| Abstract: | In China geotomography has widely used in engineering projects since 1985. The technique of geotomography includes three fields, i.e., seismic, electromagnetic and resistivity tomography.Both corresponding instrumentation and software are developed be Chinese technicians. Seismic tomography is a powerful tool in industrial exploration. Combiming the information of velocity and Q-value images, We are able to identify the mineral and oil structure. As examples, the author presents some relevant results obtained from deep seismic sounding, mineral exploration and cross-borehole surveys in China.It seems that electromagnetic tomography is quite suitable to be used in metal and groundwater exploration, especial for limestone areas where the absorption coefficient of electromagnetic wave is small and geological body has a large property contrast with country rock It should be pointed out that there exit some uncertainties in geological interpretation of EM tomogram, corresponding laboratory tests for rock physical property ae always necessary.Resistivity tomography provides us a new useful tool especial in geotechnical engineering, due to borehole is no more a dispensable condition in the field observation. Electrode array can be placed on a undulating hills and fields, so that the technique has been adoped in many projects, for instances exploring groundwater, metal mine, faults, dam stability, basement structure and so on. The appearance of joint imaging of seismic and resistivity tomography is now an attractive technique, because the joint information of images can greatly decrease the uncertainties in geological interpretation.Geotomography has become an outstanding and advanced technique in geophysics. |
