GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 3.3 GNGTS 2024 where the subscript j indicates that the inversion process can be split in diferent inversion cycles: in each cycle j it is possible to change the forward computaton for each dataset (e.g., from 1-D to 3-D), as well as to insert/remove data/constraints from the objectve functon (Fiandaca et al., 2023). However, when using the resistvity and IP method to map subsurface geological structures with complex geometries, 1-D and 2-D inversion schemes are not always sufcient and 3-D modelling and inversion of the data are required. For this reason, EEMverter is also developed for 3-D inversion, following Madsen et al., (2020). To discretze the 3-D problem, a combined triple-grid inversion approach (presented by Günther et al. 2006) is adopted: a coarse tetrahedral mesh is used for the inversion (the model mesh) and two fner discretzed tetrahedral meshes (one for the primary potental feld and one for the secondary potental feld) are used to compute the forward responses, balancing the modelling accuracy, the computatonal speed and memory usage. The results of the 2-D implementaton on synthetc and feld data, as well as the 3-D implementaton under development, will be presented at the conference. References Binley, A. (2015). DC electrical methods. Cole, K.S. & Cole, R.H., (1941). Dispersion and absorpton in dielectrics I. Alternatng current characteristcs, J. Chem. Phys., 9, 341–351. Fiandaca, G., Auken, E., Gazoty, A. & Christansen, A.V., (2012). Time-domain induced polarizaton: full-decay forward modeling and 1D laterally constrained inversion of Cole-Cole parameters, Geophysics, 77, E213–E225. Fiandaca, G., Ramm, J., Binley, A., Gazoty, A., Christansen, A. V., & Auken, E. (2013). Resolving spectral informaton from tme domain induced polarizaton data through 2-D inversion. Geophysical Journal Internatonal , 192 (2), 631-646. Fiandaca G., Christansen A. and Auken E. (2015). Depth of investgaton for mult-parameters inversions. Near Surface Geoscience 2015–21st European meetng of environmental and engineering geophysics. Fiandaca, G., Madsen, L.M. & Maurya, P.K., (2018). Re-parameterisatons of the Cole–Cole model for improved spectral inversion of induced polarizaton data, Near Surf. Geophys., 16 (4), 385–399. Fiandaca, G., Zhang, B., Chen, J., Signora, A., Daut, F., Galli, S., Sullivan, N.A.L., Bollino, A., Viezzoli, A. (2024). EEMverter, a new 1D/2D/3D inversion tool for Electric and Electromagnetc data with focus on Induced Polarizaton. GNGTS 2024, 13-16 February 2024, Ferrara, Italy. Fiterman, D. V., & Anderson, W. L. (1987). Efect of transmiter turn-of tme on transient soundings. Geoexploraton , 24 (2), 131-146. Gazoty, A., Fiandaca, G., Pedersen, J., Auken, E., Christansen, A.V. & Pedersen, J.K., (2012). Applicaton of tme domain induced polarizaton to the mapping of lithotypes in a landfll site, Hydrol. Earth Syst. Sci., 16, 1793–1804. Günther, T., R¨ucker, C. & Spitzer, K., 2006. Three-dimensional modelling and inversion of dc resistvity data incorporatng topography - II. Inversion, Geophys. J. Int., 166, 506–517.