eprintid: 2247 rev_number: 11 eprint_status: archive userid: 6 dir: disk0/00/00/22/47 datestamp: 2020-03-13 11:32:23 lastmod: 2020-03-13 11:32:23 status_changed: 2020-03-13 11:32:23 type: article metadata_visibility: show creators_name: Orlecka-Sikora, Beata creators_name: Cielesta, Szymon creators_id: orlecka@igf.edu.pl corp_creators: Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland corp_creators: Institute of Geophysics, Polish Academy of Sciences, Warsaw, Poland title: Evidence for subcritical rupture of injection-induced earthquakes subjects: MP4 subjects: MP6_3 subjects: RU1_1 subjects: SG divisions: IP13 full_text_status: none abstract: Seismicity induced by geo-engineering operations may be hazardous for people, infrastructure and the environment. The crucial information for assessing induced seismic hazards and related risks is knowledge of the time-dependent strength of rocks and the deformation due to fluid injection. Our studies of seismic and injection data from a geothermal field indicate that pressurized injections lead to rock fracturing at stress levels below the rock toughness, i.e., subcritical fracture growth. We provide a relation between the rate of this subcritical fracture growth and the injection rate. Based on this relation, we estimate the maximum subcritical magnitude. We hypothesize that subcritical fracture growth may be controlled by the amount of stress asymmetry, i.e., the relative values of the principal stresses. We discuss the conditions under which the subcritical fracturing regime can transform to a critical state and critical rupture may occur. We present the possibility of using these results in the operational reservoir to manage seismic hazards. date: 2020-03-04 date_type: published publication: Scientific Reports volume: 10 number: 4016 publisher: Nature Research id_number: doi:10.1038/s41598-020-60928-0 issn: 2045-2322 official_url: https://doi.org/10.1038/s41598-020-60928-0 access_IS-EPOS: limited owner: Publisher acknowledgments2: IS-EPOS_platform acknowledgments2: S4CE_project citation: Orlecka-Sikora, Beata and Cielesta, Szymon (2020) Evidence for subcritical rupture of injection-induced earthquakes. Scientific Reports, 10 (4016). DOI: https://doi.org/10.1038/s41598-020-60928-0