Detection, Location and Characterisation of CO2 Releases in Near Surface Regions Using a Hierarchical Monitoring Concept

Carbon dioxide capture and storage technology (CCS) offers the possibility of achieving climate protection targets by reducing industrial greenhouse gas emissions. However, there are still uncertainties related to the large-scale implementation of this emergent technology, while public perception of geological CO2 storage in geological formations remains generally negative - motivated in particular by perceived leakage risks and their associated health impacts. Therefore, a monitoring strategy combining appropriate methods is needed to gain information about the location of migration paths, seepages, and the CO2 distribution in the shallow subsurface. Adoption of such systems can also lead to increased public acceptance of CCS technology. This presentation will give an introduction into the development of a hierarchical monitoring concept and show the validation results at a natural analogue. Promising results achieved from measurements taken at natural analogue sites indicate that the hierarchical monitoring approach represents a multi-disciplinary modular concept which works in different scales and resolutions. The notable combination of distinct gas analysis and geophysical methods results in a reliable detection and characterization of gas release zones.