Spectral Inversion of Capacitive Resistivity Data for the Investigation Frozen Ground
J. Mudler, G. Fiandaca, A. Hördt, C. Hauck, P.K. Maurya and A. Przyklenk
Event name: 23rd European Meeting of Environmental and Engineering Geophysics
Session: Cryosphere and Arctic Geophysics II
Publication date: 03 September 2017
Info: Extended abstract, PDF ( 1.31Mb )
Price: € 20
The capacitively coupled resistivity method measures frequency dependent electrical parameters in the frequency range between 1 Hz and 240 kHz. The method may potentially be useful for permafrost research, because the electrical permittivity of frozen ground and ice exhibits a characteristic frequency dependence. There is little experience with this type of measurement, as the equipment and appropriate inversion routines have only recently become available. Here, we present a case history from the Schilthorn mountain/Switzerland, where we acquired data with a dipole-dipole configuration along a profile of 28m length. A single site spectral inversion, in which we fit a Cole-Cole model to each of the configurations, yields pseudosections of five electrical parameters. We then apply a 2-D spectral inversion, which was extended to include the Cole-Cole permittivity inversion. The depth sections obtained this way are consistent with the pseudosections obtained from the single site inversions, which is taken as an indication for the robustness of the procedure. The electrical parameters basically reveal a 2-layered structure, consistent with the known snow cover over frozen ground. The excellent data quality and the consistency encourage further research into the extraction of parameters useful for permafrost research, such as ice content.