Seismic anisotropy beneath Southern Tibet

摘要: We have examined shear-wave splitting in teleseismic waves (SKS) recorded on 20 seismographs deployed a profile that followed the Southern Tibet highway during 1992 Sino-French seismic experiment. The “cross-correlation” method is applied to derive parameters. most striking feature abrupt variation orientation across ITS. North of ITS, 12 stations an average N70°E fast wave, with delay between and slow up 1 second. On contrary, 7 located south ITS show N25°W smaller magnitude. compare observations surface geological features discuss source anisotropy its constraints deformation model Tibetan Plateau. Our studies suggest may be generated by high strain induced underthrusting India lithosphere relate ductile flow upper mantle. Analysis pattern models Plateau suggests both internal continental northeastward extrusion contribute crustal shortening uplift