Field GPS data inversion to model Fiandaca tectonic lineament that caused seismic event on 26th December 2018 ( Mt. Etna Volcano, Sicily)

We present the analyses of geodethic monitoring of the main tectonic lineaments of Mt. Etna Eastern flank, affected by 2018 volcanic unrest. Acoording to Bonforte et al. 2019, & Novellis et al. 2019, the 26th December 2018 seismic crisis was triggered by the intrusion of an hydrofracture responsable of 12/24/18 event. This caused East-West oriented remote stress field determine radial deformation along both east and west eor orthogonal to the geometry of the dike, in the both slopes of the Etna volcanic complex. The hydrofracture triggered and increased the stress concentration along the main tectonic features on the eastern flank; in particular, the Fiandaca lineament, being in a stress limit state, developed an earthquake of magnitude 4.9 (http://cnt.rm.ingv.it/event/21285011). A little less than a month after this event there was another one of equal importance that affected the Pernicana structure. In fact, on 01/09/2019 it generated an earthquake of magnitude 4.1 ( http://cnt.rm.ingv.it/event/21355221). In this scenario, the work is aimed at geodetic monitoring of the structures affected by this deformation event and by future events, such as Fiandaca and Nizzeti faults and also define a source model for them. The inversion of geodetic data, relating to the ground deformation, represents one of the main steps for analysis of volcano-tectonic sources (Cannavò, 2019). The use of the GAME tools, runs in matlab and developed by INGV, allowed the determination of fault segments source model, responsible for the seismic event of 26th december 2018. Through the implementation of Okada sources and the use of different GPS data inversion algorithms has been defined a model source congruent with the geological, geometric and seismic characteristics of the tectonic structures analyzed, in agreement with previous studies like Monaco et al., 2021. This work made possible to place an important starting point for better understanding volcano-tectonic dynamics which affect the eastern flank of Mt. Etna Volcano. Bibliography: