Earth's core

The internal structure of Earth is the spatial variation of chemical and physical properties in the solid Earth. The primary structure is a series of layers: Its mechanical structure is of a rigid lithosphere, a semi-fluid asthenosphere, a semi-fluid mesosphere, a liquid outer core, and a solid, rigid inner core. Its chemical structure is of a silicate crust, a ferromagnesian mantle, and an iron-nickel core whose flowing upper portion generates the Earth's magnetic field.