What does isostasy refer to?

Isostasy describes the state of gravitational equilibrium between the Earth's crust and the underlying mantle. This concept explains how the lithosphere (the rigid outer layer of the Earth) floats on the more fluid asthenosphere below it, similar to how icebergs float in water. In this equilibrium, the crust's thickness and density influence its elevation. For instance, continental crust is thicker and less dense compared to oceanic crust, enabling continents to "float" higher on the mantle. Any changes to the weight on the crust, such as glacial melting or sediment accumulation, can cause adjustments in the elevation, maintaining this balance. Thus, the principle of isostasy is fundamental to understanding landscape changes, mountain formation, and the geological history of the Earth.