Name: The Mystifying Structures Hidden Within Earth’s Mantle
Uploaded: 2020-03-30T02:30:52.000Z
Duration: 3 min 40 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

As you're watching this video, thousands of kilometers beneath your feet, edging on

the brink of alien and terrestrial, lies two vast structures with unknown origins, and

These 'blobs' have been a big geologic mystery that researchers believe are having

an untold effect on our planet and it's baffled scientists for over 40 years.

Well, Earth blobs have picked up this rather un-sciency name because they look sort of

Scientists call them Large Low Shear Velocity Provinces, because waves of energy slow down

through these zones, but boy, that's a mouthful so let's just stick to Earth blobs for now.

They're hidden underneath Earth's crust, like really, really deep - about 2,000 kilometers

These blobs are so massive that if we moved them to Earth's surface, the International

Space Station would need to navigate around them.

So to better understand these gigantic structures, we need to journey into the center of the

They begin where Earth's mantle meets the outer molten core.

In the 1970's, scientists discovered that one of the blobs sits under the Pacific ocean,

while the other one sits under Africa and part of the Atlantic ocean.

So we know their general location and we know that these regions are different from the

surrounding mantle material because seismic waves move through these massive regions slower

But there are still many unanswered questions.

No one knows for sure where they came from, how long they've been around, or even what

But yah know, scientists love a good mystery hidden deep within the Earth's crust.

So it's been an ongoing debate ever since they were discovered 40 years ago with a whole

One hypothesis has described them as plumes of hot upwelling rock that connect to surface

volcanoes to form island chains like Hawaii and Iceland.

Another has speculated that the blobs are disrupting Earth's magnetic field.

And others have suggested that the blobs are connected to super volcanoes that at one time

So yeah... the ideas run from the generally benign to the apocalyptic.

Because it's impossible to reach these depths in one piece—temperature and pressure would

kill you —scientists have to rely on a multitude of techniques to tell us what the interior

looks like, and maybe even explain how these mysterious regions affect our planet.

One way is with seismic tomography, a technique that helps us look below the crust by tracking

This was how scientists actually discovered the blobs in the first place.

But while the method revealed where the blobs are and how large they are, it can't really

So one researcher turned to a new technique called tidal tomography to peer under Earth's

It uses sensitive GPS measurements to track Earth's body tides and can give us a better

Preliminary results showed that the blobs were pretty dense and could be composed of

iron and have similarities to primordial material.

While geochemists are analyzing the chemical composition of lava samples to help determine

One study, looking at underwater lava flows along Costa Rica, suggested that at least

one of the blobs may have been a source for an extinction level event millions of years

So evidently more research is needed to demystify the blobs before we make any conclusions.

What's important to keep in mind is that each of the earlier ideas may present a different

picture of Earth's inner workings and the role the blobs could play on our planet, which

is why these regions are so scientifically interesting.

They could tell us very different things about the planet, from its earliest beginnings to

the magnetic field to even super volcanoes.

But until Brendan Fraser figures out a way to journey back to the center of the Earth,

we'll use the techniques at our disposal to reveal the mysterious blobs wrapped around

If you liked this episode, let us know if there are any other mysterious science phenomenons you'd like us to

cover down in the comments. Make sure to subscribe and thanks for watching.