Time-Dependent Seismic Hazard Analysis for Induced Seismicity: The Case of St Gallen (Switzerland), Geothermal Field

Reliable seismic hazard analyses are crucial to mitigate risk. When dealing with induced seismicity the standard Probabilistic Seismic Hazard Analysis (PSHA) has be modified because of peculiar characteristics events. In particular, relative shallow depths, small magnitude, a correlation field operations, and eventually non-Poisson recurrence time. addition well-known problem estimating maximum expected it is important take into account how industrial operations affect temporal spatial distribution earthquakes. fact, during specific stages project may hard modelled as Poisson process—as usually done in PSHA—and can cluster near well or migrate toward hazardous known or—even worse—not faults. Here we present technique which modify PSHA compute time-dependent hazard. The allows using models (BPT, Weibull, gamma ETAS) whose parameters fitted record distinct operations. As test case, procedure been implemented by data recorded at St. Gallen deep geothermal field, Switzerland, fluid injection. results suggest that analyses, appropriate model, ground motion predictive equations, magnitude allow ground-motion reliably predicted study area. predictions support site managers decide proceed avoiding adverse consequences.