A strategy to build a unified data set of moment magnitude (Mw) estimates for low-to-moderate seismicity regions based on European–Mediterranean data: application to metropolitan France

Aurore Laurendeau (1) , Oona Scotti (1) , Christophe Clément (1)

1 IRSN/PSE-ENV/SCAN/BERSSIN - Bureau d'évaluation des risques sismiques pour la sûreté des installations

The moment magnitude (Mw) scale is largely used in seismic hazard assessment to characterize earthquake events both in the earthquake catalogues and in the ground motion databases. Several Mw values can be published by different authors for the same event due to the use of different computation methods, input data, or seismic networks. In this study, we developed a novel strategy to assign a unique and unified Mw value to each event. This hybrid strategy is based on (i) ranking Mw sources in five levels from global to specific studies, (ii) inter-comparisons of Mw estimates at the EuropeanMediterranean scale with a reference dataset, consisting of Mw values given by the global and European centroid moment tensor services and (iii) using a Mw value threshold that are useful for low-to moderate seismicity regions such as metropolitan France, the target region ofour study. For the EuropeanMediterranean region, we collected from 34 sources (bulletins, publications, ...) 6752 Mw estimates of 4454 shallow events that occurred between 1963 and 2019. A unified Mw value could be attributed to 3351 events and to 185 events in the case ofthe France region. Comparison of this new unified Mw dataset shows good agreement with the Italian CPTI15 catalogue over the 4.0

Domaines: Planète et Univers [physics]

Aurore Laurendeau, Oona Scotti, Christophe Clément. A strategy to build a unified data set of moment magnitude (Mw) estimates for low-to-moderate seismicity regions based on European–Mediterranean data: application to metropolitan France. 2022 Annual Meeting SSA Technical Sessions, Seismological Society of America, Apr 2022, Bellevue (USA), United States. pp.1328, ⟨10.1785/0220220087⟩. ⟨irsn-03927385⟩