scholarly journals Kinematic finite fault and 3D seismic wave propagation of the 24 August, 2016, Mw 6.0 central Italy earthquake

2016 ◽  
Vol 59 ◽  
Author(s):  
Federica Magnoni ◽  
Emanuele Casarotti
Keyword(s):  
Wave Propagation ◽  
Seismic Wave ◽  
Structural Model ◽  
Central Italy ◽  
Seismic Wave Propagation ◽  
Source Model ◽  
Geological Structure ◽  
Fault System ◽  
Central Italy Earthquake ◽  
Finite Fault

The magnitude Mw 6.0 earthquake of 24th August 2016 caused severe damages and nearly 300 fatalities in the central Italy region. Initial reports revealed an asymmetrical distribution of damage and coseismic effects, suggesting a major role of heterogeneities, both in the rupture history and in the geological structure of the region. Near realtime availability of seismological data afforded a timely determination of a finite fault model (Tinti et al., 2016). Here we test this source model by performing a 3D simulation of seismic wave propagation within a 3D structural model containing the major geological features of the region. Agreement between modeled seismograms and observed seismograms suggests that some complexities in the waveforms, such as high amplification in the region of the Mt. Vettore fault system, can be accounted for by complexities in the fault rupture and 3D structural models. Finally, the consistency of the hypothesis of two distinct events has been analyzed.

Active Faulting in Source Region of 2016–2017 Central Italy Event Sequence

2018 ◽  
Vol 34 (4) ◽  
pp. 1557-1583 ◽  
Author(s):  
Fabrizio Galadini ◽  
Emanuela Falcucci ◽  
Stefano Gori ◽  
Paolo Zimmaro ◽  
Daniele Cheloni ◽  
...  
Keyword(s):  
Source Region ◽  
Central Italy ◽  
Active Faults ◽  
Earthquake Sequence ◽  
Fault System ◽  
Fault Plane Solutions ◽  
Moment Tensors ◽  
Central Italy Earthquake ◽  
Finite Fault ◽  
Main Shocks

The Central Italy earthquake sequence produced three main shocks: M6.1 24 August, M5.9 26 October, and M6.5 30 October 2016. Additional M5–5.5 events struck this territory on 18 January 2017 in the Campotosto area. Fault plane solutions for the main shocks exhibit normal faulting (characteristic of crustal extension occurring in the inner central Apennines). Significant evidence, including hypocenter locations, strike and dip angles of the moment tensors, inverted finite fault models (using GPS, interferometric aperture radar, and ground motion data), and surface rupture patterns, all point to the earthquakes having been generated on the Mt. Vettore–Mt. Bove fault system (all three main shocks) and on the Amatrice fault, in the northern sector of the Laga Mountains (portion of 24 August event). The earthquake sequence provides examples of both synthetic and antithetic ruptures on a single fault system (30 October event) and rupture between two faults (24 August event). We describe active faults in the region and their segmentation and present understanding of the potential for linkages between segments (or faults) in the generation of large earthquakes.

A Procedure for 3D Seismic Simulation from Rupture to Structures by Coupling SEM and FEM

2020 ◽  
Vol 110 (3) ◽  
pp. 1134-1148
Author(s):  
Lei Zhang ◽  
Jin-Ting Wang ◽  
Yan-Jie Xu ◽  
Chun-Hui He ◽  
Chu-Han Zhang
Keyword(s):  
Wave Propagation ◽  
Seismic Wave ◽  
Earthquake Engineering ◽  
Seismic Wave Propagation ◽  
3D Seismic ◽  
Step Method ◽  
Entire Area ◽  
Fine Mesh ◽  
Finite Fault ◽  
Element Method

ABSTRACT This article aims at numerically simulating the 3D seismic wave propagation from rupture to structures. A two-step method coupling the spectral element method (SEM) and the finite-element method (FEM) is proposed based on the domain reduction method to simultaneously simulate the seismic wave propagation in large-scale regions and analyze the dynamic behavior of structures in local sites. First, the concept of the proposed two-step method is illustrated. In the first step, the seismic wave propagation of the entire area, involving the source, propagation media, and local region of interest, is simulated using the SEM. In the second step, the dynamic analysis of structure-foundation system with local geological and topographical conditions is implemented using the FEM in a fine mesh based on the results in the first step. Subsequently, the FEM grid size is evaluated to match the SEM results, and the proposed SEM–FEM procedure is verified using both point-source and finite-fault model in a layered flat model. Finally, two analysis examples are presented using the proposed procedure. The analysis results show that the proposed SEM–FEM procedure can well consider the effects of local geological and topographical conditions on synthesized ground motions and can be applied to the rupture-to-structure simulations in earthquake engineering.

scholarly journals Fast 3D seismic wave simulations of 24 August 2016 Mw 6.0 central Italy earthquake for visual communication

2016 ◽  
Vol 59 ◽  
Author(s):  
Emanuele Casarotti ◽  
Federica Magnoni ◽  
Licia Faenza ◽  
Francesca Comunello ◽  
Piero Polidoro ◽  
...  
Keyword(s):  
Seismic Wave ◽  
Seismic Event ◽  
Central Italy ◽  
Seismic Wave Propagation ◽  
Natural Phenomenon ◽  
3D Seismic ◽  
Civil Protection ◽  
Italian Region ◽  
The Public ◽  
Central Italy Earthquake

We present here the first application of the fast reacting framework for 3D simulations of seismic wave propagation generated by earthquakes in the Italian region with magnitude Mw 5. The driven motivation is to offer a visualization of the natural phenomenon to the general public but also to provide preliminary modeling to expert and civil protection operators. We report here a description of this framework during the emergency of 24 August 2016 Mw 6.0 central Italy Earthquake, a discussion on the accuracy of the simulation for this seismic event and a preliminary critical analysis of the visualization structure and of the reaction of the public.

scholarly journals Consecutive ruptures on a complex conjugate fault system during the 2018 Gulf of Alaska earthquake

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinji Yamashita ◽  
Yuji Yagi ◽  
Ryo Okuwaki ◽  
Kousuke Shimizu ◽  
Ryoichiro Agata ◽  
...  
Keyword(s):  
Gulf Of Alaska ◽  
Source Model ◽  
Fault System ◽  
Complex Conjugate ◽  
Inversion Method ◽  
Fault Geometry ◽  
Conjugate System ◽  
Finite Fault Inversion ◽  
Finite Fault ◽  
Alaska Earthquake

AbstractWe developed a flexible finite-fault inversion method for teleseismic P waveforms to obtain a detailed rupture process of a complex multiple-fault earthquake. We estimate the distribution of potency-rate density tensors on an assumed model plane to clarify rupture evolution processes, including variations of fault geometry. We applied our method to the 23 January 2018 Gulf of Alaska earthquake by representing slip on a projected horizontal model plane at a depth of 33.6 km to fit the distribution of aftershocks occurring within one week of the mainshock. The obtained source model, which successfully explained the complex teleseismic P waveforms, shows that the 2018 earthquake ruptured a conjugate system of N-S and E-W faults. The spatiotemporal rupture evolution indicates irregular rupture behavior involving a multiple-shock sequence, which is likely associated with discontinuities in the fault geometry that originated from E-W sea-floor fracture zones and N-S plate-bending faults.

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