GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.2 GNGTS 2024 Conclusions The results presented in this study are surprising: in a two-layer environment with a chargeable cover over a resistve bedrock, even small chargeability values (e.g. 10 mV/V) creates signifcant efect in the responses measurable with the portable Loupe System, also with detectable data change of sign. Furthermore, these efects are not confned to low values of the tme constant of the Cole-Cole model (e.g. below 1 ms), but persist also for tau values in the range of seconds. These results imply that the IP efect cannot be overlooked when operatng with the Loupe system, for instance in surveys involving mine wastes, permafrost and weathered covers over bedrock on mountainous areas. References Auken E., Christansen A.V., Kirkegaard C., Fiandaca G., Schamper C., Behroozmand A.A., Binley A., Nielsen E., Eferso F., Christensen N.B., Sorensen K., Foged N. & Vignoli G., 2015. An overview of a highly versatle forward and stable inverse algorithm for airborne, ground-based and borehole electromagnetc and electric data, Exploraton Geophysics, 46, 223-235. 10.1071/eg13097 Couto Junior, M. A., Fiandaca, G., Maurya, P. K., Christansen, A. V., Porsani, J. L., & Auken, E. (2020). AEMIP robust inversion using maximum phase angle Cole–Cole model re- parameterisaton applied for HTEM survey over Lamego gold mine, Quadrilátero Ferrífero, MG, Brazil. Exploraton Geophysics, 51(1), 170-183. Grombacher, D., Auken, E., Foged, N., Bording, T., Foley, N., Doran, P. T., ... & Tulaczyk, S., 2021. Induced polarizaton efects in airborne transient electromagnetc data collected in the McMurdo Dry Valleys, Antarctca. Geophysical Journal Internatonal, 226(3), 1574-1583. Lee, T., 1981. Transient electromagnetc response of a polarizable ground. Geophysics, 46,7, 1037-1041. Lin, C., Fiandaca, G., Auken, E., Couto, M. A., & Christansen, A. V., 2019. A discussion of 2D induced polarizaton efects in airborne electromagnetc and inversion with a robust 1D laterally constrained inversion scheme. Geophysics, 84(2), E75-E88. Pelton, W. H., Rijo, L., & Swif Jr, C. M., 1978. Inversion of two-dimensional resistvity and induced- polarizaton data. Geophysics, 43(4), 788-803. Spies, B.R., 1980. A feld occurrence of sign reversals with the transient electromagnetc method. Geophysical Prospectng, 28, 620-632. Street, G., Duncan, A., Fullagar, P., Tresidder, R., 2018. LOUPE – A Portable EM Profling System. System, ASEG Extended Abstracts, 2018:1, 1-3, DOI: 10.1071/ASEG2018abW10_3G. Viezzoli, A., Kaminski, V., Fiandaca, G., 2017. Modeling induced polarizaton efects in helicopter TEM data: Synthetc case studies. Geophysics, (82-2) E31-E50. Reference Author: Francesco Daut, francesco.daut@unimi.it