5 km

1. coh 1.0 0.9 0.8 s/m2 pos 0.0 neg 5 km (a) (b) Figure 1. Time slice at 1200 ms through (a) coherence and (b) long wavelength most positive curvature volumes for a survey acquired in the Delaware Basin, TX, USA. Coherence clearly shows collapse features in and a few of the faults. The most positive curvature shows not only the collapse features but the fault/flexure systems interconnecting them. Since the most positive curvature always has a value that is greater or equal to the most negative curvature, the green negative values indicate bowl shaped collapse features. (Data courtesy of Devon Energy)

2. channel channel (b) 5 km (a) Figure 2. Time slice at 1400 ms through (a) coherence and (b) EW coherent energy gradient volumes corresponding to a survey in the Delaware Basin, NM, USA. While coherence will highlight discontinuities, thin channels often result only in lateral changes in amplitude, not in waveform (Widess, 1974). For this reason, the ‘gradient’ (lateral derivative of the coherent component of the seismic amplitude) better illuminates the channels indicated by arrows in (b). (Data courtesy Marathon Oil Co.)