Answer:
The internal heat source and the external heat source(sun)
Explanation:
The two sources of energy that powers processes on earth are classified into the internal and external heat sources.
These heat sources powers the internal heat engine and the external heat engine.
The internal heat sources causes earthquake, igneous activities, mantle convection e.t.c. Internal heat sources are derieved from:
- Primordial heat during the formation of the earth
- Radioactivity in the crust
- Frictional heating from movement of different layers of the earth
- Geothermal gradient
The external heat sources provides energy for living processes, drives agent of denudation to work, warms the surface of the earth. The ultimate source of energy for external processes is the sun
