Imaging the tectonic framework of the 24 August 2016, Amatrice (central Italy) earthquake sequence: new roles for old players?

Lorenzo Bonini, Francesco Emanuele Maesano, Roberto Basili, Pierfrancesco Burrato, Michele Matteo Cosimo Carafa, Umberto Fracassi, Vanja Kastelic, Gabriele Tarabusi, Mara Monica Tiberti, Paola Vannoli, Gianluca Valensise

Abstract


We reconstruct the tectonic framework of the 24 August 2016, Amatrice earthquake. At least three main faults, including an older thrust fault (Sibillini Thrust), played an active role in the sequence. The mainshock nucleated and propagated along an extensional fault located in the footwall of the Sibillini Thrust, but due to the preliminary nature of the data the role of this thrust is still unclear. We illustrate two competing solutions: 1) the coseismic rupture started along an extensional fault and then partially used the thrust plane in extensional motion; 2) the thrust fault acted as an upper barrier to the propagation of the mainshock rupture, but was partially reactivated during the aftershock sequence. In both cases our tectonic reconstruction suggests an active role of the thrust fault, providing yet another example of how structures inherited from older tectonic phases may control the mainshock ruptures and the long-term evolution of younger seismogenic faults.

Keywords


Amatrice earthquake

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References


DOI: http://dx.doi.org/10.4401/ag-7229


 

Published by INGV, Istituto Nazionale di Geofisica e Vulcanologia - ISSN:  2037-416X