Why would a thickness of continental crust displace less mantle than the same thickness of oceanic crust?

Continental crust is generally thicker and less dense than oceanic crust, which is denser and thinner. When continental crust is added or displaced, it exerts less force on the underlying mantle due to its buoyancy, resulting in less mantle displacement. In contrast, the denser oceanic crust displaces more mantle when submerged or altered, leading to a greater effect on the mantle beneath it. This difference in density and buoyancy explains why the same thickness of continental crust displaces less mantle than oceanic crust.