abstract
Most seismic theory is confined to a consideration of crustal structures that can be abstracted as plane parallel elastic layers. For such configurations, the response of each element of a seismic array will be similar to any other except for a time delay. Signal enhancement of an array located on such an idealized structure can be accomplished by suitable time delays of the individual traces followed by superposition.
On the other hand, if the crustal structure is anything but a plane parallel configuration, the signals received by the individual elements will not be identical to one another, but will include distortion effects characteristic of the local geometry. As a result, the records of seismic arrays located on realistic crustal configurations will have to be equalized to some standard reference if optimum signal processing is to be achieved.
In this paper we introduce a ray procedure for the calculation of theoretical seismograms for the teleseismic response of an array of stations located above a uniform dipping crust (wedge-shaped). In terms of this mathematical model, we demonstrate the signal distortion effects of the geometry and discuss equalization techniques that will permit a superior recovery of the desired signal.
Ambient seismic noise tomography of Canada and adjacent regions: Part I. Crustal structures