Stable isotopes show that earthquakes enhance permeability and release water from mountains.

Hydrogeological properties can change in response to large crustal earthquakes. In particular, permeability can increase leading to coseismic changes in groundwater level and flow. These processes, however, have not been well-characterized at regional scales because of the lack of datasets to describe water provenances before and after earthquakes.

Fault stress inversion reveals seismogenic asperity of the 2011 Mw 9.0 Tohoku-Oki earthquake.

We predict, with a model (earthquake stress model) that inverts the displacements documented at 163 GNSS onshore stations of the GEONET, the change of shear and normal stresses on the megathrust near the Japan Trench over the seven years before the 2011 Mw 9.0 Tohoku-Oki earthquake. We find three areas on the megathrust with greater accumulations of shear and normal stresses before the earthquake, which match the ruptured areas of the mainshock and two largest aftershocks (M 7.

New streams and springs after the 2014 Mw6.0 South Napa earthquake.

Many streams and springs, which were dry or nearly dry before the 2014 Mw6.0 South Napa earthquake, started to flow after the earthquake. A United States Geological Survey stream gauge also registered a coseismic increase in discharge.