Discussion: On 'Negative apparent resistivity in dipole-dipole electrical surveys' (Jung, H.K., Min, D.J., Lee, H.S., Oh, S.H., and Chung, H., Exploration Geophysics, 40, 33-40)

摘要

The DC resistivity method is a well known geophysical exploration technique and is widely applied in mining exploration, groundwater surveys, and engineering and environmental investigations. Negative apparent resistivities, especially in 2D surface dipole-dipole surveys, are often observed and generally have been regarded as measurement errors or the effect of noise. Cho et al. (2002) insisted that if the earth is isotropic and flat, and the survey line is straight, apparent resistivity is always positive regardless of subsurface structures.