GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.2 GNGTS 2024 Figure 3 – Lef panel: Ascending (upper lef), descending (upper right), E-W (lower lef) and vertcal (lower right) ground displacement maps over Sangay volcano. In the upper right panel is visible the change detecton map performed with S1 data acquired on 22 November and 4 December 2021, instead in the lower right panel the vertcal displacement tme series ploted at the black triangle can be appreciated. Concluding remarks Regarding Etna volcano, through InSAR methods we found out the presence of several subsidence areas that overlap with lava fow footprints identfed by S2 and literature data. Horizontal displacements at lava fows are directed downslope on areas with high slope angles but directed upslope on areas characterized by low slope angles and larger lava thickness. Results also allowed us to establish the infuence that the physical mechanisms have on the observed moton, suggestng that the main factors causing ground displacements are thermal contracton of the lava body and viscous compacton of the underlying substrate, the later predominant for older lava fows. We tried to apply the same approach in the study of lava fows on Sangay volcano but, diferent climatc conditons and the inadequacy of some satellite datasets did not allow complete replicability. However, we were able to correlate the dynamics highlighted by the InSAR DTS analysis with the emplacement of a pyroclastc current in the N fank of Sangay at the end of November 2021 by using a polarimetric change detecton approach that allows emphasizing changes due to the volcanic erupton. As future developments, we plan to analyze in detail the displacement paterns measured by InSAR methods to relate them to other volcanic phenomena (e.g., infaton, lava fows, pyroclastc currents) by exploitng polarimetric change detecton radar approach and also numerical modeling methods.