New steps toward estimating the driving and resistive forces on the Eurasian plate

We aim to quantify the likely ranges of magnitudes and directions of forces that may explain present-day natural stresses within the Eurasian plate. We first focus on one of the driving forces, horizontal gravitational stresses (HGSs) resulting from lateral variations in gravitational potential energy, which are particularly relevant in the context of the Eurasian plate because there are no major slabs attached to it (i.e., no slab pull force). We show that different published models of lithospheric density including lateral variations in the lithosphere-asthenosphere boundary result in significantly different HGSs. Other driving forces are mantle convective tractions including dynamic topography, and plate interaction tractions with bounding plates. Second, we include observed major faults into a 2D spherical cap elastic model of the Eurasian plate. We show results of forward FEM calculations based on the best model parameters of Warners et al. (2013) and compare them with observed stress directions. We propose different objective functions that quantify the (relative contributions to the) misfit of the modelled and observed stresses, fault slip directions, and magnitudes, the deviation of the net torque on the plate from zero, and the model representation error. Our study represents a stepping stone towards a Bayesian inference workflow to constrain the dynamics of the Eurasian plate of which we show preliminary results.

Warners-Ruckstuhl, K. N., R. Govers, and R. Wortel, 2013, Tethyan collision forces and the stress field of the Eurasian Plate: Geophys. J. Int., v. 195, no. 1, p. 1–15, doi:10.1093/gji/ggt219.