My research focuses on the interaction of the solid earth and climate - I am working to understand how aquifers respond to drought using the Earth's ambient wavefield. Specifically, I calculate the change in seismic velocity of the subsurface, dv/v, from the cross-correlation of ambient seismic noise. dv/v scales linearly with changes in groundwater level.
Research
San Gabriel Valley Groundwater and dv/v
In our recent paper we showed that variations in groundwater levels can be mapped using perturbations in seismic velocity (dv/v). We measure dv/v in the San Gabriel Valley, California, from cross correlation of the ambient seismic field. dv/v reproduces the groundwater level changes that are marked by the multi‐year depletions and rapid recharges, typical of California's cycles of droughts and floods. dv/v correlates spatially with vertical surface displacements and deformation measured with GPS. Our results successfully predict the volume of water lost in the San Gabriel Valley during the 2012‐2016 drought and thus provide a new, complementary approach to monitor groundwater storage.