Induced earthquakes in Basel and St. Gallen highlight how important it is to competently and independently assess seismic hazard and risk for the approval and implementation of deep geothermal energy projects.
The Swiss Seismological Service (SED) at ETH Zurich aims to support the involved authorities and industries in establishing uniform quality standards across cantonal borders regarding earthquake-related issues, approval procedures, and project implementation. With this aim in mind, the SED offers competent, project-based seismological consulting and monitoring services through the GEOBEST-CH project, supported by SwissEnergy.
Based on its field of activity and the expertise of its staff, the SED has extensive knowledge of the area of induced seismology and is closely involved in research activities related to this issue worldwide. In the last 10 years, the SED has made its competence available to operators and especially to cantonal authorities at their request, with a view to supporting them in the seismological aspects of the environmental impact assessment (EIA) and in examining the operating and intervention concepts of deep geothermal energy projects (the cantons of Basel, Jura, Vaud, and Thurgau and the city of St. Gallen, for example). In view of its activities, the SED was and is involved in all past and current deep geothermal energy projects in Switzerland that aim to supply power as well as heat. The SED’s range of services is based on the principles of independence and transparency found here. Furthermore, the SED also plays a leading role in European and national research projects on the topic of induced seismicity (e.g. SCCER-SoE, GEOBEST-CH, GeoSim, GEISER, GEOTHERM1+2).
With a view to fulfilling its diverse tasks and requirements, the SED comprises a series of research groups dedicated to studying the topic of induced seismicity and seismic risk assessment. In addition to this, the SED also has extensive experience in setting up and operating seismic measuring stations. It runs the Swiss broadband network made up of around 45 stations, as well as a strong motion network, which is currently being modernized using funds from the federal government and expanded to include more than 100 measurement stations. In collaboration with the Seismology and Geodynamics (SEG) group at the Institute of Geophysics at ETH Zurich, the SED maintains a pool of portable seismic instruments used specifically for aftershock measurements and scientific projects.
In connection with the GeoBest project supported by the SFOE, the SED monitored the geothermal energy project in the city of St. Gallen and provided operators, authorities and the public with real-time information on observed seismicity within the vicinity of the project. The detailed seismological analysis of the earthquake sequence induced in St. Gallen made a significant contribution to understanding its causes, communication with the public and ultimately the decision regarding the course of the project. This role was hugely appreciated by the St. Gallen public utilities company and the St. Gallen city council, particularly during the months of crisis in summer 2013.