The Earth has a hard, thin crust and molten mantle. However, experts now say the latter is less homogenous than we once thought and new tech is finally letting us figure out just what’s under there.
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00:00This is Earth, and this is what Earth looks like on the inside, but that's not the whole
00:08story.
00:09While we have a hard, thin crust and molten mantle, experts now say the latter is less
00:13homogenous than we once thought, and new tech is finally letting us figure out just what's
00:17under there.
00:18So what have they found?
00:19Well, these blobs.
00:21Experts from ETH Zurich have used seismic waves in concert with the Pisdon supercomputer
00:25to analyze the lower mantle.
00:27These blobs could be what they say are tectonic plate remnants, ones that are cooler and higher
00:31density than the rest of the material around them.
00:33They say they could have been bits of our planet's crust that were sucked down via
00:36a process called subduction, or when two tectonic plates collide and one is sent underneath
00:41the other.
00:42What has surprised geologists, however, is that these plates have ended up far from where
00:45they were expected.
00:47That is, far from their initial subduction zones.
00:49So how did they get there?
00:50Well, experts aren't exactly sure.
00:52They say that rather than subduction, there's a possibility they've always been there.
00:56Or these blobs could actually be zones where iron-rich rocks accumulate as a consequence
01:00of mantle movements over billions of years.