The 2013 Marche offshore earthquakes: new insights into the active tectonic setting of the outer northern Apennines

Abstract

A seismic sequence offshore the Marche region sheds new light on the active tectonic setting of the outer northern Apennines, revealing the existence of a previously unknown transcurrent seismogenic structure. In contrast to the Po Plain area, where vigorous seismicity testifies to active frontal thrusting, the seismotectonic setting of the Adriatic domain is characterized by the occurrence of active crustal strike-slip faults dissecting the thrust belt. As recent studies suggest that thrust faults represent the unique seismogenic sources characterizing the Adriatic sector of the outer northern Apennines, our results pose new challenges to the identification of seismogenic structures in the region.