A groundwater-radon monitoring station is in operation at Gallicano, a thermomineral spring located in Garfagnana, a high seismic area in Tuscany (Italy). The station automatically and continuously measures the radon concentration of the groundwater, and then transmits online the data to a dedicated web page [1]. Radon monitoring is performed along with the measurement of some geochemical parameters of the water, done by another dedicated station which operates together with the previous one, and belongs to a wider geochemical monitoring network operating in Tuscany since 2002 [2]. The purpose of these two stations is examining possible correlations between radon levels and geochemical parameter anomalies before an earthquake. The radon station measures the radon concentration in groundwater by means of gamma spectroscopy with a 2”x2” NaI(Tl) scintillation detector, analysing groundwater samples drawn into a Marinelli-type container after equilibrium is reached between radon and its short decay progenies. The energy and efficiency calibration of the scintillator detector is performed using a radon source with known radon concentration, placed inside a Marinelli beaker like the one used in the station. In this work, an independent verification of the efficiency calibration of the radon station is obtained by an intercomparison with the liquid scintillation counting of radon in groundwater, considering the same water sample as that one of the station. Prior to the measurements, a precise determination of the efficiency of radon counting with the liquid scintillation spectrometer was determined by measuring a set of calibrations vials [3]. The vials contained 226Ra standard solution diluted with distilled water and organic scintillation cocktail. 226Ra activity concentration covered the anticipated activity range of the samples to be analyzed. An accurate knowledge of radon concentration is mandatory to validate the acquired data series and to identify possible anomalies with respect to the radon average value and correlations with the geochemical parameters of the water. When an anomaly is identified, after removing all the other possible causes of radon concentration variation, this may be considered as a possible index of variation of the seismic activity.
Calibration of a groundwater-radon monitoring station for seismic precursor study
R. Ciolini;F. d’Errico;
2019-01-01
Abstract
A groundwater-radon monitoring station is in operation at Gallicano, a thermomineral spring located in Garfagnana, a high seismic area in Tuscany (Italy). The station automatically and continuously measures the radon concentration of the groundwater, and then transmits online the data to a dedicated web page [1]. Radon monitoring is performed along with the measurement of some geochemical parameters of the water, done by another dedicated station which operates together with the previous one, and belongs to a wider geochemical monitoring network operating in Tuscany since 2002 [2]. The purpose of these two stations is examining possible correlations between radon levels and geochemical parameter anomalies before an earthquake. The radon station measures the radon concentration in groundwater by means of gamma spectroscopy with a 2”x2” NaI(Tl) scintillation detector, analysing groundwater samples drawn into a Marinelli-type container after equilibrium is reached between radon and its short decay progenies. The energy and efficiency calibration of the scintillator detector is performed using a radon source with known radon concentration, placed inside a Marinelli beaker like the one used in the station. In this work, an independent verification of the efficiency calibration of the radon station is obtained by an intercomparison with the liquid scintillation counting of radon in groundwater, considering the same water sample as that one of the station. Prior to the measurements, a precise determination of the efficiency of radon counting with the liquid scintillation spectrometer was determined by measuring a set of calibrations vials [3]. The vials contained 226Ra standard solution diluted with distilled water and organic scintillation cocktail. 226Ra activity concentration covered the anticipated activity range of the samples to be analyzed. An accurate knowledge of radon concentration is mandatory to validate the acquired data series and to identify possible anomalies with respect to the radon average value and correlations with the geochemical parameters of the water. When an anomaly is identified, after removing all the other possible causes of radon concentration variation, this may be considered as a possible index of variation of the seismic activity.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
