If the asthenosphere cooled and stopped flowing. how would you expect the movement of tectonic plates in the lithosphere to change? the tectonic plates would

If the asthenosphere cooled and stopped flowing. The movement of tectonic plates in the lithosphere  changes. The tectonic plateswould move  less than 2 cm a year.
> The asthenosphere is the highly viscous, mechanically weak and ductilely deforming region of the upper mantle of the Earth.

They both determine the exact age of rocks.