The 26 December 2018, Mw 4.9 earthquake represents the strongest event that occurred at Mt. Etna (Sicily, Italy) in the last 70 years; it produced heavy damage and impressive surface faulting along the Fiandaca Fault, a structure of the Timpe tectonic system on the volcano’s eastern flank. The EMERGEO WG of INGV promptly carried out a field survey to map the coseismic features: ca. 874 points of measurement describe the geometry, kinematics and offset of the ruptures. Overall, earthquake faulting extends for 7.5 km along strike and is characterized by dextral, oblique-slip displacements, with a net-slip up to 33 cm. Evidence of multi-fault ruptures, or triggered faulting, is observed along a splay-fault branching out southwards from Fiandaca Fault (EMERGEO WG 2019a,b and references therein). The UAV Team of the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, gave his support during fieldwork; in particular, four target-areas were surveyed by means of a DJI Phantom 4 Pro drone, operating in automatic mode with a fly altitude ranging between 30 and 60 m above the take-off point. Images were acquired by a 20 Mpx camera and then elaborated by Structure-from-Motion techniques to create Orthophotos and DEMs (Digital Elevation Model), with an average resolution of 1 cm/px.
The following 3D model shows one of the four overflown areas, located 300 m westward of Pennisi village, the survey was realized overflying the fracture at about 30 m of altitude the day after the earthquake (approximate geographical location coordinate: 37 38 47.6; 15 7 20.66 in WGS 84). The deformation zone is expressed by a 50 cm open fractures.
Credits: UAV-based survey provided by the UAV– Team (INGV-OE) Massimo Cantarero, Emanuela De Beni, funding from DPC All. A. Model description by Emanuela De Beni.
- EMERGEO WG (2019 a). Il terremoto etneo del 26 dicembre 2018, Mw4.9: rilievo degli effetti di fagliazione cosismica superficiale. Rapporto INGV n. 1 del 21/01/2019, 9 pp., doi 10.5281/zenodo.2545555.
- EMERGEO WG (2019 b) The 2018 Mw4.9 Mt. Etna earthquake (Italy): how fault rupture fits SHA based on geologic approaches. FAULT2SHA WORKING GROUP 4 th Workshop 3-5 June 2019 – Barcelona (SP)
- EMERGEO Working Group (Emergenza Etna 2018): Raffaele Azzaro, Stefano Pucci, Rosa Nappi, Paolo Marco De Martini, Marco Moro, Stefano Branca, Carlo Alberto Brunori, Marco Caciagli, Francesca Cinti, Riccardo Civico, Luigi Cucci, Salvatore D’amico, Maria Teresa Mariucci, Rosella Nave, Tullio Ricci, Alessandra Smedile, Stefano Gori, Paola Montone, Daniela Pantosti, Luca Pizzimenti, Vincenzo Sapia, Gabriele Tarabusi, Roberto Vallone, Alessandra Venuti, Fabio Villani.