The Sulmona valley, located in the internal portion of the Central Apennine (Central Italy) is characterized by the presence of NW-SE active faults, with extensional kinematics, is considerate historically capable of generating damaging earthquakes.
The present-day seismicity of the Sulmona valley (mainly micro-seismicity), has been studied in the recent past by authors (generally using a simplified 1D velocity model) with the aim to constrain the geometry of the Sulmona extensional faults system using the earthquakes relocation and analyse the seismic hazard associated to the possible earthquake enucleation.
Indeed, the very low seismicity detected for the Sulmona area (seismic gap), can represent a concrete risk if contextualized with the active tectonics of the Central Apennine, as observed for the seismic sequence of Accumoli-Amatrice and Norcia 2016.
The aim of this project is to use a 3D approach, implementing for the study of the seismicity of the Sulmona valley, a detailed 3D geological and velocity model (constructed during the three years of my Ph.D. for the study area).
In particular, the 3D velocity model will be used for the 3D relocation of the earthquakes of the area using the 3D tomographic software of the INGV institute of Rome.
As a next step, a 3D structural analysis of the main potential seismogenic extensional fault of the area will be carried out using the software Petrel and MOVE, in order to estimate the 3D faults properties (e.g. the fault dip and the displacement) and their variation in 3D.
Finally, the 3D velocity model will be also crucial for the study of the seismic waves propagation in the subsurface, resulted by the possible earthquake enucleation.
In this sense, Ground Motion analysis can be useful to characterize the seismic hazard of the area, in which the amplification of the seismic waves due to the presence of the Plio-Quaternary deposits represents a concrete risk in the valley.
The seismicity of the Central Italy was widely studied by the literature up to present present-day, because of the catastrophic earthquakes that historically characterize the area (e.g. the earthquakes of L¿Aquila 2009, Accumoli-Amatrice and Norcia 2016; Boncio et al., 2004; Pace et al., 2006; Bagh et al., 2007; Chiarabba et al., 2010; Lavecchia et al., 2012; Valoroso et al., 2013; Chiaraluce et al., 2017; Galadini et al 2018; De Crescenzo et al., 2018).
Anyway, most of the study related to the relocation of these seismic events and the analysis of the seismogenic faults are based on the use of a single 1D velocity model, more or less simplified, which it can hardly represent the effectively geological variations that characterize Central Italy (Pace et al., 2002; Boncio et al., 2004; Bagh et al., 2007; Romano et al., 2013; Frepoli et a., 2017).
In a similar way, a very simplified 3D grid model was used for the Sulmona valley, in order to study the seismic hazard of the area (Villani et al., 2014).
Therefore, for all issues discussed above, our 3D geological/structural and velocity model can represent an important basis for the still in progress study of the seismicity and mitigation of the seismic hazard of the Sulmona valley, representing a possible precious analogue (in terms of modelling results and workflow) for the other geological analogues of the Central Italy.
Bibliography
-Bagh et al., (2007). Background seismicity in the Central Apennines of Italy: The Abruzzo region case study.
-Boncio et al., (2004). Defining a model of 3D seismogenic sources for Seismic Hazard Assessment applications: the case of central Apennines (Italy).
-Buttinelli et al., (2018). Tectonics inversions, fault segmentation, and triggering mechanisms in the central Apennines normal fault system
-Cavinato et al., (2002). Sedimentary and tectonic evolution of Plio¿Pleistocene alluvial and lacustrine deposits of Fucino Basin (central Italy).
-Chiarabba et al., (2020). Large earthquakes driven by fluid overpressure: The Apennines normal faulting system case.
-Chiaraluce et al., (2017). The 2016 central Italy seismic sequence: A first look at the mainshocks, aftershocks, and source models.
-Cosentino et al., (2017). New insights into the onset and evolution of the central Apennine extensional intermontane basins based on the tectonically active L¿Aquila Basin
-De Crescenzo et al., (2018). Seismic characterization of the accelerometric stations along an array in the Sulmona basin.
-Di Filippo & Miccadei (1997). Analisi gravimetriche della Conca di Sulmona.
-Frepoli et al., (2017). Seismic sequences and swarms in the Latium-Abruzzo-Molise Apennines (central Italy): New observations and analysis from a dense monitoring of the recent activity.
-Ghisetti & Vezzani (1998). Segmentation and tectonic evolution of the Abruzzi-Molise thrust belt (central Apennines, Italy).
-Lavecchia, et al., (2012). From surface geology to aftershock analysis: Constraints on the geometry of the L¿Aquila 2009 seismogenic fault system.
-Miccadei et al., (1998). La geologia quaternaria della conca di Sulmona (Abruzzo, Italia centrale).
-Minelli et al., (2018). Aeromagnetic investigation of the central Apennine Seismogenic Zone (Italy): From basins to faults.
-Nicolai & Gambini (2007). Structural architecture of the Adria platform-and-basin system.
-Pace et al., (2006). Layered seismogenic source model and probabilistic seismic-hazard analyses in central Italy.
-Paolucci et al., (2016). The 3D numerical simulation of near-source ground motion during the Marsica earthquake, central Italy, 100 years later.
-Piacentini & Miccadei (2014). The role of drainage systems and intermontane basins in the Quaternary landscape of the Central Apennines chain (Italy).
-Pizzi, et al., (2014). First level seismic microzoning of Sulmona (central Italy): major results and evidences of 2D/3D amplification.
-Romano et al., (2013). Preliminary analysis of the microearthquakes¿faults association in the Sulmona basin (central Apennines, Italy).
-Romano et al., (2013b). Temporary seismic monitoring of the Sulmona area (Abruzzo, Italy): a quality study of microearthquake locations.
-Smerzini et al., (2011). Comparison of 3D, 2D and 1D numerical approaches to predict long period earthquake ground motion in the Gubbio plain, Central Italy.
-Speranza & Chiappini (2002). Thick¿skinned tectonics in the external Apennines, Italy: New evidence from magnetic anomaly analysis.
-Valoroso et al., (2014). Earthquakes and fault zone structure.
-Valoroso et al., (2013). Radiography of a normal fault system by 64,000 high¿precision earthquake locations: The 2009 L'Aquila (central Italy) case study.
-Vezzani et al., (2010). Geology and tectonic evolution of the Central-Southern Apennines, Italy (Vol. 469).
-Villani et al., (2014). High-resolution seismic hazard analysis in a complex geological configuration: the case of the Sulmona Basin in Central Italy.