GNGTS 2013 - Atti del 32° Convegno Nazionale

Simultaneous analysis of all data in the database, and an integrated interpretation of all the precursors studied within the project. Conclusions. All earthquakes of magnitude > 3.0 were preceded by anomalies. It can be said that the success rate is 100%, but, for low magnitude, the duration and the time precursor does not seem to have a strictly constant trend with respect to the magnitude. The duration of the Anomaly and the Time Precursor seem to be proportional to the high magnitude. High magnitude earthquakes seems to have anomalies with order of years. With this type of analysis is difficult, however, to discriminate the false positives, because, each anomaly precedes an earthquake although of low magnitude (<3.0) selected according Hauksson and Goddard (1981). From the data analysed above only one anomaly not relatable to any seismic event was found. Conversely, all significant long period anomalies were followed by earthquakes of magnitude > 5.0. Of course all Anomalies have been identified in retrospect. Analysis will be done with another method of calculation, which will also be applied to other data that are part of the database. The results obtained in previous works, suggest that the variations of radon are indicative of the state of stress of the preparation area of the earthquake and then the deformation. The presence of Anomalies in the same periods and in different sites, gives hope in the fact that increasing the number of monitoring sites, located throughout the country, could make a great contribution.The comparison with other observable, last but not least, should lead to identifying areas involved in the processes of deformation. Acknowledgements. The research was carried out in the framework of the activities of the seismological projects S3 (2012-2013) financed by the Italian Department of Civil Protection and the National Institute of Geophysics and Volcanology. References Gutenberg B. and Richter C.F.; 1944: Frequency of earthquakes in California Bull. Seism. Soc. Am., 34 , 185-188. Hauksson E. and Goddard J.G.; 1981: Radon Earthquake Precursor studies Iceland. J.Geophys.Res. 86, 7037-7054 ISIDE; 2002-2013: Lista degli eventi sismici registrati dalla Rete Sismica Nazionale. OGS; 2002-2012: Bollettino della Rete Sismometrica del Friuli – Venezia Giulia. OGS, Trieste. Petrini R., Italiano F., Riggio A., Slejko F.F., Santulin M., Buccianti A., Bonfanti P. and Slejko D.; 2012: Coupling geochemical and geophysical signatures to constrain strain changes along thrust faults, Bollettino di Geofisica Teorica ed Applicata. Vol. 53, n. 1, pp. 113-134; March 2012. Riggio A. and Sancin S.; 1986: Variazione nel tempo del parametro b quale precursore. In: Atti del 5° Convegno GNGTS, Esagrafica, Roma, pp. 407-419. A.Riggio, M.Santulin ; 2013: Radon as seismic precursor. Relazione I semester Progetto S3, 2012-2013. Riggio A., Sancin S., Santulin M., Popit A., Vaupotic J. and Zmazek B.; 2003: Radon e sismicità in Italia nord-orientale. In: Atti del 22° Convegno Nazionale GNGTS, file /06.26, Prospero, Trieste, CD-Rom A. Riggio, M. Santulin; 2012: Potential seismic precursors: analysis of the recent earthquakes previous periods and problems related to interpretation. 31° Convegno Nazionale GNGTS, Potenza 2012. A. Riggio, M. Santulin; 2013: Radon as seismic precursor. Relazione I semestre Progetto S3, 2012-2013 Zhang Guomin, LI Xuanhu, LI Li;1996: Research on Earthquake Prediction in China Since the 1980s, in The Selected Papers of Earthquake Prediction in China. State Seismological Bureau. Seismological Press. Editor in Chief, GE Zhizhou, Beijing, pp. 9-18. ISBN 7-5028-1331-4/P.836 (1768). 130 GNGTS 2013 S essione 2.1