@article{epos2208,
          volume = {67},
          number = {1},
          author = {Konstantinos Michail Leptokaropoulos and Monika Staszek},
           title = {Temporal response of magnitude distribution to fluid injection rates in The Geysers geothermal field},
       publisher = {Versita, Warsaw and Springer-Verlag Berlin Heidelberg},
         journal = {Acta Geophysica},
           pages = {327--339},
            year = {2019},
        keywords = {Injection-induced seismicity Magnitude distribution Geothermal fields Statistical seismology},
             url = {https://episodesplatform.eu/eprints/2208/},
        abstract = {The influence of fluid injection rates on the magnitude distribution of the seismicity which occurred in the NW part of The Geysers geothermal site is studied here. A direct comparison between injection rate changes and b value response is attempted after appropriate selection of data subsets. Due to the relatively small sample (1121 events, corresponding to an average rate of {\texttt{\char126}} 0.45 events/day), we also aggregated seismic activity into two families corresponding to increasing and decreasing injection rates, respectively. The b values were calculated as a function of time lag related to the injection activity. In agreement with previous studies, we found a statistically significant direct relation between b values and injection rate changes, which occurred at a zero or very short time lag (from 0 to {\texttt{\char126}} 15 days). However, the b value changes are related to the slope (i.e., the second derivative of injection volume), instead of the absolute values of injection rates. The increasing injection rates correspond to b = 1.18 {$\pm$} 0.06, whereas the decreasing injection rates correspond to b = 1.10 {$\pm$} 0.05. The corresponding values estimated by the repeated medians technique are b = 1.97 {$\pm$} 0.20 and b = 1.50 {$\pm$} 0.13. Both differences are significant at 0.05 level.}
}