The California drought is favorising uplift and seismicity along the San Andreas Fault.
Human-induced groundwater depletion is responsible for observed seasonality in microseismicity at Parkfield and potentially affecting long-term seismicity rates for fault systems along the San Andreas Fault.
The observed uplift closely matches that predicted by a simple elastic model driven by current rates of water-storage loss within the valley. This activity may reduce the effective normal stress resolved on the adjacent San Andreas Fault, which may explain some of the annual modulation of seismicity observed in this area.