Soil gas monitoring for identifying potential ground movements and earthquakes in the frame of mine flooding – Requirements, methods and developments

Soil gas surveys (e.g. 222Rn, CO2, O2 etc.) are very well known in diverse backgrounds such as the detection of geological faults, prediction of earthquakes or monitoring of gas contamination risks at building sites. Risk monitoring using soil gases in the frame of mine flooding is a quite new field of application currently investigated in the frame of the German BMBF funded project FloodRisk. Analogies to some of the classical soil gas applications highlight a relevant potential for technology transfer to the mining industry. Flooding of closed-down mines can induce ground movements and earthquakes that can potentially be monitored with soil gases provided that site-specific characteristics meet soil gas survey requirements. Such relevant requirements, as well as standard soil gas methods used, but in particular also first steps for new, low-cost sensor developments for permanent soil gas monitoring will be presented in this contribution.