Three main layers of the earth
1. Core the innermost part
2. Mantle the middle part
3. Crust the outermost part
The special feature of the upper mantle is the asthenosphere. It is located just below the lithosphere and is made up of rock that is fluid and can move. The fluidity of these rocks powered the movement of tectonic plates on the earth's crust. Circular convection cycles in the hot, fluid upper mantle rock move the plates over the surface of the Earth.