The Influence of Lithospheric Thickness Variations Beneath Australia on Seismic Anisotropy and Mantle Flow

Abstract Rapid plate motion, alongside pronounced variations in age and thickness of the Australian continental lithosphere, makes it an excellent location to assess relationship between seismic anisotropy lithosphere‐asthenosphere dynamics. In this study, SKS PKS shear‐wave splitting is conducted for 176 stations covering transition from South Craton eastern Phanerozoic Australia. Comparisons are made with models lithospheric as well numerical simulations mantle flow. Splitting results show uniform ENE‐WSW aligned fast directions over Gawler broader Craton, similar orientation crustal structures generated during episode NW‐SE directed compression volcanism ∼1.6 billion years ago. We propose that heat weakened aiding widespread deformation, which has since been preserved form frozen‐in anisotropy. Conversely, Australia, strong alignment NNE absolute motion. Overall, our suggest when lithosphere thin (<125 km), contributions minimal asthenospheric dominate, reflecting shear underlying by Australia's rapid motion above. Further insights geodynamical regional flow field, incorporate adjacent upper structure, predict material would be drawn south east toward fast‐moving keel. Such a mechanism, interactions field provides plausible explanation smaller‐scale anomalous patterns beneath Australia do not align