eprintid: 2275 rev_number: 9 eprint_status: archive userid: 6 dir: disk0/00/00/22/75 datestamp: 2020-07-13 08:17:02 lastmod: 2020-07-13 08:17:02 status_changed: 2020-07-13 08:17:02 type: article metadata_visibility: show creators_name: Zbinden, Dominik creators_name: Rinaldi, Antonio P. creators_name: Diehl, Tobias creators_name: Wiemer, Stefan corp_creators: Swiss Seismological Service, Swiss Federal Institute of Technology, ETHZ, Zürich, Switzerland corp_creators: Swiss Seismological Service, Swiss Federal Institute of Technology, ETHZ, Zürich, Switzerland corp_creators: Swiss Seismological Service, Swiss Federal Institute of Technology, ETHZ, Zürich, Switzerland corp_creators: Swiss Seismological Service, Swiss Federal Institute of Technology, ETHZ, Zürich, Switzerland title: Hydromechanical Modeling of Fault Reactivation in the St. Gallen Deep Geothermal Project (Switzerland): Poroelasticity or Hydraulic Connection? subjects: MP6 subjects: RS2 subjects: SG divisions: S4CE-1 full_text_status: none abstract: In 2013, fluid injection during the St. Gallen deep geothermal project, Switzerland, induced hundreds of seismic events, including a urn:x-wiley:grl:media:grl60115:grl60115-math-0001 3.5 earthquake on a fault hundreds of meters away from the well. Recent studies have suggested the direct pressure effect through permeable hydraulic connections and poroelastic effects as possible mechanisms for inducing seismicity on distant faults. In St. Gallen, operational, seismic, and earthquake data are available to investigate the underlying physical mechanisms using a numerical model. The results show that Coulomb stress changes at the fault can be 3 orders of magnitude greater when a hydraulic connection is present. Combining this with several field observations, we conclude that the direct pressure effect was more likely the predominant mechanism behind the seismicity induced in St. Gallen. The detection of hydraulic connections may be important for future projects as pressure can be driven far from the well and reactivate remote faults. date: 2020 date_type: published publication: Geophysical Research Letters volume: 47 number: 3 publisher: American Geophysical Union id_number: doi:10.1029/2019GL085201 issn: 0094-8276 official_url: https://doi.org/10.1029/2019GL085201 access_IS-EPOS: limited owner: Publisher citation: Zbinden, Dominik and Rinaldi, Antonio P. and Diehl, Tobias and Wiemer, Stefan (2020) Hydromechanical Modeling of Fault Reactivation in the St. Gallen Deep Geothermal Project (Switzerland): Poroelasticity or Hydraulic Connection? Geophysical Research Letters, 47 (3). DOI: https://doi.org/10.1029/2019GL085201