Predicting present-day Earth’s lithospheric stress using analytical upper mantle flow models

Understanding the internal dynamics, structure, and composition of our planet is a fundamental goal of Earth science, and geodynamic modelling has been central to this effort by providing a theoretical window into mantle convection. Moreover, the asthenosphere plays a key role in linking mantle dynamics to surface observations; its channelized nature allows it to be described analytically within the framework of Couette and Poiseuille flow regimes.

Using this framework, we predict global stress fields and compare them directly with observations from the World Stress Map (WSM), a global compilation of crustal stress indicators. Our approach enables fast hypothesis testing and the development of first-order expectations for how different mantle flow states influence surface stress patterns. It also identifies three distinct basal shear traction regimes, depending on whether the asthenosphere locally moves faster than, slower than, or at the same velocity as the overlying plate. As a result, some regions experience driving tractions, others resisting tractions, while some are nearly traction-free. These results show that stress field patterns cannot be explained without realistic upper mantle flow geometries, particularly the spatial distribution and combined effects of plumes, slabs, and plate-driven flow.