EGU21-15554
https://doi.org/10.5194/egusphere-egu21-15554
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Structural reconstruction, fault parameterization, and slip rate analysis in the northern Adriatic Sea (Italy): implications for the Plio-Pleistocene tectonic activity of long-lived offshore buried thrusts.

Yuri Panara1,5, Francesco Emanuele Maesano2, Chiara Amadori1,5, Jakub Fedorik3, Manlio Ghielmi4, Giovanni Toscani1,5, and Roberto Basili2
Yuri Panara et al.
  • 1Dipartimento di Scienze della Terra e dell’Ambiente, Università di Pavia, Pavia, Italy
  • 2Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy
  • 3King Abdullah University of Science and Technology (KAUST), Saudi Arabia
  • 4Eni Upstream & Technical Services, San Donato Milanese, Italy
  • 5Centro InteRUniversitario per l’Analisi SismoTettonica Tridimensionale con applicazioni territoriali (CRUST), Università di Pavia, Italy

The northern Apennines foredeep is characterized by a Plio-Pleistocene tectonic activity whose driving structures (thrust faults and related anticlines) are always buried by a high amount of syntectonic sediments, both onshore (Po Plain) and offshore (Adriatic Sea), thereby leaving subtle or none apparent signatures in the topo-bathymetry. Compared to the rest of Italy, this area has a relatively moderate earthquake hazard, but historical reports and instrumental recordings testify for significant seismicity. Seismological analyses of recent sizeable earthquakes (e.g., the Mw 6.1, Emilia earthquake in 2012) confirmed that the seismic activity is mainly due to the outermost northern Apennines buried thrusts. In this work, we reconstructed and parameterized the 3D geometry of such buried faults in an offshore sector just south of the Po River delta by interpreting a dense network of 2D seismic reflection profiles. The availability of two regional seismic reflection profiles, coupled with a detailed reconstruction of Plio-Pleistocene horizons, allowed us to restore the deformation cumulated by these thrusts. Our analysis was aimed at (1) establishing the age of inception of the main crustal thrusts, (2) reconstruct the main Plio-Pleistocene tectonic events affecting the study area, and (3) calculate the Plio-Pleistocene slip rates at different time slices and reporting them through probability distribution functions that take into account the uncertainties associated with horizon ages and restoration parameters. Our results show that the Plio-Pleistocene tectonic activity is variably distributed on different thrust faults and decreases exponentially over time after the Gelasian. The analysis performed on the most recent reflectors suggests that a low but not negligible tectonic activity characterizes the main thrusts in the studied region in the last 4-500 ka and hints at a residual activity that may last until the present.

How to cite: Panara, Y., Maesano, F. E., Amadori, C., Fedorik, J., Ghielmi, M., Toscani, G., and Basili, R.: Structural reconstruction, fault parameterization, and slip rate analysis in the northern Adriatic Sea (Italy): implications for the Plio-Pleistocene tectonic activity of long-lived offshore buried thrusts., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15554, https://doi.org/10.5194/egusphere-egu21-15554, 2021.

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