The Core from Above

摘要

Earth's core is split into a solid inner core and a fluid outer core. The convection and rotation of the outer core produce Earth's magnetic field and redistribute mass within the planet. Measured from orbiting satellites, variations in the magnetic field over time indicate changing outer core dynamics. Mass redistribution from fluid motion in the outer core should be detectable by gravity-sensing satellites, but surface processes such as the movement of water in the oceans and within river basins tend to dominate local gravity measurements.