The role of gravitational potential energy in active deformation in the southwestern United States

In orogenic belts, intrinsic (buoyancy) and extrinsic (boundary) forces act on the continental lithosphere; determining the relative importance of these forces is fundamental to understanding the dynamics of continental deformation. In the western United States, estimates of gravitational potential energy show that, given available constraints on rheology, buoyancy forces are sufficient to produce the wide variety of rates and styles of observed deformation, including absence of deformation. This underscores the importance of gravitational potential energy for deformation in orogenic belts.