The surface on which lithospheric plates move around Earth's surface is called the asthenosphere.

Here's why:

* Lithosphere: The rigid outer layer of Earth, consisting of the crust and the uppermost part of the mantle.

* Asthenosphere: A soft, partially molten layer within the upper mantle. It behaves like a very viscous fluid, allowing the lithospheric plates to move on top of it.

The movement of lithospheric plates on the asthenosphere is driven by convection currents within the mantle. These currents are caused by heat from the Earth's core, which causes hot, less dense material to rise, while cooler, denser material sinks. This cycle drags the lithospheric plates along with it, resulting in the phenomena of plate tectonics, including earthquakes, volcanic eruptions, and mountain formation.