Evidence for periodic influences on radon time series was obtained from the active Manisa Fault Zone, Western Anatolia Extensional Province, Turkey

Abstract Soil gas radon anomalies have been used for predicting earthquakes since it was proved that radon is one of the most effective natural process tracers. Analysis of the radon time series is the crucial phase to demonstrate the relationship between an earthquake and radon anomaly. A major part of the analysis of a time series is the characterization of its periodic and non-periodic components. This study, it is aimed to reveal the periodic components in the soil gas radon time series obtained from the Manisa Fault Zone (MFZ), one of the active seismic sources of Western Anatolia. Periodic components of the short-term radon time series were tested with Fast Fourier Transform (FFT). The obtained results show that atmospheric pressure component S1, which acts periodically, has been encountered in the radon time series. It is also found that soil gas radon activity concentrations were quite variable during the study period independently from the periodic components.