Answer:
Movement of the Asthenosphere
Explanation:
The Asthenosphere is the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur. This convention causes warmer magma in the earth's core to rise and cooler to fall and be heated again. The circular motion caused by this convection is what is thought to cause the Earth's crust to move.
