GNGTS 2013 - Atti del 32° Convegno Nazionale

Caccamo D., Barbieri F. M., Laganà C., D’Amico S., Parrillo F., 2007a. A study about the aftershock sequence of 27 December 2003 in Loyalty Islands. Boll. Geo. Teor. Appl., 48 (1), 53-63. Caccamo D., D’Amico S., Parrillo F., Barbieri F. M., Laganà C., 2007c. Umbria-Marche sequence (central-Italy): a study about its aftershock sequence. Boll. Geo. Teor. Appl., 48, 385-398 Caccamo D., Parrillo F., D’Amico S., Barbieri F. M., Laganà C., 2007b. Seismic anomalies in the aftershock sequence of November 16, 2000 in Papua New Guinea, Izvestiya - Physics of the Solid Earth. 43, 662-668, doi:10.1134/ S106935130708006X. Coleman T. F.; Y. Li, 1994. On the convergence of reflective Newton methods for large-scale nonlinear minimization subject to bounds, Mathematical Programming, Vol. 67, N. 2, 189-224. Coleman T. F.; Y. Li, 1996. An interior, trust region approach for nonlinear minimization subject to bounds, SIAM Journal on Optimization, Vol. 6, 418-445. D’Amico S., Caccamo D., Parrillo F., Laganà C., Barbieri F., 2010. The 20th September 1999 Chi-Chi earthquake (Taiwan): a case of study for its aftershock seismic sequence. Izvestiya - Physics of the Solid Earth. 46, 4, 317-326, doi: 10.1134/ S106935131004004X. Dennis, J. E. Jr., 1977. Nonlinear Least Squares, State of the Art in Numerical Analysis, ed. D. Jacobs, Academic Press, 269-312. Gutenberg B. & Richter, C.F., 1942. Earthquake Magnitude, intensity, energy and acceleration, Bull. Seism. Soc. Am., 32, 162-191. Gutenberg, B. and Richter, C.F., 1954. Seismicity of the earth, Princenton University Press, Princenton, N. J. 310. Gutenberg, B. and Richter, C.F., 1956. Magnitude and energy of earthquakes, Ann. Geopys., 9, 1. Levenberg K., 1944. A method for the solution of certain problems in least squares, Quarterly Applied Math. 2, 164-168. Marquardt D., 1963. An algorithm for least-squares estimation of nonlinear parameters, SIAM Journal Applied Math. Vol. 11, 431-441. Matsu’ura R. S., 1986. Precursory quiescence and recovery of aftershock activities before some large aftershocks. Bulletin of the Earthquake Research Institute University of Tokyo, 61, 1-65. More J. J., 1977. The Levenberg-Marquardt algorithm: implementation and theory, Numerical Analysis, ed. G. A. Watson, Lecture Notes in Mathematics 630, Springer Verlag, 105-116. Page R., 1968. Aftershocks and microaftershocks of the great Alaska earthquake of 1964. Bull. Seism. Soc. America, 58, 1131-1168. Udias A., 2001. Principles of seismology. Cambridge University Press. Utsu T., 1961. A statistical study of the occurrence of aftershocks, Geophys. Magazine, 30, 521-605. Utsu T., 1969. Aftershocks and earthquake statistics - source parameters which characterize an aftershock sequence and their interrelations, J. Phys. Earth, 43, 1-33. Utsu T., Ogata Y., Matsu’ura R., 1995. The Centenary of the Omori Formula for a Decay Law of Aftershock Activity. J. Phys. Earth, 43, 1-33. The significance of the “hidden” faults of the eastern flank of Mt. Etna and their seismogenic potential: new geological constraints S. Catalano 1 , G. Tortorici 1 , A. Torrisi 2 , G. Romagnoli 1 , F. Pavano 1 1 Dipartimento di Scienze Biologiche, Geologiche e Ambientali – Sezione di Scienze della Terra, Università di Catania, Italy 2 Regione Sicilia – Dipartimento Regionale di Protezione Civile – Servizio Regionale per la Provincia di Catania, Italy Introduction. The main seismic events on the eastern flank of Mt. Etna, characterized by low to medium magnitude (M≤ 5; Azzaro et al. , 2009), are generally accompanied by the development of well-defined coseismic fracture zones. Their coincidence with the elongation of the mesoseismic areas, where most of the damages are confined, suggests interpreting the fractures as the emergence at surface of capable seismogenic structures (Azzaro, 1999; Barreca et al. , 2013). This hypothesis is fully demonstrated along the NNW-oriented tectonic alignments, where the historical coseismic fracturing matched oblique (dextral) normal faults, showing well defined Late Quaternary cumulative scarps (e.g. Timpa of Acireale and Moscarello; see inset in Fig. 1; Monaco et al. , 1997). On the contrary, discrete NW-SE oriented fracture zones cyclically form along alignments, where neither morphological nor geological cumulative displacements can be recognized. Even if their relation with rooted faults is obscure and mostly based on their cyclical coseismic renewal, these alignments have been interpreted as seismogenic “hidden” faults (e.g. Fiandaca Fault and S. Tecla Fault), responsible for part of the main local seismicity (Azzaro, 1999). The full understanding of the origin and nature of the 40 GNGTS 2013 S essione 1.1