New Constraints on the Seismic Crustal Structure of the Southern Apennines (Italy): Numerical Modeling of P- and S- Body Waves for Moderate Earthquakes at Regional Scale
Description:
The Apennines mountain range and the Tyrrhenian back-arc basin originated in the central Mediterranean area, due to the convergence and collision of the Eurasia and the Africa-Adria plates. Geological and geophysical studies reveal variations in structural, tectonic and seismogenic patterns along the chain axis, and across the western Tyrrhenian and eastern Adriatic domains (Di Luccio et al. 2022).
Our focus lies on the southern Apennines, where the Adriatic plate subducts westward under the thinner Tyrrhenian plate, forming a complex “overlapping-Moho” setting. This area exhibits high seismic activity and heterogeneous CO2 gas emissions at the surface. Notably, these emissions cease to the east, where high-pressure fluids are trapped in the crust, influencing the seismogenic cycle (Chiodini et al. 2004).
Our approach involves P- and S-body waveform analysis and numerical modeling of moderate magnitude crustal earthquakes, at the regional scale. We concentrate on a SW-NE oriented transect cutting across the southern Apennines chain. Along this path the observed waveforms exhibit significant variations in frequency content and pulse shape, depending on both distance and azimuth. We analyze the 2018 Montecilfone (Mmax 5.1) and the 2013 Sannio-Matese (Mmax 5.0) seismic sequences, to examine the characteristics of westward and eastward wave propagation respectively.
We explore the trade-off between velocity and geometry perturbations starting from a 1D velocity model (Di Stefano et al. 1999). We upgrade the reference EPcrust model (Molinari et al. 2011) by incorporating external information on Moho and sedimentary layer structures (Spada et al. 2013, Nicolai and Gambini 2007). By employing the finite difference modeling code from Li et al. (2014), we generate synthetic waveforms to better fit the observed data, in terms of arrival time, pulse shape and waveform complexity on the three-component seismograms. Our results contribute to the understanding of the interplay between fluids and seismicity in the region, by providing higher resolution constraints on the structure of the southern Apennines.
Session: Numerical Modeling in Seismology: Developments and Applications [Poster Session]
Type: Poster
Date: 5/1/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Matteo
Student Presenter: No
Invited Presentation:
Authors
Matteo Scarponi Presenting Author Corresponding Author matteo.scarponi@ingv.it Istituto Nazionale di Geofisica e Vulcanologia - INGV |
Francesca Di Luccio francesca.diluccio@ingv.it Istituto Nazionale di Geofisica e Vulcanologia - INGV |
Claudia Piromallo claudia.piromallo@ingv.it Istituto Nazionale di Geofisica e Vulcanologia - INGV |
Daoyuan Sun sdy2014@ustc.edu.cn University of Science and Technology of China |
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New Constraints on the Seismic Crustal Structure of the Southern Apennines (Italy): Numerical Modeling of P- and S- Body Waves for Moderate Earthquakes at Regional Scale
Category
Numerical Modeling in Seismology: Developments and Applications