was already known to scientists. However, unlike the new idea that these zones are widespread, these zones were earlier said to be present in the regions where hot rock moves and creates volcanic island chains like Hawaii. 

Also Read: Hundreds of meteorites originating from only 5 craters on Mars hit Earth

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The experts have now discovered that these mysterious black hole zones can slow down seismic waves by around 50 per cent, however, scientists are unaware of what they are made of or what their exact role is in the process.

"Here's one of the most extreme features that we see anywhere inside the planet," said geophysicist Michael Thorne, of the University of Utah, while speaking to Live Science.

"And we don't know what they are, where they're coming from, what they're made of, [or] what role they play inside the Earth," he added.

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Did meteors form these mysterious zones in Earth's mantle?

According to some researchers, the ULVZs may have been the remains of the giant impacts created by meteors which relentlessly bombarded the Earth. 

However, as per Thorne, if they are ubiquitous, then that means such zones are getting generated actively even today.

He said that there are chances of volcanic rock basalt - which gets formed at mid-ocean ridges - making these wave-sucking structures. 

Once this basalt enters into the mantle through subduction, it melts quickly and can form pockets which have slow seismic waves.

Watch: Earth slows down by 1.33 milliseconds

Thorne and his team analysed the waves that were created by large, powerful earthquakes, called PKP waves.

Speaking to Live Science, Thorne said that his findings revealed something was slowing the earthquake waves dramatically from scattering their energy.

It was the valleys and ridges which were present along the core-mantle boundary which were slowing the earthquake waves, he said.

Thorne said that signatures of ULVZs were detected across the planet in North America, North Africa, East Asia, Papua New Guinea, the Pacific Northwest, and the western Pacific.

(With inputs from agencies)