AZIMUTHAL ANISOTROPY BENEATH THE BOHEMIAN MASSIF FROM BROAD-BAND SEISMOGRAMS OF SKS WAVES

Shear-wave splitting in SKS phases recorded by the two broad-band stations KHC (South Bohemia) and KSP (Lower Silesia) is used to determine the anisotropic properties of the lithosphere beneath the marginal regions of the Bohemian Massif. Directions of fast velocity of 80° and 120° clockwise from North were obtained for KHC and KSP, respectively. These directions are consistent with the predominantly E-W direction of fast velocity found by different authors using similar techniques in some regions of Western Europe. They disagree, however, with the directions found for the investigated region by other authors on the basis of teleseismic P-wave traveltime residuals. The value of the time delay between the two splitted shear waves is close to 1 s for both stations implying that the thickness of the anisotropic zone in the upper mantle essentially exceeds 80 km. © 1990.