Condori, CristobalFrança, George S.Tavera, HernandoEakin, Caroline M.Lynner, ColtonBeck, Susan L.Villegas Lanza, Juan Carlos2021-04-292021-04-292021-03Condori, C., França, G. S., Tavera, H. J., Eakin, C. M., Lynner, C., Beck, S. L., & Villegas-Lanza, J. C. (2021). Variable seismic anisotropy across the Peruvian flat-slab subduction zone with implications for upper plate deformation.==$Journal of South American Earth Sciences, 106,$==103053. https://doi.org/10.1016/j.jsames.2020.103053index-oti2018http://hdl.handle.net/20.500.12816/4939We performed shear wave splitting analyses to investigate seismic anisotropy across the northern extent of the Peruvian flat-slab subduction region. We used core-mantle refracted SKS, SKKS and PKS phases from teleseismic events (88° > Δ < 150°) recorded at 45 broadband seismic stations from the Peruvian permanent and portable seismic networks as well as from, international networks (CTBTO, RSBR-Brazil, and RENSIG-Ecuador). The results reveal a complex anisotropy pattern with distinct variations in shear wave splitting along strike. In the northernmost region, the mean delay times range between 1.0 ± 0.2 s and 1.5 ± 0.2 s with fast directions predominantly oriented ENE-WSW approximately perpendicular to the trench, parallel with the motion of the subducting Nazca plate. In the central region of Peru, the predominant fast directions change to a SE-NW orientation that is oblique with the trench. These fast splitting directions are consistent with the pattern seen previously over the southern extent of the flat-slab and correlate well with the current geodetically derived motion of the overriding forearc, the Peruvian Sliver. These characteristics suggest a fundamental change in anisotropic behavior between the northern and central portions of the Peruvian flat-slab and imply that the upper plate deformation is a controlling factor.application/pdfenginfo:eu-repo/semantics/closedAccessSeismic anisotropyShear wave splittingFlat-slab subductionNorthern Peruinfo:eu-repo/semantics/articlehttps://purl.org/pe-repo/ocde/ford#1.05.04https://purl.org/pe-repo/ocde/ford#1.05.06Journal of South American Earth Scienceshttps://doi.org/10.1016/j.jsames.2020.103053