Investigation of geothermal structures by magnetotellurics (MT): an example from the Mt. Amiata area, Italy

During 1999 a magnetotelluric (MT) survey was carriedout on the southern margin of the Mt. Amiata geothermal region (Tuscany, Italy), with the aim of defining the shallow and deep electric structures relatedto the local geothermal reservoirs and system heat recharge. Local andremote data were collected along a SW–NE profile andprocessedwith two different robust algorithms. After a detailed study of the EM strike, the data were inverted and twodimensional (2D) models of electrical resistivity and impedance phase were computed. The interpretation revealeda goodcorrelation between the features of the geothermal field and resistivity distribution at depth. In particular, a shallow conductor (0.5–4 km) detected by the MT survey shows a goodcorrelation with the areal extension of the geothermal reservoirs. # 2003 CNR. Published by Elsevier Science Ltd. All rights reserved