An Experimental Approach for Estimating Seismic Amplification Effects at the Top of a Ridge, and the Implication for Ground-Motion Predictions: The Case of Narni, Central Italy

2010 ◽  
Vol 100 (6) ◽  
pp. 3020-3034 ◽  
Author(s):  
M. Massa ◽  
S. Lovati ◽  
E. D'Alema ◽  
G. Ferretti ◽  
M. Bakavoli
Keyword(s):  
Ground Motion ◽  
Experimental Approach ◽  
Central Italy ◽  
Seismic Amplification

scholarly journals Near-Source Simulation of Strong Ground Motion in Amatrice Downtown Including Site Effects

Geosciences ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 186
Author(s):  
Alessandro Todrani ◽  
Giovanna Cultrera
Keyword(s):  
Ground Motion ◽  
Site Effects ◽  
Central Italy ◽  
Strong Motion ◽  
Seismic Source ◽  
Spectral Ratio ◽  
Intensity Measures ◽  
Standard Spectral Ratio ◽  
Heavy Damage ◽  
Strong Ground

On 24 August 2016, a Mw 6.0 earthquake started a damaging seismic sequence in central Italy. The historical center of Amatrice village reached the XI degree (MCS scale) but the high vulnerability alone could not explain the heavy damage. Unfortunately, at the time of the earthquake only AMT station, 200 m away from the downtown, recorded the mainshock, whereas tens of temporary stations were installed afterwards. We propose a method to simulate the ground motion affecting Amatrice, using the FFT amplitude recorded at AMT, which has been modified by the standard spectral ratio (SSR) computed at 14 seismic stations in downtown. We tested the procedure by comparing simulations and recordings of two later mainshocks (Mw 5.9 and Mw 6.5), underlining advantages and limits of the technique. The strong motion variability of simulations was related to the proximity of the seismic source, accounted for by the ground motion at AMT, and to the peculiar site effects, described by the transfer function at the sites. The largest amplification characterized the stations close to the NE hill edge and produced simulated values of intensity measures clearly above one standard deviation of the GMM expected for Italy, up to 1.6 g for PGA.

Characteristics of strong ground motion data recorded in the Gubbio sedimentary basin (Central Italy)

2006 ◽  
Vol 5 (1) ◽  
pp. 27-43 ◽  
Author(s):  
F. Pacor ◽  
D. Bindi ◽  
L. Luzi ◽  
S. Parolai ◽  
S. Marzorati ◽  
...  
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Sedimentary Basin ◽  
Central Italy ◽  
Motion Data ◽  
Strong Ground

Ground-motion amplification at the Colle di Roio ridge, central Italy: a combined effect of stratigraphy and topography

2016 ◽  
Vol 206 (1) ◽  
pp. 1-18 ◽  
Author(s):  
S. Hailemikael ◽  
L. Lenti ◽  
S. Martino ◽  
A. Paciello ◽  
D. Rossi ◽  
...  
Keyword(s):  
Ground Motion ◽  
Central Italy ◽  
Combined Effect ◽  
Ground Motion Amplification

scholarly journals Physical stratigraphy and geotechnical properties controlling the local seismic response in explosive volcanic settings: the Stracciacappa maar (central Italy)

2020 ◽  
Vol 80 (1) ◽  
pp. 179-199
Author(s):  
M. Moscatelli ◽  
G. Vignaroli ◽  
A. Pagliaroli ◽  
R. Razzano ◽  
A. Avalle ◽  
...  
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Central Italy ◽  
Volcanic Event ◽  
Ground Motion Amplification ◽  
Local Seismic Response ◽  
Single Station ◽  
Seismic Scenarios ◽  
Physical Stratigraphy ◽  
Subsoil Model

AbstractNowadays, policies addressed to prevention and mitigation of seismic risk need a consolidated methodology finalised to the assessment of local seismic response in explosive volcanic settings. The quantitative reconstruction of the subsoil model provides a key instrument to understand how the geometry and the internal architecture of outcropping and buried geological units have influence on the propagation of seismic waves. On this regard, we present a multidisciplinary approach in the test area of the Stracciacappa maar (Sabatini Volcanic District, central Italy), with the aim to reconstruct its physical stratigraphy and to discuss how subsoil heterogeneities control the 1D and 2D local seismic response in such a volcanic setting. We first introduce a new multidisciplinary dataset, including geological (fieldwork and log from a 45-m-thick continuous coring borehole), geophysical (electrical resistivity tomographies, single station noise measurements, and 2D passive seismic arrays), and geotechnical (simple shear tests performed on undisturbed samples) approaches. Then, we reconstruct the subsoil model for the Stracciacappa maar in terms of vertical setting and distribution of its mechanical lithotypes, which we investigate for 1D and 2D finite element site response analyses through the application of two different seismic scenarios: a volcanic event and a tectonic event. The numerical modelling documents a significant ground motion amplification (in the 1–1.5 Hz range) revealed for both seismic scenarios, with a maximum within the centre of the maar. The ground motion amplification is related to both 1D and 2D phenomena including lithological heterogeneity within the upper part of the maar section and interaction of direct S-waves with Rayleigh waves generated at edges of the most superficial lithotypes. Finally, we use these insights to associate the expected distribution of ground motion amplification with the physical stratigraphy of an explosive volcanic setting, with insights for seismic microzonation studies and local seismic response assessment in populated environments.

Dynamic Rupture and Ground Motion Modeling of the 2016 M6.2 Amatrice and M6.5 Norcia, Central Italy, Earthquakes Constrained by Bayesian Dynamic Source Inversion

2020 ◽  
Author(s):  
Taufiq Taufiqurrahman ◽  
Alice-Agnes Gabriel ◽  
Frantisek Gallovic ◽  
Lubica Valentova
Keyword(s):  
Ground Motion ◽  
Dynamic Models ◽  
Central Italy ◽  
Foot Wall ◽  
Source Inversion ◽  
Dynamic Rupture ◽  
Highly Efficient ◽  
Starting Point ◽  
Dynamic Source ◽  
Strong Ground

<p>The complex evolution of earthquake rupture during the 2016 Central Italy sequence and the uniquely dense seismological observations provide an opportunity to better understand the processes controlling earthquake dynamics, strong ground motion, and earthquake interaction. </p><p>We here use fault initial stress and friction conditions constrained by a novel Bayesian dynamic source inversion as a starting point for high-resolution dynamic rupture scenarios. The best-fitting forward models are chosen out of ~10<sup>6</sup> highly efficient simulations restricted to a simple planar dipping fault. Such constrained, highly heterogeneous dynamic models fit strong motion data well. Utilizing the open-source SeisSol software (www.seissol.org), we then take into account non-planar (e.g., listric) fault geometries, inelastic off-fault damage rheology, free surface effects and topography which cannot be accounted for in the highly efficient dynamic source inversion. SeisSol is based on the discontinuous Galerkin method on unstructured tetrahedral meshes optimized for modern supercomputers. </p><p>We investigate the effects of including the realistic modeling ingredients on rupture dynamics and strong ground motions up to 5 Hz. Synthetic PGV mapping reveals that specifically fault listricity decreases ground motion amplitudes by  ~50 percent in the extreme near field on the foot-wall. On the hanging-wall shaking is increased by ~150 percent as a consequence of wave-focusing effects within 10 km away from the fault. Dynamic modeling thus suggests that geometrical fault complexity is important for seismic hazard assessment adjacent to dipping faults but difficult to identify by kinematic source inversions.</p>

scholarly journals What is the impact of the August 24, 2016 Amatrice earthquake on the seismic hazard assessment in central Italy?

2016 ◽  
Vol 59 ◽  
Author(s):  
Maura Murru ◽  
Matteo Taroni ◽  
Aybige Akinci ◽  
Giuseppe Falcone
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Central Italy ◽  
Seismic Hazard Assessment ◽  
Motion Prediction ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
The Impact

<p>The recent Amatrice strong event (M<sub>w</sub>6.0) occurred on August 24, 2016 in Central Apennines (Italy) in a seismic gap zone, motivated us to study and provide better understanding of the seismic hazard assessment in the macro area defined as “Central Italy”. The area affected by the sequence is placed between the M<sub>w</sub>6.0 1997 Colfiorito sequence to the north (Umbria-Marche region) the Campotosto area hit by the 2009 L’Aquila sequence M<sub>w</sub>6.3 (Abruzzo region) to the south. The Amatrice earthquake occurred while there was an ongoing effort to update the 2004 seismic hazard map (MPS04) for the Italian territory, requested in 2015 by the Italian Civil Protection Agency to the Center for Seismic Hazard (CPS) of the Istituto Nazionale di Geofisica e Vulcanologia INGV. Therefore, in this study we brought to our attention new earthquake source data and recently developed ground-motion prediction equations (GMPEs). Our aim was to validate whether the seismic hazard assessment in this area has changed with respect to 2004, year in which the MPS04 map was released. In order to understand the impact of the recent earthquakes on the seismic hazard assessment in central Italy we compared the annual seismic rates calculated using a smoothed seismicity approach over two different periods; the Parametric Catalog of the Historical Italian earthquakes (CPTI15) from 1871 to 2003 and the historical and instrumental catalogs from 1871 up to 31 August 2016. Results are presented also in terms of peak ground acceleration (PGA), using the recent ground-motion prediction equations (GMPEs) at Amatrice, interested by the 2016 sequence.</p>

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