In geology, lithospheric flexure is the process by which the lithosphere bends under the action of forces such as the weight of a growing orogeny or changes in ice thickness related to glaciation. The lithosphere rests on the asthenosphere, a viscous layer that in geological time scales behaves like a fluid. Thus, when loaded, the lithosphere progressively reaches an isostatic equilibrium, which represents Archimedes' principle applied to geological settings.