Correlating precursory declines in groundwater radon with earthquake magnitude

Factors Controlling the Spatial and Temporal Variability in Groundwater 222Rn and U Levels

Radon (222Rn) and uranium (U) measurements were conducted in 98 groundwater samples in Yongin area, Korea to identify the factors controlling their levels and spatial distributions. Groundwater samples were obtained from the different depth of wells used for drinking water and irrigation. 222Rn and U concentrations were measured using a liquid scintillation counter (LSC) equipped with a pulse-shape analyzer and inductively coupled plasma mass spectrometers (ICP-MS), respectively. Large variations were observed in groundwater concentrations of 222Rn and U, ranging between 0.6 ± 0.1–673.7 ± 8.7 Bq L−1 and 0.02–117.00 µg L−1, respectively. Correlation analysis revealed no significant relationship between field parameters (temperature, electrical conductivity, pH, and dissolved oxygen) and 222Rn or U concentrations. The fact that 222Rn and U concentrations were higher in granite areas than gneiss areas suggests that lithology plays a significant role in controlling the levels and spatial distributions of the two radionuclides. Furthermore, groundwater 222Rn and U behaviors have been affected by the existence of fault and well depth. Especially, the temporal monitoring of 222Rn suggests that 222Rn concentrations in the shallow groundwater may be controlled by variation in rainfall and artificial effects such as water curtain cultivation conducted in the winter season in this study area.

Measurement of radon in ground waters of the Western Caucasus for seismological application

Results of radon ((222)Rn) concentration measurement in ground waters in the Western Caucasus are described. In 2010-2011 each day at 12:00 Moscow winter time (9:00 GMT) sampling in volume of 0.5 l of waters was carried out in two wells at depth of 30 m and 180 m. In 2012 three times per day (7:00, 12:00, 17:00) this sampling was already carried out. Radon from water was extracting by degassing method with use of bubbler. Measurements of alpha activity of gas in scintillation (ZnS) chambers were done. The water radon data with seismic, meteorological and the Sun-Lunar data were compared. The mathematical method of definition of "splashes" in radon data before regional earthquakes is considered. The greatest probability in 72% of the forecast of regional earthquakes for the data from a well of 30 m depth was received. Correlation between meteo and radon data is absent. Correlation of lunar phases and solar activity with radon data is discussed. In July-December, 2012 sampling of water from 15 wells and measurements of radon were carried out. The distance between wells was near 50 km. Changes of radon maps in territory of South Russia during earthquakes are shown.