Research Projects

The project aims to understand the interaction between magmatism and tectonics in oceanic settings. Motivated by the most recent observations from the ocean floor, we plan to develop physics-based models that capture the details of magma generation in the mantle and how it travels to the surface to create and shape the seafloor. Funding awarded by the Royal Society between 2024-2031.

A classic problem in geophysics, what is the nature of the lithosphere-asthenosphere boundary (LAB)? The LAB is the boundary between tectonic plates and the convecting mantle below, but also marks a transition between heat transport by conduction in the lithosphere and by convection in the asthenosphere. Multiple geophysical observations suggest a weaker and shallower LAB. Small melt fractions enriched in volatiles (water, carbon dioxide) may explain these geophysical observations and the geochemistry of intraplate volcanoes. Right: two-phase flow models show how volatile-assisted melting impacts convective flow in the asthenosphere.

Mid-ocean ridge are tectonic plate boundaries where most of magmatism on Earth occurs. In the classical view, the partially molten region extends symmetrically beneath the ridge axis. Observations, instead, show significant degree of asymmetry at various mid-ocean ridges. Here, we developed a mid-ocean ridge model to investigate buoyancy-driven flow due to porosity, composition, and temperature. Right: simulation showing development of asymmetry beneath the ridge axis and small-scale convection at the lithosphere-asthenosphere boundary. Top panel represents melt fraction (porosity); bottom panel represents bulk density relative to reference solid mantle.

How does magmatism promote and shape rifts in continental and oceanic lithosphere? In this project (PI Richard Katz, U. Oxford), we focused on magma generation and transport at spreading ridges, but also on deformation of the host rock to investigate processes such as diking and faulting. We also developed numerical tools (FD-PDE framework) that are suitable for magma dynamics theory with visco-elasto-plastic rheology. (2019-2024)

During the COVID pandemic, we (the authors) transformed a short EGU course into this collaborative perspectives paper on methods, practices, and philosophy of geodynamic modelling. The paper aims to be an introduction to geodynamic modelling for students and non-geodynamicists, but also invites feedback from a more expert audience.

Subduction zones represent the only major pathway by which continental material (sediments) can be returned to the Earth's mantle. When sediments are considered, convergent margins appear to fall into one of two classes: accretionary and erosive. In this study, we run 2-D subduction simulations to investigate how sediment fluxes influence subduction dynamics and plate coupling.

Same-dip double subduction is a special tectonic configuration, where two slabs dip in the same direction. Examples exist for the India-Asia and the present day Ryukyu-Izu-Bonin-Mariana (Pacific, Philippines Sea Plates) settings. We run 2-D and 3-D models to investigate the formation and stability of double subduction, and we propose a new sequence of events for the India-Asia convergence history.

The Himalayas, the Tibetan Plateau, or the Andes are remarkable features on the surface of the Earth. However, it is unclear how they formed or why they are so high. In this project, we ran lots of 3-D simulations of subduction/collision to understand how high topography (>5km) is formed. And it turns out it's not so easy to build topography in numerical models. However, we do provide semi-analytical insights on the conditions necessary for building high mountains and plateaus.

Rocks deform in a visco-elasto-plastic manner, which is difficult to solve numerically (nonlinear system) and the coefficients are poorly constrained from observations and laboratory experiments. So, previous numerical studies used various approximations for rock rheology. In this study, we investigate the effect of such rheological approximations in a 3-D subduction/collision model.

Part of our research involves developing the numerical techniques employed. By knowing and mastering the tools we are using, our work can achieve far better quality, a principle we try to follow and instill in others. Topics: numerical methods for single/two-phase flow theory, finite difference discretisation scheme, non-linear solvers for complex rheology.