On 04/04/2018 an earthquake of Mw 4.0 occurred in the Muccia area (Camerino) in central Italy.
Hypocentres show a clear distribution, where they show the presence of a detachment by NE-dipping and a master faults by SW-dipping (f). Moreover hypocenters highlight the presence of a dilated wedge (type I), located in the hangingwall of the master fault (f) and a secondary fault (R') antithetical to f. This two faults
Dilated wedge is characterized by earthquakes with a extensional focal mechanism. This indicates how the area is subject to SW-NE extension, at a depth of between 7-10 km about. The two conjugate faults, f and R', delimit a wedge (W) with a crustal thickness of 6-7 km about and without a co-seismic deformation inside it.
|Trace A-A' in map|
The continuous seismic deformation in the dilated wedge and in outside wedge area, could lead to gravitational collapse of the wedge and generate strong graviquakes along master fault (f). It is not possible to define a time of occurrence, but it is plausible to consider the area "tectono-gravitationally" unstable.
- Terremoto di magnitudo Mw 4.0 del 04-04-2018 ore 04:19:45 (Italia) in zona: 2 km SW Muccia (MC)
- Considerations on the seismotectonics and seismogenesis of the Tiberina-Gubbio Valley extensional system (central Italy)
- STRUCTURAL STYLE OF SEISMOGENIC EXTENSION IN CENTRAL ITALY – A 3D INSIGHT FROM L’AQUILA 2009 AND CENTRAL ITALY 2016-17 SEISMIC SEQUENCES
- Normal fault earthquakes or graviquakes