Prevalence of Power Law Profiles in Passive Margin Escarpments

Abstract

An analysis of elevation data from several great escarpment regions across the globe revealed a prevalence of inverse power law forms among the escarpment profiles. The best fit power law exponent varies among profiles and has a global median value of 0.9 and standard deviation of 1.8. The power law form is consistent with the shape of a detachment-limited escarpment that is retreating headward while maintaining a constant shape. Such a constant-shape evolution requires the local denudation rate to be equal to the product of escarpment retreat rate and local slope. The available basin-averaged denudation rate data from several great escarpment regions are consistent with this constraint, and this allows estimation of the recent retreat rates of the escarpments within the constant-shape assumption.