eprintid: 2029 rev_number: 17 eprint_status: archive userid: 9 dir: disk0/00/00/20/29 datestamp: 2017-12-14 08:42:52 lastmod: 2019-02-06 09:46:13 status_changed: 2017-12-14 08:42:52 type: article metadata_visibility: show creators_name: Leptokaropoulos, Konstantinos Michail creators_name: Staszek, Monika creators_name: Lasocki, Stanislaw creators_name: Martinez-Garzon, Patricia creators_name: Kwiatek, Grzegorz creators_id: kleptoka@igf.edu.pl creators_id: lasocki@igf.edu.pl corp_creators: Institute of Geophysics, Polish Academy of Sciences corp_creators: Institute of Geophysics, Polish Academy of Sciences corp_creators: Institute of Geophysics, Polish Academy of Sciences corp_creators: Helmholtz-Centre Potsdam, GFZ German Research Centre for Geosciences corp_creators: Helmholtz-Centre Potsdam, GFZ German Research Centre for Geosciences title: Evolution of seismicity in relation to fluid injection in the North-Western part of The Geysers geothermal field subjects: MP4 subjects: RU1_1 subjects: SG divisions: IP13 divisions: SHEER-5 full_text_status: none abstract: The Geysers geothermal field located in California, USA, is the largest geothermal site in the world, operating since the 1960s. We here investigate and quantify the correlation between temporal seismicity evolution and variation of the injection data by examination of time-series through specified statistical tools (binomial test to investigate significant rate changes, cross correlation between seismic and injection data, b-value variation analysis). To do so, we utilize seismicity and operational data associated with two injection wells (Prati-9 and Prati-29) which cover a time period of approximately 7 yr (from November 2007 to August 2014). The seismicity is found to be significantly positively correlated with the injection rate. The maximum correlation occurs with a seismic response delay of ∼2 weeks, following injection operations. Those results are very stable even after considering hypocentral uncertainties, by applying a vertical shift of the events foci up to 300 m. Our analysis indicates also time variations of b-value, which exhibits significant positive correlation with injection rates. date: 2017-11 date_type: published publication: Geophysical Journal International volume: 212 number: 2 publisher: Oxford University Press pagerange: 1157-1166 id_number: doi:10.1093/gji/ggx481 issn: 0956-540X official_url: https://www.researchgate.net/publication/320910738_Evolution_of_Seismicity_in_Relation_to_Fluid_Injection_in_the_North-Western_Part_of_The_Geysers_Geothermal_Field access_IS-EPOS: limited owner: Publisher acknowledgments2: IS-EPOS_platform acknowledgments2: SHEER_project citation: Leptokaropoulos, Konstantinos Michail and Staszek, Monika and Lasocki, Stanislaw and Martinez-Garzon, Patricia and Kwiatek, Grzegorz (2017) Evolution of seismicity in relation to fluid injection in the North-Western part of The Geysers geothermal field. Geophysical Journal International, 212 (2). pp. 1157-1166. DOI: https://doi.org/10.1093/gji/ggx481