Groundwater extraction-induced seismicity around Delhi region, India.

The non-tectonic deformation, either of natural or anthropogenic origin, may influence the earthquake occurrence process and seismicity rate along the plate-boundary or 'stable' plate-interiors domains. The low magnitude but moderate seismicity rate of Delhi region on the stable plate-interiors domains of India, exhibits significant variation both in short-term at annual seasonal scale and in long-term at decadal scale. It correlates with the anthropogenic groundwater pumping for the extensive irrigation, urban activities, and seasonally controlled hydrological loading cycle of Indo-Ganga Basin hosted freshwater aquifers. Our coupled hydro-mechanical simulation and poro-mechanical analysis of basement fault stability suggest that the combined aquifer contraction and basement rock expansion act together to modulate the effective stress regime and anthropogenic seismicity on the basement faults in Delhi region.