SiMoN – Seismic Monitoring in the northern Upper Rhine Rift (Germany)

Induced seismicity related to deep geothermal projects represents a significant factor of uncertainty in the realization of German geothermal projects, especially in the Upper Rhine Rift due to the special geological situation. These circumstances do not only lead to restraint by investors and project operators, but also to a strongly decreasing public acceptance. Especially since the seismic events in Basel, Landau and Insheim, German geothermal projects cannot be planned and implemented without a focus on the seismic risk. A declared aim is therefore to minimize induced seismicity.
Within the joint research project SiMoN the universities of Frankfurt and Stuttgart as well as the Hessian State Office for Environment and Geology (HLUG) carried out fundamental research to gain a deeper insight into the connection between natural nano-, micro- and macro-seismic and induced or triggered seismicity through technical measures. This leads to a better understanding of the regional stress field. Active fault zones can be identified better and the overall understanding of the tectonic setting of the region can be broadened. This can help to adapt the necessary steps related to the project implementation in a way that triggered or induced seismicity is minimized.
Within the scope of the project, a regional network for long-term seismic monitoring has been installed in the northern part of the Upper Rhine Rift where several geothermal projects are planned for the future. The monitoring network comprises 13 new stations at the university of Frankfurt as well as five permanent stations of other operators like the HLUG. A total of three nano-seismic measurement campaigns were performed, which even detect vibrations below perception level. The Überlandwerk Groß-Gerau GmbH (ÜWG) therefore provided information on its project planning for the best possible practical relevance. GeoThermal Engineering GmbH was acting as a service provider for ÜWG and was supplying its knowledge and experience in project development in the Upper Rhine Rift.