ALBERT

Description: The widespread lack of awareness of seismic hazard and the inadequate preparedness to protect people and property explains the high cost of damage caused by earthquakes worldwide to date. Efficient communication is of paramount importance as part of effective risk mitigation strategies. Over the past twenty years, efforts have been pursued at the local, regional, national, and international level to disseminate information on seismic hazard to populations at risk.Focusing on Europe, we analyze the main features of seismic risk communication from 2000 to 2022, and present here an overview of the results obtained based on a scoping review of the scientific literature. Our review was conducted on publications selected from Scopus, Web of Science, and Google Scholar databases and the information was gathered on the basis of the 5 ‘Ws questions’ (Who, What, When, Where, and Why). Overall, the selected publications document the relatively limited engagement of the scientific community in this risk field compared to other natural disasters. Nevertheless, the growing trend over time of publications dealing with seismic risk communication highlights the effort to attract selected targeted audiences (particularly children), using new contents, methods of implementation, and channels such as social networks and the Internet.

Description: We apply the Probabilistic Seismic Hazard Analysis (PSHA) and Physics-Based Simulations (PBS) to compute the ground motion for three dams in the Campotosto area (Central Italy). The dams, which confine an artificial water reservoir feeding hydroelectric power plants, are located in an active seismic zone between the areas that experienced the 2009 L’Aquila and 2016–2017 Central Italy seismic sequences. The probabilistic disaggregation estimated for a return period of 2475 years, corresponding to the collapse limit state for critical facilities, indicates that the most dangerous fault is associated with a maximum magnitude of 6.75±0.25 within a distance of 10 km. This fault is used in PBS to emulate the Maximum Credible Earthquake scenario. To capture the ground motion variability, we input a pseudo-dynamic source model to encompass spatial and temporal variations in the slip, rise time and rupture propagation, heavily affecting the near-source ground motion. Indeed, the ground motion above the rupture volume is mainly influenced by the epistemic uncertainties of rupture nucleation and slip distribution. The computed broadband seismograms are consistent with the near-source shaking recorded during the 2016 M〈sub〉W〈/sub〉 6.6 Norcia earthquake and constrain the upper bound of the simulated ground motion at specific sites. Our modelling reinforces the importance of considering vertical ground motion near the source in seismic design. It could reach shaking values comparable to or larger than those of the horizontal components. This approach can be applied in other areas with high seismic hazard to evaluate the seismic safety of existing critical facilities.

Description: Risk communication has evolved significantly over the past two decades. In this study, we provide an overview of the timing, methods and tools we observed in a review study of earthquake risk communication in Europe. Our study shows that communication occurs predominantly in the pre-event phase and that communication during the earthquake crisis is often limited to seismological information. Only one-fifth of the publications reviewed explicitly rely on theories of risk communication. There is an increasing convergence toward a two- or three-way communication model, i.e., the adoption of frameworks in which seismic risk experts promote proactive citizen participation; moreover, the goals of communication become more proactive than informative. The goals of earthquake risk communication are to share information, raise awareness, change behaviors/beliefs, and increase preparedness. Students and citizens are the main target groups for communication activities. The involvement of schools is based on the idea of a 'domino effect," where students share and promote earthquake mitigation information and best practices within their families. In an effort to reach an age-, culturally-, and educationally-diverse audience, traditional education/communication methods such as handouts and lesson plans are gradually giving way to exercises and hands-on activities, as well as more advanced communication tools such as infographics, video scribing, serious (video) games, and augmented reality applications. The results also show the growing role of social media as an information and dissemination channel.

Description: The moment magnitude is closely related to the seismic moment, which quantifies the energy released by earthquakes, and is therefore important for understanding volcanic dynamics and assessing seismic hazard. In this study, we calculate the moment-based magnitude (MW) for selected seismic data sets, using different approaches in distinct magnitude ranges to cover the widest possible range of magnitude that characterizes Etna's seismicity. Specifically, we computed the MW from a dataset of full moment tensor solutions of earthquakes that occurred in the magnitude range 3.4≤ ML ≤ 4.8 during 2005-2020; we created a dataset of seismic moment and associated MW for earthquakes 2.0 ≤ ML 〈 3.4 obtained by analyzing source spectra; we fine-tuned two relationships, for shallow and deep earthquakes, to obtain MW from response spectra. Finally, we calibrated a specific relationship between MW and ML for the Etna area earthquakes in the range 2.0 ≤ ML ≤ 4.8 and for microseismicity (ML 〈 2.0) using synthetic data. Our results show that the scaling between ML and MW is 1 for magnitude 2.0 ≤ ML ≤ 4.8, while it becomes 2/3 when we extend the relationships to ML 〈 2.0. All the empirical relationships obtained in this study can be applied in real-time analysis of the seismicity to provide fast and robust information on the released seismic energy.

Description: In this article, we describe the infrastructure developed and managed by the Italian National Institute of Oceanography and Applied Geophysics – OGS for the seismological and geodetic monitoring of northeastern Italy. The infrastructure was constituted in response to the ML 6.4 Friuli destructive earthquake of 1976, with the main mandate of supporting civil protection emergency activities. The OGS monitoring infrastructure is presently composed of a seismometric and a strong-motion network, complemented by a number of Global Navigation Satellite Systems stations, each delivering observational data in real time, which are collected and processed by the headquarters of the Center for Seismological Research of OGS in Udine. The OGS networks operate in close cooperation with Italian and international networks from neighboring countries, within the framework of the agreements for real-time data exchange, to obtain improved rapid earthquake location and magnitude estimations. Information regarding seismic events is released to the public through a dedicated web portal and, since 2013, through social media. Aside from the standard monitoring activities ( 〉 30;000 events have been recorded since 1976), the OGS has progressively increased the number of services to the public and to the Civil Protection of the Friuli Venezia Giulia and Veneto regions. The high availability of good quality data has resulted in the enhancement of scientific products, including advanced seismological studies of the area, spanning broadly from seismic source characterization to engineering seismology. In the future, the OGS networks are expected to further contribute to the development of seismological research and monitoring infrastructures of the Central European region.