Measuring the radon concentration and investigating the mechanism of decline prior an earthquake (Jooshan, SE of Iran)

Variation in earth gas level like radon in soil and groundwater is a proven technique for tracing the changes in stresses due to seismotectonic activities. Radon concentrations were measured and investigated in Jooshan hot spring complex, SE of Iran, near Golbaf-Sirch fault system from December 2011 until March 2012. Afterward, by considering and studying environmental parameters, the relationship between radon anomalous decline and all earthquakes with ratio D/R that introducing by Dobrovolsky et al. was examined. So before earthquakes, the correlation between this ratio and level of variation in radon concentration in magnitude ranging from 2.6 to 5.4 has been studied and the correlation coefficient of 0.74 was obtained. This research shows a good correlation between groundwater radon variations and such earthquake parameters. (author)