GNGTS 2015 - Atti del 34° Convegno Nazionale

GNGTS 2015 S essione 3.3 151 due to rock-fluid interaction. Within certain limits, the higher is the volume percent of alteration products occluding rock fissures and pores, the higher is m . For the examined SRP field case, high m values, up to 0.95, have been required to model the MT profile, fully consistent with values found in other volcanic and geothermal environments (Patella et al. , 1991; Coppola et al. , 1993; Giammetti et al. , 1996; Di Maio et al ., 2000; Mauriello et al. , 2000, 2004). We thus feel we can consider the 3D refinement of the original 2D model as an evidence of the greater accuracy that can be reached by a 3D approach to the interpretation of MT data supposed to be affected by dispersive effects. References Berton, J. and J. Loeb, 1976, Experimental and Theoretical Aspects of Induced Polarization , Gebrüder- Borntraeger, Berlin-Stuttgart. Chang-Chin, Y., and L. Bin, 1994, The research on the 3D TDEM modeling and IP effect, Chinese J. Geophys., S2, P.631.3, CJFDTotal-DQWX4S2.053. Cole, K.S. and R.H. Cole, 1941, Dispersion and absorption in dielectrics. Part I. Alternating current characteristics, J. Chem. Phys ., 9 , 341-351, do: 10.1063/1.1750906. Coppola, B., R. Di Maio, I. Marini, A. Merla, D. Patella, G. Pulelli, F. M. Rossi, and A. Siniscalchi, “Study of the Simplon area geothermal anomaly in the frame of a transalpine deep railway tunnel feasibility project,” Underground Transportation Infrastructures, 93–102, ed. J. L. Reith, Balkema, Rotterdam, 1993. Di Maio, R., P. Mauriello, D. Patella, Z. Petrillo, S. Piscitelli, A. Siniscalchi, and M. Veneruso, “Self-potential, geoelectric and magnetotelluric studies in Italian active volcanic areas,” Ann. Geofis., Vol. 40, 519–537, 1997. Di Maio, R., D. Patella, Z. Petrillo, A. Siniscalchi, G. Cecere, and P. de Martino, “Application of electric and electromagnetic methods to the study of the Phlegrean Fields caldera,” Ann. Geofis., Vol. 43, 375-390, 2000. Esposito, R., and D. Patella, 2009, The role of the impedivity in the magnetotelluric response, PIER, 89, 225-253, doi: 10.2528/PIER081 21203. Fink, J.B., E.O. McAlister, B.K. Sternberg, W.G. Wieduwilt and S.H. Ward (eds.), 1990, Induced Polarization: Applications and Case Histories , Investigations in Geophysics, 4 , SEG, Tulsa, Oklahoma. Fig. 3 – The Snake River Plain MT TM and TE synthetic pseudosections, reconstructed from the 3D model in Fig. 2 at the top and at the bottom the misfit between the observed MT TM and TE pseudosections and the synthetic ones.