Details of the Abstract
| Title of paper | Distorted Transient Electromagnetic data modelling |
| List of authors | F. Sharifi, B. Tezkan, I.M. Ibraheem, P. Yogeshwar |
| Affiliation(s) | Institute of Geophysics and Meteorology, University of Cologne, Germany |
| Summary | Observed transient electromagnetic (TEM) data are often distorted by IP effects as well as by the subsurface geometry. Therefore, a reliable interpretation needs to incorporate both effects into the data modelling. The objective of this study is to incorporate IP effects in a forward modelling and to be able to recover the IP parameters from distorted TEM data using an efficient inversion algorithm. To achieve this aim, we developed a 1D forward and inversion algorithm to investigate the incorporation of IP effects using different IP parameterizations including Cole-Cole, maximum phase angle (MPA), maximum imaginary conductivity (MIC) and the Jeffrey transform of Cole-Cole parameters. For the 1D inversion of IP-distorted TEM data we used the Levenberg-Marquardt (LM) algorithm. However, the result of the inversion strongly depends on the starting model. The result of 1D forward calculation and inversion of synthetic TEM data revealed that the Cole-Cole parametrization is more robust and reliable than MPA, MIC, and Jeffrey transform. Subsequently, we performed a 3D modelling study to better understand the effect of 3D geometry, which may cause a sign reversal in the TEM data similar to the IP effect. To evaluate the performance of our algorithm, we carried out a 1D inversion of TEM data acquired from a landfill located near Cologne, Germany. To obtain priori information and validate the results of TEM data modelling, we conducted an electrical resistivity tomography (ERT) and time-domain IP (TDIP) survey along the TEM profile. Subsequently, the retrieved Cole-Cole parameters from these data were used as input for TEM data interpretation. By including the IP information, the TEM field data can be explained quantitively, and a consistent and improved interpretation of the waste body is achieved. |
| Session Keyword | 2.0 EM theory, modelling and Inversion |
| File upload |
2.0_distorted_transient_elect_sharifi.pdf
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