High-resolution static corrections derived from surface-wave tomography: Application to mineral exploration

In hard-rock mineral exploration using reflection seismics, standard methods to estimate the static corrections based on the analysis of seismic body waves, might be ineffective due to near-surface complexities. A workflow to estimate the P-wave statics based on high-resolution surface-wave tomography is adopted. We combine the S-wave velocity model retrieved by surface-wave tomography, a method known for its high resolution, with the Poisson s ratio estimated by the Wavelength-Depth method, a technique based on the analysis of skin depth of surface waves. We apply the workflow to a 2D data set recorded at a phosphate mining site in Finland and to a 2D data set acquired at an iron-oxide mining site in Sweden. The retrieved models and statics are evaluated using prior information and the stacked sections are compared with the ones resulting after standard body-wave statics. Improvement in the continuity of deep reflectors and increase in the extent and in the amplitude of the horizon associated to the orebody are evident in the stacked section whose statics were computed with the proposed workflow that we call Surface-Wave Tomostatics.