X- and C-Band InSAR data to identify local effects following the 2016 Central Italy seismic sequence

Helsinki, Finland

The 2016 Central Italy seismic sequence consisted of more than three months long sequence, and still on going, that produced
several damages in the areas surrounding the epicenters of the earthquakes causing hundreds of victims. The surface displacement
fields due to the main events occurred on August and on October respectively, were effectively constrained by means of X-, C- and Lband
InSAR data. The retrieved results revealed significant deformation patterns close the Amatrice, Visso and Norcia towns showing
ground subsidence values greater than 20 cm.
Moreover, we also observed some local complexities in the interferometric fringes patterns, not directly attributed to the main tectonic
patterns. These local effects were effectively analyzed by Cosmo-SkyMed (X-band) and Sentinel-1 (C-band) data because of their
wavelength more suitable to the scale of the investigated phenomena. In particular, we detected a clear local signal along the Mount
Vettore, the highest mountainous relief of the Mount Sibillini, following the Mw 6.0 Amatrice/Accumuli earthquake. It was constrained
by Cosmo-SkyMed data acquired along both the ascending and descending track.
In addition, a deformation pattern was observed by Sentinel-1 and Cosmo-SkyMed descending data along the already known Deepseated
Gravitational Slope Deformation (DGSD) of Mt. Frascare, in the proximity of the Fiastra Lake Dam.
Finally, the seismic events of October 2016 produced some interferometric fringes (with the number depending on the used frequency
band) along the sector of Mount Sibillini at the eastside of Acquacanina district.
Geomorphological and geological post-processing analysis allowed us to ascribe such patterns to ground displacement occurred
along local effects due to gravitative and karst phenomena.