A new magnetotelluric monitoring network operating in Agri Valley (Southern Italy): study of stability of apparent resistivity estimates

Variations detected ill geophysical. especially electromagnetic. parameters in seismic active areas have been sometimes attributed to modifications of the stress field. Among the different geophysical methods, magnetotellurics (MT) Could be one of the most effective because it allows LIS to explore down to seismogenic depths. Continuous NIT recording Could allow LIS to evaluate whether possible variations are significantly correlated with the seismic activity of investigated area. To assess the significance Of Such observations we Must be able to say how well all apparent resistivity curve should be reproduced when measurements are repeated at I later time. To do this properly it is essential to know that the estimated error bars accurately represent the true uncertainties in comparing the transfer functions. In this work we will show the preliminary results obtained from the analysis of the data coming, from the new MT monitoring network installed in Agri Valley. This analysis gives LIS the possibility: i) to better study the temporal stability of the signals. ii) to better discriminate the noise affecting the measures by remote reference estimation. The performed analysis disclosed a relatively low degree of noise in the investigated area. which is a promising condition for monitoring.