The ERD-Alps project aims to develop an integrated study of surface processes and relief evolution in the western Alps by combining observational studies of actualistic processes with proxy records and numerical models for the evolution of relief and denudation rates on different timescales. Our aim is to provide detailed quantitative constraints on rates and mechanisms of relief change in the western Alps on three different interlocked timescales: (1) present-day and Holocene; (2) Pliocene-Quaternary (post-5 Ma); (3) Late Cainozoic (post-30 Ma). Three teams consisting of members from the different partner institutes collaborate in studying each timescale. Each of these studies will provide unique datasets that will be used to constrain the others.
On the shortest timescale, we collect high-resolution data on the spatial and temporal distribution of erosion rates. Because of the strong imprint of Quaternary glaciations on the current topography of the western Alps, and because glacial erosion remains one of the least understood and quantified mechanisms for relief development, a strong emphasis will be on studying the effects of glacial erosion. These data will provide first-order constraints on the efficiency of erosional mechanisms, which will be used to interpret the denudation rates inferred on longer time scales, as well as for calibrating numerical surface-process models of relief development.
On the intermediate timescale (Pliocene/Quaternary), we aim to elucidate the mechanisms leading to recent increased denudation rates in the western Alps. This study will provide the boundary conditions for interpreting the short-term spatial variations in erosion rates. It will be constrained both by process rates inferred from the short-timescale study and by the long-term study which will provide the initial relief and drainage patterns on which increased denudation rates were superposed.
The long-term (post-30 Ma) study will provide quantitative constraints on relief and drainage development of the western Alps since the onset of collision, with important implications for sediment supply to basins as well as regional paleoclimate conditions.