Which layer within the mantle is described as less rigid and behaving plastically over long time periods?

Answer

Asthenosphere

The asthenosphere is a distinct zone within the upper mantle characterized by its ability to flow slowly (plastic behavior), which is essential for driving plate tectonics.

Which layer within the mantle is described as less rigid and behaving plastically over long time periods?

#Videos

An Overview of Earth's Layers - YouTube

GeologyEarthstructurelayerprocess