Abstract
<p>We present a Finite Element inverse analysis of the static deformation field for the M<sub>w</sub>= 6.3, 2009 L’Aquila earthquake, in order to infer the rupture slip distribution on the fault plane. An univocal solution for the rupture slip distribution has not been reached yet with negative impact for reliable hazard scenarios in a densely populated area. In this study, Finite Element computed Green’s functions were implemented in a linear joint inversion scheme of geodetic (GPS and InSAR) and seismological (strong motion) coseismic deformation data. In order to fully exploit the informative power of our dense dataset and to honor the complexities of the real Earth, we implemented an optimized source model, represented by a fault plane subdivided in variable size patches, embedded in a high-resolution realistic three-dimensional model of the Apenninic seismo-tectonic setting, accounting for topographic reliefs and rheological heterogeneities deduced from local tomography. We infer that the investigated inversion domain contains two minima configurations in the solution space, i.e. a single- and a double-patch slip distribution, which are almost equivalent, so that the available datasets and numerical models are not able to univocally discriminate between them. Nevertheless our findings suggest that a two high-slip patch pattern is slightly favoured.</p>
Highlights
The 2009 April 6 Mw= 6.3 L’Aquila earthquake is the largest event that struck the Abruzzi region in the last 300 years since the 1703 earthquake [Boschi et al 2000]
We implemented a recently proposed source model consisting in a variable patch fault plane, in order to achieve a detailed information of the slip release on the rupture plane
We computed the Green’s functions by means of 3D Finite Element (FE) simulations and built up a procedure to use the synthetic displacements in a linear inversion scheme of coseismic deformation data (GPS, InSAR and strong motion (SM))
Summary
The 2009 April 6 Mw= 6.3 L’Aquila earthquake is the largest event that struck the Abruzzi region in the last 300 years since the 1703 earthquake [Boschi et al 2000]. The earthquake occurred at a hypocentral depth of 9.5 km and at a distance of about 2 km from L’Aquila city center [Chiarabba et al 2009] It was felt all over the central Italy, causing more than 300 casualties and extended damage. Our findings predicted a source model featured by a concentrated slip distribution on the rupture plane, evidencing a single area of high slip release fully localized south-east of the hypocenter. This result was consistent with other studies [Atzori et al 2009, Walters et al 2009, Trasatti et al 2011, Serpelloni et al 2012]. This suggests that slip complexity may be a modelistic artifact due to the simplification of the structural model
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call