Quantifying the impact of climate and tectonic gradients on landscape evolution across timescales: Explicit integration of cosmogenic radio nuclide and thermochronometric data in numerical landscape evolution models.

The evolution of the earth surface holds clues on the interaction between uplift and climate. Uplift builds topography and climate mediates erosion processes that break topography down. However, reconstructing earth surface evolution is far from evident given the large spatial and temporal timescales at play. Technological innovations now allow to measure erosion rates at different timescales. Nonetheless, these observations are typically derived at point locations thereby only covering a fraction of the Earth’s surface.  Moreover, they are difficult to compare directly as they integrate over different time scales. We propose the use of a process based model to bridge the spatial and temporal scales covered by observations. As a proof of concept, we already performed a small scale study showing that process based models indeed allow to explain spatial variation in millennial erosion rates much better than widely used statistical models. In this proposal we plan to scale this first experiment up to much longer temporal (>70 Myr) and bigger spatial scales. We aim to do this by explicitly integrating data covering different timescales in our numerical models. If we succeed, this is a major step forward in our understanding of the Earth surface. Our modelling approach would, for a first time, allow to reproduce a virtually continuous reconstruction of the Earth surface based on a joint integration of topography and observations covering 100 to several millions of years.