Radon behaviour in mineral spring water of Bad Brambach (Vogtland, Germany) in the temporal vicinity of the 1992 Roermond earthquake, the Netherlands

Abstract

The correlation between the Vogtland micro earthquakes and the fluctuations of 222Rn concentration in spring water and soil air has been investigated in the Saxon State Spa of Bad Brambach for more than three years. In contrast to the soil air, spring water shows significant radon anomalies at the time of about 50% of the earthquakes or earthquake swarms (ML < 4, epicentral distance < 50 km). The 1992 Roermond earthquake has confirmed for the first time that it is possible to register an anomaly effect in Bad Brambach related to seismic wave motion from earthquakes with larger epicentral distances. Recent investigations have shown that CO2 outgassing due to tectonic processes may act as a gas lift for radon. A model conception and first results of continuous radon and CO2 measurements in spring water are presented.