The geosciences perspective on seismic response assessment and application to risk mitigation - Guest Editorial

Earthquake effects cause dramatic social damage in terms of deaths, injuries and homeless, as well as economic losses when they impact human activities and infrastructures. During the last four decades, the number of people living in areas potentially exposed to earthquakes has almost doubled, as about 2.7 billion people presently reside in seismically active regions. In the period 2001-2020, earthquakes (and tsunamis) were responsible for an average (per year) of 38,000 killed people, more than 6.2 million affected people, and economic losses of about 35 billion US$ (CRED’s Emergency Events Database, 2021; https://www.cred.be/publications). Not only the most destructive events (e.g., Sumatra 2004, Haiti 2010, Fukushima 2011), but also minor worldwide distributed earthquakes (about 15,000 per year events with magnitude between 7.0 and 4.0) are continuously revealing the essential role of prevention activities devoted to the assessment, management, and mitigation of seismic risk in urban settlements. This is the case of Italy, one of the Mediterranean regions more prone to seismic activity where even earthquakes of moderate magnitude produced dramatic scenarios of devastated villages and loss of lives. The last earthquakes in northern-central Italy (the 2009 Mw=6.1 L’Aquila event, the 2012 ML=5.9. Emilia event, the 2016-2017 up to Mw 6.5 Amatrice- Norcia sequence) severely damaged many residential and strategic infrastructures, and hundreds of people died after the collapses of structures and unreinforced masonry buildings. For these seismic sequences, several technical and scientific activities were carried out in the emergency and postemergency phases (i) to collect information related the nature and the source of the seismic event (e.g., Lavecchia et al., 2012; Chiaraluce et al., 2017; Wilkinson et al., 2017; Pezzo et al., 2018), (ii) to identify the extent and evaluation of local site effects in comparison to the building damage pattern (e.g., Tertulliani et al., 2012; Douglas et al., 2015), and (iii) to support reconstruction in the damaged settlements (e.g., Moscatelli et al., 2020; Vessia et al., 2021).