GNGTS 2022 - Atti del 40° Convegno Nazionale

GNGTS 2022 Sessione 1.1 25 are likely related to a more active seismicity (Castro et al. , 2000; Tusa et al. , 2012) and to less attenuation in the more stable northeast region (Castro et al. , 1996; Malagnini et al. , 2002). One of our goals in the future is to investigate the spectral decay parameter κ before and after the main events of Amatrice (M6.0) of 24 August 2016, and Norcia (M6.5) of 30 October 2016. Preliminary results (Castro et al. , 2022b) showed that for both two earthquake sequence, the temporal variation of κ parameter could be a good indicator to monitor the earthquake cycle. Acknowledgements We are very grateful to Daniele Spallarossa from the University of Genova for providing the data set used in this study. This research was supported by Istituto Nazionale di Geofisica e Vulcanologia (INGV) in the frame of the project Pianeta Dinamico (Working Earth) in the task concerning the Seismic attenuation and variability of seismic motion. References Akinci, A., Del Pezzo, E. and Malagnini, L.; 2020. Intrinsic and scattering seismic wave attenuation in the central Apennines (Italy) . Phys. Earth Planet. In., 303 , DOI: 10.1016/j.pepi.2020.106498. Anderson, J. G.; 1991. A preliminary descriptive model for the distance dependence of the spectral decay parameter in southern California . Bull. Seismol. Soc. Am., 81 , 2186-2193. DOI: 10.1785/BSSA0810062186. Anderson, J. G., and Hough, S.; 1984. A model for the shape of the Fourier amplitude spectrum of acceleration at high frequencies . Bull. Seism. Soc. Am., 74 , 1969-1984. DOI: 10.1785/BSSA0740051969. Anderson, J. G., and Lei, Y.; 1994. Nonparametric description of peak acceleration as a function of magnitude, distance, and site in Guerrero, Mexico . Bull. Seismol. Soc. Am., 87 , 67-84. DOI:10.1785/BSSA0840041003. Bennington, N., Thurber, C., and Roecker, S.; 2008. Three-dimensional seismic attenuation structure around the SAFOD site, Parkfield, California . Bull. Seismol. Soc. Am., 98 , 6, 2934-2947. DOI: 10.1785/0120080175. Castro, R. R., Pacor, F., Sala, A., and Petrungaro, C.; 1996. S wave attenuation and site effects in the region of Friuli, Italy . J. Geophys. Res. 101, B10, 22, 3552-2,369. DOI: 10.1029/96JB02295. Castro, R. R., Trojani, L., Monachesi, G., Mucciarelli, M., and Cattaneo, M.; 2000. The spectral decay parameter in the region of Umbria-Marche, Italy . J. Geophys. Res. 105, 23,811-23,823. DOI: 10.1029/96JB02295. Castro, R. R., Pacor, F. and Spallarossa, D.; 2021. Depth-dependent shear-wave attenuation in central Apennines, Italy . Pure Appl. Geophys. 178, 2059-2075. DOI: 10.1007/s00024-021-02744-9. Castro, R. R., Colavitti, L., Vidales-Basurto, C. A., Pacor, F., Sgobba, S., and Lanzano, G.; 2022a. Near-Source Attenuation and Spatial Variability of the Spectral Decay Parameter Kappa in Central Italy . Seismol. Res. Lett. XX, 1-12. DOI: 10.1785/0220210276. Castro, R. R., Spallarossa, D., Lanzano, G., Colavitti, L., Pacor, F., Vidales-Basurto, C. A., and Sgobba, S.; 2022b. Temporal Variation of the Spectral Decay Parameter Kappa in Central Italy . Geophys. Res. Lett., in prep . Chiarabba, C., De Gori, P., Cattaneo, M., Spallarossa, D., and Segou, M.; 2018. Faults geometry and the role of fluids in the 2016-2017 central Italy seismic sequence . Geophys. Res. Lett., 45 , 14, 6’963-6’971. DOI: 10.1029/2018GL077485. Chiarabba, C., Buttinelli, M., Cattaneo, M., and De Gori, P.; 2020. Large earthquakes driven by fluid overpressure: The Apennines normal faulting system case . Tectonics, 39 , 4, e2019TC006014. DOI: 10.1029/2019TC006014. Fernández, A. I., Castro, R. R., and Huerta, C. I.; 2010. The spectral decay parameter kappa in northeastern Sonora, Mexico . Bull. Seismol. Soc. Am., 100 , 196-206. DOI: 10.1785/0120090049. Gabrielli, S., Akinci, A., Ventura, G., Napolitano, F., Del Pezzo, E., and De Siena, L.; 2021. Changes in seismic attenuation due to fracturing and fluid migration during the 2016-2017 central Italy seismic sequence . J. Earth Space Sci. Open Archive, 33 . DOI:10.1002/essoar.10507643.1. Ktenidou, O.-J., Cotton, F., Abrahamson, N. A., and Anderson, J. G.; 2014. Taxonomy of κ: A review of definitions and estimation approaches targeted to applications . Seismol. Res. Lett. 85 , 1, 135-146. DOI: 10.1785/0220130027. Ktenidou, O.-J., Abrahamson, N. A., Drouet, S., and Cotton, F.; 2015. Understanding the physics of kappa (κ): Insights from a downhole array . Geophys. J. Int., 203 , 1, 678–691. DOI: 10.1093/gji/ggv315. Lanzano, G., Felicetta, C., Pacor, F., Spallarossa, D., and Traversa, P.; 2020. Methodology to identify the reference rock sites in regions of medium-to-high seismicity: An application in central Italy . Geophys. J. Int. 22 , 2053-2067. DOI: 10.1093/gji/ggaa261. Lanzano, G., Felicetta, C., Pacor, F., Spallarossa, D., and Traversa, P.; 2022. Generic-to-reference rocks scaling factors for the seismic ground motion in Italy . Bull. Seismol. Soc. Am. DOI: 10.1785/0120210063.