Numerical Simulations of Mantle Convection and Plate Tectonics in the Earth and Planets: From Magma Oceans to Present Day

The coupled system of convection of the Earth’s solid mantle and plate tectonics is the driver of geological change on our planet, including continental drift, volcanoes, earthquakes, crustal production, atmospheric degassing the recycling, and cooling of the core, which drives the geodynamo. Modelling of this process is challenging due to the wide range of length scales (from faults to continents) and time scales (seconds to billions of years) and the complex rheology of rocks, which exhibit visco-elasto-plastic behaviour with strongly temperature-dependent viscosity varying by orders of magnitude over short length scales. Nevertheless, it is now routine to perform global-scale 3-D spherical simulations that span the 4.5 billion year age of our planet and contain complex effects such as partial melting and crustal production and solid-solid phase transitions.
StagYY [1] is one of the leading codes for performing such simulations. It uses a finite-volume discretization on a yin-yang spherical grid. Both built-in geometric multigrid, and the range of solvers available through PETSc, can be used. Here, technical details will be discussed, including recent enhancements made with funding from the Swiss Platform for Advanced Scientific Computing (PASC) project. Recent scientific results on contrasting tectonic regimes and the long-term evolution of Earth, solar system planets and exoplanets will be presented [2-4].

[1] Tackley, P. J. (2008) Phys. Earth Planet. Int., doi:10.1016/j.pepi.2008.1008.1005.
[2] Lourenço, D. L., A. B. Rozel, T. Gerya, and P. J. Tackley (2018) Nature Geoscience, doi:10.1038/s41561-018-0094-8.
[3] Rozel, A. B., G. J. Golabek, C. Jain, P. J. Tackley, and T. Gerya (2017) Nature, doi:10.1038/nature22042.
[4] Tackley, P. J., M. Ammann, J. P. Brodholt, D. P. Dobson, and D. Valencia (2013) Icarus, doi:http://dx.doi.org/10.1016/j.icarus.2013.03.013.