Correlation between changes in groundwater levels and surface deformation from GPS measurements in the San Gabriel Valley, California

Kang Hyeun Ji, & Thomas A. Herring

Published 2011, SCEC Contribution #1549

Changes in groundwater levels cause water-bearing basins to deform. Here we provide a detailed history of horizontal surface displacements in the San Gabriel Valley, California, which we show are highly correlated with the water level changes measured at a nearby well: correlation coefficient of 0.96 ` 0.01. We use the surface response from a one year period during which water level change in the nearby well was over 16 m, to monitor the deformations over a 14 year period from 1998 to 2011. The water level changes lead surface deformation by 21 days, but the significance of the offset is only weakly supported (p-value = 0.129). The projection method can be used as a real-time monitoring or detection system for deformation caused by a variety of mechanisms such as fluid injection and removal (groundwater development, oil production, carbon sequestration), and by seismic and volcanic activity. Citation: Ji, K. H., and T. A. Herring (2012), Correlation between changes in ground- water levels and surface deformation from GPS measurements in the San Gabriel Valley, California, Geophys. Res. Lett., 39, L01301, doi:10.1029/2011GL050195.

Citation
Ji, K., & Herring, T. A. (2011). Correlation between changes in groundwater levels and surface deformation from GPS measurements in the San Gabriel Valley, California. Geophysical Research Letters, 39, L01301. doi: 10.1029/2011GL050195.