多层弹性半空间中的地震波（二）

一、引言 地震面波的频散性质、地震波辐射的方向性等特性已经广泛地用于地壳和上地幔结构以及震源机制的研究中,并且取得了许多有用的成果.研究地震波如何从震源辐射出来、如何在实际介质中传播和衰减的这一问题,对于利用地震波确定地壳和上地幔结构以及震源的参数,是很有必要的.关于这一问题的研究,已经作过许多工作。已往的工作中,为了分析方便,往往采用简单的地壳-上地幔模型或简单的震源模型,或两者都相

SEISMIC WAVES IN MULTILAYERED ELASTIC HALF-SPACE （Ⅱ）

On the basis of spectra expressions, obtained previously by using Hansen's expansion method and Haskell matrix formulation, for the displacement fields due to general types of sources in a multilayered homogeneous isotropic and perfectly elastic half-space, the spectra expressions for the displacement fields of surface waves radiated from the sources are derived by evaluating the contribution of the residues. It is shown that the displacement spectra for these surface waves can always be separated into seven factors representing source tine-function, seismic moment, propagation effect of fracture, radiation pattern, source depth, receiver depth and structure of elastic half-space respectively. For the multilayered elastic half-space, general expressions for both Rayleigh and Love wave radiation patterns are given explicitly in a form representing their dependence on the characteristics of the source, source depth as well as on the structure of the medium. Results here obtained can be used to determine focal depth, crust and mantle structure and source mechanism.