Earth's outer core
Videos
Earth's outer core is a fluid layer about 2,260 km thick, composed of mostly iron and nickel that lies above Earth's solid inner core and below its mantle. The outer core begins approximately 2,889 km
An artist's illustration of what Earth might have looked like early in its formation.
Inner core super-rotation
Videos
Inner core super-rotation is a hypothesized eastward rotation of the inner core of Earth relative to its mantle, for a net rotation rate that is usually faster than Earth as a whole. A 1995 model of E
Schematic of PKP(BC) and PKP(DF) waves
