Velocity structure of the continental upper mantle: evidence from southernAfrica

The velocity model for southern Africa of Qiu et al. [Qiu, X., Priestley, I C., McKenzie, D., 1996. Average lithospheric structure of southern Africa. Geophys. J. Int. 127, 563-587] is revised so as to satisfy both the regiona l seismic waveform data and the fundamental mode Rayleigh wave phase veloci ty data for the region. The revised S-wave model is similar to the original model of Qiu et al. except that the high velocity, upper mantle lid extend s to 160 km depth in the revised model rather than to 120 km in the origina l model. Sensitivity tests of the regional seismic data show that the minim um velocity in the S-wave low velocity zone can be as high as 4.45 km s(-1) compared to 4.32 km s(-1) in the Qiu et al. model. The vertical S-wave tra vel time for the revised south African model is compared with the vertical S-wave travel times for the global tomographic models S12WM13 and S16B30, a nd they are found to be similar. (C) 1999 Elsevier Science B.V. All rights reserved.