GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.2 GNGTS 2023 Urban Seismic Networks: Challenges and Limitations A. Costanzo, A. D'Alessandro, S. Scudero, G. Vitale Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Nazionale Terremoti, Rome, Italy Introduction The number of fatalities due to earthquakes are expected to largely increase in the future because of the increase of global population (Holzer and Savage, 2013). Unfortunately, the recent seismic history proves that the effects of large earthquakes are often destructive in the high vulnerable urban areas (e.g., Indonesia 2006, China 2008, Italy 2009 and 2016, Haiti 2010 and 2021, Nepal 2015). Some of these earthquakes caused disproportionate amount of damage and number of casualties with respect the size of their shocks. Properly, in the last decade the awareness of the seismic risk together with the support represented by the technological developments, resulted in the increasing interest in the monitoring of urban centers, with focusing in particular at those most exposed or most vulnerable. Devoted seismic networks are useful for several tasks related to the earthquake emergency in urban areas which include both operational tasks and scientific products; among these: i) earthquake early warning; ii) mapping earthquake intensity; iii) assessment of the damage scenarios; iv) seismic zonation; v) shakemaps. The aims of urban-scale seismic monitoring networks are different with respect the “traditional” country scale-networks which are intended for earthquake observation and seismological studies at a broader scale. However, both the type of network can be integrated, each one with its own characteristics and peculiarities, in the objective of earthquake risk reduction (D’Alessandro et al., 2019a). The urban-scale networks have really distinct characteristics in terms of coverage areas and densities of nodes with respect a country-scale network; they may even differ some order of magnitude (Fig. 1). The Figure 1 also suggests that the number of nodes of a country-scale network can be one order of magnitude higher with respect the urban-scale. In this contribution we illustrate the general characteristics of the urban seismic networks: we describe the practical and scientific challenges they support but also their drawbacks.