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ORIGINAL RESEARCH article

Front. Earth Sci.
Sec. Structural Geology and Tectonics
Volume 12 - 2024 | doi: 10.3389/feart.2024.1474036

Relocation of earthquake clusters show seismogenic transverse structures in the Inner Northern Apennines

Provisionally accepted
Lauretta Kaerger Lauretta Kaerger 1*Chiara Del Ventisette Chiara Del Ventisette 1Paola Vannucchi Paola Vannucchi 1Giancarlo Molli Giancarlo Molli 2Carolina Pagli Carolina Pagli 2Derek Keir Derek Keir 1,3
  • 1 University of Florence, Florence, Italy
  • 2 University of Pisa, Pisa, Tuscany, Italy
  • 3 University of Southampton, Southampton, Hampshire, United Kingdom

The final, formatted version of the article will be published soon.

    The Inner Northern Apennines are a region with a dominant N-S to NNW-SSE fault system, but dissected and offset by several E-W to NE-SW trending structures and lineaments. The knowledge about the nature of these transverse structures, their origin, activity and role in current tectonic motions is limited and debated. To better establish the location, subsurface shape, and kinematics of faults related to the Livorno-Empoli lineament, one of the major transverse structures in the Northern Apennines, we analysed the seismicity in western Tuscany. In the Viareggio Basin we identified and relocated two distinct earthquake clusters as well as calculated 12 new focal mechanisms. The results show that the clusters consisted of several swarms from the years 2006, 2015, 2016 and 2021. The events had a depth between 2 and 15 km and were located along a NE-SW oriented, SE dipping fault system dissecting the Viareggio Basin. Focal mechanisms show oblique normal slip. We interpret the fault system to form a connection between the Viareggio Basin and the Lucca Basin to the east as well as continuing offshore. The results show that the transversal faults of the Inner Northern Apennines are seismogenic, with the length, position and onshore to offshore nature of the fault suggesting reactivation of pre-existing structures.

    Keywords: Seismicity and tectonics, transversal structures, Earthquakes, Apennines, Italy

    Received: 31 Jul 2024; Accepted: 24 Sep 2024.

    Copyright: © 2024 Kaerger, Del Ventisette, Vannucchi, Molli, Pagli and Keir. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Lauretta Kaerger, University of Florence, Florence, Italy

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