eprintid: 2349 rev_number: 7 eprint_status: archive userid: 6 dir: disk0/00/00/23/49 datestamp: 2022-12-01 08:41:59 lastmod: 2022-12-01 08:41:59 status_changed: 2022-12-01 08:41:59 type: article metadata_visibility: show creators_name: Lasocki, Stanisław creators_name: Rudziński, Łukasz creators_name: Tokarski, Antek K. creators_name: Orlecka-Sikora, Beata corp_creators: Institute of Geophysics, Polish Academy of Sciences, Księcia Janusza 64, 01-452 Warszawa, Poland corp_creators: Institute of Geophysics, Polish Academy of Sciences, Księcia Janusza 64, 01-452 Warszawa, Poland corp_creators: Research Centre in Krakow, Institute of Geological Sciences, Polish Academy of Sciences, Senacka 1, 31-002 Krakow, Poland corp_creators: Institute of Geophysics, Polish Academy of Sciences, Księcia Janusza 64, 01-452 Warszawa, Poland title: A Hydrofracturing-Triggered Earthquake Occurred Three Years after the Stimulation subjects: RP5 divisions: SHEER-1 full_text_status: none keywords: hydrofracturing; injection-induced seismicity; shale gas abstract: Hydrofracturing, used for shale gas exploitation, may induce felt, even damaging earthquakes. On 15 June 2019, an Mw2.8 earthquake occurred, spatially correlated with the location of earlier exploratory hydrofracturing operations for shale gas in Wysin in Poland. However, this earthquake was atypical. Hydrofracturing-triggered seismicity mainly occurs during stimulation; occasionally, it continues a few months after completion of the stimulation. In Wysin, there were only two weaker events during two-month hydrofracturing and then 35 months of seismic silence until the mentioned earthquake occurred. The Wysin site is in Gdańsk Pomerania broader region, located on the very weakly seismically active Precambrian Platform. The historical documents, covering 1000 years, report no natural earthquakes in Gdańsk Pomerania. We conclude, therefore, that despite the never observed before that long lag time after stimulation, the Mw2.8 earthquake was triggered by hydrofracturing. It is possible that its unusually late occurrence in relation to the time of its triggering technological activity was caused by changes in stresses due to time-dependent deformation of reservoir shales. The Wysin earthquake determines a new time horizon for the effect of HF on the stress state, which can lead to triggering earthquakes. Time-dependent deformation and its induced stress changes should be considered in shall gas reservoir exploitation plans. date: 2022 publication: Energies volume: 15 number: 1 pagerange: 336 id_number: doi:10.3390/en15010336 issn: 1996-1073 official_url: https://doi.org/10.3390/en15010336 access_IS-EPOS: limited owner: Publisher citation: Lasocki, Stanisław and Rudziński, Łukasz and Tokarski, Antek K. and Orlecka-Sikora, Beata (2022) A Hydrofracturing-Triggered Earthquake Occurred Three Years after the Stimulation. Energies, 15 (1). p. 336. DOI: https://doi.org/10.3390/en15010336