Answer:
Convection in the asthenosphere.
Explanation:
Convection in the asthenosphere
Heat which is present in the Earth maintain the malleability of the asthenosphere , and hence provides lubrication to the Earth's tectonic plates for movement .
The convection current that is generated in the asthenosphere , tries to push the magma upward via the vents that are present in the volcanoes and thereby spreads and create a new crust .
And this generates a hotspots on the Earth's crust .
