Quantitative modeling of fault-fluid-discharge and fault-dilation- induced fluid-pressure variations in the seismogenic zone

Abstract

The rise of fluid pressure along a fault plane can trigger an earthquake as shear strength decreases. Recent models have thus suggested that the rate of interseismic fluid-pressure increase may control earthquake recurrence. In electric-analog model simulations incorporating new experimental data on rock properties within the lower seismogenic zone, resultant fluid-pressure fluctuations are restricted to the fault plane, and are strongly attenuated during their slow propagation into the country rock. The results may imply that if elevated fluid pressure weakens transcrustal fault zones, they are likely to remain weak after earthquakes. -from Authors