Seismicity at the Castor gas reservoir driven by pore pressure diffusion and asperities loading Cesca, Simone Stich, Daniel López Comino, José Ángel We are thankful to Dr. J. V. Cantavella and IGN for providing waveform data and metadata of the network ES. S.C. and P.N. received funding by the European Union RFCS project PostMinQuake grant 899192. J.A.L.-C. was financed by the European Union's Horizon 2020 research and innovation program under the Marie Skodowska-Curie grant agreement 754446 and UGR Research and Knowledge Transfer Found-Athenea3i and the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Projektnummer (407141557). D.S. received funding by the Spanish National FEDER/MINECO Project PID2019-109608GB-I00/AEI/10.13039/501100011033, FEDER/Junta de Andalucia project A-RNM-421-UGR18 and Research group RNM104 of the Junta de Andalucia. F.G. was financed by the European Union's Horizon 2020 Framework Programme under the Marie Skodowska Curie Grant agreement (790900). The 2013 seismic sequence at the Castor injection platform offshore Spain, including three earthquakes of magnitude 4.1, occurred during the initial filling of a planned Underground Gas Storage facility. The Castor sequence is one of the most important cases of induced seismicity in Europe and a rare example of seismicity induced by gas injection into a depleted oil field. Here we use advanced seismological techniques applied to an enhanced waveform dataset, to resolve the geometry of the faults, develop a greatly enlarged seismicity catalog and record details of the rupture kinematics. The sequence occurred by progressive fault failure and unlocking, with seismicity initially migrating away from the injection points, triggered by pore pressure diffusion, and then back again, breaking larger asperities loaded to higher stress and producing the largest earthquakes. Seismicity occurred almost exclusively on a secondary fault, located below the reservoir, dipping opposite from the reservoir bounding fault. 2021-10-04T07:21:23Z 2021-10-04T07:21:23Z 2021-08-10 journal article Cesca, S... [et al.]. Seismicity at the Castor gas reservoir driven by pore pressure diffusion and asperities loading. Nat Commun 12, 4783 (2021). [https://doi.org/10.1038/s41467-021-24949-1] http://hdl.handle.net/10481/70591 10.1038/s41467-021-24949-1 eng info:eu-repo/grantAgreement/EC/H2020/754446 info:eu-repo/grantAgreement/EC/H2020/790900 http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Nature