eprintid: 2154 rev_number: 20 eprint_status: archive userid: 6 dir: disk0/00/00/21/54 datestamp: 2018-12-20 09:50:06 lastmod: 2019-07-24 05:22:40 status_changed: 2018-12-20 09:50:06 type: article metadata_visibility: show creators_name: Grasso, Jean-Robert creators_name: Karimov, A. creators_name: Amorese, Daniel creators_name: Sue, C. creators_name: Voisin, C. creators_id: creators_id: creators_id: daniel.amorese@unicaen.fr creators_id: creators_id: corp_creators: Université de Grenoble‐Alpes, ISTerre, corp_creators: Université de Grenoble‐Alpes, ISTerre, corp_creators: Observatoire Volcanologique et Sismologique de Guadeloupe, Institut de Physique du Globe de Paris, Department of Biology and Earth Sciences, Université de Caen‐Normandie corp_creators: UBFC/CNRS‐UMR Chrono‐environnement, 16 route de Gray, corp_creators: Université de Grenoble‐Alpes, ISTerre, title: Patterns of Reservoir‐Triggered Seismicity in a Low‐Seismicity Region of France subjects: MP4 subjects: RF5 subjects: SR divisions: IP2 divisions: IP3 divisions: IP18 full_text_status: none abstract: We analyzed the impact of the 26 largest impounded reservoirs on reservoir‐triggered seismicity (RTS) patterns in the low‐seismicity region of continental France. We treat reservoir‐triggered earthquakes as tectonic earthquakes and apply similar concepts in our analysis. Generally, the spatial extent of an aftershock zone is controlled by the mainshock rupture length. In a similar manner, we use reservoir length as an equivalent length to the rupture length to assess the spatial extent of reservoir‐triggering earthquakes and one to three reservoir lengths as a proxy for the near‐field distance where the stress change induced by reservoir impoundment may trigger seismicity. Accordingly, we define the 1Lr distance as the near‐field reservoir effect on seismicity and the 10Lr distance as the far field, null effect of reservoir stress change on background seismicity. We find that (1) about a quarter of the reservoirs trigger Mmax=2.5–4.7 within the 1Lr distance in a 15 yr space time window, and (2) as tested against a randomized series, superposed epoch analysis demonstrates a robust increase in the average seismicity rate within 2 yrs for the 1–3Lr distance from reservoirs. The reservoirs that trigger in the (⁠ 1Lr ⁠) near‐field distance are significantly larger than the nontriggering ones. While considering the distance of triggering of earthquakes from the reservoir, it is more appropriate to consider the normalized distance (the distance normalized by the reservoir length) to identify earthquake triggering reservoirs at a 1Lr distance. While considering reservoir dimensions, the reservoir length appears to be a more important parameter than the reservoir depth, as the length is proportional to the area of significant stress change. Our results suggest that the RTS mimics the aftershock sequence of a slow reservoir‐impoundment loading, with a corresponding M∗reservoir=M(Lr) mainshock magnitude. Further, when considering mainshock–aftershock interactions, our analysis and observations support that the Mmax for RTS for a given reservoir remains, on average, smaller than the reservoir magnitude equivalent. date: 2018 date_type: published publication: Bulletin of the Seismological Society of America volume: 108 number: 5B publisher: Seismological Society of America pagerange: 2967-2982 id_number: doi:10.1785/0120180172 issn: 0037-1106 official_url: http://doi.org/10.1785/0120180172 access_IS-EPOS: limited software_references: Estimate_of_maximum_possible_magnitude owner: Publisher acknowledgments2: IS-EPOS_platform acknowledgments2: EPOS-IP_project acknowledgments2: SERA_project citation: Grasso, Jean-Robert and Karimov, A. and Amorese, Daniel and Sue, C. and Voisin, C. (2018) Patterns of Reservoir‐Triggered Seismicity in a Low‐Seismicity Region of France. Bulletin of the Seismological Society of America, 108 (5B). pp. 2967-2982. DOI: https://doi.org/10.1785/0120180172