Answer:
Heat
Explanation:
The outer layers of the Earth are divided into the lithosphere and asthenosphere. This is based on differences inmechanical properties and in the method for the transfer of heat. Mechanically, the lithosphere is cooler and more rigid, while the asthenosphere is hotter and flows more easily. In terms of heat transfer, the lithosphere loses heat byconduction, whereas the asthenosphere also transfers heat by convection and has a nearly adiabatic temperature gradient.
