Figure 2. Interpreted P-SV sequences (bottom) and their equivalent P-P sequence intervals (top). DR = depth-registration feature showing time-warped PSV geology is positioned 100 ms earlier than P-P geology. Intervals A through D are depth equivalent and show that a P-SV sequence boundary often has no equivalent P-P sequence boundary, or that the depth-equivalent P-P event is much fainter than its companion P-SV boundary.