Mining applications of seismic tomography

CIM Bulletin, Vol. 87, No. 977, 1994

W.J. McGaughey, R.G. McCreary, Noranda Technology Centre, Pointe Claire, Quebec R.P. Young and S.C. Maxwell, Queen's University, Kingston, Ontario

Seismic tomography is a process for obtaining images or maps of seismic velocity or other seismic properties of a rock mass. Seismic velocity images reveal variation in elastic moduli which, in turn, are related to several properties required in the geological or geo-mechanical assessment of a rock mass. Seismic velocity is sensitive to lithology, discontinuities, and in situ stress. Spatial or temporal variation of these properties may be indirectly assessed. Tomographic measurements are sensitive to volumes of ground, rather than determinations at points, or along lines or surfaces, as in conventional geological or geomechanical measurements or mappings. Tomography surveys are complementary to conventional measurements as they have the capability to interrogate a substantially larger volume of ground. They are thus useful in discerning trends or patterns in regions between or surrounding conventional "point" measurements of lithology, rock quality, stress, or other parameters of interest. Seismic velocity images give broad indications of trends in velocity; their spatial resolution of ground properties is typically on the order of five to ten per cent of the nominal survey dimension.

Keywords: Geophysics, Rock mechanics, Seismic tomography, Micro-seismic, Stress, Research and development.