Constraining mantle rheology with time-dependent convection

Last updated: August 2026

About

Mantle rheology controls the rate and style of mantle convection, yet the dominant deformation mechanism in the lower mantle remains uncertain. Linear diffusional creep was long favoured because the lower mantle shows little seismic anisotropy. Mineral-physics studies have proposed non-linear pure-climb creep as an alternative mechanism that can also avoid generating strong anisotropy.

This project will test how these competing rheological assumptions affect time-dependent mantle convection and its observable consequences. It will assess which predictions for seismic heterogeneity, dynamic topography, geoid structure, and mantle evolution are consistent with independent observations.

Research questions

• How do linear and non-linear lower-mantle rheologies change mantle-flow history?
• Which observables discriminate between competing deformation mechanisms?
• How do rheological assumptions affect the interpretation of present-day mantle structure?

Methods and data

Projects can use time-dependent mantle-convection models, mineral-physics constraints, seismic tomography, geoid observations, dynamic topography, and sensitivity analysis.

Possible projects

Possible directions include implementing alternative rheologies, comparing their time-dependent flow fields, evaluating predicted geoid and topography, or identifying observations that best distinguish the models.

Essential background

Useful preparation includes mineral physics, geodynamics, geophysics, physics, mathematics, programming, or numerical modelling.