@article{epos1930,
          volume = {44},
          number = {2},
           month = {January},
          author = {Patricia Martinez-Garzon and Grzegorz Kwiatek and Marco Bohnhoff and Georg Dresen},
           title = {Volumetric components in the earthquake source related to fluid injection and stress state},
       publisher = {American Geophysical Union},
            year = {2017},
         journal = {Geophysical Research Letters},
           pages = {800--809},
             url = {https://episodesplatform.eu/eprints/1930/},
        abstract = {We investigate source processes of fluid-induced seismicity from The Geysers geothermal reservoir in California to determine their relation with hydraulic operations and improve the corresponding seismic hazard estimates. Analysis of 869 well-constrained full moment tensors (Mw 0.8?3.5) reveals significant non-double-couple components ({\ensuremath{>}}25\%) for about 65\% of the events. Volumetric deformation is governed by cumulative injection rates with larger non-double-couple components observed near the wells and during high injection periods. Source mechanisms are magnitude dependent and vary significantly between faulting regimes. Normal faulting events (Mw {\ensuremath{<}} 2) reveal substantial volumetric components indicating dilatancy in contrast to strike-slip events that have a dominant double-couple source. Volumetric components indicating closure of cracks in the source region are mostly found for reverse faulting events with Mw {\ensuremath{>}} 2.5. Our results imply that source processes and magnitudes of fluid-induced seismic events are strongly affected by the hydraulic operations, the reservoir stress state, and the faulting regime.}
}