Sparse laterally constrained inversion of surface wave dispersion curves via minimum gradient support regularization

We present a 1D laterally constrained inversion of surface wave dispersion curves based on the minimum gradient support regularization, which allows solutions with tunable sharpness in both vertical and horizontal directions. The forward modelling consists of a finite elements approach incorporated in a flexible non-parametric gradient-based inversion scheme, which has already demonstrated good stability and convergence capabilities when tested on other kinds of data. Our deterministic inversion procedure is performed in the shear-wave velocity log-space as we noticed that the associated Jacobian shows a reduced model dependency, and this, in turn, decreases the risks of local non-convexity. We show several synthetics and one field example to demonstrate the effectiveness and the applicability of the proposed approach.