资源环境科技发展态势分析平台

Seismic hazard forecasts of induced seismicity often require estimates of the maximum possible magnitude (M_max). Empirical models suggest that maximum magnitudes, or expected numbers of earthquakes, are related to the volume of injected fluid. We perform a suite of 3D physics-based earthquake simulations with rate- and state-dependent friction, systematically varying the area of the pressurized region and the amplitude of the initial homogeneous or heterogeneous shear stress. Using the resulting catalogs we explore the conditions that result in pressure-controlled versus runaway ruptures that extend outside the pressurized zone. We find that proposed empirical scaling laws correctly predict M_max when shear stresses are further from failure ( ≤ 90% of maximum shear stress) and for short wavelength, high amplitude stress fields. Runaway ruptures are observed for higher initial shear stresses and smoother stress fields. In these cases, runaway ruptures occur early after the onset of injection and are rarely preceded by foreshock activity.