Bayesian Estimation of Surface Strain Rates in the Peri-Adriatic, Balkans and Aegean region from GNSS Velocities

The calculation of spatial derivatives of the lithosphere surface velocity field has become a routine task in geosciences. It provides a continuous description of strain rates characteristics (dilation, rotation, strain rate intensity, etc) and facilitates the comparison between observed strain and theoretical strain computed from rigid or viscous lithospheric deformation models. However, this derivation is highly non-unique and standard methods may fail at correctly computing the strain rate tensor. This is especially the case in regions with strong spatial heterogeneities in strain rates like the Balkans, significantly limiting the understanding of their geodynamics. We tackle this issue in the peri-Adriatic and western Aegean region, using the bayesian transdimensional approach implemented in the B-Strain code, successfully applied in California. We show that our results, providing reliable probabilistic estimates of strain rates all over the region, are less prone to interpolation artifact than those produced from standard techniques, opening new perspectives for modeling and understanding the forces at play in this seismically active region of Europe.