Seismo Lab Seminar
Fluid-driven seismicity typically refers to (minor) seismic events that (partially) involve fluid flows. Examples range from natural flows associated with rainfalls and volcanic eruptions to human-made contexts including wastewater injection wells, hydraulic fracturing, and geothermal power plants. In the cases of industrial operations fluid-driven seismicity is a side effect and arises when high-pressure fluids are pumped into the earth's crust to, for example, increase oil and/or gas flow to a well from petroleum-bearing rock formations or to improve permeability in underground geothermal reservoirs. One of the challenges associated with subsurface high-pressure fluid injections is the estimation of the seismic hazard and its spatial footprint: how far away from the injection site can seismicity be induced? Another challenge is to distinguish between seismic events that are a direct or primary consequence of the fluid injections due to the associated increase in shear stress and/or pore pressure, for example, and those that are instead triggered from these or other seismic events due to static and/or dynamic stress changes, for example, commonly denoted as aftershocks. Identifying these and the specific underlying event-event triggering mechanisms has important consequences in terms of seismic hazard assessment, earthquake forecasting, and effective mitigation strategies. A third and related challenge is to what extent fluid-driven anthropogenic seismicity bears similarities with its natural analog when it comes to event-event triggering. In this talk, I will discuss recent progress towards solving these three challenges.