Wave-Front Diagrams in Seismic Interpretation

Subsurface structure can be derived from seismic data by graphical methods based upon wave-front diagrams. The method of construction of these diagrams is shown, and the nature and origin of the important underlayer wave is explained. Coincident-time curves and secondary shotpoints are defined and some applications are illustrated. The diagrams are used to explain some of the simpler seismic rules, and the original determination of simple underlayer structure is illustrated. The paper is only an introduction to wave-front methods; the principles developed can be applied by experienced seismologists to more complex situations.