GNGTS 2024 - Atti del 42° Convegno Nazionale

Session 1.1 GNGTS 2024 on a small space-tme scale and diferent methodological approaches. For the spatal defniton, we used the Kernel Density calculaton to determine an event's density probability in each radius. The tme duraton is defned using the approach described by Roland et al. 2009 based on the evaluaton of the percentage of seismicity rate. We identfed 53 polyphasic seismic clusters in the complete catalog (37-year tme window), and 30 in the improved catalog (7-year tme window). The clusters were subsequently divided into swarms and sequences. The difusivity was calculated for each cluster using the Shapiro et al. (1997) relatonship. Most of the seismicity is expressed as swarm-type and characterized by high difusivity values (≥ 1m 2 /sec) with short temporal duratons (days-months). This result confrms that the clustered seismicity is linked to highly permeable fault zones and the natural injecton of fuids under pressure. The swarms present in this sector of the Apennine chain can, therefore, be linked to the deep migraton of CO 2 -rich fuids (Chiodini et al., 2004), which exploit pre-existng fault zones as a preferental path. References Amezawa Y., Taeta T., Kosuga M. (2021) Migraton difusivity as a controlling factor in the duraton of earthquake swarms; htps://doi.org/10.1186/s40623-021-01480-7 Chiodini, G., C. Cardellini, A. Amato, E. Boschi, S. Caliro, F. Frondini, and G. Ventura (2004). Carbon dioxide Earth degassing and seismogenesis in central and southern Italy, Geophys. Res. Let., 31, L07615. doi: 10.1029/2004GL019480 Latorre D., Di Stefano R., Castello B., Michele M., Chiaraluce L. (2022) Catalogo delle Localizzazioni ASSolute (CLASS): locatons (Version 1). Isttuto Nazionale di Geofsica e Vulcanologia (INGV). htps://doi.org/10.13127/class.1.0 Roland E., McGuire J.J. (2009) Earthquake swarms on transform faults htps://doi.org/10.1111/ j.1365-246X.2009.04214.x Shapiro A.S., Huenges E., Borm G. (1997) Estmatng the crust permeability from fuid-injecton- induced seismic emission at the KTB site htps://doi.org/10.1111/j.1365-246X.1997.tb01215.x Vuan A., Sugan M., Amat G., Kato A. (2018). Improving the Detecton of Low-Magnitude Seismicity Preceding the Mw 6.3 L’Aquila Earthquake: Development of a Scalable Code Based on the Cross Correlaton of Template Earthquakes.doi:10.1785/0120170106 Zaliapin, I., & Ben‐Zion, Y. (2020). Earthquake declustering using the nearest‐neighbor approach in space‐ tme‐magnitude domain. Journal of Geophysical Research: Solid Earth, 125, e2018JB017120. htps://doi.org/ 10.1029/2018JB017120 Corresponding author: gemmacipressi@gmail.com