Method and system to invert tectonic boundary or rock mass field in in-situ stress computation

A method to invert boundary conditions for rock mass field in-situ stress computation for a geologic structure comprising:

• a. building a numerical model from a geological model of the geologic structure;
• b. inputting source data measured from the geologic structure into the numerical model;
• c. computing gravitational stress of the geologic structure by gravitational loading;
• d. computing at least one tectonic stress induced by unit tectonic effect;
• e. solving normal equations of penalized weighted least squares, wherein the penalized weighted least squares method is represented by:
• f(β)=δ′V−1δ+ω·g(β), where δV−1δ represents the sums of weighted square errors, g(β) represents the penalty function, and ω is the penalty parameter;
• f. determining whether the end criterion has been reached and if not return to step d, and if the end criterion has been reached, proceed to step g;
• and
• g. outputting boundary conditions and compute and output final in-situ stress field of the geologic structure.