The asthenosphere is weaker and less rigid than the overlying lithosphere.
Explanation:
The asthenosphere is the layer of the earth below the lithosphere. It is a solid rock layer that has so much pressure and heat that rocks can flow like a liquid.
The asthenosphere rocks are less dense than the lithosphere rocks. This allows the tectonic plates in the lithosphere to move on the Earth's surface "floating" over slowly flowing rocks.
