Radon (Rn-222)
It is possible to obtain the detailed information about geodynamic events (natural events such as earthquakes, volcanic eruptions, landslides, floods) by utilizing the geochemistry of gases (Giammanco ve Gurrieri, 1997; Neri et al., 2006, La Delfa et al., 2008; Siniscalchi et al., 2010, Saç et al., 2011, İçhedef et al., 2014, Tarakçı et al., 2014, Günay et al., 2018, İçhedef et al., 2020).
Seismically live (active) faults have relatively high permeability values. Terrestrial-produced gases such as CO2, He, H2, Rn, CH4, N2 and highly volatile metals such as Hg, As, Sb can be easily removed to the atmosphere from live (active) faults (Zmazek et al., 2002). For this reason, variations in gas concentrations, the identification of these processes, the magnitude and the determination of its effects on environment or predictions can be used to produce many information. The main tracers used to monitor geodynamic processes until today which are hydrogeological parameters (such as groundwater levels, water temperature, mineralization, turbidity and flux) and hydrogeochemical tracers (such as Radon and other soluble gas compounds, 234U/238U, Radium, He), deep crust gases (He, N2, CO2 and CH4) are shown (Dubinchuk, 1993). Trace gases as radon (222Rn) and helium (He) can move to the surface from deep sources, generally with carrier gases as CO2 and CH4. Both carbon dioxide (CO2) and nitrogen (N2) are potential carrier gases for radon and helium gases at fault sites (Fu et al., 2008). Due to the radon among the tracers, standing as a noble gas and a product of Uranium decay series, it is produced in the earth's crust and migrating to the atmosphere.
Radon (222Rn) is a noble gas which takes part in group VIIIA at the periodic table. Radon with atomic number 86 is colorless, odorless, tasteless and therefore indistinguishable by humans. 222Rn formed by the decay of radium (226Ra) in the uranium decay series is a radon isotope which is the most abundant with a half-life of 3.82 days. Since radon is a product of radioactive decay series and the isotopes in these series are found in the earth's crust, the most of its sources are the earth's crust, soil and rocks. Radon gas, which is formed by the decay of Radium (226Ra) emerging in these geological structures, tends to migrate towards the atmosphere.
