Climatic forcings in the desertic Andes

**Description of the project

"This project contributes to the environment of a post doc and is part of the transversal axis "Continental surfaces, physical and chemical forcings". Its objective is to study climatic forcing on the erosion of the Andes. In Peru, the region of Cañete in the Western Cordillera has been selected, lying between altitudes of about 4000 m and the base level of the Atacama on the Pacific slope in a hyper-arid climate. The marker of this erosion is in the form of megafans of several tens of km3 located on the Peruvian coast at the outlet of large canyons in the topography. These megafans have not yet been studied or even mapped. The example of Lima is striking because the city is installed on one of these giant cones. These alluvial megacones will be studied through high resolution (<1m) DTMs created by us to estimate their volumes, by coupling different cosmogenic and OSL nuclides (CRPG ²¹Ne, CEREGE ¹⁰Be ²⁶Al, GTC platform). The objective is to determine the erosion rates and the ages of the different transport events of these km3 of Andean sediments in order to link them or not to the initiation of the El Nino phenomenon, to the wet periods of the High Andes and to the last episode of Andean exhumation. This project involves members of the CYCLE and TRB teams, the GTC platform as well as our collaborators from IRD in Peru and CRPG in France".