STL decomposition analysis for anomaly detection in soil radon and thoron concentrations along Chite fault in Aizawl

Abstract

This paper explores the correlation between soil radon and thoron concentrations and seismic events at Chite fault in Aizawl over a three year period using SSNTDs. The data analysis was done using STL method which decomposes a time series into three components: seasonal, trend, and remainder. Elevated residual concentrations of these gases were observed prior to the M5.4 earthquake that occurred at a distance of 123.9 km from the monitoring station, suggesting a potential link between gas emanation and seismicity. The results of the study demonstrated the effectiveness of the STL method in detecting anomalies in diverse time series datasets.