Topography as a proxy for inter-plate coupling

The topography of active mountain belts is shaped by long-term crustal deformation and strain from tectonic plates. To test this hypothesis, we correlated mean topography, topographic slope and GPS derived strain rates along the active orogenic belts of South America (Ecuador and northern Peru segments), where relatively rapid convergence occurs between the Nazca and South America plates. Our results show that the Ecuador and northern Peru segments follow well-defined power-law relation with distinct exponents that are consistent with the nonlinear deformation associated with dislocation-creep occurring at depth. We propose that the depth of dislocation-creep and distinct power-law exponents have first order control over mean topography, and that the topographic slope can be used as proxy for inter-plate coupling.