Relocation of Seismicity in the Guadalentín Tectonic Valley, Eastern Betics Shear Zone (Southeast Iberia) Sánchez-Roldan, José Luis Martínez Díaz, José J. Cantavella, Juan V. Álvarez Gómez, José A. Morales Soto, José Eastern Betics 3D seismic velocity model Relocation reprocessing The authors would like to acknowledge the Andalusian Geophysics Institute (IAG) for its kindness in providing their seismic network data, as well as the Geographic Institute of Spain, in particular Jaime Barco, for supporting the earthquake catalog, the software, and the hardware used in this study. The authors want to thank the anonymous reviewers, Editor-in-Chief Allison Bent, and Managing Editor Annastasia Pratt for their careful and constructive revisions that helped improve this article. This research is supported by the project QUAKESTEP (CGL2017-83931-C3-1-P), founded by the Spanish Ministry of Science and Innovation. The author J. L. Sánchez Roldán owns a predoctoral research grant (FPI) supported by the same project. The eastern Betics shear zone comprises one of the most seismically active areas in Iberia, due to the presence of large active faults loaded by the oblique convergence between Eurasia and Africa plates. We focus our study on the sector of the eastern Betic Cordillera affected by the Alhama de Murcia fault (AMF) and other nearby faults that are the source of large paleoseismic events and some damaging historical earthquakes. This study aims to give more accurate locations to the hypocenters in the region around these faults, using a model that accounts for lateral variations of P-wave velocity. This task was accomplished, developing a new 3D velocity crustal model of the region, by combining recent regional and local geological and geophysical data, such as geological mapping, gravimetry, seismic-wave tomography, and seismic exploration surveys. Afterward, as a preliminary test of performance, we compared the hypocenters obtained with this model against the ones computed with other 1D velocity models, using NonLinLoc with a seismic dataset of the highest possible quality (i.e., filtered by a minimum magnitude) in this area within the period January 2015–December 2018. Then, for comparing the reliability of the new 3D local model against a larger 3D regional model, we carried out a final relocation with all the earthquakes of the Spanish Seismic Catalog in the study area for the period April 2011–October 2019. New locations obtained with the local model, which show better clustering near active structures and lower epicentral uncertainty in comparison with the regional model, allow us to observe possible genetic relation between seismicity and specific faults after the inversion, in particular, the AMF. 2026-01-12T12:36:53Z 2026-01-12T12:36:53Z 2021 journal article Publisher version: Sánchez-Roldán, J.L., Martínez-Díaz, J.J., Cantavella, J.V., Álvarez-Gómez, J.A., Morales, J. (2021). Relocation of seismicity in the Guadalentín tectonic valley, eastern betics shear zone (southeast iberia). Seismological Research Letters, 92(5), pp. 3046–3064. https://doi.org/10.1785/0220200341 0895-0695 1938-2057 https://hdl.handle.net/10481/109565 10.1785/0220200341 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ open access Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Seismological Society of America