Global Stream description:
The overall objective of the Global research stream is to develop dynamic Earth models and quantify the effect of dynamic topography on basin evolution. A series of projects focusing on key aspects of the geodynamics, tectonics and surface processes are detailed below:
1- The role of subduction-driven dynamic topography on the vertical motions of rigid plates
2- The role of mantle plumes on the topography of tectonically-active regions
Currently, five permanents researchers, four postdoctoral researchers, and 4 Ph.D. students are working on these different sub-projects:
3- To develop and improve the Global paleogeographic digital model.
4- To quantify the role of dynamic topography and lithospheric deformation on the topography of -active regions
5- The application of 3D Underworld-Badlands coupled models for different tectonic settings in rift and convergent margin settings.
The use of different scales modelling is needed to answer the previous geodynamic questions.
The software GPlates, pyGplates, CitcomS, and StagYY are used to investigate the global geodynamics subprojects. Two sets of mantle convection models, also called 4d virtual Earth, have been developed. The first one, the CitcomS geodynamic models, contains mantle upwellings and reconstruction velocities as well as stretching maps for different regions, like the North Atlantic Margins. It allows to link surface and mantle dynamics. The workflow to connect GPlates and CitcomS model output is completed and published on GitHub. The second set of virtual Earth, created with the code StagYY, have been used to link the spatial distribution of dynamic topography and the Earth’s geodynamic wavelengths.
The GPlates database is in continuous development with the publication of reconstruction refinements and new maps as paleogeographic and contourite maps. All the database is available on the Earthbyte website. A new global plate motion model including deformation along rifts and orogens with revised absolute plate motions optimized with regard to hotspot tracks, lithospheric net rotation and trench migration for last 240 million years is also available on the Earthbyte website. New sea-level curves have been created from Jurassic to Present have been digitized. Both the long-term and short-term sea-level curves will allow better sea level estimations in surface processes models.
To answer sub-surface deformation and how deep mantle wavelength influence the evolution of sedimentary basins, two codes are used: Badlands and Underworld.
A lot of surface processes models are available on Badlands GitHub. New tools have been developed to study the evolution of basin filling together with lithospheric deformation and a submarine incision capability.
Underworld 2D models are used to quantify the impact of lateral asthenospheric flow on the plates topography, especially to explain the Neogene tilting of the Indian peninsula and Eocene tilting of the Australian plate. New functionalities have been added in the UWGeodynamics open source code, which allow to generate 3D geometries and to solve the horizontal advection in the Badlands/Underworld models. The first 3D Underworld models fully coupled with the surface processes code Badlands have been created to study the filling of sedimentary basins in 2 tectonic contexts: Rift margin evolution and Pull-apart basin setting up.