HR: 0802h
AN: NS11C-0697    [Abstracts]
TI: Electromagnetic Coupling in Spectral Induced Polarization Data
AU: * Klitzsch, N
EM: klitzsch@geophysik.rwth-aachen.de
AF: RWTH Aachen University Applied Geophysics and Geothermal Energy, Locnerstr. 4-20, Aachen, 52056, Germany
AU: Pawlik, A
EM: a.pawlik@geophysik.rwth-aachen.de
AF: RWTH Aachen University Applied Geophysics and Geothermal Energy, Locnerstr. 4-20, Aachen, 52056, Germany
AU: Rath, V
EM: v.rath@geophysik.rwth-aachen.de
AF: RWTH Aachen University Applied Geophysics and Geothermal Energy, Locnerstr. 4-20, Aachen, 52056, Germany
AB: Spectral induced polarisation (SIP) can be applied to derive hydraulic permeabilities by using the complete spectral information, i.e., by analyzing the frequency dependence (typically in the range from 1 mHz to 10 kHz) in terms of relaxation times. The relation between the Cole Cole relaxation time and the hydraulic conductivity was deduced from laboratory measurements on sedimentary rocks. Unfortunately, this relation can not be directly used to derive hydraulic conductivities from field data because they are influenced by electromagnetic coupling. This is crucial even for small arrays and particularly for conductive environments and at high frequencies. Coupling occurs between the electric wires and the ground as well as among the wires themselves. We focus on inductive coupling of the current wires to the ground. The influence of inductive coupling will be shown. Furthermore, a method for the removal of the inductive coupling is introduced and applied for a field example.
DE: 0600 ELECTROMAGNETICS
DE: 0925 Magnetic and electrical methods (5109)
SC: Near-Surface Geophysics [NS]
MN: 2007 Fall Meeting