Solid Rock Caught Flowing 1,700 Miles Beneath Surface in Experimental First

alternative_right writes: They found something else, too: that the solid rock above the D" layer can flow in a convection pattern. This type of movement, which varies across different parts of Earth's layers, determines the alignment of post-perovskite crystals.

It's driven by a combination of cooler material, which is sinking, and hotter material, which is rising. It's the first experimental evidence we have of such movement in this region of Earth's insides – though of course direct observations are impossible.