[M-IS04] Interdisciplinary studies on pre-earthquake processes

[MIS04-P06] Fixed-point observation of radon flux at Asahi

*Fukunaga Shiori¹, Shu Kaneko¹, Haruna Kojima, Kazuhide Nemoto, Kitade Akitugu¹, Ota Yuichiro¹, Chie Yoshino¹, Toshiharu Konishi², Tomonobu Miyakawa², Katsumi Hattori¹ (1.Chiba university, 2.Ohyo Koken Kogyo, Co., Ltd)

Keywords:radon, Flux

In recent years, earthquake prediction using radon gas measurements based on chemical channels in the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) has attracted attention. In this model, radon gas generated in the atmosphere is ionized, increasing the concentration of atmospheric ions, which reduces the electric field in the atmosphere and causes an anomaly in the ionosphere. The 1996 South Hyogo Prefecture Earthquake was reportedly preceded by increased atmospheric radon. (Kobe Pharmaceutical Univ., 2012) On the other hand, it has been confirmed that the increase or decrease of radon gas is greatly affected by meteorological components such as precipitation and wind direction, in addition to changes in ground stress.
Therefore, meteorological components were extracted from the observed radon gas using Multi-Channel Singular Spectrum Analysis (MSSA), a time series analysis, to analyze the increase and decrease of radon gas due to changes in ground stress at depths of 60 cm and 100 cm, respectively. The results showed that the baseline was higher at 100cm than at 60 cm and was less affected by fluxes due to precipitation. Details will be discussed on-site.