ALBERT

Description: The Italian Tsunami Alert Centre of the Istituto Nazionale di Geofisica e Vulcanologia (Centro di Allerta Tsunami, hereinafter CAT-INGV) supported a computer-assisted telephone interview (CATI) survey to investigate tsunami risk perception in two pilot regions of southern Italy. The survey was carried out on a stratified sample of 1021 interviewees representing about 3.2 million people living in 183 coastal municipalities of the two regions, namely Calabria and Apulia. The main goal of this research is to verify whether and how people's perception of tsunami hazard compares to the results of (PTHA) – probabilistic tsunami hazard assessment (TSUMAPS-NEAM project; Basili et al., 2018). As shown by the results of this project, both investigated regions are characterised by high tsunami hazard. Nonetheless, the long return time of such events could lead people to consider the occurrence of a tsunami in the Mediterranean Sea to be very unlikely. The survey results reveal that people's risk perception is low: for almost half of the whole sample the occurrence of a tsunami in the Mediterranean Sea is considered quite unlikely, with a clear difference between Apulia and Calabria. In the latter region the risk perception is much higher than in the former, probably due to the shorter time elapsed since the last event. Also, belonging to different coastal areas1 appears to have a significant influence on the way tsunami hazard is conceived, having a stronger effect on risk characterisation: the interviewees of Tyrrhenian Calabria are indeed more likely to associate tsunami risk with volcanoes than the Ionian citizens. This is coherent considering the presence of active volcanoes and related tsunami precedents in the Tyrrhenian. Television emerged as the most relevant source of knowledge for almost 90 % of the sample, and the influence of media also results in the way tsunami risk is characterised. In particular, the survey showed that people's perception and understanding of tsunamis are affected by media accounts of large events, such as the 2004 Sumatra and the 2011 Japan tsunamis. At the same time, it is evident that the risk posed by smaller events is underrated. Furthermore, the survey's results show that the word “tsunami” occupies a different semantic space in comparison to the Italian traditional headword maremoto, with differences among sample strata. In other words, the same physical phenomenon would be understood in two different ways by younger, educated people and elders with a low education level. The results of this study, although limited to two regions, provide a first assessment of tsunami risk perception in Italy, also entailing important consequences for both risk communication practice and mitigation policies.

Description: The Istituto Nazionale di Geofisica e Vulcanologia (INGV) is an Italian research institution, with focus on Earth Sciences. INGV runs the Italian National Seismic Network (Rete Sismica Nazionale, RSN) and other networks at national scale for monitoring earthquakes and tsunami as a part of the National Civil Protection System coordinated by the Italian Department of Civil Protection (Dipartimento di Protezione Civile, DPC). RSN is composed of about 400 stations, mainly broadband, installed in the Country and in the surrounding regions; about 110 stations feature also co-located strong motion instruments, and about 180 have GPS receivers and belong to the National GPS network (Rete Integrata Nazionale GPS, RING). The data acquisition system was designed to accomplish, in near-real-time, automatic earthquake detection, hypocenter and magnitude determination, moment tensors, shake maps and other products of interest for DPC. Database archiving of all parametric results are closely linked to the existing procedures of the INGV seismic monitoring environment and surveillance procedures. INGV is one of the primary nodes of ORFEUS (Observatories & Research Facilities for European Seismology) EIDA (European Integrated Data Archive) for the archiving and distribution of continuous, quality checked seismic data. The strong motion network data are archived and distributed both in EIDA and in event based archives; GPS data, from the RING network are also archived, analyzed and distributed at INGV. Overall, the Italian earthquake surveillance service provides, in quasi real-time, hypocenter parameters to the DPC. These are then revised routinely by the analysts of the Italian Seismic Bulletin (Bollettino Sismico Italiano, BSI). The results are published on the web, these are available to both the scientific community and the general public. The INGV surveillance includes a pre-operational tsunami alert service since INGV is one of the Tsunami Service providers of the North-eastern Atlantic and Mediterranean Tsunami warning System (NEAMTWS).

Description: According to a deep-rooted conviction, the occurrence of a tsunami in the Mediterranean Sea would be very rare. However, in addition to the catastrophic event of Messina and Reggio Calabria (1908) and the saved danger for the tsunami occurred on Cycladic sea in 1956, 44 events are reported in the Mediterranean Sea between 1951 and 2003, and other smaller tsunamis occurred off Morocco, Aegean and Ionian seashores between 2017 and 2018. Such events, that are just a little part of the over 200 historically events reported for the Mediterranean (Maramai, Brizuela & Graziani, 2014) should remind geoscientists, civil protection officers, media and citizens that 1) tsunami hazard in the Mediterranean is not negligible, and 2) tsunamis come in all shapes and colours, and even a small event can result in serious damages and loss of lives and properties. Recently, a project funded by the European Commission (TSUMAPS-NEAM, Basili et al., 2018) has estimated the tsunami hazard due to seismic sources in the NEAM region (one of the four ICG coordinated by the UNESCO IOC) finding that a significant hazard is present in most coasts of the area, particularly in those of Greece and Italy. In such a scenario, where low probability and high uncertainty match with poor knowledge and familiarity with tsunami hazard, risk mitigation strategies and risk communicators should avoid undue assumptions about public’s supposed attitudes and preparedness, as these may results in serious consequences for the exposed population, geoscientists, and civil protection officers. Hence, scientists must carefully shape their messages and rely on well-researched principled practices rather than on good intuitions (Bostrom, & Löfstedt, 2003). For these reasons, the Centro Allerta Tsunami of the Istituto Nazionale di Geofisica e Vulcanologia (hereinafter CAT-INGV) promoted a survey to investigate tsunami’s risk perception in two pilot regions of Southern Italy, Calabria and Apulia, providing a stratified sample of 1021 interviewees representing about 3.2mln people living in 183 coastal municipalities of two regions subjected (along with Sicily) to relatively high probability to be hit by a tsunami. Results show that people’s perception and understanding of tsunami are affected by media accounts of large tsunamis of 2004 (Sumatra) and 2011 (Tohoku, North East Japan): television emerged as the most relevant source of knowledge for almost 90 % of the sample, and the influence of media also results in the way tsunami risk is characterized. Risk perception appears to be low: for almost half of the sample the occurrence of a tsunami in the Mediterranean sea is considered quite unlikely. Furthermore, the survey’s results show that the word tsunami occupies a different semantic space with respect to the Italian traditional headword maremoto, with differences among sample strata. In other words, the same physical phenomenon would be understood in two different ways by younger, educated people and elders with low education level. Also belonging to different coastal areas appears to have a significant influence on the way tsunami hazard is conceived, having a stronger effect on risk characterization, for instance the interviewees of Tyrrhenian Calabria are more likely to associate tsunami risk to volcanoes with respect to other considered coastlines. The results of this study provide a relevant account of the issues at a stake, also entailing important implication both for risk communication and mitigation policies.

Description: n the last decade temporary teleseismic transects have become a powerful tool for investigating the crustal and upper mantle structure. In order to gain a clearer picture of the lithosphere-asthenosphere structure in peninsular Italy, between 1994 and 1996, we have deployed three teleseismic transects in northern, central, and southern Apennines, in the framework of the project GeoModAp (European Community contract EV5V-CT94–0464). Some hundreds of teleseisms were recorded at each deployment which lasted between 3 and 4 months. Although many analyses are still in progress, the availability of this high quality data allowed us to refine tomographic images of the lithosphere-asthenosphere structure with an improved resolution in the northern and central Apennines, and to study the deformation of the upper mantle looking at seismic anisotropy through shear-wave splitting analysis. Also, a study of the depth and geometry of the Moho through the receiver function technique is in progress. Tomographic results from the northernmost 1994 and the central 1995 teleseismic experiments confirm that a high-velocity anomaly (HVA) does exist in the upper 200–250 km and is confined to the northern Apenninic arc. This HVA, already interpreted as a fragment of subducted lithosphere is better defined by the new temporary data, compared to previous works, based only on data from permanent stations. No clear high-velocity anomalies are detected in the upper 250 km below the central Apennines, suggesting either a slab window due to a detachment below southern peninsular Italy, or a thinner, perhaps continental slab of Adriatic lithosphere not detectable by standard tomography. We found clear evidence of seismic anisotropy in the uppermost mantle, related to the main tectonic processes which affected the studied regions, either NE–SW compressional deformation of the lithosphere beneath the mountain belt, or arc-parallel asthenospheric flow (both giving NW–SE fast polarization direction), and successive extensional deformation ( E–W trending) in the back-arc basin of northern Tyrrhenian and Tuscany. Preliminary results of receiver function studies in the northern Apennines show that the Moho depth is well defined in the Tyrrhenian and Adriatic regions while its geometry underneath the mountain belt is not yet well constrained, due to the observed high complexity.

Description: Published

Description: 479-493

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: Nella Struttura Terremoti dell’INGV la Linea di Attività T5 “Sorveglianza sismica ed operatività postterremoto” si occupa delle attività di sviluppo di strumenti e procedure per la valutazione in tempo reale degli effetti di terremoti e tsunami e della gestione delle emergenze sismiche. Uno dei suoi obiettivi del 2015 era la formalizzazione dei protocolli di intervento di Gruppi d’Emergenza, avvenuta per Emergeo, Emersito, IES, QUEST e Sismiko con Decreto del Presidente nel luglio 2015. Altro obiettivo era l’elaborazione di un Protocollo di Ente per la gestione delle emergenze sismiche. La bozza preparata nel 2015 prevede l’importante novità dell’Unità di Crisi, mai formalizzata in precedenza. Attraverso questo Protocollo di Ente si auspica di migliorare la risposta logistico-operativa dell’INGV durante l’emergenza, di avere una più rapida conoscenza del fenomeno in corso e di realizzare un’efficace comunicazione verso Protezione Civile, media e pubblico. Per verificare il tutto è stata organizzata un’esercitazione in cui è stato simulato un terremoto di magnitudo 6.4 nel basso Lazio. Si sono così sperimentate l’efficacia del flusso azioni/informazioni durante un’emergenza, il funzionamento dell’Unità di Crisi, la funzionalità dei protocolli dei Gruppi d’Emergenza, l’efficienza delle attività in sede per gli aspetti tecnico-logistici, il flusso di comunicazione interno e le comunicazioni istituzionali esterne (queste ultime simulate). In questo articolo sono descritte le fasi di organizzazione ed attuazione dell’esercitazione. Inoltre, durante il suo svolgimento, la valutazione dell’efficacia dell’organizzazione e delle attività svolte dai gruppi coinvolti è stata affidata ad alcuni osservatori e qui è allegata l’elaborazione dei commenti riportati. Abbiamo fatto infine una sintesi dei risultati positivi e delle criticità emerse dall’esercitazione, attività così importante a nostro avviso da considerarne indispensabile la ripetizione con cadenza quanto meno annuale.

Description: Published

Description: 1SR. TERREMOTI - Servizi e ricerca per la Società

Description: N/A or not JCR

Description: open

Description: We examined shear wave splitting in SKS and S phases from 22 teleseisms at 10 temporary stations on a transect across the Northern Apenninic arc. The array, near 43øN, spans from Corsica Island across the Tyrrhenian region and the Apenninic belt to the Adriatic coast. We applied particle motion, covariance matrix decomposition, and cross correlation methods to estimate the polarization direction of the fast split - shear wave (q•) and the delay time between split phases (fit). Most of the analyzed shear waves show clear evidence of splitting. The q• in the Adriatic foreland and in the Apennines are approximately parallel to the strike of the mountain belt (NW-SE). The largest fit correspond to the highest elevations, suggesting that anisotropy is related to the compressional tectonics which built the Apennines, and that this tectonic compression involved at least the entire lithosphere. In the Tyrrhenian area we observe q• oriented about E-W, suggesting a reorientation of the mantle fabric due to astenospheric flow, responsible for the E-W post-orogenic extension observed at the surface.

Description: Published

Description: 2721-2724

Description: 7T. Struttura della Terra e geodinamica

Description: JCR Journal

Description: In this paper, we describes the role of the INGVterremoti blog in information management during the first part of the earthquake sequence in Central Italy (August 24-September 30). In the last four years, we have been working on the INGVterremoti blog in order to provide quick updates on the ongoing seismic activity in Italy and in-depth scientific information. These include articles on specific historical earthquakes, seismic hazard, geological interpretations, source models from different types of data, effects at the surface, and so on. We have delivered information in quasi-real-time also about all the recent magnitude M≥4.0 earthquakes in Italy, as well as on the strongest events that occurred in the Mediterranean and in the world. During the 2016, central Italy earthquake sequence, the INGVterremoti blog has continuously released information with three types of posts: i) updates on the ongoing seismic activity; ii) reports on the activities carried out by the INGV teams in the field and by other working groups; iii) in-depth scientific articles describing some specific analysis and results. All the blog posts have been shared automatically and in real time on the other social media of the INGVterremoti platform, also to counter the bad information, and to fight rumors. These include Facebook, Twitter and the INGVterremoti App on IOS and Android. As well, both the main INGV home page (www.ingv.it) and the INGV earthquake portal (http://terremoti.ingv.it) have published the contents of the blog on dedicated pages that were fed automatically. The work done day by day on the INGVterremoti blog has been coordinated with the INGV Press Office that has written several press releases based on the contents of the blog. Since August 24th, 53 articles were published on the blog, and they have had more than 1.9 million views and 1 million visitors. The peak in the number of views, which was more than 800,000 in a single day, was registered on August 24, 2016, following the M 6.0 earthquake.

Description: Published

Description: 4TM. Web e Social

Description: JCR Journal