It is the concept of isostasy.
isostasy
Its floating on a liquid.
convection currents in the upper mantle
convection currents in the upper mantle
it is floating on it
The crust lies on top of the mantle because it is composed of less dense materials than the mantle is. The crust is essentially floating on the mantle.
because they are floating on top of a liquid mantle
They are called tectonic plates.
how the thin outer crust is floating on the thick liquid mantle, causing the crust to move and form a divergent plate boundary
Tectonic plates.
The plates of crustal rock floating on the mantle rockand being moved by the flow of mantle rock in convection cells driven by the heating of radioactive decay deep in the core and lower mantle.
isostasy