Publication Date:
2023-08-02
Description:
The moment magnitude is closely related to the seismic moment, which quantifies the energy released by earthquakes, and is therefore important for understanding volcanic dynamics and assessing seismic hazard. In this study, we calculate the moment-based magnitude (MW) for selected seismic data sets, using different approaches in distinct magnitude ranges to cover the widest possible range of magnitude that characterizes Etna's seismicity. Specifically, we computed the MW from a dataset of full moment tensor solutions of earthquakes that occurred in the magnitude range 3.4≤ ML ≤ 4.8 during 2005-2020; we created a dataset of seismic moment and associated MW for earthquakes 2.0 ≤ ML 〈 3.4 obtained by analyzing source spectra; we fine-tuned two relationships, for shallow and deep earthquakes, to obtain MW from response spectra. Finally, we calibrated a specific relationship between MW and ML for the Etna area earthquakes in the range 2.0 ≤ ML ≤ 4.8 and for microseismicity (ML 〈 2.0) using synthetic data. Our results show that the scaling between ML and MW is 1 for magnitude 2.0 ≤ ML ≤ 4.8, while it becomes 2/3 when we extend the relationships to ML 〈 2.0. All the empirical relationships obtained in this study can be applied in real-time analysis of the seismicity to provide fast and robust information on the released seismic energy.
Language:
English
Type:
info:eu-repo/semantics/conferenceObject
