Estimating exhumation rate and relief evolution by spectral analysis of age-elevation datasets

Extracting independent information on mean exhumation rate and the rate of surface relief change from thermochronometric datasets is essential to improve our understanding of the complex coupling between tectonics and surface erosion, i.e. the time-scale over which landforms react to changes in uplift rate and/or climate. A new method, based on spectral analysis of age-elevation data collected along one-dimensional profiles, is presented that provides independent estimates of the mean exhumation rate and the relative change in surface relief. The results are shown to be independent of the assumed geothermal gradient. The method is applied to an existing age dataset from the Sierra Nevada, California, and provides constraints on the evolution of the present-day relief. The spectral analysis demonstrates how current sampling strategies should be modified to optimize the tectonic and geomorphic information that can be retrieved from a thermochronometric dataset.