Structure of the Earth
The interior structure of the Earth is layered in spherical shells, like an onion. These layers can be defined by either their chemical or their rheological properties. Earth has an outer silicate solid crust, a highly viscous mantle, a liquid outer core that is much less viscous than the mantle, and a solid inner core. Scientific understanding of Earth's internal structure is based on observations of topography and bathymetry, observations of rock in outcrop, samples brought to the surface from greater depths by volcanic activity, analysis of the seismic waves that pass through Earth, measurements of the gravity field of Earth, and experiments with crystalline solids at pressures and temperatures characteristic of Earth's deep interior.
|0–60||0–37||Lithosphere (locally varies between 5 and 200 km)|
|0–35||0–22||… Crust (locally varies between 5 and 70 km)|
|35–60||22–37||… Uppermost part of mantle|
|100–200||210-270||… Upper mesosphere (upper mantle)|
|660–2,890||410–1,790||… Lower mesosphere (lower mantle)|