ABSTRACT
Exploration geophysics is the science of “seeing” into the earth without digging or drilling. It is the Earth Science equivalent of medical radiology, and in an analogous fashion, employs a signal that passes through (or emanates from within) the earth to record variations in some physical property of the subsurface. This is done by measuring the signal at the ground surface, sending signal from boreholes to the surface, and/or sending signals between boreholes. In order to view different types of targets within the earth, geophysicists select from an array of signals/techniques encompassing seismic, gravimetric, and electrical/electromagnetic methods (see Table 9.1), with the choice of technique based on the physical properties of the features to be imaged.
