Lithospheric plates float on the uppermost part of the mantle called the
Which sphere do the plates of the lithosphere float on?
In effect, the lithosphere floats on the asthenosphere "carrying" the lithospheric plates that are constantly changing position. In 1929, about the time Wegener's ideas began to be dismissed, Arthur Holmes elaborated on one of Wegener's many hypotheses; the idea that the mantle undergoes thermal convection.
Why does lithosphere float on asthenosphere?
Since the Lithosphere has a lower density, it floats on top of the Asthenosphere similar to the way in which an iceberg or a block of wood floats on water. The lower mantle below the Asthenosphere is more rigid and less plastic.
