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.
