Asthenospheric Flow Around the Paraná Basin Cratonic Nucleus Measured with SKS splitting

Anisotropy within and beneath continental lithosphere is often studied with a technique called shear wave splitting. ­e wave is split into two shear waves,  polarized  in  the  fast  and  slow  directions  and  accumulates  a  delay  time  along  with  their  paths.  To  measure  the  e‑ect  of  splitting  we  use  a  Mat-lab-based environment called SplitRacer, presented by Reiss and Rumpker, 2017. ­e shear wave splitting analyses is based on the minimum transverse energy method by Silver and Chan, 1991. A compilation of previous fast directions in South America, together with new results from stations from the Brazilian Seismograph Network (RSBR) are presented. In general, in the stable part of South America, most fast directions are oriented roughly parallel to the absolute plate motion, however, in the southern part of the Paraná Basin, the fast directions suggest that the observed anisotropies have a contribution from asthenospheric ow deected by a deeper lithospheric.