How is earths crust able to stay balanced on the mantle?

The Earth's crust remains balanced on the mantle due to isostasy, a principle that describes how the crust floats on the denser, semi-fluid mantle beneath it. Variations in crustal thickness and density create buoyancy forces that ensure equilibrium. When tectonic forces cause changes in the crust, such as mountain building or erosion, the crust adjusts its elevation to maintain this balance. This dynamic equilibrium allows the crust to remain stable despite ongoing geological processes.