scholarly journals The ShakeMaps of the Amatrice, M6, earthquake

2016 ◽  
Vol 59 ◽  
Author(s):  
Licia Faenza ◽  
Valentino Lauciani ◽  
Alberto Michelini

In this paper we describe the performance of the ShakeMap software package and the fully automatic procedure, based on manually revised location and magnitude, during the main event of the Amatrice sequence with special emphasis to the M6 main shock, that struck central Italy on the 24th August 2016 at 1:36:32 UTC. Our results show that the procedure we developed in the last years, with real-time data exchange among those institutions acquiring strong motion data, allows to provide a faithful description of the ground motion experienced throughout a large region in and around the epicentral  area. The prompt availability of the rupture fault model, within three hours after the earthquake occurrence, provided a better descriptions of the level of strong ground motion throughout the affected area.  Progressive addition of  station data and  manual verification of the data insures improvements in the description of the experienced ground motions.  In particular, comparison between the MCS intensity shakemaps and preliminary field macroseismic reports show favourable similarities.  Finally the overall  spatial pattern of the ground motion of the main shock is consistent with reported rupture directivity toward NW and reduced levels of ground shaking toward SW probably linked to the peculiar source effects of the earthquake.

1977 ◽  
Vol 67 (2) ◽  
pp. 493-515
Author(s):  
Christopher Rojahn ◽  
B. J. Morrill

Abstract Two earthquakes occurred on the island of Hawaii on November 29, 1975, a magnitude (Ms) 5.7 event at 0335 (local time) and a magnitude (Ms) 7.2 event at 0447. During the larger event, a maximum acceleration of 0.22 g was recorded in the southern part of Hilo, 43 km north of the epicenter. A 0.05 g threshold duration of 13.7 sec was measured for the same component. Smaller amplitude accelerograph records were obtained at two other locations on the island along with four seismoscope records. During or subsequent to the larger event, a large sector of the southeastern coastline subsided by as much as 3.5 meters. A tsunami generated by the larger event caused at least one death (one person also missing), injury to 28 persons, and significant structural and nonstructural damage. Only scattered evidence of strong ground shaking was observed in the epicentral area, and most of the several dozen nearby structures sustained little or no structural damage from ground shaking. In Hilo, 45 km north of the Ms = 7.2 epicenter, structural and nonstructural damage was slight to moderate but more extensive than elsewhere on the island.


2016 ◽  
Vol 59 ◽  
Author(s):  
Filomena de Silva ◽  
Stefania Sica ◽  
Francesco Silvestri ◽  
Stefano Aversa

<p>The paper illustrates and compares simplified approaches to interpret the mechanisms of damage observed on rigid bodies in the cemetery of Amatrice, after the main shock (August 24, 2016, M<sub>W</sub>=6.0) of the Central Italy earthquake. The final goal of the work is to link the observed movements of the fallen objects to specific characteristics of the ground motion occurred at the specific site.</p>


2021 ◽  
pp. 875529302110445
Author(s):  
Ivan Wong ◽  
Robert Darragh ◽  
Sarah Smith ◽  
Qimin Wu ◽  
Walter Silva ◽  
...  

The damaging 4 May 2018 M 6.9 Kalapana earthquake and its aftershocks have provided the largest suite of strong motion records ever produced for an earthquake sequence in Hawaii exceeding the number of records obtained in the deep 2006 M 6.7 Kiholo Bay earthquake. These records provided the best opportunity to understand the processes of strong ground shaking in Hawaii from shallow crustal (< 20 km) earthquakes. There were four foreshocks and more than 100 aftershocks of M 4.0 and greater recorded by the seismic stations. The mainshock produced only a modest horizontal peak ground acceleration (PGA) of 0.24 g at an epicentral distance of 21.5 km. In this study, we evaluated the 2018 strong motion data as well as previously recorded shallow crustal earthquakes on the Big Island. There are still insufficient strong motion data to develop an empirical ground motion model (GMM) and so we developed a GMM using the stochastic numerical modeling approach similar to what we had done for deep Hawaiian (>20 km) earthquakes. To provide inputs into the stochastic model, we performed an inversion to estimate kappa, stress drops, Ro, and Q(f) using the shallow crustal earthquake database. The GMM is valid from M 4.0 to 8.0 and at Joyner–Boore (RJB) distances up to 400 km. Models were developed for eight VS30 (time-averaged shear-wave velocity in the top 30 m) values corresponding to the National Earthquake Hazards Reduction Program (NEHRP) site bins: A (1500 m/s), B (1080 m/s), B/C (760 m/s), C (530 m/s), C/D (365 m/s), D (260 m/s), D/E (185 m/s), and E (150 m/s). The GMM is for PGA, peak horizontal ground velocity (PGV), and 5%-damped pseudo-spectral acceleration (SA) at 26 periods from 0.01 to 10 s. In addition, we updated our GMM for deep earthquakes (>20 km) to include the same NEHRP site bins using the same approach for the crustal earthquake GMM.


Geosciences ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 186
Author(s):  
Alessandro Todrani ◽  
Giovanna Cultrera

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.


2006 ◽  
Vol 5 (1) ◽  
pp. 27-43 ◽  
Author(s):  
F. Pacor ◽  
D. Bindi ◽  
L. Luzi ◽  
S. Parolai ◽  
S. Marzorati ◽  
...  

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Giuliana Alessio ◽  
Laura Alfonsi ◽  
Carlo Alberto Brunori ◽  
Pierfrancesco Burrato ◽  
Giuseppe Casula ◽  
...  

<p>On May 20, 2012, a Ml 5.9 seismic event hit the Emilia Po Plain, triggering intense earthquake activity along a broad area of the Po Plain across the provinces of Modena, Ferrara, Rovigo and Mantova (Figure 1). Nine days later, on May 29, 2012, a Ml 5.8 event occurred roughly 10 km to the SW of the first main shock. These events caused widespread damage and resulted in 26 victims. The aftershock area extended over more than 50 km and was elongated in the WNW-ESE direction, and it included five major aftershocks with 5.1 ≤Ml ≤5.3, and more than 2000 minor events (Figure 1). In general, the seismic sequence was confined to the upper 10 km of the crust. Minor seismicity with depths ranging from 10 km to 30 km extended towards the southern sector of the epicentral area (ISIDe, http://iside.rm.ingv.it/). […]</p><br />


2016 ◽  
Vol 59 ◽  
Author(s):  
Marco Massa ◽  
Ezio D'Alema ◽  
Chiara Mascandola ◽  
Sara Lovati ◽  
Davide Scafidi ◽  
...  

<p><em>ISMD is the real time INGV Strong Motion database. During the recent August-September 2016 Amatrice, Mw 6.0, seismic sequence, ISMD represented the main tool for the INGV real time strong motion data sharing.  Starting from August 24<sup>th</sup>,  the main task of the web portal was to archive, process and distribute the strong-motion waveforms recorded  by the permanent and temporary INGV accelerometric stations, in the case of earthquakes with magnitude </em><em>≥</em><em> 3.0, occurring  in the Amatrice area and surroundings.  At present (i.e. September 30<sup>th</sup>, 2016), ISMD provides more than 21.000 strong motion waveforms freely available to all users. In particular, about 2.200 strong motion waveforms were recorded by the temporary network installed for emergency in the epicentral area by SISMIKO and EMERSITO working groups. Moreover, for each permanent and temporary recording site, the web portal provide a complete description of the necessary information to properly use the strong motion data.</em></p>


Author(s):  
Arben Pitarka ◽  
Aybige Akinci ◽  
Pasquale De Gori ◽  
Mauro Buttinelli

ABSTRACT The Mw 6.5 Norcia, Italy, earthquake occurred on 30 October 2016 and caused extensive damage to buildings in the epicentral area. The earthquake was recorded by a network of strong-motion stations, including 14 stations located within a 5 km distance from the two causative faults. We used a numerical approach for generating seismic waves from two hybrid deterministic and stochastic kinematic fault rupture models propagating through a 3D Earth model derived from seismic tomography and local geology. The broadband simulations were performed in the 0–5 Hz frequency range using a physics-based deterministic approach modeling the earthquake rupture and elastic wave propagation. We used SW4, a finite-difference code that uses a conforming curvilinear mesh, designed to model surface topography with high numerical accuracy. The simulations reproduce the amplitude and duration of observed near-fault ground motions. Our results also suggest that due to the local fault-slip pattern and upward rupture directivity, the spatial pattern of the horizontal near-fault ground motion generated during the earthquake was complex and characterized by several local minima and maxima. Some of these local ground-motion maxima in the near-fault region were not observed because of the sparse station coverage. The simulated peak ground velocity (PGV) is higher than both the recorded PGV and predicted PGV based on empirical models for several areas located above the fault planes. Ground motions calculated with and without surface topography indicate that, on average, the local topography amplifies the ground-motion velocity by 30%. There is correlation between the PGV and local topography, with the PGV being higher at hilltops. In contrast, spatial variations of simulated PGA do not correlate with the surface topography. Simulated ground motions are important for seismic hazard and engineering assessments for areas that lack seismic station coverage and historical recordings from large damaging earthquakes.


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