Children of a Lesser Seismological God: The 1971 Tuscania (Central Italy) “Historical” Earthquake

2020 ◽  
Vol 91 (5) ◽  
pp. 2563-2578 ◽  
Author(s):  
Luigi Cucci ◽  
Andrea Tertulliani ◽  
Corrado Castellano

Abstract The 6 February 1971 Tuscania (central Italy) earthquake belongs to a peculiar family of destructive seismic events that have occurred in an area classified as low-seismic hazard, causing heavy damage and tens of casualties. However, this earthquake took place at the dawn of modern seismology in Italy and is far from being fully characterized from an instrumental and macroseismological point of view. This article aims at bridging the gap of information that affects that earthquake, through a twofold research path: (1) with an archival investigation looking for new available sources and with the use of the European Macroseismic Scale-98 (EMS-98) intensity scale, and (2) with the calculation of a more constrained hypocentral location. The results of this investigation can be summarized as follows: the reappraisal of the earthquake in terms of EMS-98 provides a maximum intensity 8 in Tuscania (previously quoted 8–9 Mercalli–Cancani–Sieberg [MCS] in the catalog), and a general decrease of intensity in many damaged localities. The new epicenter location is shifted almost 10 km southeast of the old one, at about 3 km depth. This new location is more robust than the previous one and is consistent with the general distribution of the most damaged localities; however, we cannot exclude that effects of directivity might have played a role in the peculiar pattern of damage caused by the event. Finally, we provide new values of magnitude (MD 4.9 and ML 5.1) that point to an upward scaling of the earthquake. The ultimate lesson of this work is that a deepening of the research can always provide room for an improvement of our knowledge even for significant earthquakes that have occurred relatively recently.

Author(s):  
C. Pezzica ◽  
A. Piemonte ◽  
C. Bleil de Souza ◽  
V. Cutini

<p><strong>Abstract.</strong> This paper identifies the application domain, context of use, processes and goals of low-cost street-level photogrammetry after urban disasters. The proposal seeks a synergy between top-down and bottom-up initiatives carried out by different actors during the humanitarian response phase in data scarce contexts. By focusing on the self-organisation capacities of local people, this paper suggests using collaborative photogrammetry to empower communities hit by disasters and foster their active participation in recovery and reconstruction planning. It shows that this task may prove technically challenging depending on the specifics of the collected imagery and develops a grounded framework to produce user-centred image acquisition guidelines and fit-for-purpose photogrammetric reconstruction workflows, useful in future post-disaster scenarios. To this end, it presents an in-depth analysis of a collaborative photographic mapping initiative undergone by a group of citizen-scientists after the 2016 Central Italy earthquake, followed by the explorative processing of some sample datasets. Specifically, the paper firstly presents a visual ethnographic study of the photographic material uploaded by participants from September 2016 to November 2018 in the two Italian municipalities of Arquata del Tronto and Norcia. Secondly, it illustrates from a technical point of view issues concerning the processing of crowdsourced data (e.g. image filtering, selection, quality, semantic content and 3D model scaling) and discusses the viability of using it to enrich the pool of geo-information available to stakeholders and decision-makers. Final considerations are discussed as part of a grounded framework for future guidelines tailored to multiple goals and data processing scenarios.</p>


2017 ◽  
Vol 59 ◽  
Author(s):  
Angelo Masi ◽  
Giuseppe Santarsiero ◽  
Leonardo Chiauzzi ◽  
Maria Rosaria Gallipoli ◽  
Sabatino Piscitelli ◽  
...  

<p>The authors have surveyed many damaged villages located at the epicentre of the ML=6.0 earthquake which occurred on August 24, 2016 in central Italy. Some unexpected anomalies were discovered such as very different levels of damage in Vezzano and Pescara del Tronto villages (Arquata del Tronto Municipality, Ascoli Piceno province). The two villages are situated just 1300 meters from each other. Pescara del Tronto suffered very heavy damage with many masonry building collapses and 48 fatalities, while Vezzano suffered only light damage to few buildings. This paper provides a preliminar analysis from an engineering and geophysics perspective. Particularly, rapid visual surveys were carried out in the two villages in order to detect possible significant differences in the vulnerability of their building stocks and site geophysical investigations were performed to detect possible local amplification effects.</p>


2021 ◽  
Vol 73 (04) ◽  
pp. 389-398
Author(s):  
Stjepan Lakusic

The ASA (Advanced Seismic Assessment) module is a post-earthquake technical intervention service, developed over the years by the EUCENTRE Foundation through a series of national and European pilot projects, field exercises, and direct experience, after the latest major seismic events that struck Italy since 2009. The system consists of a service managed at the headquarters in Pavia for the development of damage scenarios, and of a mobile unit for the on-site damage assessments. After the Central Italy earthquake, the Foundation has been involved for about eight months in several activities, including provision of technical support to the Italian Department of Civil Protection, joint reconnaissance with internationally acknowledged research institutes.


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.


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.


2018 ◽  
Author(s):  
Angelo De Santis ◽  
Gianfranco Cianchini ◽  
Rita Di Giovambattista ◽  
Cristoforo Abbattista ◽  
Lucilla Alfonsi ◽  
...  

Abstract. Geosystemics (De Santis 2009, 2014) studies the Earth system as a whole focusing on the possible coupling among the Earth layers (the so called geo-layers), and using universal tools to integrate different methods that can be applied to multi-parameter data, often taken on different platforms. Its main objective is to understand the particular phenomenon of interest from a holistic point of view. In this paper we will deal with earthquakes, considered as a long term chain of processes involving, not only the interaction between different components of the Earth’s interior, but also the coupling of the solid earth with the above neutral and ionized atmosphere, and finally culminating with the main rupture along the fault of concern (De Santis et al., 2015a). Some case studies (particular emphasis is given to recent central Italy earthquakes) will be discussed in the frame of the geosystemic approach for better understanding the physics of the underlying complex dynamical system.


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