Pre-earthquake chain processes detected from ground to satellite altitude in preparation of the 2016–2017 seismic sequence in Central Italy

2019 ◽  
Vol 229 ◽  
pp. 93-99 ◽  
Author(s):  
Dedalo Marchetti ◽  
Angelo De Santis ◽  
Serena D'Arcangelo ◽  
Federica Poggio ◽  
Alessandro Piscini ◽  
...  
Buildings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 58 ◽  
Author(s):  
Francesco Clementi

This paper presents a detailed study of the damages and collapses suffered by various masonry churches in the aftermath of the seismic sequence of Central Italy in 2016. The damages will first be analyzed and then compared with the numerical data obtained through 3D simulations with eigenfrequency and then nonlinear static analyses (i.e., pushover). The main purposes of this study are: (i) to create an adequately consistent sensitivity study on several definite case studies to obtain an insight into the role played by geometry—which is always unique when referred to churches—and by irregularities; (ii) validate or address the applicability limits of the more widespread nonlinear approach, widely recommended by the Italian Technical Regulations. Pushover analyses are conducted assuming that the masonry behaves as a nonlinear material with different tensile and compressive strengths. The consistent number of case studies investigated will show how conventional static approaches can identify, albeit in a qualitative way, the most critical macro-elements that usually trigger both global and local collapses, underlining once again how the phenomena are affected by the geometry of stones and bricks, the texture of the wall face, and irregularities in the plan and elevation and in addition to hypotheses made on the continuity between orthogonal walls.


Author(s):  
Iunio Iervolino ◽  
Pasquale Cito ◽  
Chiara Felicetta ◽  
Giovanni Lanzano ◽  
Antonio Vitale

AbstractShakeMap is the tool to evaluate the ground motion effect of earthquakes in vast areas. It is useful to delimit the zones where the shaking is expected to have been most significant, for civil defense rapid response. From the earthquake engineering point of view, it can be used to infer the seismic actions on the built environment to calibrate vulnerability models or to define the reconstruction policies based on observed damage vs shaking. In the case of long-lasting seismic sequences, it can be useful to develop ShakeMap envelopes, that is, maps of the largest ground intensity among those from the ShakeMap of (selected) events of a seismic sequence, to delimit areas where the effects of the whole sequence have been of structural engineering relevance. This study introduces ShakeMap envelopes and discusses them for the central Italy 2016–2017 seismic sequence. The specific goals of the study are: (i) to compare the envelopes and the ShakeMap of the main events of the sequence to make the case for sequence-based maps; (ii) to quantify the exceedance of design seismic actions based on the envelopes; (iii) to make envelopes available for further studies and the reconstruction planning; (iv) to gather insights on the (repeated) exceedance of design seismic actions at some sites. Results, which include considerations of uncertainty in ShakeMap, show that the sequence caused exceedance of design hazard in thousands of square kilometers. The most relevant effects of the sequence are, as expected, due to the mainshock, yet seismic actions larger than those enforced by the code for structural design are found also around the epicenters of the smaller magnitude events. At some locations, the succession of ground-shaking that has excited structures, provides insights on structural damage accumulation that has likely taken place; something that is not accounted for explicitly in modern seismic design. The envelopes developed are available as supplemental material.


2015 ◽  
Vol 203 (1) ◽  
pp. 399-415 ◽  
Author(s):  
G. Calderoni ◽  
A. Rovelli ◽  
Y. Ben-Zion ◽  
R. Di Giovambattista

2018 ◽  
Vol 11 ◽  
pp. 314-321 ◽  
Author(s):  
M. Poiani ◽  
V. Gazzani ◽  
F. Clementi ◽  
G. Milani ◽  
M. Valente ◽  
...  

2016 ◽  
Vol 59 ◽  
Author(s):  
Laura Scognamiglio ◽  
Elisa Tinti ◽  
Matteo Quintiliani

<p>We present the revised Time Domain Moment Tensor (TDMT) catalogue for earthquakes with M_L larger than 3.6 of the first month of the ongoing Amatrice seismic sequence (August 24th - September 25th). Most of the retrieved focal mechanisms show NNW–SSE striking normal faults in agreement with the main NE-SW extensional deformation of Central Apennines. We also report a preliminary finite fault model analysis performed on the larger aftershock of this period of the sequence (M_w 5.4) and discuss the obtained results in the framework of aftershocks distribution.</p>


2016 ◽  
Vol 59 ◽  
Author(s):  
Arrigo Caserta ◽  
Fawzi Doumaz ◽  
Antonio Costanzo ◽  
Anna Gervasi ◽  
William Thorossian ◽  
...  

<p><em>We used the moderate-magnitude aftershocks succeeding to the 2016 August 24<sup>th</sup>, Mw = 6.0, Amatrice (Italy) mainshok to asses, specially during an ongoing seismic sequence, the soil-structure interaction where cultural Heritage is involved. We have chosen as case study the</em><em> San Giovanni Battista</em><em> church (A.D. 1039)  in Acquasanta Terme town, about 20 Km northeast of Amatrice. First of all we studied the soil shaking features in order to characterize the input to the monument. Then, using the recordings in the church, we tried to figure out  how the input seismic energy is distributed over the different monument parts. Some preliminary results are shown and discussed.</em></p><p><em><br /></em></p>


2017 ◽  
Vol 122 (11) ◽  
pp. 9149-9165 ◽  
Author(s):  
Daniele Maestrelli ◽  
Marco Bonini ◽  
Dario Delle Donne ◽  
Michael Manga ◽  
Luigi Piccardi ◽  
...  

2021 ◽  
Author(s):  
Simona Gabrielli ◽  
Aybige Akinci ◽  
Ferdinando Napolitano ◽  
Luca De Siena ◽  
Edoardo Del Pezzo ◽  
...  

&lt;p&gt;Between August and October 2016, the Central Apennines in Italy have been struck by a long-lasting seismic sequence, known as the Amatrice (Mw 6.0) - Visso (Mw 5.9) - Norcia (Mw 6.5) sequence. The cascading ruptures occurred in this sequence have been considered connected to the fluid migration in the fault network, as suggested by previous studies. The behaviour of fluids in the crust is crucial to understand earthquakes occurrence and stress changes since fluids reduce fault stability. It has long been understood that the seismic attenuation is strongly controlled by the structural irregularity and heterogeneities; micro-cracks and cavities, either fluid-filled or dry, temperature and pressure variations cause a decrease in seismic wave amplitude and pulse broadening. Hence seismic attenuation imagining is a powerful tool to be a relevant provenance of information about the influence and abundance of fluids in a seismic sequence.&lt;/p&gt;&lt;p&gt;The aim of this work is to separate scattering and absorption contributions to the total attenuation of coda waves and to provide their spatial and temporal variations at different frequency bands of these quantities using two datasets: the first one comprising 592 earthquakes occurred before the sequence (March 2013-August 2016) and the second one comprising 763 events (ML &gt; 2.8) from the Amatrice-Visso-Norcia sequence. Scattering and absorption have been measured through peak-delay and coda-wave attenuation parameters (the latter inverted using frequency-dependent sensitivity kernels).&lt;/p&gt;&lt;p&gt;The preliminary results show a clear difference between the pre-sequence and sequence images, mainly at low frequencies (1.5 Hz), where we can define a spatial increase of scattering with time attributed to rock fracturing and fluid circulation. The coda attenuation tomography also demonstrates a clear variation between the pre-sequence and the sequence over series of time windows being before and after the largest main shocks of the seismic sequence, with an increase of the attenuation in space with decreasing time. The peak delay indicates a high scattering area corresponding to the Gran Sasso massif and L&amp;#8217;Aquila zone, where an important seismic sequence (Mw 6.3) occurred in 2009.&lt;/p&gt;


2021 ◽  
Author(s):  
Giovanni Forte ◽  
Melania De Falco ◽  
Federica Iannicelli ◽  
Antonio Santo

&lt;p&gt;The seismic sequence that struck Central Italy in 2016 was characterized by three main shocks respectively occurred on August 24&lt;sup&gt;th&lt;/sup&gt; Mw 6.0; October 26&lt;sup&gt;th&lt;/sup&gt; Mw5.9 and October 30&lt;sup&gt;th&lt;/sup&gt; Mw 6.5. The seismic sequence caused several ground effects over a large area of &amp;#8203;&amp;#8203;the central Apennine mountain range, mainly affecting transportation routes.&lt;/p&gt;&lt;p&gt;In the aftermath of the sequence, several research groups mapped around 820 landslides involving road cuts in rock and fill slopes over an area of about 2000 km&lt;sup&gt;2&lt;/sup&gt; (GEER,ISPRA, C.E.R.I. by Roma La Sapienza). These data are summarized in the CEDIT catalog by Martino et al., (2017), where almost 150, 250 and 420 instability phenomena were respectively triggered by each mainshock. Further updates were carried out by the Authors in the framework of the Reluis projects of the Department of Civil Protection. In particular, other 550 phenomena were mapped by interpretation of aero photos provided by google-earth. For some of the largest ones, field surveys were carried out for mechanical, structural, and geometrical characterization.&lt;/p&gt;&lt;p&gt;The dataset distribution was analyzed with geological, geomorphological, and seismic parameters, such as lithology, fault distance, landslide run-out, estimates of mobilized volumes, distance from the epicenter, PGA, and damages.&lt;/p&gt;&lt;p&gt;The triggered events are mainly characterized by Category I of Keefer (1984) classification, namely rockfalls and rockslides. The maximum triggering distance resulted as high as 50 km far from the epicenter. The most affected areas are characterized by ridge crests or flanks of valleys in carbonate rocks.&lt;/p&gt;&lt;p&gt;This study permitted to highlight the most relevant parameters for the assessment of earthquake-triggered susceptibility for the study area and identify some meaningful and critical case studies for the future development of the research.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;


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