  We present a new method to invert variable stress changes of fractures from
InSAR ground displacements. Fractures can be either faults or magma intrusions,
embeded in a 3D heterogeneous crust with prominent topographies. The method is
based on a fictituous domain approach using a finite element discretization of
XFEM type. A cost function involves the misfit between the solution of the
physical problem and the observed data together with the smoothing terms.
Regularization parameters are determined by using L-curves. The method is then
reformulated to be applied to InSAR data (masked and noisy), projected in
Earth-Satellite directions. Synthetic tests confirm the efficiency and
effectiveness of our method.
