Geophysicists have found sunken worlds in the Earth’s mantle — the planet’s bulky middle layer — that, according to both earlier imaging and understanding of plate tectonics, simply shouldn’t be there.
When neighboring tectonic plates continue their slow-motion collision, sometimes one subducts, or slides underneath the other, often leaving geological remnants behind. Now, new imaging techniques have revealed similar leftovers far from tectonic boundaries. Geophysicists detected these secret worlds beneath large oceans or under the middle of continents — even though there is no record of subduction in those areas, according to a study in Scientific Reports.
“Apparently, such zones in the Earth's mantle are much more widespread than previously thought,” Thomas Schouten, a graduate student at ETH Zurich and an author of the paper, said in a news release.