GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 Stress drop scaling is stll a very controversial topic: is it real or apparent? G. Calderoni 1 1 Isttuto Nazionale di Geofsica e Vulcanologia (INGV, Italy) The stress drop scaling is stll an unresolved issue and contnues to be controversial in the scientfc community. However, knowledge of seismic source scaling parameters plays a fundamental role in assessing the seismic forecastng in a given area and in improving ground moton predictons for seismic hazard mitgaton. For this reason, this study compares the Brune stress drop of the earthquake sequence that struck the 2010-2014 Pollino area in the southern Apennines with those estmated for other earthquakes that occurred in diferent areas of the Apennines during the following seismic sequences: 2009 L’Aquila (Calderoni et al., 2013), 2016-2017 Amatrice (Calderoni & Abercrombie 2023), 2013-2014 Sannio-Matese (Calderoni et al., 2023) and 2019 Northern Edge of the Calabrian Arc Subducton Zone (Calderoni et al., 2020). Three diferent methods are used, and the results are compared with previous studies.In the frst procedure (Calderoni et al. 2019) a two-step approach is used to model the atenuaton and then estmate the source parameters from individual earthquake spectra. In the second procedure, an EGF approach is applied. In the third procedure, a modifed EGF approach is applied using a scaling law derived by Calderoni et al., (2013) for the L’Aquila 2009 seismic sequence. To gain deeper insights into the interpretaton of the result, the structural complexites and tectonic barriers that control seismic actvity in the Pollino area are considered (Cirillo et al., 2022). References Calderoni, G., & Abercrombie, R. E. (2023). Investgatng spectral estmates of stress drop for small to moderate earthquakes with heterogeneous slip distributon: Examples from the 2016– 2017 Amatrice earthquake sequence. Journal of Geophysical Research: Solid Earth, 128, e2022JB025022. htps://doi.org/10.1029/2022JB025022 Calderoni, G., L. Improta, and R. Di Giovambatsta (2023). Investgatng the Role of Fluids in the Source Parameters of the 2013–2014 Mw 5 Matese Seismic Sequence, Southern Italy, Seismol. Res. Let. XX, 1–21, doi: 10.1785/0220230046. Calderoni, G., A. Gervasi, M. La Rocca, and G. Ventura (2020). Strike-Slip Earthquakes at the Northern Edge of the Calabrian Arc Subducton Zone, Seismol. Res. Let. XX, 1–13, doi: 10.1785/0220200251.