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

In hard-rock mineral exploration using reflection seismic imaging, 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 (SW) tomography is adopted. We combine the S-wave velocity model retrieved by SW 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 SWs. 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. Improvements in the continuity of deep reflectors and increase in the extent and the amplitude of the horizons associated with the orebodies are evident in the stacked sections whose statics are computed with our workflow that we call SW tomostatics.