74 E. I. Gal'perin et al. 



SUMMARY 



The method we have described for solving three-dimensional linear problems 

 in geometrical seismics of multi-layered media with interfaces of arbitrary 

 shape is based on the use of stereographic projections. Such projections 

 make it possible to follow the seismic rays in space and thereby open up 

 new possibilities for solving problems in geometrical seismics. The method 

 enables us to study the laws governing surface hodographs for various 

 waves whatever the shape and quantity of the interfaces. 



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