The newly-detected molten rock layer is located about 150 km (93 miles) from the surface of our planet and is part of the asthenosphere, which sits under tectonic plates in the upper mantle. Hua et al. discovered a previously unknown layer of partly molten rock in a key region just below the tectonic plates. Image credit: Leonello Calvetti / Dreamstime. The asthenosphere is the denser, weaker layer beneath the lithospheric mantle. It lies between...
