Arthur Briaud Email and Phone Number

Due to its proximity to the Sun, the planet Mercury is subjected to strong tidal forces. The work is to becarried out within the framework of a project on "Measurement and Modeling of the Tidal Deformation of the Planet Mercury", which is funded by the DFG (German Research Foundation). The project is carried out in close collaboration with DLR (German Aerospace Center).

Lunar tidal Deformation from earth-based and orbital Laser Ranging (LDLR)

It is widely accepted that the gravitational instabilities of cold, dense, subducting lithospheres constitute the main driving force for plate tectonics. Unravelling the complex processes of subduction zones which originate from the down-going plate and its interplay with the surrounding mantle remains challenging. My PhD was focused on: (1) analysing how the surface fingerprint of the upper plate may be affected by the deep slab dynamics, especially once slabs starts to interact with the… Show more It is widely accepted that the gravitational instabilities of cold, dense, subducting lithospheres constitute the main driving force for plate tectonics. Unravelling the complex processes of subduction zones which originate from the down-going plate and its interplay with the surrounding mantle remains challenging. My PhD was focused on: (1) analysing how the surface fingerprint of the upper plate may be affected by the deep slab dynamics, especially once slabs starts to interact with the mantle transition zone. Thanks to 2D numerical models, it is systematically investigated the role of the mantle rheology as well as plate strength on the slab dynamics. Those different slabs dynamics depict that transient slab dynamics (i.e., slab avalanche) have a profound impact on the large-scale dynamic topography of the upper plate. Additionally, the dynamic topography shows a tilting of the upper plate towards and fromward the trench following the slab folding at depth. (2) 2D numerical outcomes which are exported to the analysis of the Neotethys subduction system, in particular of the central Iran from ~100 to 30 Ma. Results show that the slab folding behaviour into the transition zone is a reasonable scenario for explaining the particular episodic back-arc closure and opening of the central Iran as well as large-marine flooding events in the Eocene and early Miocene, before the onset of the collision. (3) 3D numerical models of subduction with the aim to understand if and how the slab may evolve lateral with simple model of flattening slab into the mantle transition zone. These models demonstrate that the width of the subduction system have an impact on the way that slab propagate down into the mantle in the centre of wide model domain and stagnate on the leading plate edge. Moreover, the lateral variability of slab morphology from penetrating to stagnation into the mantle transition zone control the dynamic topography of the upper plate. Show less