This awesome model, with an aereal extent of about 80m x 40 m, shows the traces left by coseismic fault movements occurred during the Mw 4.9, December 26, 2018 Fleri earthquake, on the eastern slope of Mt Etna (Italy), along the NW-SE Fiandaca fault; the fault affected a series of walls and a road. In the lower corner of the image (left of the large garden) the road is offset by a surface splay of the fault; by zooming in, a left-lateral component of motion can be recognized on the wall located to the right side of the road. Along the road there are other two main zones of splay fault damage: the central one shows an extensional offset and a component of dip-slip downthrow. The other zone of damage also shows a normal downthrow of one block. Looking in detail at the high wall located on the right side of the image, it is possible to appreciate the component of left-lateral strike-slip offset. Finally, in the concrete platform located near the larger garden, it is possible to observe the presence of two pressure ridges made of concrete slabs; one mimics a small fold. They may have been created by secondary movements of adjustment of the concrete platform that downwarped on the hanging wall fault block, or by the left-lateral strike-slip component of fault motion. Details for this event are reported in Azzaro et al. (2019) and Bella et al. 2019.

Credits: UAV-based survey and 3D DOM by Fabio L. Bonali, in collaboration with Osservatorio Etneo, INGV-Catania (Italy); funding is from MIUR project ACPR15T4_00098 ( Model description by Alessandro Tibaldi.


  • Azzaro, R., Pucci, S., Nappi, R., De Martini, P. M., Branca, S., Brunori, C. A., … & D’Amico, S. (2019). Il terremoto di Fleri (Etna) del 26 dicembre 2018 Mw 4.9. Parte II: rilievo degli effetti di fagliazione cosismica superficiale. 38° convegno nazionale del GNGTS.
  • Bella D., Tringali G., Boso D., Livio F., Ferrario M.F., Michetti A.M., Porfido S., Blumetti A.M., Di Manna P., Vittori E., Guerrieri L. (2019). Surface faulting and environmental effects accompanying the Dec. 26, 2018, Mw 4.9 Fleri earthquake, Mt. Etna volcano, Italy. 20th Congress of the International Union for Quaternary Research (INQUA).