GNGTS 2015 - Atti del 34° Convegno Nazionale

GNGTS 2015 S essione 2.1 41 The corrected daily mean radon series will be published in the database of the S3 project. For this purpose, a dedicated metadata sheet, in which the time series is described in its content and format, was compiled. The time series depurated from such component have been treated again with the PCA method, to verify possible correlations between the various sites. The Prato series was corrected by both the methods of cross-correlation and spectral analysis. Fig. 3 shows the diagram of the various sites referred to the PCA1 and PCA3. The sites that seem to have common characteristics are Gozzano, Pogno, Cazzaso and Borgolavezzaro. On the other hand, these are the sites where the sensors are installed in the basement and at least at 1 m depth, or in deep wells. Conclusions . The anomalies that greatly exceed the limit of 2-sigma are not cancelled by the procedures used to clean meteorological phenomena. This result, as well as the presence of anomalies at the same time at different sites, supports the possibility of a correlation between anomalous geochemical transients and deformations preceding earthquakes. Acknowledgements. This research was developed in the frame of the Seismological Project S3 (2014-2015), This study has benefited from funding provided by the Italian Presidenza del Consiglio dei Ministri – Dipartimento della Protezione Civile (DPC). This paper does not necessarily represent DPC official opinion and policies. References Albarello D.; 2013: Project S3 - Short-term earthquake prediction and preparation. Final Report , https://sites.google . com/site/ingvdpc2012progettos3/home. pp. 1 - 31. Albarello D.; 2015: Project S3 – Short-term earthquake prediction and preparation. Final Scientific Report. pp. 1 – 31. Bailey S.; 2012: Principal Component Analysis with Noisy and/or Missing Data. Publications of the Astronomical Society of the Pacific 124.919 (2012), pp. 1015 -1023. Gregoric A., Zmazek B., Dzeroski S., Torkar D., Vaupotic J.; 2012: Radon as an Earthquake Precursor – Methods for Detecting Anomalies. Earthquake Research and Analysis – Statistical Studies, Observations and Planning, Sebastiano D’Amico (ED), (460), pp. 179 – 196. Gualadini A.; 2014: Analisi delle Componenti Principali: cenni storici. Seminario all’interno del progetto S3, Bologna, 10/07/2014, pp. 1 – 18. Hauksson E. and Goddard J.G.; 1981: Radon Earthquake Precursor studies in Iceland. J. Geophys. Res. 86, pp. 7037 – 7054. Fig. 3 – Analysis of PCA for all the considered time series.