Centre Européen
de Recherche et d'Enseignement
des Géosciences de l'Environnement

The nonunique nature of lithologic and climatic controls on topographic evolution

Dans le cadre du CYCLE DES GRANDS SÉMINAIRES, Joel P.L. Johnson, Associate Professor à l'Université du Texas à Austin au Département de Géologie, interviendra jeudi 9 juin 2022 à 13h.

Feedbacks between landscape erosion, climate, and tectonics are thought to be fundamental to the evolution of Earth’s surface and environmental conditions.  However, we have significant knowledge gaps in understanding mechanistically what controls the strength—and therefore the significance--of these feedbacks. In this talk, I will explore different ways in which climate and lithology influence fluvial bedrock erodibility. Erodibility is a model-dependent parameter that scales hydraulic forcing to bedrock erosion. I argue that chemical weathering, rock strength changes, and sediment production can make relationships between topography and erodibility nonunique. This in turn explains how the strength of climate-erosion coupling can be different in different places, mediated by lithology.  Field studies from the Kohala Peninsula, Hawai’i and the Guadalupe Mountains, New Mexico and Texas, USA, as well as landscape evolution modeling, are used to explore specific climatic, lithologic, and sediment supply controls on topographic evolution.

Séminaires de haut niveau en lien avec les thématiques du laboratoire.

Ampithéâtre Bâtiment Pasteur CEREGE