%0 Conference Paper
%A Leptokaropoulos, Konstantinos Michail
%A Staszek, Monika
%A Lasocki, Stanislaw
%A Kwiatek, Grzegorz
%A Martinez-Garzon, Patricia
%A Institute of Geophysics, Polish Academy of Sciences, Seismology, Warsaw, Poland,
%A Institute of Geophysics, Polish Academy of Sciences, Seismology, Warsaw, Poland,
%A Institute of Geophysics, Polish Academy of Sciences, Seismology, Warsaw, Poland,
%A Helmholtz-Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany,
%A Helmholtz-Centre Potsdam GFZ German Research Centre for Geosciences, Potsdam, Germany,
%B EGU General Assembly 2017
%C Vienna, Austria
%D 2017
%F epos:1970
%T Space-Time Evolution of Seismicity in North-Western Geysers  Geothermal Field and its Connection to Stimulation Processes
%U https://episodesplatform.eu/eprints/1970/
%X The rising needs for energy along with the recent requirements for more efficient usage and exploitation of the  deep underground have resulted to a growing scientific and public concern on related environmental impacts.  Hydraulic fracturing that has been carried out during the last decades is occasionally connected with triggered  and induced seismicity worldwide. Data from geothermal fields can be used as a proxy for shale gas exploitation  associated seismicity since they are both tightly connected to hydraulic fracturing. For that reason we utilize  ‘The Geysers’ data from the compiled SHEER (Shale Gas Exploration and Exploitation Induced Risks) database.  The Geysers (California, USA) is the largest producing geothermal field in the world and has been sufficiently  monitored and studied since the last decades. Seismic and technological data gathered during the past ∼40 years  indicate a connection of seismic activity with the fluctuations of the injected fluid volume. In this study we verify  and quantify this correlation by analyzing the data associated with 2 injection wells (Prati-9 and Prati-29) which  covers a time period of approximately 7 years (from November 2007 to August 2014). The correlation between  spatio-temporal seismicity evolution and variation of the injection data is performed by elaboration of original and  smoothed time-series through specified statistical tools (cross correlation, binomial test to investigate significant  rate changes, b-value variation). Our analysis indicate a short time delay of seismicity occurrence at distances  larger than 200m from the injection well, whereas no evidence of significant correlation between injection rates  and b-values was discovered. The obtained results are expected to contribute to a better comprehension of the role  of hydraulic fracturing and the physical processes controlling seismogenesis in fluid injection sites.    Acknowledgements:  This work was supported within SHEER: "Shale Gas Exploration and Exploitation Induced Risks" project funded  from Horizon 2020 – R&I Framework Programme, call H2020-LCE-2014-1 and within statutory activities  No3841/E-41/S/2016 of Ministry of Science and Higher Education of Poland.