Earth’s innermost layer is a 644 kilometer wide ball of iron, new study finds
This article shows the layers of the Earth as being perfectly spherical, like the oblate spheroid that is the top layer of Earth's crust. Little 8km high Everest mountain ranges or 8km deep Mariana trenches are peach fuzz on the 12,750 km diameter billiard ball, and I suppose it seems reasonable to assume that the mantle and core beneath are similarly shaped by gravity to near-perfect spheroids.But I recently learned about the African and Central Pacific mantle plumes, which rise far above the circles in those Pac-man renderings:https://www.theatlantic.com/science/archive/2020/01/seismic-...I expect that's old news to someone in the field, but I haven't thought critically about that diagram since high school.