Description du projet
Le rôle du climat dans la dénudation des montagnes
Des recherches indiquent que les chaînes de montagne ne sont pas statiques, mais qu’elles évoluent (et réagissent) en fonction du climat et du soulèvement tectonique de la Terre. Les scientifiques débattent encore sur la manière dont ce processus d’érosion appelé dénudation (la fracture et l’arrachement des roches de la surface terrestre) est influencé par les variations du climat. Il s’agit d’une problématique complexe à résoudre, car aucune technique actuelle n’est capable d’analyser les variations des taux d’érosion pendant les périodes glaciaires et interglaciaires. Le projet ICED, financé par l’UE, mettra fin à ce débat en créant une chronologie de l’érosion rocheuse sur une période de 1 000 à 1 000 000 d’années. Cette méthode permettra de corréler pour la première fois les variations des taux d’érosion à des variations et processus météorologiques particuliers.
Objectif
Mountain ranges evolve in response to tectonic uplift, erosion and climatic change, but decoupling the feedbacks between these processes remains one of the most active debates in Earth Science. Resolving this debate is fundamental for successful projection of Earth’s surface response under a changing climate. The Impact of ClimatE on mountain Denudation remains highly contested because no technique is available to resolve changes in erosion rates over the timescale of glacial-interglacial cycles i.e. 10^3-6 years, a key time range for quantifying the role that silicate weathering and denudation plays in modulating global climatic change. ICED will resolve this debate through establishing time-series of rock erosion over 10^3-6 years, allowing erosion rate changes to be related to specific climatic changes, and specific processes, for the first time. These data will show whether tectonics or climatic feedbacks on surface processes are dominant in determining rates of surface denudation, providing insights into the influence of the lithosphere on global climatic change throughout the Quaternary period (ice age).
The objective of ICED will be achieved through the development and application of recently established thermochronometers based on the luminescence and electron spin resonance of quartz and feldspar minerals. Thermochronometers measure the rate of rock cooling, from which rates of rock exhumation and thus erosion rates can be calculated. Unlike existing methods, the new techniques developed within ICED are capable of resolving changes in erosion over timescales of between 10^3-6 years. Combining these new methods with cosmogenic nuclide data, using numerical models developed within ICED, will allow the generation of high-resolution time-series of erosion. The strategic application of these new techniques to the western European Alps will allow the Impact of ClimatE on mountain Denudation rates to be resolved for the first time.
Champ scientifique
Programme(s)
Thème(s)
Régime de financement
ERC-STG - Starting GrantInstitution d’accueil
1015 LAUSANNE
Suisse