Geometry and evolution of a fault‐controlled Quaternary basin by means of TDEM and single‐station ambient vibration surveys: The example of the 2009 L'Aquila earthquake area, central Italy. Issue 3 (25th March 2017)

• Record Type: Journal Article
• Authors: Civico, R.; Sapia, V.; Di Giulio, G.; Villani, F.; Pucci, S.; Baccheschi, P.; Amoroso, S.; Cantore, L.; Di Naccio, D.; Hailemikael, S.; Smedile, A.; Vassallo, M.; Marchetti, M.; Pantosti, D.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 3(2017)
• Page Start: 2236
• Page End: 2259
• Publication Date: 2017-03-25
• Subjects: time domain electromagnetic -- ambient vibration -- Quaternary basin -- 2009 L'Aquila earthquake -- central Apennines -- Italy; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1002/2016JB013451
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: We applied a joint survey approach integrating time domain electromagnetic soundings and single‐station ambient vibration surveys in the Middle Aterno Valley (MAV), an intermontane basin in central Italy and the locus of the 2009 L'Aquila earthquake. By imaging the buried interface between the infilling deposits and the top of the pre‐Quaternary bedrock, we reveal the 3‐D basin geometry and gain insights into the long‐term basin evolution. We reconstruct a complex subsurface architecture, characterized by three main depocenters separated by thresholds. Basin infill thickness varies from ~200–300 m in the north to more than 450 m to the southeast. Our subsurface model indicates a strong structural control on the architecture of the basin and highlights that the MAV experienced considerable modifications in its configuration over time. The buried shape of the MAV suggests a recent and still ongoing predominant tectonic control by the NW‐SE trending Paganica‐San Demetrio Fault System (PSDFS), which crosscuts older ~ENE and NNE trending extensional faults. Furthermore, we postulate that the present‐day arrangement of the PSDFS is the result of the linkage of two previously isolated fault segments. We provide constraints on the location of the southeastern boundary of the PSDFS, defining an overall ~19 km long fault system characterized by a considerable seismogenetic potential and a maximum expected magnitude larger than M 6.5. This study emphasizes the benefit of combining two easily deployable geophysical methods for reconstructing the 3‐D geometry of a tectonically controlled basin. Our joint approach provided us with a consistent match between these two independent estimations of the basin substratum depth within 15%. Key Points: 3‐D imaging of a fault‐controlled basin architecture via time domain electromagnetic and ambient vibration surveys Complex subsurface architecture characterized by buried faults and depocenters separated by thresholds Insights into the long‐term Paganica‐San Demetrio Fault System evolution and behavior (2009 L'Aquila earthquake fault)