GNGTS 2018 - 37° Convegno Nazionale

730 GNGTS 2018 S essione 3.3 Conclusion. In this work, we have proposed and validated a novel method based on the PFT to study the volcanic environment and estimate the geometric parameters of the source model responsible for the ground deformation field. We use Multiridge and ScalFun methods to provide information on depth, horizontal position and source shape without any a priori information. In conclusion, we stress that the proposed methodology is definitely different from the methods currently used for modeling ground-deformation sources, mainly based on forward or inverse techniques. In fact, (i) it does not require any assumptions about the source type, and (ii) it is not influenced by the distribution of medium elastic parameters or (iii) the presence of high-frequency noise in the dataset. References Biggs J., Lu Z., Fournier T. and Freymueller J.; 2010: Magma flux at Okmok Volcano, Alaska, from a joint inversion of continuous GPS, campaign GPS, and interferometric synthetic aperture radar . J. Geophys. Res., 115, B12401. Blakely R. J.; 1996: Potential theory in gravity and magnetic applications . Cambridge University Press. Castaldo R., Barone A., Fedi M., Tizzani P.; 2018: Multiridge method for studying ground-deformation sources: application to volcanic environments . Scientific Reports, 8, 13420. Fedi M.; 2007: DEXP: a fast method to determine the depth and the structural index of potential fields sources . Geophysics, 72, 1, I1-I11. Fig. 2 - (a-b) LOS deformation in the E-W and N-S profiles evaluated from Fig. 1b; (c-d) results of the Multiridge method applied to the E-W and N-S profiles; the red solid lines, which represent the regression lines, estimate the source position at their intersection, and the black solid line indicates the real source depth. For each regression line we indicate the coefficient of determination (R 2 ); (e-f) results of the ScalFun method applied to the central cyan multiridge subsets reported in (c-d), where represents the value of the field corresponding to the selected ridge.