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EXPLORATION GEOPHYSICS 



Fig. 423. — Wave Front Chart. The coordinates along the H and Z axes represent 

 thousands of feet. The wave fronts are labeled with the reflection time corresponding to 

 the time required in seconds for the wave to reach the respective position in space and 

 return to the surface. The normal ray paths are labeled with values of the sine of the 

 emergence angles for respective normal ray paths. (Courtesy of Geophysical Engineer- 

 ing Corp.) 



