We present a new method for determining anisotropic earth models using observations of split shear waves (such as SKS). The method consists of first constructing two timeseries, x(t) and y(t), that contain information about both the observed seismograms and a hypothetical earth model, and then varying the earth model so as to minimize the misfit, e(t)=x(t)−y(t). The timeseries are defined by th...

Normal mode solutions for • spherical earth model are superposed to obtain realistic synthetic surface waves for various force systems. The calculation of excitation functions is greatly facilitated by the variational technique. The effects of attenuation anal instrument response are included in the synthesis. The synthesized seismograms are compared with the actual seismograms for wave form, a...

S U M M A R Y We examine the characteristics of seismic radiation produced by localized fault-opening and shear motions in a homogeneous solid, along with the effects of having dissimilar solids across the fault on the seismic radiation. The study employs calculations of synthetic seismograms generated at various receiver locations by shear and tensile dislocation sources. The results indicate ...

The wavelet packet transform gives information in both the time and frequency domains, and it is very useful for describing nonstationary signals like seismograms. Moreover, this structure is dependent on the signal under study; hence we can choose the time–frequency decomposition more appropriate for every signal. In this article, we propose a new method for filtering based on the wavelet pack...

The main focus of this study is to develop an efficient frequency-wavenumber code to synthesize high-frequency (say, 10 Hz) regional seismograms (up to a distance of more than 1000 km) in a medium consisting of a large number of crustal layers, and investigate effects of regional waveguides on L, waves. In this newly developed code, the frequency-wavenumber response is evaluated by using the Fi...

Expressions for displacements on the surface of a layered half-space due to point force are given in terms of generalized reflection and transmission coefficient matrices (Kennett, 1980) and the discrete wavenumber summation method (Bouchon, 1981). The Bouchon method with complex frequencies yields accurate near-field dynamic and static solutions. The algorithm is extended to include simultaneo...