A database of damaging small-to-medium magnitude earthquakes

Abstract

Interest in small-to-medium magnitude earthquakes and their potential consequences has increased significantly in recent years, mostly due to the occurrence of some unusually damaging small events, the development of seismic risk assessment methodologies for existing building stock, and the recognition of the potential risk of induced seismicity. As part of a clear ongoing effort of the earthquake engineering community to develop knowledge on the risk posed by smaller events, a global database of earthquakes with moment magnitudes in the range from 4.0 to 5.5 for which damage and/or casualties have been reported has been compiled and is made publicly available. The two main purposes were to facilitate studies on the potential for earthquakes in this magnitude range to cause material damage and to carry out a statistical study to characterise the frequency with which earthquakes of this size cause damage and/or casualties (published separately). The present paper describes the data sources and process followed for the compilation of the database, while providing critical discussions on the challenges encountered and decisions made, which are of relevance for its interpretation and use. The geographic, temporal, and magnitude distributions of the 1958 earthquakes that make up the database are presented alongside the general statistics on damage and casualties, noting that these stem from a variety of sources of differing reliability. Despite its inherent limitations, we believe it is an important contribution to the understanding of the extent of the consequences that may arise from earthquakes in the magnitude range of study.

Green, yellow, red, or out of the blue? An assessment of Traffic Light Schemes to mitigate the impact of hydraulic fracturing-induced seismicity

“…This being the case, global observations of earthquake damage (e.g. Nievas et al, 2020a) can provide a basis for calibrating magnitude thresholds, provided certain assumptions are made regarding the completeness of reporting for damaging events (Nievas et al 2020b) and that the exposed building stock is analogous to that affected by the earthquakes for which damage was reported. However, a critical question is whether the red-light threshold of a TLS should be fixed at the target risk level, or whether it is necessary to set the red light at a lower threshold if the risk target is to be achieved.…”

The damaging character of shallow 20th century earthquakes in the Hainaut coal area (Belgium)

“…In seismically active regions, even though M w = 4.0 earthquakes can be locally damaging (Nappi et al, 2021), current hazard is associated with the upper part of this magnitude range. In western Europe, M w = 4.0 to 5.0 shallow earthquakes represent the most probable current source of seismic risks, which is currently enhanced by the increase of induced seismicity by underground energetic resources (Grigoli et al, 2017;Nievas et al, 2020). In western Europe, the potential for destruction of shallow earthquakes is exemplified by the damaging impact of the 11 May 2011 Lorca (Spain, M w = 5.1; Association Française de génie Parasismique, 2011), 16 August 2012 Huizinge (The Netherlands, M w = 3.6; Dost and Kraaijpoel, 2013) and 11 November 2019 Le Teil (France, M w = 4.9; Schlupp et al, 2021) earthquakes.…”

Seismic reliability assessment of a non-seismic reinforced concrete framed structure designed according to ABNT NBR 6118:2014

“…Since seismic risk is a combination of seismic hazard, exposure and structures' vulnerability, and although strong earthquakes are not expected or less frequent, if buildings are not properly detailed and designed to withstand seismic loads, high losses due to small-to-moderate events may be expected. For instance, Nievas et al [3] present an extensive database of events worldwide with M from 4.0 to 5.5 for which damage and/or casualties have been reported. It also has to be highlighted damaging events that have occurred in Brazil, e.g., the João Câmara earthquake in Rio Grande do Norte state and the Itacarambi earthquake in Minas Gerais state ([2], Takeya et al [4]); the latter causing the first reported fatal victim due to earthquakes in Brazil.…”