Matching the technology at the surface to the geology of the substrate:
This figure illustrates the levels at which refined geophysical studies can differentiate among various subsurface situations. The "or" at each junction is based on the results of one or more specific geophysical surveys that enable the interpreter to discriminate between two or more possible cases. Each geophysical tool has unique strengths (and weaknesses) at each level of investigation that need to be assessed when planning the survey(s) and, ultimately, when interpreting the results.

Elements of Geophysical Methods Relevant to Environmental and Groundwater Investigations