th
Departmental Seminars: http://www3.imperial.ac.uk/earthscienceandengineering/research/seminars
Abstract
Glaciers and rivers control the shape of the high relief topography of mountain ranges. However, their relative contribution in response to climatic oscillations and tectonic forcing and whether landscape can reach equilibrium conditions during the Quaternary are still unclear.
In this talk, I will first present how we quantify rates of erosion from a global to local scale using lowtemperature thermochronology. In turn, these results help us develop a novel glacial erosion model which includes subglacial hydrology unlike previous models. This new model suggests that the distribution of glacial erosion is bimodal; with a first peak at the equilibrium line altitude and a second at much lower altitudes within the ablation area where water due to melting abounds. This has important implications because it explains why glacial erosion can simultaneously set a limit on the mean elevation of mountain ranges and carve large fjords or glacial lakes. Second, by combining the landscape evolution modelling results with erosion rates inferred from thermochronological data in the
Alps and Alaska, I will illustrate the role of tectonics in modulating changes in erosion rates in response to climatic variations.